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Diffstat (limited to 'src/vdbeInt.h')
| -rw-r--r-- | src/vdbeInt.h | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/src/vdbeInt.h b/src/vdbeInt.h new file mode 100644 index 0000000..803ae16 --- /dev/null +++ b/src/vdbeInt.h @@ -0,0 +1,449 @@ +/* +** 2003 September 6 +** +** 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 is the header file for information that is private to the +** VDBE. This information used to all be at the top of the single +** source code file "vdbe.c". When that file became too big (over +** 6000 lines long) it was split up into several smaller files and +** this header information was factored out. +*/ +#ifndef _VDBEINT_H_ +#define _VDBEINT_H_ + +/* +** SQL is translated into a sequence of instructions to be +** executed by a virtual machine. Each instruction is an instance +** of the following structure. +*/ +typedef struct VdbeOp Op; + +/* +** Boolean values +*/ +typedef unsigned char Bool; + +/* Opaque type used by code in vdbesort.c */ +typedef struct VdbeSorter VdbeSorter; + +/* +** A cursor is a pointer into a single BTree within a database file. +** The cursor can seek to a BTree entry with a particular key, or +** loop over all entries of the Btree. You can also insert new BTree +** entries or retrieve the key or data from the entry that the cursor +** is currently pointing to. +** +** Every cursor that the virtual machine has open is represented by an +** instance of the following structure. +*/ +struct VdbeCursor { + BtCursor *pCursor; /* The cursor structure of the backend */ + Btree *pBt; /* Separate file holding temporary table */ + KeyInfo *pKeyInfo; /* Info about index keys needed by index cursors */ + int iDb; /* Index of cursor database in db->aDb[] (or -1) */ + int pseudoTableReg; /* Register holding pseudotable content. */ + int nField; /* Number of fields in the header */ + Bool zeroed; /* True if zeroed out and ready for reuse */ + Bool rowidIsValid; /* True if lastRowid is valid */ + Bool atFirst; /* True if pointing to first entry */ + Bool useRandomRowid; /* Generate new record numbers semi-randomly */ + Bool nullRow; /* True if pointing to a row with no data */ + Bool deferredMoveto; /* A call to sqlite3BtreeMoveto() is needed */ + Bool isTable; /* True if a table requiring integer keys */ + Bool isIndex; /* True if an index containing keys only - no data */ + Bool isOrdered; /* True if the underlying table is BTREE_UNORDERED */ + Bool isSorter; /* True if a new-style sorter */ + sqlite3_vtab_cursor *pVtabCursor; /* The cursor for a virtual table */ + const sqlite3_module *pModule; /* Module for cursor pVtabCursor */ + i64 seqCount; /* Sequence counter */ + i64 movetoTarget; /* Argument to the deferred sqlite3BtreeMoveto() */ + i64 lastRowid; /* Last rowid from a Next or NextIdx operation */ + VdbeSorter *pSorter; /* Sorter object for OP_SorterOpen cursors */ + + /* Result of last sqlite3BtreeMoveto() done by an OP_NotExists or + ** OP_IsUnique opcode on this cursor. */ + int seekResult; + + /* Cached information about the header for the data record that the + ** cursor is currently pointing to. Only valid if cacheStatus matches + ** Vdbe.cacheCtr. Vdbe.cacheCtr will never take on the value of + ** CACHE_STALE and so setting cacheStatus=CACHE_STALE guarantees that + ** the cache is out of date. + ** + ** aRow might point to (ephemeral) data for the current row, or it might + ** be NULL. + */ + u32 cacheStatus; /* Cache is valid if this matches Vdbe.cacheCtr */ + int payloadSize; /* Total number of bytes in the record */ + u32 *aType; /* Type values for all entries in the record */ + u32 *aOffset; /* Cached offsets to the start of each columns data */ + u8 *aRow; /* Data for the current row, if all on one page */ +}; +typedef struct VdbeCursor VdbeCursor; + +/* +** When a sub-program is executed (OP_Program), a structure of this type +** is allocated to store the current value of the program counter, as +** well as the current memory cell array and various other frame specific +** values stored in the Vdbe struct. When the sub-program is finished, +** these values are copied back to the Vdbe from the VdbeFrame structure, +** restoring the state of the VM to as it was before the sub-program +** began executing. +** +** The memory for a VdbeFrame object is allocated and managed by a memory +** cell in the parent (calling) frame. When the memory cell is deleted or +** overwritten, the VdbeFrame object is not freed immediately. Instead, it +** is linked into the Vdbe.pDelFrame list. The contents of the Vdbe.pDelFrame +** list is deleted when the VM is reset in VdbeHalt(). The reason for doing +** this instead of deleting the VdbeFrame immediately is to avoid recursive +** calls to sqlite3VdbeMemRelease() when the memory cells belonging to the +** child frame are released. +** +** The currently executing frame is stored in Vdbe.pFrame. Vdbe.pFrame is +** set to NULL if the currently executing frame is the main program. +*/ +typedef struct VdbeFrame VdbeFrame; +struct VdbeFrame { + Vdbe *v; /* VM this frame belongs to */ + int pc; /* Program Counter in parent (calling) frame */ + Op *aOp; /* Program instructions for parent frame */ + int nOp; /* Size of aOp array */ + Mem *aMem; /* Array of memory cells for parent frame */ + int nMem; /* Number of entries in aMem */ + VdbeCursor **apCsr; /* Array of Vdbe cursors for parent frame */ + u16 nCursor; /* Number of entries in apCsr */ + void *token; /* Copy of SubProgram.token */ + int nChildMem; /* Number of memory cells for child frame */ + int nChildCsr; /* Number of cursors for child frame */ + i64 lastRowid; /* Last insert rowid (sqlite3.lastRowid) */ + int nChange; /* Statement changes (Vdbe.nChanges) */ + VdbeFrame *pParent; /* Parent of this frame, or NULL if parent is main */ +}; + +#define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))]) + +/* +** A value for VdbeCursor.cacheValid that means the cache is always invalid. +*/ +#define CACHE_STALE 0 + +/* +** Internally, the vdbe manipulates nearly all SQL values as Mem +** structures. Each Mem struct may cache multiple representations (string, +** integer etc.) of the same value. +*/ +struct Mem { + sqlite3 *db; /* The associated database connection */ + char *z; /* String or BLOB value */ + double r; /* Real value */ + union { + i64 i; /* Integer value used when MEM_Int is set in flags */ + int nZero; /* Used when bit MEM_Zero is set in flags */ + FuncDef *pDef; /* Used only when flags==MEM_Agg */ + RowSet *pRowSet; /* Used only when flags==MEM_RowSet */ + VdbeFrame *pFrame; /* Used when flags==MEM_Frame */ + } u; + int n; /* Number of characters in string value, excluding '\0' */ + u16 flags; /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */ + u8 type; /* One of SQLITE_NULL, SQLITE_TEXT, SQLITE_INTEGER, etc */ + u8 enc; /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */ +#ifdef SQLITE_DEBUG + Mem *pScopyFrom; /* This Mem is a shallow copy of pScopyFrom */ + void *pFiller; /* So that sizeof(Mem) is a multiple of 8 */ +#endif + void (*xDel)(void *); /* If not null, call this function to delete Mem.z */ + char *zMalloc; /* Dynamic buffer allocated by sqlite3_malloc() */ +}; + +/* One or more of the following flags are set to indicate the validOK +** representations of the value stored in the Mem struct. +** +** If the MEM_Null flag is set, then the value is an SQL NULL value. +** No other flags may be set in this case. +** +** If the MEM_Str flag is set then Mem.z points at a string representation. +** Usually this is encoded in the same unicode encoding as the main +** database (see below for exceptions). If the MEM_Term flag is also +** set, then the string is nul terminated. The MEM_Int and MEM_Real +** flags may coexist with the MEM_Str flag. +*/ +#define MEM_Null 0x0001 /* Value is NULL */ +#define MEM_Str 0x0002 /* Value is a string */ +#define MEM_Int 0x0004 /* Value is an integer */ +#define MEM_Real 0x0008 /* Value is a real number */ +#define MEM_Blob 0x0010 /* Value is a BLOB */ +#define MEM_RowSet 0x0020 /* Value is a RowSet object */ +#define MEM_Frame 0x0040 /* Value is a VdbeFrame object */ +#define MEM_Invalid 0x0080 /* Value is undefined */ +#define MEM_TypeMask 0x00ff /* Mask of type bits */ + +/* Whenever Mem contains a valid string or blob representation, one of +** the following flags must be set to determine the memory management +** policy for Mem.z. The MEM_Term flag tells us whether or not the +** string is \000 or \u0000 terminated +*/ +#define MEM_Term 0x0200 /* String rep is nul terminated */ +#define MEM_Dyn 0x0400 /* Need to call sqliteFree() on Mem.z */ +#define MEM_Static 0x0800 /* Mem.z points to a static string */ +#define MEM_Ephem 0x1000 /* Mem.z points to an ephemeral string */ +#define MEM_Agg 0x2000 /* Mem.z points to an agg function context */ +#define MEM_Zero 0x4000 /* Mem.i contains count of 0s appended to blob */ +#ifdef SQLITE_OMIT_INCRBLOB + #undef MEM_Zero + #define MEM_Zero 0x0000 +#endif + +/* +** Clear any existing type flags from a Mem and replace them with f +*/ +#define MemSetTypeFlag(p, f) \ + ((p)->flags = ((p)->flags&~(MEM_TypeMask|MEM_Zero))|f) + +/* +** Return true if a memory cell is not marked as invalid. This macro +** is for use inside assert() statements only. +*/ +#ifdef SQLITE_DEBUG +#define memIsValid(M) ((M)->flags & MEM_Invalid)==0 +#endif + + +/* A VdbeFunc is just a FuncDef (defined in sqliteInt.h) that contains +** additional information about auxiliary information bound to arguments +** of the function. This is used to implement the sqlite3_get_auxdata() +** and sqlite3_set_auxdata() APIs. The "auxdata" is some auxiliary data +** that can be associated with a constant argument to a function. This +** allows functions such as "regexp" to compile their constant regular +** expression argument once and reused the compiled code for multiple +** invocations. +*/ +struct VdbeFunc { + FuncDef *pFunc; /* The definition of the function */ + int nAux; /* Number of entries allocated for apAux[] */ + struct AuxData { + void *pAux; /* Aux data for the i-th argument */ + void (*xDelete)(void *); /* Destructor for the aux data */ + } apAux[1]; /* One slot for each function argument */ +}; + +/* +** The "context" argument for a installable function. A pointer to an +** instance of this structure is the first argument to the routines used +** implement the SQL functions. +** +** There is a typedef for this structure in sqlite.h. So all routines, +** even the public interface to SQLite, can use a pointer to this structure. +** But this file is the only place where the internal details of this +** structure are known. +** +** This structure is defined inside of vdbeInt.h because it uses substructures +** (Mem) which are only defined there. +*/ +struct sqlite3_context { + FuncDef *pFunc; /* Pointer to function information. MUST BE FIRST */ + VdbeFunc *pVdbeFunc; /* Auxilary data, if created. */ + Mem s; /* The return value is stored here */ + Mem *pMem; /* Memory cell used to store aggregate context */ + int isError; /* Error code returned by the function. */ + CollSeq *pColl; /* Collating sequence */ +}; + +/* +** An instance of the virtual machine. This structure contains the complete +** state of the virtual machine. +** +** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare() +** is really a pointer to an instance of this structure. +** +** The Vdbe.inVtabMethod variable is set to non-zero for the duration of +** any virtual table method invocations made by the vdbe program. It is +** set to 2 for xDestroy method calls and 1 for all other methods. This +** variable is used for two purposes: to allow xDestroy methods to execute +** "DROP TABLE" statements and to prevent some nasty side effects of +** malloc failure when SQLite is invoked recursively by a virtual table +** method function. +*/ +struct Vdbe { + sqlite3 *db; /* The database connection that owns this statement */ + Op *aOp; /* Space to hold the virtual machine's program */ + Mem *aMem; /* The memory locations */ + Mem **apArg; /* Arguments to currently executing user function */ + Mem *aColName; /* Column names to return */ + Mem *pResultSet; /* Pointer to an array of results */ + int nMem; /* Number of memory locations currently allocated */ + int nOp; /* Number of instructions in the program */ + int nOpAlloc; /* Number of slots allocated for aOp[] */ + int nLabel; /* Number of labels used */ + int nLabelAlloc; /* Number of slots allocated in aLabel[] */ + int *aLabel; /* Space to hold the labels */ + u16 nResColumn; /* Number of columns in one row of the result set */ + u16 nCursor; /* Number of slots in apCsr[] */ + u32 magic; /* Magic number for sanity checking */ + char *zErrMsg; /* Error message written here */ + Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */ + VdbeCursor **apCsr; /* One element of this array for each open cursor */ + Mem *aVar; /* Values for the OP_Variable opcode. */ + char **azVar; /* Name of variables */ + ynVar nVar; /* Number of entries in aVar[] */ + ynVar nzVar; /* Number of entries in azVar[] */ + u32 cacheCtr; /* VdbeCursor row cache generation counter */ + int pc; /* The program counter */ + int rc; /* Value to return */ + u8 errorAction; /* Recovery action to do in case of an error */ + u8 explain; /* True if EXPLAIN present on SQL command */ + u8 changeCntOn; /* True to update the change-counter */ + u8 expired; /* True if the VM needs to be recompiled */ + u8 runOnlyOnce; /* Automatically expire on reset */ + u8 minWriteFileFormat; /* Minimum file format for writable database files */ + u8 inVtabMethod; /* See comments above */ + u8 usesStmtJournal; /* True if uses a statement journal */ + u8 readOnly; /* True for read-only statements */ + u8 isPrepareV2; /* True if prepared with prepare_v2() */ + int nChange; /* Number of db changes made since last reset */ + yDbMask btreeMask; /* Bitmask of db->aDb[] entries referenced */ + yDbMask lockMask; /* Subset of btreeMask that requires a lock */ + int iStatement; /* Statement number (or 0 if has not opened stmt) */ + int aCounter[3]; /* Counters used by sqlite3_stmt_status() */ +#ifndef SQLITE_OMIT_TRACE + i64 startTime; /* Time when query started - used for profiling */ +#endif + i64 nFkConstraint; /* Number of imm. FK constraints this VM */ + i64 nStmtDefCons; /* Number of def. constraints when stmt started */ + char *zSql; /* Text of the SQL statement that generated this */ + void *pFree; /* Free this when deleting the vdbe */ +#ifdef SQLITE_DEBUG + FILE *trace; /* Write an execution trace here, if not NULL */ +#endif + VdbeFrame *pFrame; /* Parent frame */ + VdbeFrame *pDelFrame; /* List of frame objects to free on VM reset */ + int nFrame; /* Number of frames in pFrame list */ + u32 expmask; /* Binding to these vars invalidates VM */ + SubProgram *pProgram; /* Linked list of all sub-programs used by VM */ +}; + +/* +** The following are allowed values for Vdbe.magic +*/ +#define VDBE_MAGIC_INIT 0x26bceaa5 /* Building a VDBE program */ +#define VDBE_MAGIC_RUN 0xbdf20da3 /* VDBE is ready to execute */ +#define VDBE_MAGIC_HALT 0x519c2973 /* VDBE has completed execution */ +#define VDBE_MAGIC_DEAD 0xb606c3c8 /* The VDBE has been deallocated */ + +/* +** Function prototypes +*/ +void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*); +void sqliteVdbePopStack(Vdbe*,int); +int sqlite3VdbeCursorMoveto(VdbeCursor*); +#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE) +void sqlite3VdbePrintOp(FILE*, int, Op*); +#endif +u32 sqlite3VdbeSerialTypeLen(u32); +u32 sqlite3VdbeSerialType(Mem*, int); +u32 sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int); +u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*); +void sqlite3VdbeDeleteAuxData(VdbeFunc*, int); + +int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *); +int sqlite3VdbeIdxKeyCompare(VdbeCursor*,UnpackedRecord*,int*); +int sqlite3VdbeIdxRowid(sqlite3*, BtCursor *, i64 *); +int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*); +int sqlite3VdbeExec(Vdbe*); +int sqlite3VdbeList(Vdbe*); +int sqlite3VdbeHalt(Vdbe*); +int sqlite3VdbeChangeEncoding(Mem *, int); +int sqlite3VdbeMemTooBig(Mem*); +int sqlite3VdbeMemCopy(Mem*, const Mem*); +void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int); +void sqlite3VdbeMemMove(Mem*, Mem*); +int sqlite3VdbeMemNulTerminate(Mem*); +int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*)); +void sqlite3VdbeMemSetInt64(Mem*, i64); +#ifdef SQLITE_OMIT_FLOATING_POINT +# define sqlite3VdbeMemSetDouble sqlite3VdbeMemSetInt64 +#else + void sqlite3VdbeMemSetDouble(Mem*, double); +#endif +void sqlite3VdbeMemSetNull(Mem*); +void sqlite3VdbeMemSetZeroBlob(Mem*,int); +void sqlite3VdbeMemSetRowSet(Mem*); +int sqlite3VdbeMemMakeWriteable(Mem*); +int sqlite3VdbeMemStringify(Mem*, int); +i64 sqlite3VdbeIntValue(Mem*); +int sqlite3VdbeMemIntegerify(Mem*); +double sqlite3VdbeRealValue(Mem*); +void sqlite3VdbeIntegerAffinity(Mem*); +int sqlite3VdbeMemRealify(Mem*); +int sqlite3VdbeMemNumerify(Mem*); +int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*); +void sqlite3VdbeMemRelease(Mem *p); +void sqlite3VdbeMemReleaseExternal(Mem *p); +#define MemReleaseExt(X) \ + if((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame)) \ + sqlite3VdbeMemReleaseExternal(X); +int sqlite3VdbeMemFinalize(Mem*, FuncDef*); +const char *sqlite3OpcodeName(int); +int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve); +int sqlite3VdbeCloseStatement(Vdbe *, int); +void sqlite3VdbeFrameDelete(VdbeFrame*); +int sqlite3VdbeFrameRestore(VdbeFrame *); +void sqlite3VdbeMemStoreType(Mem *pMem); +int sqlite3VdbeTransferError(Vdbe *p); + +#ifdef SQLITE_OMIT_MERGE_SORT +# define sqlite3VdbeSorterInit(Y,Z) SQLITE_OK +# define sqlite3VdbeSorterWrite(X,Y,Z) SQLITE_OK +# define sqlite3VdbeSorterClose(Y,Z) +# define sqlite3VdbeSorterRowkey(Y,Z) SQLITE_OK +# define sqlite3VdbeSorterRewind(X,Y,Z) SQLITE_OK +# define sqlite3VdbeSorterNext(X,Y,Z) SQLITE_OK +# define sqlite3VdbeSorterCompare(X,Y,Z) SQLITE_OK +#else +int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *); +void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *); +int sqlite3VdbeSorterRowkey(VdbeCursor *, Mem *); +int sqlite3VdbeSorterNext(sqlite3 *, VdbeCursor *, int *); +int sqlite3VdbeSorterRewind(sqlite3 *, VdbeCursor *, int *); +int sqlite3VdbeSorterWrite(sqlite3 *, VdbeCursor *, Mem *); +int sqlite3VdbeSorterCompare(VdbeCursor *, Mem *, int *); +#endif + +#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0 + void sqlite3VdbeEnter(Vdbe*); + void sqlite3VdbeLeave(Vdbe*); +#else +# define sqlite3VdbeEnter(X) +# define sqlite3VdbeLeave(X) +#endif + +#ifdef SQLITE_DEBUG +void sqlite3VdbeMemPrepareToChange(Vdbe*,Mem*); +#endif + +#ifndef SQLITE_OMIT_FOREIGN_KEY +int sqlite3VdbeCheckFk(Vdbe *, int); +#else +# define sqlite3VdbeCheckFk(p,i) 0 +#endif + +int sqlite3VdbeMemTranslate(Mem*, u8); +#ifdef SQLITE_DEBUG + void sqlite3VdbePrintSql(Vdbe*); + void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf); +#endif +int sqlite3VdbeMemHandleBom(Mem *pMem); + +#ifndef SQLITE_OMIT_INCRBLOB + int sqlite3VdbeMemExpandBlob(Mem *); +#else + #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK +#endif + +#endif /* !defined(_VDBEINT_H_) */ |