diff options
author | Hans-Christoph Steiner <hans@eds.org> | 2012-03-30 20:42:12 -0400 |
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committer | Hans-Christoph Steiner <hans@eds.org> | 2012-03-30 20:42:12 -0400 |
commit | 7bb481fda9ecb134804b49c2ce77ca28f7eea583 (patch) | |
tree | 31b520b9914d3e2453968abe375f2c102772c3dc /src/test_stat.c |
Imported Upstream version 2.0.3
Diffstat (limited to 'src/test_stat.c')
-rw-r--r-- | src/test_stat.c | 638 |
1 files changed, 638 insertions, 0 deletions
diff --git a/src/test_stat.c b/src/test_stat.c new file mode 100644 index 0000000..ef81769 --- /dev/null +++ b/src/test_stat.c @@ -0,0 +1,638 @@ +/* +** 2010 July 12 +** +** 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 contains an implementation of the "dbstat" virtual table. +** +** The dbstat virtual table is used to extract low-level formatting +** information from an SQLite database in order to implement the +** "sqlite3_analyzer" utility. See the ../tool/spaceanal.tcl script +** for an example implementation. +*/ + +#ifndef SQLITE_AMALGAMATION +# include "sqliteInt.h" +#endif + +#ifndef SQLITE_OMIT_VIRTUALTABLE + +/* +** Page paths: +** +** The value of the 'path' column describes the path taken from the +** root-node of the b-tree structure to each page. The value of the +** root-node path is '/'. +** +** The value of the path for the left-most child page of the root of +** a b-tree is '/000/'. (Btrees store content ordered from left to right +** so the pages to the left have smaller keys than the pages to the right.) +** The next to left-most child of the root page is +** '/001', and so on, each sibling page identified by a 3-digit hex +** value. The children of the 451st left-most sibling have paths such +** as '/1c2/000/, '/1c2/001/' etc. +** +** Overflow pages are specified by appending a '+' character and a +** six-digit hexadecimal value to the path to the cell they are linked +** from. For example, the three overflow pages in a chain linked from +** the left-most cell of the 450th child of the root page are identified +** by the paths: +** +** '/1c2/000+000000' // First page in overflow chain +** '/1c2/000+000001' // Second page in overflow chain +** '/1c2/000+000002' // Third page in overflow chain +** +** If the paths are sorted using the BINARY collation sequence, then +** the overflow pages associated with a cell will appear earlier in the +** sort-order than its child page: +** +** '/1c2/000/' // Left-most child of 451st child of root +*/ +#define VTAB_SCHEMA \ + "CREATE TABLE xx( " \ + " name STRING, /* Name of table or index */" \ + " path INTEGER, /* Path to page from root */" \ + " pageno INTEGER, /* Page number */" \ + " pagetype STRING, /* 'internal', 'leaf' or 'overflow' */" \ + " ncell INTEGER, /* Cells on page (0 for overflow) */" \ + " payload INTEGER, /* Bytes of payload on this page */" \ + " unused INTEGER, /* Bytes of unused space on this page */" \ + " mx_payload INTEGER, /* Largest payload size of all cells */" \ + " pgoffset INTEGER, /* Offset of page in file */" \ + " pgsize INTEGER /* Size of the page */" \ + ");" + + +typedef struct StatTable StatTable; +typedef struct StatCursor StatCursor; +typedef struct StatPage StatPage; +typedef struct StatCell StatCell; + +struct StatCell { + int nLocal; /* Bytes of local payload */ + u32 iChildPg; /* Child node (or 0 if this is a leaf) */ + int nOvfl; /* Entries in aOvfl[] */ + u32 *aOvfl; /* Array of overflow page numbers */ + int nLastOvfl; /* Bytes of payload on final overflow page */ + int iOvfl; /* Iterates through aOvfl[] */ +}; + +struct StatPage { + u32 iPgno; + DbPage *pPg; + int iCell; + + char *zPath; /* Path to this page */ + + /* Variables populated by statDecodePage(): */ + u8 flags; /* Copy of flags byte */ + int nCell; /* Number of cells on page */ + int nUnused; /* Number of unused bytes on page */ + StatCell *aCell; /* Array of parsed cells */ + u32 iRightChildPg; /* Right-child page number (or 0) */ + int nMxPayload; /* Largest payload of any cell on this page */ +}; + +struct StatCursor { + sqlite3_vtab_cursor base; + sqlite3_stmt *pStmt; /* Iterates through set of root pages */ + int isEof; /* After pStmt has returned SQLITE_DONE */ + + StatPage aPage[32]; + int iPage; /* Current entry in aPage[] */ + + /* Values to return. */ + char *zName; /* Value of 'name' column */ + char *zPath; /* Value of 'path' column */ + u32 iPageno; /* Value of 'pageno' column */ + char *zPagetype; /* Value of 'pagetype' column */ + int nCell; /* Value of 'ncell' column */ + int nPayload; /* Value of 'payload' column */ + int nUnused; /* Value of 'unused' column */ + int nMxPayload; /* Value of 'mx_payload' column */ + i64 iOffset; /* Value of 'pgOffset' column */ + int szPage; /* Value of 'pgSize' column */ +}; + +struct StatTable { + sqlite3_vtab base; + sqlite3 *db; +}; + +#ifndef get2byte +# define get2byte(x) ((x)[0]<<8 | (x)[1]) +#endif + +/* +** Connect to or create a statvfs virtual table. +*/ +static int statConnect( + sqlite3 *db, + void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVtab, + char **pzErr +){ + StatTable *pTab; + + pTab = (StatTable *)sqlite3_malloc(sizeof(StatTable)); + memset(pTab, 0, sizeof(StatTable)); + pTab->db = db; + + sqlite3_declare_vtab(db, VTAB_SCHEMA); + *ppVtab = &pTab->base; + return SQLITE_OK; +} + +/* +** Disconnect from or destroy a statvfs virtual table. +*/ +static int statDisconnect(sqlite3_vtab *pVtab){ + sqlite3_free(pVtab); + return SQLITE_OK; +} + +/* +** There is no "best-index". This virtual table always does a linear +** scan of the binary VFS log file. +*/ +static int statBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ + + /* Records are always returned in ascending order of (name, path). + ** If this will satisfy the client, set the orderByConsumed flag so that + ** SQLite does not do an external sort. + */ + if( ( pIdxInfo->nOrderBy==1 + && pIdxInfo->aOrderBy[0].iColumn==0 + && pIdxInfo->aOrderBy[0].desc==0 + ) || + ( pIdxInfo->nOrderBy==2 + && pIdxInfo->aOrderBy[0].iColumn==0 + && pIdxInfo->aOrderBy[0].desc==0 + && pIdxInfo->aOrderBy[1].iColumn==1 + && pIdxInfo->aOrderBy[1].desc==0 + ) + ){ + pIdxInfo->orderByConsumed = 1; + } + + pIdxInfo->estimatedCost = 10.0; + return SQLITE_OK; +} + +/* +** Open a new statvfs cursor. +*/ +static int statOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ + StatTable *pTab = (StatTable *)pVTab; + StatCursor *pCsr; + int rc; + + pCsr = (StatCursor *)sqlite3_malloc(sizeof(StatCursor)); + memset(pCsr, 0, sizeof(StatCursor)); + pCsr->base.pVtab = pVTab; + + rc = sqlite3_prepare_v2(pTab->db, + "SELECT 'sqlite_master' AS name, 1 AS rootpage, 'table' AS type" + " UNION ALL " + "SELECT name, rootpage, type FROM sqlite_master WHERE rootpage!=0" + " ORDER BY name", -1, + &pCsr->pStmt, 0 + ); + if( rc!=SQLITE_OK ){ + sqlite3_free(pCsr); + return rc; + } + + *ppCursor = (sqlite3_vtab_cursor *)pCsr; + return SQLITE_OK; +} + +static void statClearPage(StatPage *p){ + int i; + for(i=0; i<p->nCell; i++){ + sqlite3_free(p->aCell[i].aOvfl); + } + sqlite3PagerUnref(p->pPg); + sqlite3_free(p->aCell); + sqlite3_free(p->zPath); + memset(p, 0, sizeof(StatPage)); +} + +static void statResetCsr(StatCursor *pCsr){ + int i; + sqlite3_reset(pCsr->pStmt); + for(i=0; i<ArraySize(pCsr->aPage); i++){ + statClearPage(&pCsr->aPage[i]); + } + pCsr->iPage = 0; + sqlite3_free(pCsr->zPath); + pCsr->zPath = 0; +} + +/* +** Close a statvfs cursor. +*/ +static int statClose(sqlite3_vtab_cursor *pCursor){ + StatCursor *pCsr = (StatCursor *)pCursor; + statResetCsr(pCsr); + sqlite3_finalize(pCsr->pStmt); + sqlite3_free(pCsr); + return SQLITE_OK; +} + +static void getLocalPayload( + int nUsable, /* Usable bytes per page */ + u8 flags, /* Page flags */ + int nTotal, /* Total record (payload) size */ + int *pnLocal /* OUT: Bytes stored locally */ +){ + int nLocal; + int nMinLocal; + int nMaxLocal; + + if( flags==0x0D ){ /* Table leaf node */ + nMinLocal = (nUsable - 12) * 32 / 255 - 23; + nMaxLocal = nUsable - 35; + }else{ /* Index interior and leaf nodes */ + nMinLocal = (nUsable - 12) * 32 / 255 - 23; + nMaxLocal = (nUsable - 12) * 64 / 255 - 23; + } + + nLocal = nMinLocal + (nTotal - nMinLocal) % (nUsable - 4); + if( nLocal>nMaxLocal ) nLocal = nMinLocal; + *pnLocal = nLocal; +} + +static int statDecodePage(Btree *pBt, StatPage *p){ + int nUnused; + int iOff; + int nHdr; + int isLeaf; + int szPage; + + u8 *aData = sqlite3PagerGetData(p->pPg); + u8 *aHdr = &aData[p->iPgno==1 ? 100 : 0]; + + p->flags = aHdr[0]; + p->nCell = get2byte(&aHdr[3]); + p->nMxPayload = 0; + + isLeaf = (p->flags==0x0A || p->flags==0x0D); + nHdr = 12 - isLeaf*4 + (p->iPgno==1)*100; + + nUnused = get2byte(&aHdr[5]) - nHdr - 2*p->nCell; + nUnused += (int)aHdr[7]; + iOff = get2byte(&aHdr[1]); + while( iOff ){ + nUnused += get2byte(&aData[iOff+2]); + iOff = get2byte(&aData[iOff]); + } + p->nUnused = nUnused; + p->iRightChildPg = isLeaf ? 0 : sqlite3Get4byte(&aHdr[8]); + szPage = sqlite3BtreeGetPageSize(pBt); + + if( p->nCell ){ + int i; /* Used to iterate through cells */ + int nUsable = szPage - sqlite3BtreeGetReserve(pBt); + + p->aCell = sqlite3_malloc((p->nCell+1) * sizeof(StatCell)); + memset(p->aCell, 0, (p->nCell+1) * sizeof(StatCell)); + + for(i=0; i<p->nCell; i++){ + StatCell *pCell = &p->aCell[i]; + + iOff = get2byte(&aData[nHdr+i*2]); + if( !isLeaf ){ + pCell->iChildPg = sqlite3Get4byte(&aData[iOff]); + iOff += 4; + } + if( p->flags==0x05 ){ + /* A table interior node. nPayload==0. */ + }else{ + u32 nPayload; /* Bytes of payload total (local+overflow) */ + int nLocal; /* Bytes of payload stored locally */ + iOff += getVarint32(&aData[iOff], nPayload); + if( p->flags==0x0D ){ + u64 dummy; + iOff += sqlite3GetVarint(&aData[iOff], &dummy); + } + if( nPayload>p->nMxPayload ) p->nMxPayload = nPayload; + getLocalPayload(nUsable, p->flags, nPayload, &nLocal); + pCell->nLocal = nLocal; + assert( nPayload>=nLocal ); + assert( nLocal<=(nUsable-35) ); + if( nPayload>nLocal ){ + int j; + int nOvfl = ((nPayload - nLocal) + nUsable-4 - 1) / (nUsable - 4); + pCell->nLastOvfl = (nPayload-nLocal) - (nOvfl-1) * (nUsable-4); + pCell->nOvfl = nOvfl; + pCell->aOvfl = sqlite3_malloc(sizeof(u32)*nOvfl); + pCell->aOvfl[0] = sqlite3Get4byte(&aData[iOff+nLocal]); + for(j=1; j<nOvfl; j++){ + int rc; + u32 iPrev = pCell->aOvfl[j-1]; + DbPage *pPg = 0; + rc = sqlite3PagerGet(sqlite3BtreePager(pBt), iPrev, &pPg); + if( rc!=SQLITE_OK ){ + assert( pPg==0 ); + return rc; + } + pCell->aOvfl[j] = sqlite3Get4byte(sqlite3PagerGetData(pPg)); + sqlite3PagerUnref(pPg); + } + } + } + } + } + + return SQLITE_OK; +} + +/* +** Populate the pCsr->iOffset and pCsr->szPage member variables. Based on +** the current value of pCsr->iPageno. +*/ +static void statSizeAndOffset(StatCursor *pCsr){ + StatTable *pTab = (StatTable *)((sqlite3_vtab_cursor *)pCsr)->pVtab; + Btree *pBt = pTab->db->aDb[0].pBt; + Pager *pPager = sqlite3BtreePager(pBt); + sqlite3_file *fd; + sqlite3_int64 x[2]; + + /* The default page size and offset */ + pCsr->szPage = sqlite3BtreeGetPageSize(pBt); + pCsr->iOffset = pCsr->szPage * (pCsr->iPageno - 1); + + /* If connected to a ZIPVFS backend, override the page size and + ** offset with actual values obtained from ZIPVFS. + */ + fd = sqlite3PagerFile(pPager); + x[0] = pCsr->iPageno; + if( sqlite3OsFileControl(fd, 230440, &x)==SQLITE_OK ){ + pCsr->iOffset = x[0]; + pCsr->szPage = x[1]; + } +} + +/* +** Move a statvfs cursor to the next entry in the file. +*/ +static int statNext(sqlite3_vtab_cursor *pCursor){ + int rc; + int nPayload; + StatCursor *pCsr = (StatCursor *)pCursor; + StatTable *pTab = (StatTable *)pCursor->pVtab; + Btree *pBt = pTab->db->aDb[0].pBt; + Pager *pPager = sqlite3BtreePager(pBt); + + sqlite3_free(pCsr->zPath); + pCsr->zPath = 0; + + if( pCsr->aPage[0].pPg==0 ){ + rc = sqlite3_step(pCsr->pStmt); + if( rc==SQLITE_ROW ){ + int nPage; + u32 iRoot = sqlite3_column_int64(pCsr->pStmt, 1); + sqlite3PagerPagecount(pPager, &nPage); + if( nPage==0 ){ + pCsr->isEof = 1; + return sqlite3_reset(pCsr->pStmt); + } + rc = sqlite3PagerGet(pPager, iRoot, &pCsr->aPage[0].pPg); + pCsr->aPage[0].iPgno = iRoot; + pCsr->aPage[0].iCell = 0; + pCsr->aPage[0].zPath = sqlite3_mprintf("/"); + pCsr->iPage = 0; + }else{ + pCsr->isEof = 1; + return sqlite3_reset(pCsr->pStmt); + } + }else{ + + /* Page p itself has already been visited. */ + StatPage *p = &pCsr->aPage[pCsr->iPage]; + + while( p->iCell<p->nCell ){ + StatCell *pCell = &p->aCell[p->iCell]; + if( pCell->iOvfl<pCell->nOvfl ){ + int nUsable = sqlite3BtreeGetPageSize(pBt)-sqlite3BtreeGetReserve(pBt); + pCsr->zName = (char *)sqlite3_column_text(pCsr->pStmt, 0); + pCsr->iPageno = pCell->aOvfl[pCell->iOvfl]; + pCsr->zPagetype = "overflow"; + pCsr->nCell = 0; + pCsr->nMxPayload = 0; + pCsr->zPath = sqlite3_mprintf( + "%s%.3x+%.6x", p->zPath, p->iCell, pCell->iOvfl + ); + if( pCell->iOvfl<pCell->nOvfl-1 ){ + pCsr->nUnused = 0; + pCsr->nPayload = nUsable - 4; + }else{ + pCsr->nPayload = pCell->nLastOvfl; + pCsr->nUnused = nUsable - 4 - pCsr->nPayload; + } + pCell->iOvfl++; + statSizeAndOffset(pCsr); + return SQLITE_OK; + } + if( p->iRightChildPg ) break; + p->iCell++; + } + + while( !p->iRightChildPg || p->iCell>p->nCell ){ + statClearPage(p); + if( pCsr->iPage==0 ) return statNext(pCursor); + pCsr->iPage--; + p = &pCsr->aPage[pCsr->iPage]; + } + pCsr->iPage++; + assert( p==&pCsr->aPage[pCsr->iPage-1] ); + + if( p->iCell==p->nCell ){ + p[1].iPgno = p->iRightChildPg; + }else{ + p[1].iPgno = p->aCell[p->iCell].iChildPg; + } + rc = sqlite3PagerGet(pPager, p[1].iPgno, &p[1].pPg); + p[1].iCell = 0; + p[1].zPath = sqlite3_mprintf("%s%.3x/", p->zPath, p->iCell); + p->iCell++; + } + + + /* Populate the StatCursor fields with the values to be returned + ** by the xColumn() and xRowid() methods. + */ + if( rc==SQLITE_OK ){ + int i; + StatPage *p = &pCsr->aPage[pCsr->iPage]; + pCsr->zName = (char *)sqlite3_column_text(pCsr->pStmt, 0); + pCsr->iPageno = p->iPgno; + + statDecodePage(pBt, p); + statSizeAndOffset(pCsr); + + switch( p->flags ){ + case 0x05: /* table internal */ + case 0x02: /* index internal */ + pCsr->zPagetype = "internal"; + break; + case 0x0D: /* table leaf */ + case 0x0A: /* index leaf */ + pCsr->zPagetype = "leaf"; + break; + default: + pCsr->zPagetype = "corrupted"; + break; + } + pCsr->nCell = p->nCell; + pCsr->nUnused = p->nUnused; + pCsr->nMxPayload = p->nMxPayload; + pCsr->zPath = sqlite3_mprintf("%s", p->zPath); + nPayload = 0; + for(i=0; i<p->nCell; i++){ + nPayload += p->aCell[i].nLocal; + } + pCsr->nPayload = nPayload; + } + + return rc; +} + +static int statEof(sqlite3_vtab_cursor *pCursor){ + StatCursor *pCsr = (StatCursor *)pCursor; + return pCsr->isEof; +} + +static int statFilter( + sqlite3_vtab_cursor *pCursor, + int idxNum, const char *idxStr, + int argc, sqlite3_value **argv +){ + StatCursor *pCsr = (StatCursor *)pCursor; + + statResetCsr(pCsr); + return statNext(pCursor); +} + +static int statColumn( + sqlite3_vtab_cursor *pCursor, + sqlite3_context *ctx, + int i +){ + StatCursor *pCsr = (StatCursor *)pCursor; + switch( i ){ + case 0: /* name */ + sqlite3_result_text(ctx, pCsr->zName, -1, SQLITE_STATIC); + break; + case 1: /* path */ + sqlite3_result_text(ctx, pCsr->zPath, -1, SQLITE_TRANSIENT); + break; + case 2: /* pageno */ + sqlite3_result_int64(ctx, pCsr->iPageno); + break; + case 3: /* pagetype */ + sqlite3_result_text(ctx, pCsr->zPagetype, -1, SQLITE_STATIC); + break; + case 4: /* ncell */ + sqlite3_result_int(ctx, pCsr->nCell); + break; + case 5: /* payload */ + sqlite3_result_int(ctx, pCsr->nPayload); + break; + case 6: /* unused */ + sqlite3_result_int(ctx, pCsr->nUnused); + break; + case 7: /* mx_payload */ + sqlite3_result_int(ctx, pCsr->nMxPayload); + break; + case 8: /* pgoffset */ + sqlite3_result_int64(ctx, pCsr->iOffset); + break; + case 9: /* pgsize */ + sqlite3_result_int(ctx, pCsr->szPage); + break; + } + return SQLITE_OK; +} + +static int statRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){ + StatCursor *pCsr = (StatCursor *)pCursor; + *pRowid = pCsr->iPageno; + return SQLITE_OK; +} + +int sqlite3_dbstat_register(sqlite3 *db){ + static sqlite3_module dbstat_module = { + 0, /* iVersion */ + statConnect, /* xCreate */ + statConnect, /* xConnect */ + statBestIndex, /* xBestIndex */ + statDisconnect, /* xDisconnect */ + statDisconnect, /* xDestroy */ + statOpen, /* xOpen - open a cursor */ + statClose, /* xClose - close a cursor */ + statFilter, /* xFilter - configure scan constraints */ + statNext, /* xNext - advance a cursor */ + statEof, /* xEof - check for end of scan */ + statColumn, /* xColumn - read data */ + statRowid, /* xRowid - read data */ + 0, /* xUpdate */ + 0, /* xBegin */ + 0, /* xSync */ + 0, /* xCommit */ + 0, /* xRollback */ + 0, /* xFindMethod */ + 0, /* xRename */ + }; + sqlite3_create_module(db, "dbstat", &dbstat_module, 0); + return SQLITE_OK; +} + +#endif + +#if defined(SQLITE_TEST) || TCLSH==2 +#include <tcl.h> + +static int test_dbstat( + void *clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ +#ifdef SQLITE_OMIT_VIRTUALTABLE + Tcl_AppendResult(interp, "dbstat not available because of " + "SQLITE_OMIT_VIRTUALTABLE", (void*)0); + return TCL_ERROR; +#else + struct SqliteDb { sqlite3 *db; }; + char *zDb; + Tcl_CmdInfo cmdInfo; + + if( objc!=2 ){ + Tcl_WrongNumArgs(interp, 1, objv, "DB"); + return TCL_ERROR; + } + + zDb = Tcl_GetString(objv[1]); + if( Tcl_GetCommandInfo(interp, zDb, &cmdInfo) ){ + sqlite3* db = ((struct SqliteDb*)cmdInfo.objClientData)->db; + sqlite3_dbstat_register(db); + } + return TCL_OK; +#endif +} + +int SqlitetestStat_Init(Tcl_Interp *interp){ + Tcl_CreateObjCommand(interp, "register_dbstat_vtab", test_dbstat, 0, 0); + return TCL_OK; +} +#endif /* if defined(SQLITE_TEST) || TCLSH==2 */ |