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Diffstat (limited to 'ext/fts3/fts3_write.c')
| -rw-r--r-- | ext/fts3/fts3_write.c | 3397 |
1 files changed, 3397 insertions, 0 deletions
diff --git a/ext/fts3/fts3_write.c b/ext/fts3/fts3_write.c new file mode 100644 index 0000000..2904a9a --- /dev/null +++ b/ext/fts3/fts3_write.c @@ -0,0 +1,3397 @@ +/* +** 2009 Oct 23 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +****************************************************************************** +** +** This file is part of the SQLite FTS3 extension module. Specifically, +** this file contains code to insert, update and delete rows from FTS3 +** tables. It also contains code to merge FTS3 b-tree segments. Some +** of the sub-routines used to merge segments are also used by the query +** code in fts3.c. +*/ + +#include "fts3Int.h" +#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) + +#include <string.h> +#include <assert.h> +#include <stdlib.h> + +/* +** When full-text index nodes are loaded from disk, the buffer that they +** are loaded into has the following number of bytes of padding at the end +** of it. i.e. if a full-text index node is 900 bytes in size, then a buffer +** of 920 bytes is allocated for it. +** +** This means that if we have a pointer into a buffer containing node data, +** it is always safe to read up to two varints from it without risking an +** overread, even if the node data is corrupted. +*/ +#define FTS3_NODE_PADDING (FTS3_VARINT_MAX*2) + +/* +** Under certain circumstances, b-tree nodes (doclists) can be loaded into +** memory incrementally instead of all at once. This can be a big performance +** win (reduced IO and CPU) if SQLite stops calling the virtual table xNext() +** method before retrieving all query results (as may happen, for example, +** if a query has a LIMIT clause). +** +** Incremental loading is used for b-tree nodes FTS3_NODE_CHUNK_THRESHOLD +** bytes and larger. Nodes are loaded in chunks of FTS3_NODE_CHUNKSIZE bytes. +** The code is written so that the hard lower-limit for each of these values +** is 1. Clearly such small values would be inefficient, but can be useful +** for testing purposes. +** +** If this module is built with SQLITE_TEST defined, these constants may +** be overridden at runtime for testing purposes. File fts3_test.c contains +** a Tcl interface to read and write the values. +*/ +#ifdef SQLITE_TEST +int test_fts3_node_chunksize = (4*1024); +int test_fts3_node_chunk_threshold = (4*1024)*4; +# define FTS3_NODE_CHUNKSIZE test_fts3_node_chunksize +# define FTS3_NODE_CHUNK_THRESHOLD test_fts3_node_chunk_threshold +#else +# define FTS3_NODE_CHUNKSIZE (4*1024) +# define FTS3_NODE_CHUNK_THRESHOLD (FTS3_NODE_CHUNKSIZE*4) +#endif + +typedef struct PendingList PendingList; +typedef struct SegmentNode SegmentNode; +typedef struct SegmentWriter SegmentWriter; + +/* +** An instance of the following data structure is used to build doclists +** incrementally. See function fts3PendingListAppend() for details. +*/ +struct PendingList { + int nData; + char *aData; + int nSpace; + sqlite3_int64 iLastDocid; + sqlite3_int64 iLastCol; + sqlite3_int64 iLastPos; +}; + + +/* +** Each cursor has a (possibly empty) linked list of the following objects. +*/ +struct Fts3DeferredToken { + Fts3PhraseToken *pToken; /* Pointer to corresponding expr token */ + int iCol; /* Column token must occur in */ + Fts3DeferredToken *pNext; /* Next in list of deferred tokens */ + PendingList *pList; /* Doclist is assembled here */ +}; + +/* +** An instance of this structure is used to iterate through the terms on +** a contiguous set of segment b-tree leaf nodes. Although the details of +** this structure are only manipulated by code in this file, opaque handles +** of type Fts3SegReader* are also used by code in fts3.c to iterate through +** terms when querying the full-text index. See functions: +** +** sqlite3Fts3SegReaderNew() +** sqlite3Fts3SegReaderFree() +** sqlite3Fts3SegReaderIterate() +** +** Methods used to manipulate Fts3SegReader structures: +** +** fts3SegReaderNext() +** fts3SegReaderFirstDocid() +** fts3SegReaderNextDocid() +*/ +struct Fts3SegReader { + int iIdx; /* Index within level, or 0x7FFFFFFF for PT */ + + sqlite3_int64 iStartBlock; /* Rowid of first leaf block to traverse */ + sqlite3_int64 iLeafEndBlock; /* Rowid of final leaf block to traverse */ + sqlite3_int64 iEndBlock; /* Rowid of final block in segment (or 0) */ + sqlite3_int64 iCurrentBlock; /* Current leaf block (or 0) */ + + char *aNode; /* Pointer to node data (or NULL) */ + int nNode; /* Size of buffer at aNode (or 0) */ + int nPopulate; /* If >0, bytes of buffer aNode[] loaded */ + sqlite3_blob *pBlob; /* If not NULL, blob handle to read node */ + + Fts3HashElem **ppNextElem; + + /* Variables set by fts3SegReaderNext(). These may be read directly + ** by the caller. They are valid from the time SegmentReaderNew() returns + ** until SegmentReaderNext() returns something other than SQLITE_OK + ** (i.e. SQLITE_DONE). + */ + int nTerm; /* Number of bytes in current term */ + char *zTerm; /* Pointer to current term */ + int nTermAlloc; /* Allocated size of zTerm buffer */ + char *aDoclist; /* Pointer to doclist of current entry */ + int nDoclist; /* Size of doclist in current entry */ + + /* The following variables are used by fts3SegReaderNextDocid() to iterate + ** through the current doclist (aDoclist/nDoclist). + */ + char *pOffsetList; + int nOffsetList; /* For descending pending seg-readers only */ + sqlite3_int64 iDocid; +}; + +#define fts3SegReaderIsPending(p) ((p)->ppNextElem!=0) +#define fts3SegReaderIsRootOnly(p) ((p)->aNode==(char *)&(p)[1]) + +/* +** An instance of this structure is used to create a segment b-tree in the +** database. The internal details of this type are only accessed by the +** following functions: +** +** fts3SegWriterAdd() +** fts3SegWriterFlush() +** fts3SegWriterFree() +*/ +struct SegmentWriter { + SegmentNode *pTree; /* Pointer to interior tree structure */ + sqlite3_int64 iFirst; /* First slot in %_segments written */ + sqlite3_int64 iFree; /* Next free slot in %_segments */ + char *zTerm; /* Pointer to previous term buffer */ + int nTerm; /* Number of bytes in zTerm */ + int nMalloc; /* Size of malloc'd buffer at zMalloc */ + char *zMalloc; /* Malloc'd space (possibly) used for zTerm */ + int nSize; /* Size of allocation at aData */ + int nData; /* Bytes of data in aData */ + char *aData; /* Pointer to block from malloc() */ +}; + +/* +** Type SegmentNode is used by the following three functions to create +** the interior part of the segment b+-tree structures (everything except +** the leaf nodes). These functions and type are only ever used by code +** within the fts3SegWriterXXX() family of functions described above. +** +** fts3NodeAddTerm() +** fts3NodeWrite() +** fts3NodeFree() +** +** When a b+tree is written to the database (either as a result of a merge +** or the pending-terms table being flushed), leaves are written into the +** database file as soon as they are completely populated. The interior of +** the tree is assembled in memory and written out only once all leaves have +** been populated and stored. This is Ok, as the b+-tree fanout is usually +** very large, meaning that the interior of the tree consumes relatively +** little memory. +*/ +struct SegmentNode { + SegmentNode *pParent; /* Parent node (or NULL for root node) */ + SegmentNode *pRight; /* Pointer to right-sibling */ + SegmentNode *pLeftmost; /* Pointer to left-most node of this depth */ + int nEntry; /* Number of terms written to node so far */ + char *zTerm; /* Pointer to previous term buffer */ + int nTerm; /* Number of bytes in zTerm */ + int nMalloc; /* Size of malloc'd buffer at zMalloc */ + char *zMalloc; /* Malloc'd space (possibly) used for zTerm */ + int nData; /* Bytes of valid data so far */ + char *aData; /* Node data */ +}; + +/* +** Valid values for the second argument to fts3SqlStmt(). +*/ +#define SQL_DELETE_CONTENT 0 +#define SQL_IS_EMPTY 1 +#define SQL_DELETE_ALL_CONTENT 2 +#define SQL_DELETE_ALL_SEGMENTS 3 +#define SQL_DELETE_ALL_SEGDIR 4 +#define SQL_DELETE_ALL_DOCSIZE 5 +#define SQL_DELETE_ALL_STAT 6 +#define SQL_SELECT_CONTENT_BY_ROWID 7 +#define SQL_NEXT_SEGMENT_INDEX 8 +#define SQL_INSERT_SEGMENTS 9 +#define SQL_NEXT_SEGMENTS_ID 10 +#define SQL_INSERT_SEGDIR 11 +#define SQL_SELECT_LEVEL 12 +#define SQL_SELECT_LEVEL_RANGE 13 +#define SQL_SELECT_LEVEL_COUNT 14 +#define SQL_SELECT_SEGDIR_MAX_LEVEL 15 +#define SQL_DELETE_SEGDIR_LEVEL 16 +#define SQL_DELETE_SEGMENTS_RANGE 17 +#define SQL_CONTENT_INSERT 18 +#define SQL_DELETE_DOCSIZE 19 +#define SQL_REPLACE_DOCSIZE 20 +#define SQL_SELECT_DOCSIZE 21 +#define SQL_SELECT_DOCTOTAL 22 +#define SQL_REPLACE_DOCTOTAL 23 + +#define SQL_SELECT_ALL_PREFIX_LEVEL 24 +#define SQL_DELETE_ALL_TERMS_SEGDIR 25 + +#define SQL_DELETE_SEGDIR_RANGE 26 + +/* +** This function is used to obtain an SQLite prepared statement handle +** for the statement identified by the second argument. If successful, +** *pp is set to the requested statement handle and SQLITE_OK returned. +** Otherwise, an SQLite error code is returned and *pp is set to 0. +** +** If argument apVal is not NULL, then it must point to an array with +** at least as many entries as the requested statement has bound +** parameters. The values are bound to the statements parameters before +** returning. +*/ +static int fts3SqlStmt( + Fts3Table *p, /* Virtual table handle */ + int eStmt, /* One of the SQL_XXX constants above */ + sqlite3_stmt **pp, /* OUT: Statement handle */ + sqlite3_value **apVal /* Values to bind to statement */ +){ + const char *azSql[] = { +/* 0 */ "DELETE FROM %Q.'%q_content' WHERE rowid = ?", +/* 1 */ "SELECT NOT EXISTS(SELECT docid FROM %Q.'%q_content' WHERE rowid!=?)", +/* 2 */ "DELETE FROM %Q.'%q_content'", +/* 3 */ "DELETE FROM %Q.'%q_segments'", +/* 4 */ "DELETE FROM %Q.'%q_segdir'", +/* 5 */ "DELETE FROM %Q.'%q_docsize'", +/* 6 */ "DELETE FROM %Q.'%q_stat'", +/* 7 */ "SELECT %s WHERE rowid=?", +/* 8 */ "SELECT (SELECT max(idx) FROM %Q.'%q_segdir' WHERE level = ?) + 1", +/* 9 */ "INSERT INTO %Q.'%q_segments'(blockid, block) VALUES(?, ?)", +/* 10 */ "SELECT coalesce((SELECT max(blockid) FROM %Q.'%q_segments') + 1, 1)", +/* 11 */ "INSERT INTO %Q.'%q_segdir' VALUES(?,?,?,?,?,?)", + + /* Return segments in order from oldest to newest.*/ +/* 12 */ "SELECT idx, start_block, leaves_end_block, end_block, root " + "FROM %Q.'%q_segdir' WHERE level = ? ORDER BY idx ASC", +/* 13 */ "SELECT idx, start_block, leaves_end_block, end_block, root " + "FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?" + "ORDER BY level DESC, idx ASC", + +/* 14 */ "SELECT count(*) FROM %Q.'%q_segdir' WHERE level = ?", +/* 15 */ "SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?", + +/* 16 */ "DELETE FROM %Q.'%q_segdir' WHERE level = ?", +/* 17 */ "DELETE FROM %Q.'%q_segments' WHERE blockid BETWEEN ? AND ?", +/* 18 */ "INSERT INTO %Q.'%q_content' VALUES(%s)", +/* 19 */ "DELETE FROM %Q.'%q_docsize' WHERE docid = ?", +/* 20 */ "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)", +/* 21 */ "SELECT size FROM %Q.'%q_docsize' WHERE docid=?", +/* 22 */ "SELECT value FROM %Q.'%q_stat' WHERE id=0", +/* 23 */ "REPLACE INTO %Q.'%q_stat' VALUES(0,?)", +/* 24 */ "", +/* 25 */ "", + +/* 26 */ "DELETE FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?", + + }; + int rc = SQLITE_OK; + sqlite3_stmt *pStmt; + + assert( SizeofArray(azSql)==SizeofArray(p->aStmt) ); + assert( eStmt<SizeofArray(azSql) && eStmt>=0 ); + + pStmt = p->aStmt[eStmt]; + if( !pStmt ){ + char *zSql; + if( eStmt==SQL_CONTENT_INSERT ){ + zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName, p->zWriteExprlist); + }else if( eStmt==SQL_SELECT_CONTENT_BY_ROWID ){ + zSql = sqlite3_mprintf(azSql[eStmt], p->zReadExprlist); + }else{ + zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName); + } + if( !zSql ){ + rc = SQLITE_NOMEM; + }else{ + rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, NULL); + sqlite3_free(zSql); + assert( rc==SQLITE_OK || pStmt==0 ); + p->aStmt[eStmt] = pStmt; + } + } + if( apVal ){ + int i; + int nParam = sqlite3_bind_parameter_count(pStmt); + for(i=0; rc==SQLITE_OK && i<nParam; i++){ + rc = sqlite3_bind_value(pStmt, i+1, apVal[i]); + } + } + *pp = pStmt; + return rc; +} + +static int fts3SelectDocsize( + Fts3Table *pTab, /* FTS3 table handle */ + int eStmt, /* Either SQL_SELECT_DOCSIZE or DOCTOTAL */ + sqlite3_int64 iDocid, /* Docid to bind for SQL_SELECT_DOCSIZE */ + sqlite3_stmt **ppStmt /* OUT: Statement handle */ +){ + sqlite3_stmt *pStmt = 0; /* Statement requested from fts3SqlStmt() */ + int rc; /* Return code */ + + assert( eStmt==SQL_SELECT_DOCSIZE || eStmt==SQL_SELECT_DOCTOTAL ); + + rc = fts3SqlStmt(pTab, eStmt, &pStmt, 0); + if( rc==SQLITE_OK ){ + if( eStmt==SQL_SELECT_DOCSIZE ){ + sqlite3_bind_int64(pStmt, 1, iDocid); + } + rc = sqlite3_step(pStmt); + if( rc!=SQLITE_ROW || sqlite3_column_type(pStmt, 0)!=SQLITE_BLOB ){ + rc = sqlite3_reset(pStmt); + if( rc==SQLITE_OK ) rc = FTS_CORRUPT_VTAB; + pStmt = 0; + }else{ + rc = SQLITE_OK; + } + } + + *ppStmt = pStmt; + return rc; +} + +int sqlite3Fts3SelectDoctotal( + Fts3Table *pTab, /* Fts3 table handle */ + sqlite3_stmt **ppStmt /* OUT: Statement handle */ +){ + return fts3SelectDocsize(pTab, SQL_SELECT_DOCTOTAL, 0, ppStmt); +} + +int sqlite3Fts3SelectDocsize( + Fts3Table *pTab, /* Fts3 table handle */ + sqlite3_int64 iDocid, /* Docid to read size data for */ + sqlite3_stmt **ppStmt /* OUT: Statement handle */ +){ + return fts3SelectDocsize(pTab, SQL_SELECT_DOCSIZE, iDocid, ppStmt); +} + +/* +** Similar to fts3SqlStmt(). Except, after binding the parameters in +** array apVal[] to the SQL statement identified by eStmt, the statement +** is executed. +** +** Returns SQLITE_OK if the statement is successfully executed, or an +** SQLite error code otherwise. +*/ +static void fts3SqlExec( + int *pRC, /* Result code */ + Fts3Table *p, /* The FTS3 table */ + int eStmt, /* Index of statement to evaluate */ + sqlite3_value **apVal /* Parameters to bind */ +){ + sqlite3_stmt *pStmt; + int rc; + if( *pRC ) return; + rc = fts3SqlStmt(p, eStmt, &pStmt, apVal); + if( rc==SQLITE_OK ){ + sqlite3_step(pStmt); + rc = sqlite3_reset(pStmt); + } + *pRC = rc; +} + + +/* +** This function ensures that the caller has obtained a shared-cache +** table-lock on the %_content table. This is required before reading +** data from the fts3 table. If this lock is not acquired first, then +** the caller may end up holding read-locks on the %_segments and %_segdir +** tables, but no read-lock on the %_content table. If this happens +** a second connection will be able to write to the fts3 table, but +** attempting to commit those writes might return SQLITE_LOCKED or +** SQLITE_LOCKED_SHAREDCACHE (because the commit attempts to obtain +** write-locks on the %_segments and %_segdir ** tables). +** +** We try to avoid this because if FTS3 returns any error when committing +** a transaction, the whole transaction will be rolled back. And this is +** not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. It can +** still happen if the user reads data directly from the %_segments or +** %_segdir tables instead of going through FTS3 though. +** +** This reasoning does not apply to a content=xxx table. +*/ +int sqlite3Fts3ReadLock(Fts3Table *p){ + int rc; /* Return code */ + sqlite3_stmt *pStmt; /* Statement used to obtain lock */ + + if( p->zContentTbl==0 ){ + rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pStmt, 0); + if( rc==SQLITE_OK ){ + sqlite3_bind_null(pStmt, 1); + sqlite3_step(pStmt); + rc = sqlite3_reset(pStmt); + } + }else{ + rc = SQLITE_OK; + } + + return rc; +} + +/* +** Set *ppStmt to a statement handle that may be used to iterate through +** all rows in the %_segdir table, from oldest to newest. If successful, +** return SQLITE_OK. If an error occurs while preparing the statement, +** return an SQLite error code. +** +** There is only ever one instance of this SQL statement compiled for +** each FTS3 table. +** +** The statement returns the following columns from the %_segdir table: +** +** 0: idx +** 1: start_block +** 2: leaves_end_block +** 3: end_block +** 4: root +*/ +int sqlite3Fts3AllSegdirs( + Fts3Table *p, /* FTS3 table */ + int iIndex, /* Index for p->aIndex[] */ + int iLevel, /* Level to select */ + sqlite3_stmt **ppStmt /* OUT: Compiled statement */ +){ + int rc; + sqlite3_stmt *pStmt = 0; + + assert( iLevel==FTS3_SEGCURSOR_ALL || iLevel>=0 ); + assert( iLevel<FTS3_SEGDIR_MAXLEVEL ); + assert( iIndex>=0 && iIndex<p->nIndex ); + + if( iLevel<0 ){ + /* "SELECT * FROM %_segdir WHERE level BETWEEN ? AND ? ORDER BY ..." */ + rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE, &pStmt, 0); + if( rc==SQLITE_OK ){ + sqlite3_bind_int(pStmt, 1, iIndex*FTS3_SEGDIR_MAXLEVEL); + sqlite3_bind_int(pStmt, 2, (iIndex+1)*FTS3_SEGDIR_MAXLEVEL-1); + } + }else{ + /* "SELECT * FROM %_segdir WHERE level = ? ORDER BY ..." */ + rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0); + if( rc==SQLITE_OK ){ + sqlite3_bind_int(pStmt, 1, iLevel+iIndex*FTS3_SEGDIR_MAXLEVEL); + } + } + *ppStmt = pStmt; + return rc; +} + + +/* +** Append a single varint to a PendingList buffer. SQLITE_OK is returned +** if successful, or an SQLite error code otherwise. +** +** This function also serves to allocate the PendingList structure itself. +** For example, to create a new PendingList structure containing two +** varints: +** +** PendingList *p = 0; +** fts3PendingListAppendVarint(&p, 1); +** fts3PendingListAppendVarint(&p, 2); +*/ +static int fts3PendingListAppendVarint( + PendingList **pp, /* IN/OUT: Pointer to PendingList struct */ + sqlite3_int64 i /* Value to append to data */ +){ + PendingList *p = *pp; + + /* Allocate or grow the PendingList as required. */ + if( !p ){ + p = sqlite3_malloc(sizeof(*p) + 100); + if( !p ){ + return SQLITE_NOMEM; + } + p->nSpace = 100; + p->aData = (char *)&p[1]; + p->nData = 0; + } + else if( p->nData+FTS3_VARINT_MAX+1>p->nSpace ){ + int nNew = p->nSpace * 2; + p = sqlite3_realloc(p, sizeof(*p) + nNew); + if( !p ){ + sqlite3_free(*pp); + *pp = 0; + return SQLITE_NOMEM; + } + p->nSpace = nNew; + p->aData = (char *)&p[1]; + } + + /* Append the new serialized varint to the end of the list. */ + p->nData += sqlite3Fts3PutVarint(&p->aData[p->nData], i); + p->aData[p->nData] = '\0'; + *pp = p; + return SQLITE_OK; +} + +/* +** Add a docid/column/position entry to a PendingList structure. Non-zero +** is returned if the structure is sqlite3_realloced as part of adding +** the entry. Otherwise, zero. +** +** If an OOM error occurs, *pRc is set to SQLITE_NOMEM before returning. +** Zero is always returned in this case. Otherwise, if no OOM error occurs, +** it is set to SQLITE_OK. +*/ +static int fts3PendingListAppend( + PendingList **pp, /* IN/OUT: PendingList structure */ + sqlite3_int64 iDocid, /* Docid for entry to add */ + sqlite3_int64 iCol, /* Column for entry to add */ + sqlite3_int64 iPos, /* Position of term for entry to add */ + int *pRc /* OUT: Return code */ +){ + PendingList *p = *pp; + int rc = SQLITE_OK; + + assert( !p || p->iLastDocid<=iDocid ); + + if( !p || p->iLastDocid!=iDocid ){ + sqlite3_int64 iDelta = iDocid - (p ? p->iLastDocid : 0); + if( p ){ + assert( p->nData<p->nSpace ); + assert( p->aData[p->nData]==0 ); + p->nData++; + } + if( SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, iDelta)) ){ + goto pendinglistappend_out; + } + p->iLastCol = -1; + p->iLastPos = 0; + p->iLastDocid = iDocid; + } + if( iCol>0 && p->iLastCol!=iCol ){ + if( SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, 1)) + || SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, iCol)) + ){ + goto pendinglistappend_out; + } + p->iLastCol = iCol; + p->iLastPos = 0; + } + if( iCol>=0 ){ + assert( iPos>p->iLastPos || (iPos==0 && p->iLastPos==0) ); + rc = fts3PendingListAppendVarint(&p, 2+iPos-p->iLastPos); + if( rc==SQLITE_OK ){ + p->iLastPos = iPos; + } + } + + pendinglistappend_out: + *pRc = rc; + if( p!=*pp ){ + *pp = p; + return 1; + } + return 0; +} + +/* +** Free a PendingList object allocated by fts3PendingListAppend(). +*/ +static void fts3PendingListDelete(PendingList *pList){ + sqlite3_free(pList); +} + +/* +** Add an entry to one of the pending-terms hash tables. +*/ +static int fts3PendingTermsAddOne( + Fts3Table *p, + int iCol, + int iPos, + Fts3Hash *pHash, /* Pending terms hash table to add entry to */ + const char *zToken, + int nToken +){ + PendingList *pList; + int rc = SQLITE_OK; + + pList = (PendingList *)fts3HashFind(pHash, zToken, nToken); + if( pList ){ + p->nPendingData -= (pList->nData + nToken + sizeof(Fts3HashElem)); + } + if( fts3PendingListAppend(&pList, p->iPrevDocid, iCol, iPos, &rc) ){ + if( pList==fts3HashInsert(pHash, zToken, nToken, pList) ){ + /* Malloc failed while inserting the new entry. This can only + ** happen if there was no previous entry for this token. + */ + assert( 0==fts3HashFind(pHash, zToken, nToken) ); + sqlite3_free(pList); + rc = SQLITE_NOMEM; + } + } + if( rc==SQLITE_OK ){ + p->nPendingData += (pList->nData + nToken + sizeof(Fts3HashElem)); + } + return rc; +} + +/* +** Tokenize the nul-terminated string zText and add all tokens to the +** pending-terms hash-table. The docid used is that currently stored in +** p->iPrevDocid, and the column is specified by argument iCol. +** +** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code. +*/ +static int fts3PendingTermsAdd( + Fts3Table *p, /* Table into which text will be inserted */ + const char *zText, /* Text of document to be inserted */ + int iCol, /* Column into which text is being inserted */ + u32 *pnWord /* OUT: Number of tokens inserted */ +){ + int rc; + int iStart; + int iEnd; + int iPos; + int nWord = 0; + + char const *zToken; + int nToken; + + sqlite3_tokenizer *pTokenizer = p->pTokenizer; + sqlite3_tokenizer_module const *pModule = pTokenizer->pModule; + sqlite3_tokenizer_cursor *pCsr; + int (*xNext)(sqlite3_tokenizer_cursor *pCursor, + const char**,int*,int*,int*,int*); + + assert( pTokenizer && pModule ); + + /* If the user has inserted a NULL value, this function may be called with + ** zText==0. In this case, add zero token entries to the hash table and + ** return early. */ + if( zText==0 ){ + *pnWord = 0; + return SQLITE_OK; + } + + rc = pModule->xOpen(pTokenizer, zText, -1, &pCsr); + if( rc!=SQLITE_OK ){ + return rc; + } + pCsr->pTokenizer = pTokenizer; + + xNext = pModule->xNext; + while( SQLITE_OK==rc + && SQLITE_OK==(rc = xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos)) + ){ + int i; + if( iPos>=nWord ) nWord = iPos+1; + + /* Positions cannot be negative; we use -1 as a terminator internally. + ** Tokens must have a non-zero length. + */ + if( iPos<0 || !zToken || nToken<=0 ){ + rc = SQLITE_ERROR; + break; + } + + /* Add the term to the terms index */ + rc = fts3PendingTermsAddOne( + p, iCol, iPos, &p->aIndex[0].hPending, zToken, nToken + ); + + /* Add the term to each of the prefix indexes that it is not too + ** short for. */ + for(i=1; rc==SQLITE_OK && i<p->nIndex; i++){ + struct Fts3Index *pIndex = &p->aIndex[i]; + if( nToken<pIndex->nPrefix ) continue; + rc = fts3PendingTermsAddOne( + p, iCol, iPos, &pIndex->hPending, zToken, pIndex->nPrefix + ); + } + } + + pModule->xClose(pCsr); + *pnWord = nWord; + return (rc==SQLITE_DONE ? SQLITE_OK : rc); +} + +/* +** Calling this function indicates that subsequent calls to +** fts3PendingTermsAdd() are to add term/position-list pairs for the +** contents of the document with docid iDocid. +*/ +static int fts3PendingTermsDocid(Fts3Table *p, sqlite_int64 iDocid){ + /* TODO(shess) Explore whether partially flushing the buffer on + ** forced-flush would provide better performance. I suspect that if + ** we ordered the doclists by size and flushed the largest until the + ** buffer was half empty, that would let the less frequent terms + ** generate longer doclists. + */ + if( iDocid<=p->iPrevDocid || p->nPendingData>p->nMaxPendingData ){ + int rc = sqlite3Fts3PendingTermsFlush(p); + if( rc!=SQLITE_OK ) return rc; + } + p->iPrevDocid = iDocid; + return SQLITE_OK; +} + +/* +** Discard the contents of the pending-terms hash tables. +*/ +void sqlite3Fts3PendingTermsClear(Fts3Table *p){ + int i; + for(i=0; i<p->nIndex; i++){ + Fts3HashElem *pElem; + Fts3Hash *pHash = &p->aIndex[i].hPending; + for(pElem=fts3HashFirst(pHash); pElem; pElem=fts3HashNext(pElem)){ + PendingList *pList = (PendingList *)fts3HashData(pElem); + fts3PendingListDelete(pList); + } + fts3HashClear(pHash); + } + p->nPendingData = 0; +} + +/* +** This function is called by the xUpdate() method as part of an INSERT +** operation. It adds entries for each term in the new record to the +** pendingTerms hash table. +** +** Argument apVal is the same as the similarly named argument passed to +** fts3InsertData(). Parameter iDocid is the docid of the new row. +*/ +static int fts3InsertTerms(Fts3Table *p, sqlite3_value **apVal, u32 *aSz){ + int i; /* Iterator variable */ + for(i=2; i<p->nColumn+2; i++){ + const char *zText = (const char *)sqlite3_value_text(apVal[i]); + int rc = fts3PendingTermsAdd(p, zText, i-2, &aSz[i-2]); + if( rc!=SQLITE_OK ){ + return rc; + } + aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]); + } + return SQLITE_OK; +} + +/* +** This function is called by the xUpdate() method for an INSERT operation. +** The apVal parameter is passed a copy of the apVal argument passed by +** SQLite to the xUpdate() method. i.e: +** +** apVal[0] Not used for INSERT. +** apVal[1] rowid +** apVal[2] Left-most user-defined column +** ... +** apVal[p->nColumn+1] Right-most user-defined column +** apVal[p->nColumn+2] Hidden column with same name as table +** apVal[p->nColumn+3] Hidden "docid" column (alias for rowid) +*/ +static int fts3InsertData( + Fts3Table *p, /* Full-text table */ + sqlite3_value **apVal, /* Array of values to insert */ + sqlite3_int64 *piDocid /* OUT: Docid for row just inserted */ +){ + int rc; /* Return code */ + sqlite3_stmt *pContentInsert; /* INSERT INTO %_content VALUES(...) */ + + if( p->zContentTbl ){ + sqlite3_value *pRowid = apVal[p->nColumn+3]; + if( sqlite3_value_type(pRowid)==SQLITE_NULL ){ + pRowid = apVal[1]; + } + if( sqlite3_value_type(pRowid)!=SQLITE_INTEGER ){ + return SQLITE_CONSTRAINT; + } + *piDocid = sqlite3_value_int64(pRowid); + return SQLITE_OK; + } + + /* Locate the statement handle used to insert data into the %_content + ** table. The SQL for this statement is: + ** + ** INSERT INTO %_content VALUES(?, ?, ?, ...) + ** + ** The statement features N '?' variables, where N is the number of user + ** defined columns in the FTS3 table, plus one for the docid field. + */ + rc = fts3SqlStmt(p, SQL_CONTENT_INSERT, &pContentInsert, &apVal[1]); + if( rc!=SQLITE_OK ){ + return rc; + } + + /* There is a quirk here. The users INSERT statement may have specified + ** a value for the "rowid" field, for the "docid" field, or for both. + ** Which is a problem, since "rowid" and "docid" are aliases for the + ** same value. For example: + ** + ** INSERT INTO fts3tbl(rowid, docid) VALUES(1, 2); + ** + ** In FTS3, this is an error. It is an error to specify non-NULL values + ** for both docid and some other rowid alias. + */ + if( SQLITE_NULL!=sqlite3_value_type(apVal[3+p->nColumn]) ){ + if( SQLITE_NULL==sqlite3_value_type(apVal[0]) + && SQLITE_NULL!=sqlite3_value_type(apVal[1]) + ){ + /* A rowid/docid conflict. */ + return SQLITE_ERROR; + } + rc = sqlite3_bind_value(pContentInsert, 1, apVal[3+p->nColumn]); + if( rc!=SQLITE_OK ) return rc; + } + + /* Execute the statement to insert the record. Set *piDocid to the + ** new docid value. + */ + sqlite3_step(pContentInsert); + rc = sqlite3_reset(pContentInsert); + + *piDocid = sqlite3_last_insert_rowid(p->db); + return rc; +} + + + +/* +** Remove all data from the FTS3 table. Clear the hash table containing +** pending terms. +*/ +static int fts3DeleteAll(Fts3Table *p, int bContent){ + int rc = SQLITE_OK; /* Return code */ + + /* Discard the contents of the pending-terms hash table. */ + sqlite3Fts3PendingTermsClear(p); + + /* Delete everything from the shadow tables. Except, leave %_content as + ** is if bContent is false. */ + assert( p->zContentTbl==0 || bContent==0 ); + if( bContent ) fts3SqlExec(&rc, p, SQL_DELETE_ALL_CONTENT, 0); + fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGMENTS, 0); + fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGDIR, 0); + if( p->bHasDocsize ){ + fts3SqlExec(&rc, p, SQL_DELETE_ALL_DOCSIZE, 0); + } + if( p->bHasStat ){ + fts3SqlExec(&rc, p, SQL_DELETE_ALL_STAT, 0); + } + return rc; +} + +/* +** The first element in the apVal[] array is assumed to contain the docid +** (an integer) of a row about to be deleted. Remove all terms from the +** full-text index. +*/ +static void fts3DeleteTerms( + int *pRC, /* Result code */ + Fts3Table *p, /* The FTS table to delete from */ + sqlite3_value *pRowid, /* The docid to be deleted */ + u32 *aSz /* Sizes of deleted document written here */ +){ + int rc; + sqlite3_stmt *pSelect; + + if( *pRC ) return; + rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pSelect, &pRowid); + if( rc==SQLITE_OK ){ + if( SQLITE_ROW==sqlite3_step(pSelect) ){ + int i; + for(i=1; i<=p->nColumn; i++){ + const char *zText = (const char *)sqlite3_column_text(pSelect, i); + rc = fts3PendingTermsAdd(p, zText, -1, &aSz[i-1]); + if( rc!=SQLITE_OK ){ + sqlite3_reset(pSelect); + *pRC = rc; + return; + } + aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i); + } + } + rc = sqlite3_reset(pSelect); + }else{ + sqlite3_reset(pSelect); + } + *pRC = rc; +} + +/* +** Forward declaration to account for the circular dependency between +** functions fts3SegmentMerge() and fts3AllocateSegdirIdx(). +*/ +static int fts3SegmentMerge(Fts3Table *, int, int); + +/* +** This function allocates a new level iLevel index in the segdir table. +** Usually, indexes are allocated within a level sequentially starting +** with 0, so the allocated index is one greater than the value returned +** by: +** +** SELECT max(idx) FROM %_segdir WHERE level = :iLevel +** +** However, if there are already FTS3_MERGE_COUNT indexes at the requested +** level, they are merged into a single level (iLevel+1) segment and the +** allocated index is 0. +** +** If successful, *piIdx is set to the allocated index slot and SQLITE_OK +** returned. Otherwise, an SQLite error code is returned. +*/ +static int fts3AllocateSegdirIdx( + Fts3Table *p, + int iIndex, /* Index for p->aIndex */ + int iLevel, + int *piIdx +){ + int rc; /* Return Code */ + sqlite3_stmt *pNextIdx; /* Query for next idx at level iLevel */ + int iNext = 0; /* Result of query pNextIdx */ + + /* Set variable iNext to the next available segdir index at level iLevel. */ + rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pNextIdx, 0); + if( rc==SQLITE_OK ){ + sqlite3_bind_int(pNextIdx, 1, iIndex*FTS3_SEGDIR_MAXLEVEL + iLevel); + if( SQLITE_ROW==sqlite3_step(pNextIdx) ){ + iNext = sqlite3_column_int(pNextIdx, 0); + } + rc = sqlite3_reset(pNextIdx); + } + + if( rc==SQLITE_OK ){ + /* If iNext is FTS3_MERGE_COUNT, indicating that level iLevel is already + ** full, merge all segments in level iLevel into a single iLevel+1 + ** segment and allocate (newly freed) index 0 at level iLevel. Otherwise, + ** if iNext is less than FTS3_MERGE_COUNT, allocate index iNext. + */ + if( iNext>=FTS3_MERGE_COUNT ){ + rc = fts3SegmentMerge(p, iIndex, iLevel); + *piIdx = 0; + }else{ + *piIdx = iNext; + } + } + + return rc; +} + +/* +** The %_segments table is declared as follows: +** +** CREATE TABLE %_segments(blockid INTEGER PRIMARY KEY, block BLOB) +** +** This function reads data from a single row of the %_segments table. The +** specific row is identified by the iBlockid parameter. If paBlob is not +** NULL, then a buffer is allocated using sqlite3_malloc() and populated +** with the contents of the blob stored in the "block" column of the +** identified table row is. Whether or not paBlob is NULL, *pnBlob is set +** to the size of the blob in bytes before returning. +** +** If an error occurs, or the table does not contain the specified row, +** an SQLite error code is returned. Otherwise, SQLITE_OK is returned. If +** paBlob is non-NULL, then it is the responsibility of the caller to +** eventually free the returned buffer. +** +** This function may leave an open sqlite3_blob* handle in the +** Fts3Table.pSegments variable. This handle is reused by subsequent calls +** to this function. The handle may be closed by calling the +** sqlite3Fts3SegmentsClose() function. Reusing a blob handle is a handy +** performance improvement, but the blob handle should always be closed +** before control is returned to the user (to prevent a lock being held +** on the database file for longer than necessary). Thus, any virtual table +** method (xFilter etc.) that may directly or indirectly call this function +** must call sqlite3Fts3SegmentsClose() before returning. +*/ +int sqlite3Fts3ReadBlock( + Fts3Table *p, /* FTS3 table handle */ + sqlite3_int64 iBlockid, /* Access the row with blockid=$iBlockid */ + char **paBlob, /* OUT: Blob data in malloc'd buffer */ + int *pnBlob, /* OUT: Size of blob data */ + int *pnLoad /* OUT: Bytes actually loaded */ +){ + int rc; /* Return code */ + + /* pnBlob must be non-NULL. paBlob may be NULL or non-NULL. */ + assert( pnBlob); + + if( p->pSegments ){ + rc = sqlite3_blob_reopen(p->pSegments, iBlockid); + }else{ + if( 0==p->zSegmentsTbl ){ + p->zSegmentsTbl = sqlite3_mprintf("%s_segments", p->zName); + if( 0==p->zSegmentsTbl ) return SQLITE_NOMEM; + } + rc = sqlite3_blob_open( + p->db, p->zDb, p->zSegmentsTbl, "block", iBlockid, 0, &p->pSegments + ); + } + + if( rc==SQLITE_OK ){ + int nByte = sqlite3_blob_bytes(p->pSegments); + *pnBlob = nByte; + if( paBlob ){ + char *aByte = sqlite3_malloc(nByte + FTS3_NODE_PADDING); + if( !aByte ){ + rc = SQLITE_NOMEM; + }else{ + if( pnLoad && nByte>(FTS3_NODE_CHUNK_THRESHOLD) ){ + nByte = FTS3_NODE_CHUNKSIZE; + *pnLoad = nByte; + } + rc = sqlite3_blob_read(p->pSegments, aByte, nByte, 0); + memset(&aByte[nByte], 0, FTS3_NODE_PADDING); + if( rc!=SQLITE_OK ){ + sqlite3_free(aByte); + aByte = 0; + } + } + *paBlob = aByte; + } + } + + return rc; +} + +/* +** Close the blob handle at p->pSegments, if it is open. See comments above +** the sqlite3Fts3ReadBlock() function for details. +*/ +void sqlite3Fts3SegmentsClose(Fts3Table *p){ + sqlite3_blob_close(p->pSegments); + p->pSegments = 0; +} + +static int fts3SegReaderIncrRead(Fts3SegReader *pReader){ + int nRead; /* Number of bytes to read */ + int rc; /* Return code */ + + nRead = MIN(pReader->nNode - pReader->nPopulate, FTS3_NODE_CHUNKSIZE); + rc = sqlite3_blob_read( + pReader->pBlob, + &pReader->aNode[pReader->nPopulate], + nRead, + pReader->nPopulate + ); + + if( rc==SQLITE_OK ){ + pReader->nPopulate += nRead; + memset(&pReader->aNode[pReader->nPopulate], 0, FTS3_NODE_PADDING); + if( pReader->nPopulate==pReader->nNode ){ + sqlite3_blob_close(pReader->pBlob); + pReader->pBlob = 0; + pReader->nPopulate = 0; + } + } + return rc; +} + +static int fts3SegReaderRequire(Fts3SegReader *pReader, char *pFrom, int nByte){ + int rc = SQLITE_OK; + assert( !pReader->pBlob + || (pFrom>=pReader->aNode && pFrom<&pReader->aNode[pReader->nNode]) + ); + while( pReader->pBlob && rc==SQLITE_OK + && (pFrom - pReader->aNode + nByte)>pReader->nPopulate + ){ + rc = fts3SegReaderIncrRead(pReader); + } + return rc; +} + +/* +** Move the iterator passed as the first argument to the next term in the +** segment. If successful, SQLITE_OK is returned. If there is no next term, +** SQLITE_DONE. Otherwise, an SQLite error code. +*/ +static int fts3SegReaderNext( + Fts3Table *p, + Fts3SegReader *pReader, + int bIncr +){ + int rc; /* Return code of various sub-routines */ + char *pNext; /* Cursor variable */ + int nPrefix; /* Number of bytes in term prefix */ + int nSuffix; /* Number of bytes in term suffix */ + + if( !pReader->aDoclist ){ + pNext = pReader->aNode; + }else{ + pNext = &pReader->aDoclist[pReader->nDoclist]; + } + + if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){ + + if( fts3SegReaderIsPending(pReader) ){ + Fts3HashElem *pElem = *(pReader->ppNextElem); + if( pElem==0 ){ + pReader->aNode = 0; + }else{ + PendingList *pList = (PendingList *)fts3HashData(pElem); + pReader->zTerm = (char *)fts3HashKey(pElem); + pReader->nTerm = fts3HashKeysize(pElem); + pReader->nNode = pReader->nDoclist = pList->nData + 1; + pReader->aNode = pReader->aDoclist = pList->aData; + pReader->ppNextElem++; + assert( pReader->aNode ); + } + return SQLITE_OK; + } + + if( !fts3SegReaderIsRootOnly(pReader) ){ + sqlite3_free(pReader->aNode); + sqlite3_blob_close(pReader->pBlob); + pReader->pBlob = 0; + } + pReader->aNode = 0; + + /* If iCurrentBlock>=iLeafEndBlock, this is an EOF condition. All leaf + ** blocks have already been traversed. */ + assert( pReader->iCurrentBlock<=pReader->iLeafEndBlock ); + if( pReader->iCurrentBlock>=pReader->iLeafEndBlock ){ + return SQLITE_OK; + } + + rc = sqlite3Fts3ReadBlock( + p, ++pReader->iCurrentBlock, &pReader->aNode, &pReader->nNode, + (bIncr ? &pReader->nPopulate : 0) + ); + if( rc!=SQLITE_OK ) return rc; + assert( pReader->pBlob==0 ); + if( bIncr && pReader->nPopulate<pReader->nNode ){ + pReader->pBlob = p->pSegments; + p->pSegments = 0; + } + pNext = pReader->aNode; + } + + assert( !fts3SegReaderIsPending(pReader) ); + + rc = fts3SegReaderRequire(pReader, pNext, FTS3_VARINT_MAX*2); + if( rc!=SQLITE_OK ) return rc; + + /* Because of the FTS3_NODE_PADDING bytes of padding, the following is + ** safe (no risk of overread) even if the node data is corrupted. */ + pNext += sqlite3Fts3GetVarint32(pNext, &nPrefix); + pNext += sqlite3Fts3GetVarint32(pNext, &nSuffix); + if( nPrefix<0 || nSuffix<=0 + || &pNext[nSuffix]>&pReader->aNode[pReader->nNode] + ){ + return FTS_CORRUPT_VTAB; + } + + if( nPrefix+nSuffix>pReader->nTermAlloc ){ + int nNew = (nPrefix+nSuffix)*2; + char *zNew = sqlite3_realloc(pReader->zTerm, nNew); + if( !zNew ){ + return SQLITE_NOMEM; + } + pReader->zTerm = zNew; + pReader->nTermAlloc = nNew; + } + + rc = fts3SegReaderRequire(pReader, pNext, nSuffix+FTS3_VARINT_MAX); + if( rc!=SQLITE_OK ) return rc; + + memcpy(&pReader->zTerm[nPrefix], pNext, nSuffix); + pReader->nTerm = nPrefix+nSuffix; + pNext += nSuffix; + pNext += sqlite3Fts3GetVarint32(pNext, &pReader->nDoclist); + pReader->aDoclist = pNext; + pReader->pOffsetList = 0; + + /* Check that the doclist does not appear to extend past the end of the + ** b-tree node. And that the final byte of the doclist is 0x00. If either + ** of these statements is untrue, then the data structure is corrupt. + */ + if( &pReader->aDoclist[pReader->nDoclist]>&pReader->aNode[pReader->nNode] + || (pReader->nPopulate==0 && pReader->aDoclist[pReader->nDoclist-1]) + ){ + return FTS_CORRUPT_VTAB; + } + return SQLITE_OK; +} + +/* +** Set the SegReader to point to the first docid in the doclist associated +** with the current term. +*/ +static int fts3SegReaderFirstDocid(Fts3Table *pTab, Fts3SegReader *pReader){ + int rc = SQLITE_OK; + assert( pReader->aDoclist ); + assert( !pReader->pOffsetList ); + if( pTab->bDescIdx && fts3SegReaderIsPending(pReader) ){ + u8 bEof = 0; + pReader->iDocid = 0; + pReader->nOffsetList = 0; + sqlite3Fts3DoclistPrev(0, + pReader->aDoclist, pReader->nDoclist, &pReader->pOffsetList, + &pReader->iDocid, &pReader->nOffsetList, &bEof + ); + }else{ + rc = fts3SegReaderRequire(pReader, pReader->aDoclist, FTS3_VARINT_MAX); + if( rc==SQLITE_OK ){ + int n = sqlite3Fts3GetVarint(pReader->aDoclist, &pReader->iDocid); + pReader->pOffsetList = &pReader->aDoclist[n]; + } + } + return rc; +} + +/* +** Advance the SegReader to point to the next docid in the doclist +** associated with the current term. +** +** If arguments ppOffsetList and pnOffsetList are not NULL, then +** *ppOffsetList is set to point to the first column-offset list +** in the doclist entry (i.e. immediately past the docid varint). +** *pnOffsetList is set to the length of the set of column-offset +** lists, not including the nul-terminator byte. For example: +*/ +static int fts3SegReaderNextDocid( + Fts3Table *pTab, + Fts3SegReader *pReader, /* Reader to advance to next docid */ + char **ppOffsetList, /* OUT: Pointer to current position-list */ + int *pnOffsetList /* OUT: Length of *ppOffsetList in bytes */ +){ + int rc = SQLITE_OK; + char *p = pReader->pOffsetList; + char c = 0; + + assert( p ); + + if( pTab->bDescIdx && fts3SegReaderIsPending(pReader) ){ + /* A pending-terms seg-reader for an FTS4 table that uses order=desc. + ** Pending-terms doclists are always built up in ascending order, so + ** we have to iterate through them backwards here. */ + u8 bEof = 0; + if( ppOffsetList ){ + *ppOffsetList = pReader->pOffsetList; + *pnOffsetList = pReader->nOffsetList - 1; + } + sqlite3Fts3DoclistPrev(0, + pReader->aDoclist, pReader->nDoclist, &p, &pReader->iDocid, + &pReader->nOffsetList, &bEof + ); + if( bEof ){ + pReader->pOffsetList = 0; + }else{ + pReader->pOffsetList = p; + } + }else{ + char *pEnd = &pReader->aDoclist[pReader->nDoclist]; + + /* Pointer p currently points at the first byte of an offset list. The + ** following block advances it to point one byte past the end of + ** the same offset list. */ + while( 1 ){ + + /* The following line of code (and the "p++" below the while() loop) is + ** normally all that is required to move pointer p to the desired + ** position. The exception is if this node is being loaded from disk + ** incrementally and pointer "p" now points to the first byte passed + ** the populated part of pReader->aNode[]. + */ + while( *p | c ) c = *p++ & 0x80; + assert( *p==0 ); + + if( pReader->pBlob==0 || p<&pReader->aNode[pReader->nPopulate] ) break; + rc = fts3SegReaderIncrRead(pReader); + if( rc!=SQLITE_OK ) return rc; + } + p++; + + /* If required, populate the output variables with a pointer to and the + ** size of the previous offset-list. + */ + if( ppOffsetList ){ + *ppOffsetList = pReader->pOffsetList; + *pnOffsetList = (int)(p - pReader->pOffsetList - 1); + } + + while( p<pEnd && *p==0 ) p++; + + /* If there are no more entries in the doclist, set pOffsetList to + ** NULL. Otherwise, set Fts3SegReader.iDocid to the next docid and + ** Fts3SegReader.pOffsetList to point to the next offset list before + ** returning. + */ + if( p>=pEnd ){ + pReader->pOffsetList = 0; + }else{ + rc = fts3SegReaderRequire(pReader, p, FTS3_VARINT_MAX); + if( rc==SQLITE_OK ){ + sqlite3_int64 iDelta; + pReader->pOffsetList = p + sqlite3Fts3GetVarint(p, &iDelta); + if( pTab->bDescIdx ){ + pReader->iDocid -= iDelta; + }else{ + pReader->iDocid += iDelta; + } + } + } + } + + return SQLITE_OK; +} + + +int sqlite3Fts3MsrOvfl( + Fts3Cursor *pCsr, + Fts3MultiSegReader *pMsr, + int *pnOvfl +){ + Fts3Table *p = (Fts3Table*)pCsr->base.pVtab; + int nOvfl = 0; + int ii; + int rc = SQLITE_OK; + int pgsz = p->nPgsz; + + assert( p->bHasStat ); + assert( pgsz>0 ); + + for(ii=0; rc==SQLITE_OK && ii<pMsr->nSegment; ii++){ + Fts3SegReader *pReader = pMsr->apSegment[ii]; + if( !fts3SegReaderIsPending(pReader) + && !fts3SegReaderIsRootOnly(pReader) + ){ + sqlite3_int64 jj; + for(jj=pReader->iStartBlock; jj<=pReader->iLeafEndBlock; jj++){ + int nBlob; + rc = sqlite3Fts3ReadBlock(p, jj, 0, &nBlob, 0); + if( rc!=SQLITE_OK ) break; + if( (nBlob+35)>pgsz ){ + nOvfl += (nBlob + 34)/pgsz; + } + } + } + } + *pnOvfl = nOvfl; + return rc; +} + +/* +** Free all allocations associated with the iterator passed as the +** second argument. +*/ +void sqlite3Fts3SegReaderFree(Fts3SegReader *pReader){ + if( pReader && !fts3SegReaderIsPending(pReader) ){ + sqlite3_free(pReader->zTerm); + if( !fts3SegReaderIsRootOnly(pReader) ){ + sqlite3_free(pReader->aNode); + sqlite3_blob_close(pReader->pBlob); + } + } + sqlite3_free(pReader); +} + +/* +** Allocate a new SegReader object. +*/ +int sqlite3Fts3SegReaderNew( + int iAge, /* Segment "age". */ + sqlite3_int64 iStartLeaf, /* First leaf to traverse */ + sqlite3_int64 iEndLeaf, /* Final leaf to traverse */ + sqlite3_int64 iEndBlock, /* Final block of segment */ + const char *zRoot, /* Buffer containing root node */ + int nRoot, /* Size of buffer containing root node */ + Fts3SegReader **ppReader /* OUT: Allocated Fts3SegReader */ +){ + int rc = SQLITE_OK; /* Return code */ + Fts3SegReader *pReader; /* Newly allocated SegReader object */ + int nExtra = 0; /* Bytes to allocate segment root node */ + + assert( iStartLeaf<=iEndLeaf ); + if( iStartLeaf==0 ){ + nExtra = nRoot + FTS3_NODE_PADDING; + } + + pReader = (Fts3SegReader *)sqlite3_malloc(sizeof(Fts3SegReader) + nExtra); + if( !pReader ){ + return SQLITE_NOMEM; + } + memset(pReader, 0, sizeof(Fts3SegReader)); + pReader->iIdx = iAge; + pReader->iStartBlock = iStartLeaf; + pReader->iLeafEndBlock = iEndLeaf; + pReader->iEndBlock = iEndBlock; + + if( nExtra ){ + /* The entire segment is stored in the root node. */ + pReader->aNode = (char *)&pReader[1]; + pReader->nNode = nRoot; + memcpy(pReader->aNode, zRoot, nRoot); + memset(&pReader->aNode[nRoot], 0, FTS3_NODE_PADDING); + }else{ + pReader->iCurrentBlock = iStartLeaf-1; + } + + if( rc==SQLITE_OK ){ + *ppReader = pReader; + }else{ + sqlite3Fts3SegReaderFree(pReader); + } + return rc; +} + +/* +** This is a comparison function used as a qsort() callback when sorting +** an array of pending terms by term. This occurs as part of flushing +** the contents of the pending-terms hash table to the database. +*/ +static int fts3CompareElemByTerm(const void *lhs, const void *rhs){ + char *z1 = fts3HashKey(*(Fts3HashElem **)lhs); + char *z2 = fts3HashKey(*(Fts3HashElem **)rhs); + int n1 = fts3HashKeysize(*(Fts3HashElem **)lhs); + int n2 = fts3HashKeysize(*(Fts3HashElem **)rhs); + + int n = (n1<n2 ? n1 : n2); + int c = memcmp(z1, z2, n); + if( c==0 ){ + c = n1 - n2; + } + return c; +} + +/* +** This function is used to allocate an Fts3SegReader that iterates through +** a subset of the terms stored in the Fts3Table.pendingTerms array. +** +** If the isPrefixIter parameter is zero, then the returned SegReader iterates +** through each term in the pending-terms table. Or, if isPrefixIter is +** non-zero, it iterates through each term and its prefixes. For example, if +** the pending terms hash table contains the terms "sqlite", "mysql" and +** "firebird", then the iterator visits the following 'terms' (in the order +** shown): +** +** f fi fir fire fireb firebi firebir firebird +** m my mys mysq mysql +** s sq sql sqli sqlit sqlite +** +** Whereas if isPrefixIter is zero, the terms visited are: +** +** firebird mysql sqlite +*/ +int sqlite3Fts3SegReaderPending( + Fts3Table *p, /* Virtual table handle */ + int iIndex, /* Index for p->aIndex */ + const char *zTerm, /* Term to search for */ + int nTerm, /* Size of buffer zTerm */ + int bPrefix, /* True for a prefix iterator */ + Fts3SegReader **ppReader /* OUT: SegReader for pending-terms */ +){ + Fts3SegReader *pReader = 0; /* Fts3SegReader object to return */ + Fts3HashElem **aElem = 0; /* Array of term hash entries to scan */ + int nElem = 0; /* Size of array at aElem */ + int rc = SQLITE_OK; /* Return Code */ + Fts3Hash *pHash; + + pHash = &p->aIndex[iIndex].hPending; + if( bPrefix ){ + int nAlloc = 0; /* Size of allocated array at aElem */ + Fts3HashElem *pE = 0; /* Iterator variable */ + + for(pE=fts3HashFirst(pHash); pE; pE=fts3HashNext(pE)){ + char *zKey = (char *)fts3HashKey(pE); + int nKey = fts3HashKeysize(pE); + if( nTerm==0 || (nKey>=nTerm && 0==memcmp(zKey, zTerm, nTerm)) ){ + if( nElem==nAlloc ){ + Fts3HashElem **aElem2; + nAlloc += 16; + aElem2 = (Fts3HashElem **)sqlite3_realloc( + aElem, nAlloc*sizeof(Fts3HashElem *) + ); + if( !aElem2 ){ + rc = SQLITE_NOMEM; + nElem = 0; + break; + } + aElem = aElem2; + } + + aElem[nElem++] = pE; + } + } + + /* If more than one term matches the prefix, sort the Fts3HashElem + ** objects in term order using qsort(). This uses the same comparison + ** callback as is used when flushing terms to disk. + */ + if( nElem>1 ){ + qsort(aElem, nElem, sizeof(Fts3HashElem *), fts3CompareElemByTerm); + } + + }else{ + /* The query is a simple term lookup that matches at most one term in + ** the index. All that is required is a straight hash-lookup. */ + Fts3HashElem *pE = fts3HashFindElem(pHash, zTerm, nTerm); + if( pE ){ + aElem = &pE; + nElem = 1; + } + } + + if( nElem>0 ){ + int nByte = sizeof(Fts3SegReader) + (nElem+1)*sizeof(Fts3HashElem *); + pReader = (Fts3SegReader *)sqlite3_malloc(nByte); + if( !pReader ){ + rc = SQLITE_NOMEM; + }else{ + memset(pReader, 0, nByte); + pReader->iIdx = 0x7FFFFFFF; + pReader->ppNextElem = (Fts3HashElem **)&pReader[1]; + memcpy(pReader->ppNextElem, aElem, nElem*sizeof(Fts3HashElem *)); + } + } + + if( bPrefix ){ + sqlite3_free(aElem); + } + *ppReader = pReader; + return rc; +} + +/* +** Compare the entries pointed to by two Fts3SegReader structures. +** Comparison is as follows: +** +** 1) EOF is greater than not EOF. +** +** 2) The current terms (if any) are compared using memcmp(). If one +** term is a prefix of another, the longer term is considered the +** larger. +** +** 3) By segment age. An older segment is considered larger. +*/ +static int fts3SegReaderCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){ + int rc; + if( pLhs->aNode && pRhs->aNode ){ + int rc2 = pLhs->nTerm - pRhs->nTerm; + if( rc2<0 ){ + rc = memcmp(pLhs->zTerm, pRhs->zTerm, pLhs->nTerm); + }else{ + rc = memcmp(pLhs->zTerm, pRhs->zTerm, pRhs->nTerm); + } + if( rc==0 ){ + rc = rc2; + } + }else{ + rc = (pLhs->aNode==0) - (pRhs->aNode==0); + } + if( rc==0 ){ + rc = pRhs->iIdx - pLhs->iIdx; + } + assert( rc!=0 ); + return rc; +} + +/* +** A different comparison function for SegReader structures. In this +** version, it is assumed that each SegReader points to an entry in +** a doclist for identical terms. Comparison is made as follows: +** +** 1) EOF (end of doclist in this case) is greater than not EOF. +** +** 2) By current docid. +** +** 3) By segment age. An older segment is considered larger. +*/ +static int fts3SegReaderDoclistCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){ + int rc = (pLhs->pOffsetList==0)-(pRhs->pOffsetList==0); + if( rc==0 ){ + if( pLhs->iDocid==pRhs->iDocid ){ + rc = pRhs->iIdx - pLhs->iIdx; + }else{ + rc = (pLhs->iDocid > pRhs->iDocid) ? 1 : -1; + } + } + assert( pLhs->aNode && pRhs->aNode ); + return rc; +} +static int fts3SegReaderDoclistCmpRev(Fts3SegReader *pLhs, Fts3SegReader *pRhs){ + int rc = (pLhs->pOffsetList==0)-(pRhs->pOffsetList==0); + if( rc==0 ){ + if( pLhs->iDocid==pRhs->iDocid ){ + rc = pRhs->iIdx - pLhs->iIdx; + }else{ + rc = (pLhs->iDocid < pRhs->iDocid) ? 1 : -1; + } + } + assert( pLhs->aNode && pRhs->aNode ); + return rc; +} + +/* +** Compare the term that the Fts3SegReader object passed as the first argument +** points to with the term specified by arguments zTerm and nTerm. +** +** If the pSeg iterator is already at EOF, return 0. Otherwise, return +** -ve if the pSeg term is less than zTerm/nTerm, 0 if the two terms are +** equal, or +ve if the pSeg term is greater than zTerm/nTerm. +*/ +static int fts3SegReaderTermCmp( + Fts3SegReader *pSeg, /* Segment reader object */ + const char *zTerm, /* Term to compare to */ + int nTerm /* Size of term zTerm in bytes */ +){ + int res = 0; + if( pSeg->aNode ){ + if( pSeg->nTerm>nTerm ){ + res = memcmp(pSeg->zTerm, zTerm, nTerm); + }else{ + res = memcmp(pSeg->zTerm, zTerm, pSeg->nTerm); + } + if( res==0 ){ + res = pSeg->nTerm-nTerm; + } + } + return res; +} + +/* +** Argument apSegment is an array of nSegment elements. It is known that +** the final (nSegment-nSuspect) members are already in sorted order +** (according to the comparison function provided). This function shuffles +** the array around until all entries are in sorted order. +*/ +static void fts3SegReaderSort( + Fts3SegReader **apSegment, /* Array to sort entries of */ + int nSegment, /* Size of apSegment array */ + int nSuspect, /* Unsorted entry count */ + int (*xCmp)(Fts3SegReader *, Fts3SegReader *) /* Comparison function */ +){ + int i; /* Iterator variable */ + + assert( nSuspect<=nSegment ); + + if( nSuspect==nSegment ) nSuspect--; + for(i=nSuspect-1; i>=0; i--){ + int j; + for(j=i; j<(nSegment-1); j++){ + Fts3SegReader *pTmp; + if( xCmp(apSegment[j], apSegment[j+1])<0 ) break; + pTmp = apSegment[j+1]; + apSegment[j+1] = apSegment[j]; + apSegment[j] = pTmp; + } + } + +#ifndef NDEBUG + /* Check that the list really is sorted now. */ + for(i=0; i<(nSuspect-1); i++){ + assert( xCmp(apSegment[i], apSegment[i+1])<0 ); + } +#endif +} + +/* +** Insert a record into the %_segments table. +*/ +static int fts3WriteSegment( + Fts3Table *p, /* Virtual table handle */ + sqlite3_int64 iBlock, /* Block id for new block */ + char *z, /* Pointer to buffer containing block data */ + int n /* Size of buffer z in bytes */ +){ + sqlite3_stmt *pStmt; + int rc = fts3SqlStmt(p, SQL_INSERT_SEGMENTS, &pStmt, 0); + if( rc==SQLITE_OK ){ + sqlite3_bind_int64(pStmt, 1, iBlock); + sqlite3_bind_blob(pStmt, 2, z, n, SQLITE_STATIC); + sqlite3_step(pStmt); + rc = sqlite3_reset(pStmt); + } + return rc; +} + +/* +** Insert a record into the %_segdir table. +*/ +static int fts3WriteSegdir( + Fts3Table *p, /* Virtual table handle */ + int iLevel, /* Value for "level" field */ + int iIdx, /* Value for "idx" field */ + sqlite3_int64 iStartBlock, /* Value for "start_block" field */ + sqlite3_int64 iLeafEndBlock, /* Value for "leaves_end_block" field */ + sqlite3_int64 iEndBlock, /* Value for "end_block" field */ + char *zRoot, /* Blob value for "root" field */ + int nRoot /* Number of bytes in buffer zRoot */ +){ + sqlite3_stmt *pStmt; + int rc = fts3SqlStmt(p, SQL_INSERT_SEGDIR, &pStmt, 0); + if( rc==SQLITE_OK ){ + sqlite3_bind_int(pStmt, 1, iLevel); + sqlite3_bind_int(pStmt, 2, iIdx); + sqlite3_bind_int64(pStmt, 3, iStartBlock); + sqlite3_bind_int64(pStmt, 4, iLeafEndBlock); + sqlite3_bind_int64(pStmt, 5, iEndBlock); + sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC); + sqlite3_step(pStmt); + rc = sqlite3_reset(pStmt); + } + return rc; +} + +/* +** Return the size of the common prefix (if any) shared by zPrev and +** zNext, in bytes. For example, +** +** fts3PrefixCompress("abc", 3, "abcdef", 6) // returns 3 +** fts3PrefixCompress("abX", 3, "abcdef", 6) // returns 2 +** fts3PrefixCompress("abX", 3, "Xbcdef", 6) // returns 0 +*/ +static int fts3PrefixCompress( + const char *zPrev, /* Buffer containing previous term */ + int nPrev, /* Size of buffer zPrev in bytes */ + const char *zNext, /* Buffer containing next term */ + int nNext /* Size of buffer zNext in bytes */ +){ + int n; + UNUSED_PARAMETER(nNext); + for(n=0; n<nPrev && zPrev[n]==zNext[n]; n++); + return n; +} + +/* +** Add term zTerm to the SegmentNode. It is guaranteed that zTerm is larger +** (according to memcmp) than the previous term. +*/ +static int fts3NodeAddTerm( + Fts3Table *p, /* Virtual table handle */ + SegmentNode **ppTree, /* IN/OUT: SegmentNode handle */ + int isCopyTerm, /* True if zTerm/nTerm is transient */ + const char *zTerm, /* Pointer to buffer containing term */ + int nTerm /* Size of term in bytes */ +){ + SegmentNode *pTree = *ppTree; + int rc; + SegmentNode *pNew; + + /* First try to append the term to the current node. Return early if + ** this is possible. + */ + if( pTree ){ + int nData = pTree->nData; /* Current size of node in bytes */ + int nReq = nData; /* Required space after adding zTerm */ + int nPrefix; /* Number of bytes of prefix compression */ + int nSuffix; /* Suffix length */ + + nPrefix = fts3PrefixCompress(pTree->zTerm, pTree->nTerm, zTerm, nTerm); + nSuffix = nTerm-nPrefix; + + nReq += sqlite3Fts3VarintLen(nPrefix)+sqlite3Fts3VarintLen(nSuffix)+nSuffix; + if( nReq<=p->nNodeSize || !pTree->zTerm ){ + + if( nReq>p->nNodeSize ){ + /* An unusual case: this is the first term to be added to the node + ** and the static node buffer (p->nNodeSize bytes) is not large + ** enough. Use a separately malloced buffer instead This wastes + ** p->nNodeSize bytes, but since this scenario only comes about when + ** the database contain two terms that share a prefix of almost 2KB, + ** this is not expected to be a serious problem. + */ + assert( pTree->aData==(char *)&pTree[1] ); + pTree->aData = (char *)sqlite3_malloc(nReq); + if( !pTree->aData ){ + return SQLITE_NOMEM; + } + } + + if( pTree->zTerm ){ + /* There is no prefix-length field for first term in a node */ + nData += sqlite3Fts3PutVarint(&pTree->aData[nData], nPrefix); + } + + nData += sqlite3Fts3PutVarint(&pTree->aData[nData], nSuffix); + memcpy(&pTree->aData[nData], &zTerm[nPrefix], nSuffix); + pTree->nData = nData + nSuffix; + pTree->nEntry++; + + if( isCopyTerm ){ + if( pTree->nMalloc<nTerm ){ + char *zNew = sqlite3_realloc(pTree->zMalloc, nTerm*2); + if( !zNew ){ + return SQLITE_NOMEM; + } + pTree->nMalloc = nTerm*2; + pTree->zMalloc = zNew; + } + pTree->zTerm = pTree->zMalloc; + memcpy(pTree->zTerm, zTerm, nTerm); + pTree->nTerm = nTerm; + }else{ + pTree->zTerm = (char *)zTerm; + pTree->nTerm = nTerm; + } + return SQLITE_OK; + } + } + + /* If control flows to here, it was not possible to append zTerm to the + ** current node. Create a new node (a right-sibling of the current node). + ** If this is the first node in the tree, the term is added to it. + ** + ** Otherwise, the term is not added to the new node, it is left empty for + ** now. Instead, the term is inserted into the parent of pTree. If pTree + ** has no parent, one is created here. + */ + pNew = (SegmentNode *)sqlite3_malloc(sizeof(SegmentNode) + p->nNodeSize); + if( !pNew ){ + return SQLITE_NOMEM; + } + memset(pNew, 0, sizeof(SegmentNode)); + pNew->nData = 1 + FTS3_VARINT_MAX; + pNew->aData = (char *)&pNew[1]; + + if( pTree ){ + SegmentNode *pParent = pTree->pParent; + rc = fts3NodeAddTerm(p, &pParent, isCopyTerm, zTerm, nTerm); + if( pTree->pParent==0 ){ + pTree->pParent = pParent; + } + pTree->pRight = pNew; + pNew->pLeftmost = pTree->pLeftmost; + pNew->pParent = pParent; + pNew->zMalloc = pTree->zMalloc; + pNew->nMalloc = pTree->nMalloc; + pTree->zMalloc = 0; + }else{ + pNew->pLeftmost = pNew; + rc = fts3NodeAddTerm(p, &pNew, isCopyTerm, zTerm, nTerm); + } + + *ppTree = pNew; + return rc; +} + +/* +** Helper function for fts3NodeWrite(). +*/ +static int fts3TreeFinishNode( + SegmentNode *pTree, + int iHeight, + sqlite3_int64 iLeftChild +){ + int nStart; + assert( iHeight>=1 && iHeight<128 ); + nStart = FTS3_VARINT_MAX - sqlite3Fts3VarintLen(iLeftChild); + pTree->aData[nStart] = (char)iHeight; + sqlite3Fts3PutVarint(&pTree->aData[nStart+1], iLeftChild); + return nStart; +} + +/* +** Write the buffer for the segment node pTree and all of its peers to the +** database. Then call this function recursively to write the parent of +** pTree and its peers to the database. +** +** Except, if pTree is a root node, do not write it to the database. Instead, +** set output variables *paRoot and *pnRoot to contain the root node. +** +** If successful, SQLITE_OK is returned and output variable *piLast is +** set to the largest blockid written to the database (or zero if no +** blocks were written to the db). Otherwise, an SQLite error code is +** returned. +*/ +static int fts3NodeWrite( + Fts3Table *p, /* Virtual table handle */ + SegmentNode *pTree, /* SegmentNode handle */ + int iHeight, /* Height of this node in tree */ + sqlite3_int64 iLeaf, /* Block id of first leaf node */ + sqlite3_int64 iFree, /* Block id of next free slot in %_segments */ + sqlite3_int64 *piLast, /* OUT: Block id of last entry written */ + char **paRoot, /* OUT: Data for root node */ + int *pnRoot /* OUT: Size of root node in bytes */ +){ + int rc = SQLITE_OK; + + if( !pTree->pParent ){ + /* Root node of the tree. */ + int nStart = fts3TreeFinishNode(pTree, iHeight, iLeaf); + *piLast = iFree-1; + *pnRoot = pTree->nData - nStart; + *paRoot = &pTree->aData[nStart]; + }else{ + SegmentNode *pIter; + sqlite3_int64 iNextFree = iFree; + sqlite3_int64 iNextLeaf = iLeaf; + for(pIter=pTree->pLeftmost; pIter && rc==SQLITE_OK; pIter=pIter->pRight){ + int nStart = fts3TreeFinishNode(pIter, iHeight, iNextLeaf); + int nWrite = pIter->nData - nStart; + + rc = fts3WriteSegment(p, iNextFree, &pIter->aData[nStart], nWrite); + iNextFree++; + iNextLeaf += (pIter->nEntry+1); + } + if( rc==SQLITE_OK ){ + assert( iNextLeaf==iFree ); + rc = fts3NodeWrite( + p, pTree->pParent, iHeight+1, iFree, iNextFree, piLast, paRoot, pnRoot + ); + } + } + + return rc; +} + +/* +** Free all memory allocations associated with the tree pTree. +*/ +static void fts3NodeFree(SegmentNode *pTree){ + if( pTree ){ + SegmentNode *p = pTree->pLeftmost; + fts3NodeFree(p->pParent); + while( p ){ + SegmentNode *pRight = p->pRight; + if( p->aData!=(char *)&p[1] ){ + sqlite3_free(p->aData); + } + assert( pRight==0 || p->zMalloc==0 ); + sqlite3_free(p->zMalloc); + sqlite3_free(p); + p = pRight; + } + } +} + +/* +** Add a term to the segment being constructed by the SegmentWriter object +** *ppWriter. When adding the first term to a segment, *ppWriter should +** be passed NULL. This function will allocate a new SegmentWriter object +** and return it via the input/output variable *ppWriter in this case. +** +** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code. +*/ +static int fts3SegWriterAdd( + Fts3Table *p, /* Virtual table handle */ + SegmentWriter **ppWriter, /* IN/OUT: SegmentWriter handle */ + int isCopyTerm, /* True if buffer zTerm must be copied */ + const char *zTerm, /* Pointer to buffer containing term */ + int nTerm, /* Size of term in bytes */ + const char *aDoclist, /* Pointer to buffer containing doclist */ + int nDoclist /* Size of doclist in bytes */ +){ + int nPrefix; /* Size of term prefix in bytes */ + int nSuffix; /* Size of term suffix in bytes */ + int nReq; /* Number of bytes required on leaf page */ + int nData; + SegmentWriter *pWriter = *ppWriter; + + if( !pWriter ){ + int rc; + sqlite3_stmt *pStmt; + + /* Allocate the SegmentWriter structure */ + pWriter = (SegmentWriter *)sqlite3_malloc(sizeof(SegmentWriter)); + if( !pWriter ) return SQLITE_NOMEM; + memset(pWriter, 0, sizeof(SegmentWriter)); + *ppWriter = pWriter; + + /* Allocate a buffer in which to accumulate data */ + pWriter->aData = (char *)sqlite3_malloc(p->nNodeSize); + if( !pWriter->aData ) return SQLITE_NOMEM; + pWriter->nSize = p->nNodeSize; + + /* Find the next free blockid in the %_segments table */ + rc = fts3SqlStmt(p, SQL_NEXT_SEGMENTS_ID, &pStmt, 0); + if( rc!=SQLITE_OK ) return rc; + if( SQLITE_ROW==sqlite3_step(pStmt) ){ + pWriter->iFree = sqlite3_column_int64(pStmt, 0); + pWriter->iFirst = pWriter->iFree; + } + rc = sqlite3_reset(pStmt); + if( rc!=SQLITE_OK ) return rc; + } + nData = pWriter->nData; + + nPrefix = fts3PrefixCompress(pWriter->zTerm, pWriter->nTerm, zTerm, nTerm); + nSuffix = nTerm-nPrefix; + + /* Figure out how many bytes are required by this new entry */ + nReq = sqlite3Fts3VarintLen(nPrefix) + /* varint containing prefix size */ + sqlite3Fts3VarintLen(nSuffix) + /* varint containing suffix size */ + nSuffix + /* Term suffix */ + sqlite3Fts3VarintLen(nDoclist) + /* Size of doclist */ + nDoclist; /* Doclist data */ + + if( nData>0 && nData+nReq>p->nNodeSize ){ + int rc; + + /* The current leaf node is full. Write it out to the database. */ + rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, nData); + if( rc!=SQLITE_OK ) return rc; + + /* Add the current term to the interior node tree. The term added to + ** the interior tree must: + ** + ** a) be greater than the largest term on the leaf node just written + ** to the database (still available in pWriter->zTerm), and + ** + ** b) be less than or equal to the term about to be added to the new + ** leaf node (zTerm/nTerm). + ** + ** In other words, it must be the prefix of zTerm 1 byte longer than + ** the common prefix (if any) of zTerm and pWriter->zTerm. + */ + assert( nPrefix<nTerm ); + rc = fts3NodeAddTerm(p, &pWriter->pTree, isCopyTerm, zTerm, nPrefix+1); + if( rc!=SQLITE_OK ) return rc; + + nData = 0; + pWriter->nTerm = 0; + + nPrefix = 0; + nSuffix = nTerm; + nReq = 1 + /* varint containing prefix size */ + sqlite3Fts3VarintLen(nTerm) + /* varint containing suffix size */ + nTerm + /* Term suffix */ + sqlite3Fts3VarintLen(nDoclist) + /* Size of doclist */ + nDoclist; /* Doclist data */ + } + + /* If the buffer currently allocated is too small for this entry, realloc + ** the buffer to make it large enough. + */ + if( nReq>pWriter->nSize ){ + char *aNew = sqlite3_realloc(pWriter->aData, nReq); + if( !aNew ) return SQLITE_NOMEM; + pWriter->aData = aNew; + pWriter->nSize = nReq; + } + assert( nData+nReq<=pWriter->nSize ); + + /* Append the prefix-compressed term and doclist to the buffer. */ + nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nPrefix); + nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nSuffix); + memcpy(&pWriter->aData[nData], &zTerm[nPrefix], nSuffix); + nData += nSuffix; + nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nDoclist); + memcpy(&pWriter->aData[nData], aDoclist, nDoclist); + pWriter->nData = nData + nDoclist; + + /* Save the current term so that it can be used to prefix-compress the next. + ** If the isCopyTerm parameter is true, then the buffer pointed to by + ** zTerm is transient, so take a copy of the term data. Otherwise, just + ** store a copy of the pointer. + */ + if( isCopyTerm ){ + if( nTerm>pWriter->nMalloc ){ + char *zNew = sqlite3_realloc(pWriter->zMalloc, nTerm*2); + if( !zNew ){ + return SQLITE_NOMEM; + } + pWriter->nMalloc = nTerm*2; + pWriter->zMalloc = zNew; + pWriter->zTerm = zNew; + } + assert( pWriter->zTerm==pWriter->zMalloc ); + memcpy(pWriter->zTerm, zTerm, nTerm); + }else{ + pWriter->zTerm = (char *)zTerm; + } + pWriter->nTerm = nTerm; + + return SQLITE_OK; +} + +/* +** Flush all data associated with the SegmentWriter object pWriter to the +** database. This function must be called after all terms have been added +** to the segment using fts3SegWriterAdd(). If successful, SQLITE_OK is +** returned. Otherwise, an SQLite error code. +*/ +static int fts3SegWriterFlush( + Fts3Table *p, /* Virtual table handle */ + SegmentWriter *pWriter, /* SegmentWriter to flush to the db */ + int iLevel, /* Value for 'level' column of %_segdir */ + int iIdx /* Value for 'idx' column of %_segdir */ +){ + int rc; /* Return code */ + if( pWriter->pTree ){ + sqlite3_int64 iLast = 0; /* Largest block id written to database */ + sqlite3_int64 iLastLeaf; /* Largest leaf block id written to db */ + char *zRoot = NULL; /* Pointer to buffer containing root node */ + int nRoot = 0; /* Size of buffer zRoot */ + + iLastLeaf = pWriter->iFree; + rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, pWriter->nData); + if( rc==SQLITE_OK ){ + rc = fts3NodeWrite(p, pWriter->pTree, 1, + pWriter->iFirst, pWriter->iFree, &iLast, &zRoot, &nRoot); + } + if( rc==SQLITE_OK ){ + rc = fts3WriteSegdir( + p, iLevel, iIdx, pWriter->iFirst, iLastLeaf, iLast, zRoot, nRoot); + } + }else{ + /* The entire tree fits on the root node. Write it to the segdir table. */ + rc = fts3WriteSegdir( + p, iLevel, iIdx, 0, 0, 0, pWriter->aData, pWriter->nData); + } + return rc; +} + +/* +** Release all memory held by the SegmentWriter object passed as the +** first argument. +*/ +static void fts3SegWriterFree(SegmentWriter *pWriter){ + if( pWriter ){ + sqlite3_free(pWriter->aData); + sqlite3_free(pWriter->zMalloc); + fts3NodeFree(pWriter->pTree); + sqlite3_free(pWriter); + } +} + +/* +** The first value in the apVal[] array is assumed to contain an integer. +** This function tests if there exist any documents with docid values that +** are different from that integer. i.e. if deleting the document with docid +** pRowid would mean the FTS3 table were empty. +** +** If successful, *pisEmpty is set to true if the table is empty except for +** document pRowid, or false otherwise, and SQLITE_OK is returned. If an +** error occurs, an SQLite error code is returned. +*/ +static int fts3IsEmpty(Fts3Table *p, sqlite3_value *pRowid, int *pisEmpty){ + sqlite3_stmt *pStmt; + int rc; + if( p->zContentTbl ){ + /* If using the content=xxx option, assume the table is never empty */ + *pisEmpty = 0; + rc = SQLITE_OK; + }else{ + rc = fts3SqlStmt(p, SQL_IS_EMPTY, &pStmt, &pRowid); + if( rc==SQLITE_OK ){ + if( SQLITE_ROW==sqlite3_step(pStmt) ){ + *pisEmpty = sqlite3_column_int(pStmt, 0); + } + rc = sqlite3_reset(pStmt); + } + } + return rc; +} + +/* +** Set *pnMax to the largest segment level in the database for the index +** iIndex. +** +** Segment levels are stored in the 'level' column of the %_segdir table. +** +** Return SQLITE_OK if successful, or an SQLite error code if not. +*/ +static int fts3SegmentMaxLevel(Fts3Table *p, int iIndex, int *pnMax){ + sqlite3_stmt *pStmt; + int rc; + assert( iIndex>=0 && iIndex<p->nIndex ); + + /* Set pStmt to the compiled version of: + ** + ** SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ? + ** + ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR). + */ + rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0); + if( rc!=SQLITE_OK ) return rc; + sqlite3_bind_int(pStmt, 1, iIndex*FTS3_SEGDIR_MAXLEVEL); + sqlite3_bind_int(pStmt, 2, (iIndex+1)*FTS3_SEGDIR_MAXLEVEL - 1); + if( SQLITE_ROW==sqlite3_step(pStmt) ){ + *pnMax = sqlite3_column_int(pStmt, 0); + } + return sqlite3_reset(pStmt); +} + +/* +** This function is used after merging multiple segments into a single large +** segment to delete the old, now redundant, segment b-trees. Specifically, +** it: +** +** 1) Deletes all %_segments entries for the segments associated with +** each of the SegReader objects in the array passed as the third +** argument, and +** +** 2) deletes all %_segdir entries with level iLevel, or all %_segdir +** entries regardless of level if (iLevel<0). +** +** SQLITE_OK is returned if successful, otherwise an SQLite error code. +*/ +static int fts3DeleteSegdir( + Fts3Table *p, /* Virtual table handle */ + int iIndex, /* Index for p->aIndex */ + int iLevel, /* Level of %_segdir entries to delete */ + Fts3SegReader **apSegment, /* Array of SegReader objects */ + int nReader /* Size of array apSegment */ +){ + int rc; /* Return Code */ + int i; /* Iterator variable */ + sqlite3_stmt *pDelete; /* SQL statement to delete rows */ + + rc = fts3SqlStmt(p, SQL_DELETE_SEGMENTS_RANGE, &pDelete, 0); + for(i=0; rc==SQLITE_OK && i<nReader; i++){ + Fts3SegReader *pSegment = apSegment[i]; + if( pSegment->iStartBlock ){ + sqlite3_bind_int64(pDelete, 1, pSegment->iStartBlock); + sqlite3_bind_int64(pDelete, 2, pSegment->iEndBlock); + sqlite3_step(pDelete); + rc = sqlite3_reset(pDelete); + } + } + if( rc!=SQLITE_OK ){ + return rc; + } + + assert( iLevel>=0 || iLevel==FTS3_SEGCURSOR_ALL ); + if( iLevel==FTS3_SEGCURSOR_ALL ){ + rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_RANGE, &pDelete, 0); + if( rc==SQLITE_OK ){ + sqlite3_bind_int(pDelete, 1, iIndex*FTS3_SEGDIR_MAXLEVEL); + sqlite3_bind_int(pDelete, 2, (iIndex+1) * FTS3_SEGDIR_MAXLEVEL - 1); + } + }else{ + rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pDelete, 0); + if( rc==SQLITE_OK ){ + sqlite3_bind_int(pDelete, 1, iIndex*FTS3_SEGDIR_MAXLEVEL + iLevel); + } + } + + if( rc==SQLITE_OK ){ + sqlite3_step(pDelete); + rc = sqlite3_reset(pDelete); + } + + return rc; +} + +/* +** When this function is called, buffer *ppList (size *pnList bytes) contains +** a position list that may (or may not) feature multiple columns. This +** function adjusts the pointer *ppList and the length *pnList so that they +** identify the subset of the position list that corresponds to column iCol. +** +** If there are no entries in the input position list for column iCol, then +** *pnList is set to zero before returning. +*/ +static void fts3ColumnFilter( + int iCol, /* Column to filter on */ + char **ppList, /* IN/OUT: Pointer to position list */ + int *pnList /* IN/OUT: Size of buffer *ppList in bytes */ +){ + char *pList = *ppList; + int nList = *pnList; + char *pEnd = &pList[nList]; + int iCurrent = 0; + char *p = pList; + + assert( iCol>=0 ); + while( 1 ){ + char c = 0; + while( p<pEnd && (c | *p)&0xFE ) c = *p++ & 0x80; + + if( iCol==iCurrent ){ + nList = (int)(p - pList); + break; + } + + nList -= (int)(p - pList); + pList = p; + if( nList==0 ){ + break; + } + p = &pList[1]; + p += sqlite3Fts3GetVarint32(p, &iCurrent); + } + + *ppList = pList; + *pnList = nList; +} + +/* +** Cache data in the Fts3MultiSegReader.aBuffer[] buffer (overwriting any +** existing data). Grow the buffer if required. +** +** If successful, return SQLITE_OK. Otherwise, if an OOM error is encountered +** trying to resize the buffer, return SQLITE_NOMEM. +*/ +static int fts3MsrBufferData( + Fts3MultiSegReader *pMsr, /* Multi-segment-reader handle */ + char *pList, + int nList +){ + if( nList>pMsr->nBuffer ){ + char *pNew; + pMsr->nBuffer = nList*2; + pNew = (char *)sqlite3_realloc(pMsr->aBuffer, pMsr->nBuffer); + if( !pNew ) return SQLITE_NOMEM; + pMsr->aBuffer = pNew; + } + + memcpy(pMsr->aBuffer, pList, nList); + return SQLITE_OK; +} + +int sqlite3Fts3MsrIncrNext( + Fts3Table *p, /* Virtual table handle */ + Fts3MultiSegReader *pMsr, /* Multi-segment-reader handle */ + sqlite3_int64 *piDocid, /* OUT: Docid value */ + char **paPoslist, /* OUT: Pointer to position list */ + int *pnPoslist /* OUT: Size of position list in bytes */ +){ + int nMerge = pMsr->nAdvance; + Fts3SegReader **apSegment = pMsr->apSegment; + int (*xCmp)(Fts3SegReader *, Fts3SegReader *) = ( + p->bDescIdx ? fts3SegReaderDoclistCmpRev : fts3SegReaderDoclistCmp + ); + + if( nMerge==0 ){ + *paPoslist = 0; + return SQLITE_OK; + } + + while( 1 ){ + Fts3SegReader *pSeg; + pSeg = pMsr->apSegment[0]; + + if( pSeg->pOffsetList==0 ){ + *paPoslist = 0; + break; + }else{ + int rc; + char *pList; + int nList; + int j; + sqlite3_int64 iDocid = apSegment[0]->iDocid; + + rc = fts3SegReaderNextDocid(p, apSegment[0], &pList, &nList); + j = 1; + while( rc==SQLITE_OK + && j<nMerge + && apSegment[j]->pOffsetList + && apSegment[j]->iDocid==iDocid + ){ + rc = fts3SegReaderNextDocid(p, apSegment[j], 0, 0); + j++; + } + if( rc!=SQLITE_OK ) return rc; + fts3SegReaderSort(pMsr->apSegment, nMerge, j, xCmp); + + if( pMsr->iColFilter>=0 ){ + fts3ColumnFilter(pMsr->iColFilter, &pList, &nList); + } + + if( nList>0 ){ + if( fts3SegReaderIsPending(apSegment[0]) ){ + rc = fts3MsrBufferData(pMsr, pList, nList+1); + if( rc!=SQLITE_OK ) return rc; + *paPoslist = pMsr->aBuffer; + assert( (pMsr->aBuffer[nList] & 0xFE)==0x00 ); + }else{ + *paPoslist = pList; + } + *piDocid = iDocid; + *pnPoslist = nList; + break; + } + } + } + + return SQLITE_OK; +} + +static int fts3SegReaderStart( + Fts3Table *p, /* Virtual table handle */ + Fts3MultiSegReader *pCsr, /* Cursor object */ + const char *zTerm, /* Term searched for (or NULL) */ + int nTerm /* Length of zTerm in bytes */ +){ + int i; + int nSeg = pCsr->nSegment; + + /* If the Fts3SegFilter defines a specific term (or term prefix) to search + ** for, then advance each segment iterator until it points to a term of + ** equal or greater value than the specified term. This prevents many + ** unnecessary merge/sort operations for the case where single segment + ** b-tree leaf nodes contain more than one term. + */ + for(i=0; pCsr->bRestart==0 && i<pCsr->nSegment; i++){ + Fts3SegReader *pSeg = pCsr->apSegment[i]; + do { + int rc = fts3SegReaderNext(p, pSeg, 0); + if( rc!=SQLITE_OK ) return rc; + }while( zTerm && fts3SegReaderTermCmp(pSeg, zTerm, nTerm)<0 ); + } + fts3SegReaderSort(pCsr->apSegment, nSeg, nSeg, fts3SegReaderCmp); + + return SQLITE_OK; +} + +int sqlite3Fts3SegReaderStart( + Fts3Table *p, /* Virtual table handle */ + Fts3MultiSegReader *pCsr, /* Cursor object */ + Fts3SegFilter *pFilter /* Restrictions on range of iteration */ +){ + pCsr->pFilter = pFilter; + return fts3SegReaderStart(p, pCsr, pFilter->zTerm, pFilter->nTerm); +} + +int sqlite3Fts3MsrIncrStart( + Fts3Table *p, /* Virtual table handle */ + Fts3MultiSegReader *pCsr, /* Cursor object */ + int iCol, /* Column to match on. */ + const char *zTerm, /* Term to iterate through a doclist for */ + int nTerm /* Number of bytes in zTerm */ +){ + int i; + int rc; + int nSegment = pCsr->nSegment; + int (*xCmp)(Fts3SegReader *, Fts3SegReader *) = ( + p->bDescIdx ? fts3SegReaderDoclistCmpRev : fts3SegReaderDoclistCmp + ); + + assert( pCsr->pFilter==0 ); + assert( zTerm && nTerm>0 ); + + /* Advance each segment iterator until it points to the term zTerm/nTerm. */ + rc = fts3SegReaderStart(p, pCsr, zTerm, nTerm); + if( rc!=SQLITE_OK ) return rc; + + /* Determine how many of the segments actually point to zTerm/nTerm. */ + for(i=0; i<nSegment; i++){ + Fts3SegReader *pSeg = pCsr->apSegment[i]; + if( !pSeg->aNode || fts3SegReaderTermCmp(pSeg, zTerm, nTerm) ){ + break; + } + } + pCsr->nAdvance = i; + + /* Advance each of the segments to point to the first docid. */ + for(i=0; i<pCsr->nAdvance; i++){ + rc = fts3SegReaderFirstDocid(p, pCsr->apSegment[i]); + if( rc!=SQLITE_OK ) return rc; + } + fts3SegReaderSort(pCsr->apSegment, i, i, xCmp); + + assert( iCol<0 || iCol<p->nColumn ); + pCsr->iColFilter = iCol; + + return SQLITE_OK; +} + +/* +** This function is called on a MultiSegReader that has been started using +** sqlite3Fts3MsrIncrStart(). One or more calls to MsrIncrNext() may also +** have been made. Calling this function puts the MultiSegReader in such +** a state that if the next two calls are: +** +** sqlite3Fts3SegReaderStart() +** sqlite3Fts3SegReaderStep() +** +** then the entire doclist for the term is available in +** MultiSegReader.aDoclist/nDoclist. +*/ +int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr){ + int i; /* Used to iterate through segment-readers */ + + assert( pCsr->zTerm==0 ); + assert( pCsr->nTerm==0 ); + assert( pCsr->aDoclist==0 ); + assert( pCsr->nDoclist==0 ); + + pCsr->nAdvance = 0; + pCsr->bRestart = 1; + for(i=0; i<pCsr->nSegment; i++){ + pCsr->apSegment[i]->pOffsetList = 0; + pCsr->apSegment[i]->nOffsetList = 0; + pCsr->apSegment[i]->iDocid = 0; + } + + return SQLITE_OK; +} + + +int sqlite3Fts3SegReaderStep( + Fts3Table *p, /* Virtual table handle */ + Fts3MultiSegReader *pCsr /* Cursor object */ +){ + int rc = SQLITE_OK; + + int isIgnoreEmpty = (pCsr->pFilter->flags & FTS3_SEGMENT_IGNORE_EMPTY); + int isRequirePos = (pCsr->pFilter->flags & FTS3_SEGMENT_REQUIRE_POS); + int isColFilter = (pCsr->pFilter->flags & FTS3_SEGMENT_COLUMN_FILTER); + int isPrefix = (pCsr->pFilter->flags & FTS3_SEGMENT_PREFIX); + int isScan = (pCsr->pFilter->flags & FTS3_SEGMENT_SCAN); + int isFirst = (pCsr->pFilter->flags & FTS3_SEGMENT_FIRST); + + Fts3SegReader **apSegment = pCsr->apSegment; + int nSegment = pCsr->nSegment; + Fts3SegFilter *pFilter = pCsr->pFilter; + int (*xCmp)(Fts3SegReader *, Fts3SegReader *) = ( + p->bDescIdx ? fts3SegReaderDoclistCmpRev : fts3SegReaderDoclistCmp + ); + + if( pCsr->nSegment==0 ) return SQLITE_OK; + + do { + int nMerge; + int i; + + /* Advance the first pCsr->nAdvance entries in the apSegment[] array + ** forward. Then sort the list in order of current term again. + */ + for(i=0; i<pCsr->nAdvance; i++){ + rc = fts3SegReaderNext(p, apSegment[i], 0); + if( rc!=SQLITE_OK ) return rc; + } + fts3SegReaderSort(apSegment, nSegment, pCsr->nAdvance, fts3SegReaderCmp); + pCsr->nAdvance = 0; + + /* If all the seg-readers are at EOF, we're finished. return SQLITE_OK. */ + assert( rc==SQLITE_OK ); + if( apSegment[0]->aNode==0 ) break; + + pCsr->nTerm = apSegment[0]->nTerm; + pCsr->zTerm = apSegment[0]->zTerm; + + /* If this is a prefix-search, and if the term that apSegment[0] points + ** to does not share a suffix with pFilter->zTerm/nTerm, then all + ** required callbacks have been made. In this case exit early. + ** + ** Similarly, if this is a search for an exact match, and the first term + ** of segment apSegment[0] is not a match, exit early. + */ + if( pFilter->zTerm && !isScan ){ + if( pCsr->nTerm<pFilter->nTerm + || (!isPrefix && pCsr->nTerm>pFilter->nTerm) + || memcmp(pCsr->zTerm, pFilter->zTerm, pFilter->nTerm) + ){ + break; + } + } + + nMerge = 1; + while( nMerge<nSegment + && apSegment[nMerge]->aNode + && apSegment[nMerge]->nTerm==pCsr->nTerm + && 0==memcmp(pCsr->zTerm, apSegment[nMerge]->zTerm, pCsr->nTerm) + ){ + nMerge++; + } + + assert( isIgnoreEmpty || (isRequirePos && !isColFilter) ); + if( nMerge==1 + && !isIgnoreEmpty + && !isFirst + && (p->bDescIdx==0 || fts3SegReaderIsPending(apSegment[0])==0) + ){ + pCsr->nDoclist = apSegment[0]->nDoclist; + if( fts3SegReaderIsPending(apSegment[0]) ){ + rc = fts3MsrBufferData(pCsr, apSegment[0]->aDoclist, pCsr->nDoclist); + pCsr->aDoclist = pCsr->aBuffer; + }else{ + pCsr->aDoclist = apSegment[0]->aDoclist; + } + if( rc==SQLITE_OK ) rc = SQLITE_ROW; + }else{ + int nDoclist = 0; /* Size of doclist */ + sqlite3_int64 iPrev = 0; /* Previous docid stored in doclist */ + + /* The current term of the first nMerge entries in the array + ** of Fts3SegReader objects is the same. The doclists must be merged + ** and a single term returned with the merged doclist. + */ + for(i=0; i<nMerge; i++){ + fts3SegReaderFirstDocid(p, apSegment[i]); + } + fts3SegReaderSort(apSegment, nMerge, nMerge, xCmp); + while( apSegment[0]->pOffsetList ){ + int j; /* Number of segments that share a docid */ + char *pList; + int nList; + int nByte; + sqlite3_int64 iDocid = apSegment[0]->iDocid; + fts3SegReaderNextDocid(p, apSegment[0], &pList, &nList); + j = 1; + while( j<nMerge + && apSegment[j]->pOffsetList + && apSegment[j]->iDocid==iDocid + ){ + fts3SegReaderNextDocid(p, apSegment[j], 0, 0); + j++; + } + + if( isColFilter ){ + fts3ColumnFilter(pFilter->iCol, &pList, &nList); + } + + if( !isIgnoreEmpty || nList>0 ){ + + /* Calculate the 'docid' delta value to write into the merged + ** doclist. */ + sqlite3_int64 iDelta; + if( p->bDescIdx && nDoclist>0 ){ + iDelta = iPrev - iDocid; + }else{ + iDelta = iDocid - iPrev; + } + assert( iDelta>0 || (nDoclist==0 && iDelta==iDocid) ); + assert( nDoclist>0 || iDelta==iDocid ); + + nByte = sqlite3Fts3VarintLen(iDelta) + (isRequirePos?nList+1:0); + if( nDoclist+nByte>pCsr->nBuffer ){ + char *aNew; + pCsr->nBuffer = (nDoclist+nByte)*2; + aNew = sqlite3_realloc(pCsr->aBuffer, pCsr->nBuffer); + if( !aNew ){ + return SQLITE_NOMEM; + } + pCsr->aBuffer = aNew; + } + + if( isFirst ){ + char *a = &pCsr->aBuffer[nDoclist]; + int nWrite; + + nWrite = sqlite3Fts3FirstFilter(iDelta, pList, nList, a); + if( nWrite ){ + iPrev = iDocid; + nDoclist += nWrite; + } + }else{ + nDoclist += sqlite3Fts3PutVarint(&pCsr->aBuffer[nDoclist], iDelta); + iPrev = iDocid; + if( isRequirePos ){ + memcpy(&pCsr->aBuffer[nDoclist], pList, nList); + nDoclist += nList; + pCsr->aBuffer[nDoclist++] = '\0'; + } + } + } + + fts3SegReaderSort(apSegment, nMerge, j, xCmp); + } + if( nDoclist>0 ){ + pCsr->aDoclist = pCsr->aBuffer; + pCsr->nDoclist = nDoclist; + rc = SQLITE_ROW; + } + } + pCsr->nAdvance = nMerge; + }while( rc==SQLITE_OK ); + + return rc; +} + + +void sqlite3Fts3SegReaderFinish( + Fts3MultiSegReader *pCsr /* Cursor object */ +){ + if( pCsr ){ + int i; + for(i=0; i<pCsr->nSegment; i++){ + sqlite3Fts3SegReaderFree(pCsr->apSegment[i]); + } + sqlite3_free(pCsr->apSegment); + sqlite3_free(pCsr->aBuffer); + + pCsr->nSegment = 0; + pCsr->apSegment = 0; + pCsr->aBuffer = 0; + } +} + +/* +** Merge all level iLevel segments in the database into a single +** iLevel+1 segment. Or, if iLevel<0, merge all segments into a +** single segment with a level equal to the numerically largest level +** currently present in the database. +** +** If this function is called with iLevel<0, but there is only one +** segment in the database, SQLITE_DONE is returned immediately. +** Otherwise, if successful, SQLITE_OK is returned. If an error occurs, +** an SQLite error code is returned. +*/ +static int fts3SegmentMerge(Fts3Table *p, int iIndex, int iLevel){ + int rc; /* Return code */ + int iIdx = 0; /* Index of new segment */ + int iNewLevel = 0; /* Level/index to create new segment at */ + SegmentWriter *pWriter = 0; /* Used to write the new, merged, segment */ + Fts3SegFilter filter; /* Segment term filter condition */ + Fts3MultiSegReader csr; /* Cursor to iterate through level(s) */ + int bIgnoreEmpty = 0; /* True to ignore empty segments */ + + assert( iLevel==FTS3_SEGCURSOR_ALL + || iLevel==FTS3_SEGCURSOR_PENDING + || iLevel>=0 + ); + assert( iLevel<FTS3_SEGDIR_MAXLEVEL ); + assert( iIndex>=0 && iIndex<p->nIndex ); + + rc = sqlite3Fts3SegReaderCursor(p, iIndex, iLevel, 0, 0, 1, 0, &csr); + if( rc!=SQLITE_OK || csr.nSegment==0 ) goto finished; + + if( iLevel==FTS3_SEGCURSOR_ALL ){ + /* This call is to merge all segments in the database to a single + ** segment. The level of the new segment is equal to the the numerically + ** greatest segment level currently present in the database for this + ** index. The idx of the new segment is always 0. */ + if( csr.nSegment==1 ){ + rc = SQLITE_DONE; + goto finished; + } + rc = fts3SegmentMaxLevel(p, iIndex, &iNewLevel); + bIgnoreEmpty = 1; + + }else if( iLevel==FTS3_SEGCURSOR_PENDING ){ + iNewLevel = iIndex * FTS3_SEGDIR_MAXLEVEL; + rc = fts3AllocateSegdirIdx(p, iIndex, 0, &iIdx); + }else{ + /* This call is to merge all segments at level iLevel. find the next + ** available segment index at level iLevel+1. The call to + ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to + ** a single iLevel+2 segment if necessary. */ + rc = fts3AllocateSegdirIdx(p, iIndex, iLevel+1, &iIdx); + iNewLevel = iIndex * FTS3_SEGDIR_MAXLEVEL + iLevel+1; + } + if( rc!=SQLITE_OK ) goto finished; + assert( csr.nSegment>0 ); + assert( iNewLevel>=(iIndex*FTS3_SEGDIR_MAXLEVEL) ); + assert( iNewLevel<((iIndex+1)*FTS3_SEGDIR_MAXLEVEL) ); + + memset(&filter, 0, sizeof(Fts3SegFilter)); + filter.flags = FTS3_SEGMENT_REQUIRE_POS; + filter.flags |= (bIgnoreEmpty ? FTS3_SEGMENT_IGNORE_EMPTY : 0); + + rc = sqlite3Fts3SegReaderStart(p, &csr, &filter); + while( SQLITE_OK==rc ){ + rc = sqlite3Fts3SegReaderStep(p, &csr); + if( rc!=SQLITE_ROW ) break; + rc = fts3SegWriterAdd(p, &pWriter, 1, + csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist); + } + if( rc!=SQLITE_OK ) goto finished; + assert( pWriter ); + + if( iLevel!=FTS3_SEGCURSOR_PENDING ){ + rc = fts3DeleteSegdir(p, iIndex, iLevel, csr.apSegment, csr.nSegment); + if( rc!=SQLITE_OK ) goto finished; + } + rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx); + + finished: + fts3SegWriterFree(pWriter); + sqlite3Fts3SegReaderFinish(&csr); + return rc; +} + + +/* +** Flush the contents of pendingTerms to level 0 segments. +*/ +int sqlite3Fts3PendingTermsFlush(Fts3Table *p){ + int rc = SQLITE_OK; + int i; + for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){ + rc = fts3SegmentMerge(p, i, FTS3_SEGCURSOR_PENDING); + if( rc==SQLITE_DONE ) rc = SQLITE_OK; + } + sqlite3Fts3PendingTermsClear(p); + return rc; +} + +/* +** Encode N integers as varints into a blob. +*/ +static void fts3EncodeIntArray( + int N, /* The number of integers to encode */ + u32 *a, /* The integer values */ + char *zBuf, /* Write the BLOB here */ + int *pNBuf /* Write number of bytes if zBuf[] used here */ +){ + int i, j; + for(i=j=0; i<N; i++){ + j += sqlite3Fts3PutVarint(&zBuf[j], (sqlite3_int64)a[i]); + } + *pNBuf = j; +} + +/* +** Decode a blob of varints into N integers +*/ +static void fts3DecodeIntArray( + int N, /* The number of integers to decode */ + u32 *a, /* Write the integer values */ + const char *zBuf, /* The BLOB containing the varints */ + int nBuf /* size of the BLOB */ +){ + int i, j; + UNUSED_PARAMETER(nBuf); + for(i=j=0; i<N; i++){ + sqlite3_int64 x; + j += sqlite3Fts3GetVarint(&zBuf[j], &x); + assert(j<=nBuf); + a[i] = (u32)(x & 0xffffffff); + } +} + +/* +** Insert the sizes (in tokens) for each column of the document +** with docid equal to p->iPrevDocid. The sizes are encoded as +** a blob of varints. +*/ +static void fts3InsertDocsize( + int *pRC, /* Result code */ + Fts3Table *p, /* Table into which to insert */ + u32 *aSz /* Sizes of each column, in tokens */ +){ + char *pBlob; /* The BLOB encoding of the document size */ + int nBlob; /* Number of bytes in the BLOB */ + sqlite3_stmt *pStmt; /* Statement used to insert the encoding */ + int rc; /* Result code from subfunctions */ + + if( *pRC ) return; + pBlob = sqlite3_malloc( 10*p->nColumn ); + if( pBlob==0 ){ + *pRC = SQLITE_NOMEM; + return; + } + fts3EncodeIntArray(p->nColumn, aSz, pBlob, &nBlob); + rc = fts3SqlStmt(p, SQL_REPLACE_DOCSIZE, &pStmt, 0); + if( rc ){ + sqlite3_free(pBlob); + *pRC = rc; + return; + } + sqlite3_bind_int64(pStmt, 1, p->iPrevDocid); + sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, sqlite3_free); + sqlite3_step(pStmt); + *pRC = sqlite3_reset(pStmt); +} + +/* +** Record 0 of the %_stat table contains a blob consisting of N varints, +** where N is the number of user defined columns in the fts3 table plus +** two. If nCol is the number of user defined columns, then values of the +** varints are set as follows: +** +** Varint 0: Total number of rows in the table. +** +** Varint 1..nCol: For each column, the total number of tokens stored in +** the column for all rows of the table. +** +** Varint 1+nCol: The total size, in bytes, of all text values in all +** columns of all rows of the table. +** +*/ +static void fts3UpdateDocTotals( + int *pRC, /* The result code */ + Fts3Table *p, /* Table being updated */ + u32 *aSzIns, /* Size increases */ + u32 *aSzDel, /* Size decreases */ + int nChng /* Change in the number of documents */ +){ + char *pBlob; /* Storage for BLOB written into %_stat */ + int nBlob; /* Size of BLOB written into %_stat */ + u32 *a; /* Array of integers that becomes the BLOB */ + sqlite3_stmt *pStmt; /* Statement for reading and writing */ + int i; /* Loop counter */ + int rc; /* Result code from subfunctions */ + + const int nStat = p->nColumn+2; + + if( *pRC ) return; + a = sqlite3_malloc( (sizeof(u32)+10)*nStat ); + if( a==0 ){ + *pRC = SQLITE_NOMEM; + return; + } + pBlob = (char*)&a[nStat]; + rc = fts3SqlStmt(p, SQL_SELECT_DOCTOTAL, &pStmt, 0); + if( rc ){ + sqlite3_free(a); + *pRC = rc; + return; + } + if( sqlite3_step(pStmt)==SQLITE_ROW ){ + fts3DecodeIntArray(nStat, a, + sqlite3_column_blob(pStmt, 0), + sqlite3_column_bytes(pStmt, 0)); + }else{ + memset(a, 0, sizeof(u32)*(nStat) ); + } + sqlite3_reset(pStmt); + if( nChng<0 && a[0]<(u32)(-nChng) ){ + a[0] = 0; + }else{ + a[0] += nChng; + } + for(i=0; i<p->nColumn+1; i++){ + u32 x = a[i+1]; + if( x+aSzIns[i] < aSzDel[i] ){ + x = 0; + }else{ + x = x + aSzIns[i] - aSzDel[i]; + } + a[i+1] = x; + } + fts3EncodeIntArray(nStat, a, pBlob, &nBlob); + rc = fts3SqlStmt(p, SQL_REPLACE_DOCTOTAL, &pStmt, 0); + if( rc ){ + sqlite3_free(a); + *pRC = rc; + return; + } + sqlite3_bind_blob(pStmt, 1, pBlob, nBlob, SQLITE_STATIC); + sqlite3_step(pStmt); + *pRC = sqlite3_reset(pStmt); + sqlite3_free(a); +} + +static int fts3DoOptimize(Fts3Table *p, int bReturnDone){ + int i; + int bSeenDone = 0; + int rc = SQLITE_OK; + for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){ + rc = fts3SegmentMerge(p, i, FTS3_SEGCURSOR_ALL); + if( rc==SQLITE_DONE ){ + bSeenDone = 1; + rc = SQLITE_OK; + } + } + sqlite3Fts3SegmentsClose(p); + sqlite3Fts3PendingTermsClear(p); + + return (rc==SQLITE_OK && bReturnDone && bSeenDone) ? SQLITE_DONE : rc; +} + +/* +** This function is called when the user executes the following statement: +** +** INSERT INTO <tbl>(<tbl>) VALUES('rebuild'); +** +** The entire FTS index is discarded and rebuilt. If the table is one +** created using the content=xxx option, then the new index is based on +** the current contents of the xxx table. Otherwise, it is rebuilt based +** on the contents of the %_content table. +*/ +static int fts3DoRebuild(Fts3Table *p){ + int rc; /* Return Code */ + + rc = fts3DeleteAll(p, 0); + if( rc==SQLITE_OK ){ + u32 *aSz = 0; + u32 *aSzIns = 0; + u32 *aSzDel = 0; + sqlite3_stmt *pStmt = 0; + int nEntry = 0; + + /* Compose and prepare an SQL statement to loop through the content table */ + char *zSql = sqlite3_mprintf("SELECT %s" , p->zReadExprlist); + if( !zSql ){ + rc = SQLITE_NOMEM; + }else{ + rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0); + sqlite3_free(zSql); + } + + if( rc==SQLITE_OK ){ + int nByte = sizeof(u32) * (p->nColumn+1)*3; + aSz = (u32 *)sqlite3_malloc(nByte); + if( aSz==0 ){ + rc = SQLITE_NOMEM; + }else{ + memset(aSz, 0, nByte); + aSzIns = &aSz[p->nColumn+1]; + aSzDel = &aSzIns[p->nColumn+1]; + } + } + + while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){ + int iCol; + rc = fts3PendingTermsDocid(p, sqlite3_column_int64(pStmt, 0)); + aSz[p->nColumn] = 0; + for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){ + const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1); + rc = fts3PendingTermsAdd(p, z, iCol, &aSz[iCol]); + aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1); + } + if( p->bHasDocsize ){ + fts3InsertDocsize(&rc, p, aSz); + } + if( rc!=SQLITE_OK ){ + sqlite3_finalize(pStmt); + pStmt = 0; + }else{ + nEntry++; + for(iCol=0; iCol<=p->nColumn; iCol++){ + aSzIns[iCol] += aSz[iCol]; + } + } + } + if( p->bHasStat ){ + fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nEntry); + } + sqlite3_free(aSz); + + if( pStmt ){ + int rc2 = sqlite3_finalize(pStmt); + if( rc==SQLITE_OK ){ + rc = rc2; + } + } + } + + return rc; +} + +/* +** Handle a 'special' INSERT of the form: +** +** "INSERT INTO tbl(tbl) VALUES(<expr>)" +** +** Argument pVal contains the result of <expr>. Currently the only +** meaningful value to insert is the text 'optimize'. +*/ +static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){ + int rc; /* Return Code */ + const char *zVal = (const char *)sqlite3_value_text(pVal); + int nVal = sqlite3_value_bytes(pVal); + + if( !zVal ){ + return SQLITE_NOMEM; + }else if( nVal==8 && 0==sqlite3_strnicmp(zVal, "optimize", 8) ){ + rc = fts3DoOptimize(p, 0); + }else if( nVal==7 && 0==sqlite3_strnicmp(zVal, "rebuild", 7) ){ + rc = fts3DoRebuild(p); +#ifdef SQLITE_TEST + }else if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){ + p->nNodeSize = atoi(&zVal[9]); + rc = SQLITE_OK; + }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){ + p->nMaxPendingData = atoi(&zVal[11]); + rc = SQLITE_OK; +#endif + }else{ + rc = SQLITE_ERROR; + } + + return rc; +} + +/* +** Delete all cached deferred doclists. Deferred doclists are cached +** (allocated) by the sqlite3Fts3CacheDeferredDoclists() function. +*/ +void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *pCsr){ + Fts3DeferredToken *pDef; + for(pDef=pCsr->pDeferred; pDef; pDef=pDef->pNext){ + fts3PendingListDelete(pDef->pList); + pDef->pList = 0; + } +} + +/* +** Free all entries in the pCsr->pDeffered list. Entries are added to +** this list using sqlite3Fts3DeferToken(). +*/ +void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *pCsr){ + Fts3DeferredToken *pDef; + Fts3DeferredToken *pNext; + for(pDef=pCsr->pDeferred; pDef; pDef=pNext){ + pNext = pDef->pNext; + fts3PendingListDelete(pDef->pList); + sqlite3_free(pDef); + } + pCsr->pDeferred = 0; +} + +/* +** Generate deferred-doclists for all tokens in the pCsr->pDeferred list +** based on the row that pCsr currently points to. +** +** A deferred-doclist is like any other doclist with position information +** included, except that it only contains entries for a single row of the +** table, not for all rows. +*/ +int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *pCsr){ + int rc = SQLITE_OK; /* Return code */ + if( pCsr->pDeferred ){ + int i; /* Used to iterate through table columns */ + sqlite3_int64 iDocid; /* Docid of the row pCsr points to */ + Fts3DeferredToken *pDef; /* Used to iterate through deferred tokens */ + + Fts3Table *p = (Fts3Table *)pCsr->base.pVtab; + sqlite3_tokenizer *pT = p->pTokenizer; + sqlite3_tokenizer_module const *pModule = pT->pModule; + + assert( pCsr->isRequireSeek==0 ); + iDocid = sqlite3_column_int64(pCsr->pStmt, 0); + + for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){ + const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1); + sqlite3_tokenizer_cursor *pTC = 0; + + rc = pModule->xOpen(pT, zText, -1, &pTC); + while( rc==SQLITE_OK ){ + char const *zToken; /* Buffer containing token */ + int nToken; /* Number of bytes in token */ + int iDum1, iDum2; /* Dummy variables */ + int iPos; /* Position of token in zText */ + + pTC->pTokenizer = pT; + rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos); + for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){ + Fts3PhraseToken *pPT = pDef->pToken; + if( (pDef->iCol>=p->nColumn || pDef->iCol==i) + && (pPT->bFirst==0 || iPos==0) + && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken)) + && (0==memcmp(zToken, pPT->z, pPT->n)) + ){ + fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc); + } + } + } + if( pTC ) pModule->xClose(pTC); + if( rc==SQLITE_DONE ) rc = SQLITE_OK; + } + + for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){ + if( pDef->pList ){ + rc = fts3PendingListAppendVarint(&pDef->pList, 0); + } + } + } + + return rc; +} + +int sqlite3Fts3DeferredTokenList( + Fts3DeferredToken *p, + char **ppData, + int *pnData +){ + char *pRet; + int nSkip; + sqlite3_int64 dummy; + + *ppData = 0; + *pnData = 0; + + if( p->pList==0 ){ + return SQLITE_OK; + } + + pRet = (char *)sqlite3_malloc(p->pList->nData); + if( !pRet ) return SQLITE_NOMEM; + + nSkip = sqlite3Fts3GetVarint(p->pList->aData, &dummy); + *pnData = p->pList->nData - nSkip; + *ppData = pRet; + + memcpy(pRet, &p->pList->aData[nSkip], *pnData); + return SQLITE_OK; +} + +/* +** Add an entry for token pToken to the pCsr->pDeferred list. +*/ +int sqlite3Fts3DeferToken( + Fts3Cursor *pCsr, /* Fts3 table cursor */ + Fts3PhraseToken *pToken, /* Token to defer */ + int iCol /* Column that token must appear in (or -1) */ +){ + Fts3DeferredToken *pDeferred; + pDeferred = sqlite3_malloc(sizeof(*pDeferred)); + if( !pDeferred ){ + return SQLITE_NOMEM; + } + memset(pDeferred, 0, sizeof(*pDeferred)); + pDeferred->pToken = pToken; + pDeferred->pNext = pCsr->pDeferred; + pDeferred->iCol = iCol; + pCsr->pDeferred = pDeferred; + + assert( pToken->pDeferred==0 ); + pToken->pDeferred = pDeferred; + + return SQLITE_OK; +} + +/* +** SQLite value pRowid contains the rowid of a row that may or may not be +** present in the FTS3 table. If it is, delete it and adjust the contents +** of subsiduary data structures accordingly. +*/ +static int fts3DeleteByRowid( + Fts3Table *p, + sqlite3_value *pRowid, + int *pnDoc, + u32 *aSzDel +){ + int isEmpty = 0; + int rc = fts3IsEmpty(p, pRowid, &isEmpty); + if( rc==SQLITE_OK ){ + if( isEmpty ){ + /* Deleting this row means the whole table is empty. In this case + ** delete the contents of all three tables and throw away any + ** data in the pendingTerms hash table. */ + rc = fts3DeleteAll(p, 1); + *pnDoc = *pnDoc - 1; + }else{ + sqlite3_int64 iRemove = sqlite3_value_int64(pRowid); + rc = fts3PendingTermsDocid(p, iRemove); + fts3DeleteTerms(&rc, p, pRowid, aSzDel); + if( p->zContentTbl==0 ){ + fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, &pRowid); + if( sqlite3_changes(p->db) ) *pnDoc = *pnDoc - 1; + }else{ + *pnDoc = *pnDoc - 1; + } + if( p->bHasDocsize ){ + fts3SqlExec(&rc, p, SQL_DELETE_DOCSIZE, &pRowid); + } + } + } + + return rc; +} + +/* +** This function does the work for the xUpdate method of FTS3 virtual +** tables. +*/ +int sqlite3Fts3UpdateMethod( + sqlite3_vtab *pVtab, /* FTS3 vtab object */ + int nArg, /* Size of argument array */ + sqlite3_value **apVal, /* Array of arguments */ + sqlite_int64 *pRowid /* OUT: The affected (or effected) rowid */ +){ + Fts3Table *p = (Fts3Table *)pVtab; + int rc = SQLITE_OK; /* Return Code */ + int isRemove = 0; /* True for an UPDATE or DELETE */ + u32 *aSzIns = 0; /* Sizes of inserted documents */ + u32 *aSzDel; /* Sizes of deleted documents */ + int nChng = 0; /* Net change in number of documents */ + int bInsertDone = 0; + + assert( p->pSegments==0 ); + + /* Check for a "special" INSERT operation. One of the form: + ** + ** INSERT INTO xyz(xyz) VALUES('command'); + */ + if( nArg>1 + && sqlite3_value_type(apVal[0])==SQLITE_NULL + && sqlite3_value_type(apVal[p->nColumn+2])!=SQLITE_NULL + ){ + rc = fts3SpecialInsert(p, apVal[p->nColumn+2]); + goto update_out; + } + + /* Allocate space to hold the change in document sizes */ + aSzIns = sqlite3_malloc( sizeof(aSzIns[0])*(p->nColumn+1)*2 ); + if( aSzIns==0 ){ + rc = SQLITE_NOMEM; + goto update_out; + } + aSzDel = &aSzIns[p->nColumn+1]; + memset(aSzIns, 0, sizeof(aSzIns[0])*(p->nColumn+1)*2); + + /* If this is an INSERT operation, or an UPDATE that modifies the rowid + ** value, then this operation requires constraint handling. + ** + ** If the on-conflict mode is REPLACE, this means that the existing row + ** should be deleted from the database before inserting the new row. Or, + ** if the on-conflict mode is other than REPLACE, then this method must + ** detect the conflict and return SQLITE_CONSTRAINT before beginning to + ** modify the database file. + */ + if( nArg>1 && p->zContentTbl==0 ){ + /* Find the value object that holds the new rowid value. */ + sqlite3_value *pNewRowid = apVal[3+p->nColumn]; + if( sqlite3_value_type(pNewRowid)==SQLITE_NULL ){ + pNewRowid = apVal[1]; + } + + if( sqlite3_value_type(pNewRowid)!=SQLITE_NULL && ( + sqlite3_value_type(apVal[0])==SQLITE_NULL + || sqlite3_value_int64(apVal[0])!=sqlite3_value_int64(pNewRowid) + )){ + /* The new rowid is not NULL (in this case the rowid will be + ** automatically assigned and there is no chance of a conflict), and + ** the statement is either an INSERT or an UPDATE that modifies the + ** rowid column. So if the conflict mode is REPLACE, then delete any + ** existing row with rowid=pNewRowid. + ** + ** Or, if the conflict mode is not REPLACE, insert the new record into + ** the %_content table. If we hit the duplicate rowid constraint (or any + ** other error) while doing so, return immediately. + ** + ** This branch may also run if pNewRowid contains a value that cannot + ** be losslessly converted to an integer. In this case, the eventual + ** call to fts3InsertData() (either just below or further on in this + ** function) will return SQLITE_MISMATCH. If fts3DeleteByRowid is + ** invoked, it will delete zero rows (since no row will have + ** docid=$pNewRowid if $pNewRowid is not an integer value). + */ + if( sqlite3_vtab_on_conflict(p->db)==SQLITE_REPLACE ){ + rc = fts3DeleteByRowid(p, pNewRowid, &nChng, aSzDel); + }else{ + rc = fts3InsertData(p, apVal, pRowid); + bInsertDone = 1; + } + } + } + if( rc!=SQLITE_OK ){ + goto update_out; + } + + /* If this is a DELETE or UPDATE operation, remove the old record. */ + if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){ + assert( sqlite3_value_type(apVal[0])==SQLITE_INTEGER ); + rc = fts3DeleteByRowid(p, apVal[0], &nChng, aSzDel); + isRemove = 1; + } + + /* If this is an INSERT or UPDATE operation, insert the new record. */ + if( nArg>1 && rc==SQLITE_OK ){ + if( bInsertDone==0 ){ + rc = fts3InsertData(p, apVal, pRowid); + if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){ + rc = FTS_CORRUPT_VTAB; + } + } + if( rc==SQLITE_OK && (!isRemove || *pRowid!=p->iPrevDocid ) ){ + rc = fts3PendingTermsDocid(p, *pRowid); + } + if( rc==SQLITE_OK ){ + assert( p->iPrevDocid==*pRowid ); + rc = fts3InsertTerms(p, apVal, aSzIns); + } + if( p->bHasDocsize ){ + fts3InsertDocsize(&rc, p, aSzIns); + } + nChng++; + } + + if( p->bHasStat ){ + fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nChng); + } + + update_out: + sqlite3_free(aSzIns); + sqlite3Fts3SegmentsClose(p); + return rc; +} + +/* +** Flush any data in the pending-terms hash table to disk. If successful, +** merge all segments in the database (including the new segment, if +** there was any data to flush) into a single segment. +*/ +int sqlite3Fts3Optimize(Fts3Table *p){ + int rc; + rc = sqlite3_exec(p->db, "SAVEPOINT fts3", 0, 0, 0); + if( rc==SQLITE_OK ){ + rc = fts3DoOptimize(p, 1); + if( rc==SQLITE_OK || rc==SQLITE_DONE ){ + int rc2 = sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0); + if( rc2!=SQLITE_OK ) rc = rc2; + }else{ + sqlite3_exec(p->db, "ROLLBACK TO fts3", 0, 0, 0); + sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0); + } + } + sqlite3Fts3SegmentsClose(p); + return rc; +} + +#endif |