/* ** 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; /* Opaque type used by the explainer */ typedef struct Explain Explain; /* ** 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 */ VdbeFrame *pParent; /* Parent of this frame, or NULL if parent is main */ Op *aOp; /* Program instructions for parent frame */ Mem *aMem; /* Array of memory cells for parent frame */ u8 *aOnceFlag; /* Array of OP_Once flags for parent frame */ VdbeCursor **apCsr; /* Array of Vdbe cursors for parent frame */ void *token; /* Copy of SubProgram.token */ i64 lastRowid; /* Last insert rowid (sqlite3.lastRowid) */ u16 nCursor; /* Number of entries in apCsr */ int pc; /* Program Counter in parent (calling) frame */ int nOp; /* Size of aOp array */ int nMem; /* Number of entries in aMem */ int nOnceFlag; /* Number of entries in aOnceFlag */ int nChildMem; /* Number of memory cells for child frame */ int nChildCsr; /* Number of cursors for child frame */ int nChange; /* Statement changes (Vdbe.nChanges) */ }; #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_Cleared 0x0100 /* NULL set by OP_Null, not from data */ #define MEM_TypeMask 0x01ff /* 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 */ CollSeq *pColl; /* Collating sequence */ int isError; /* Error code returned by the function. */ int skipFlag; /* Skip skip accumulator loading if true */ }; /* ** An Explain object accumulates indented output which is helpful ** in describing recursive data structures. */ struct Explain { Vdbe *pVdbe; /* Attach the explanation to this Vdbe */ StrAccum str; /* The string being accumulated */ int nIndent; /* Number of elements in aIndent */ u16 aIndent[100]; /* Levels of indentation */ char zBase[100]; /* Initial space */ }; /* A bitfield type for use inside of structures. Always follow with :N where ** N is the number of bits. */ typedef unsigned bft; /* Bit Field Type */ /* ** 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 *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 minWriteFileFormat; /* Minimum file format for writable database files */ bft explain:2; /* True if EXPLAIN present on SQL command */ bft inVtabMethod:2; /* See comments above */ bft changeCntOn:1; /* True to update the change-counter */ bft expired:1; /* True if the VM needs to be recompiled */ bft runOnlyOnce:1; /* Automatically expire on reset */ bft usesStmtJournal:1; /* True if uses a statement journal */ bft readOnly:1; /* True for read-only statements */ bft isPrepareV2:1; /* True if prepared with prepare_v2() */ bft doingRerun:1; /* True if rerunning after an auto-reprepare */ 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 #ifdef SQLITE_ENABLE_TREE_EXPLAIN Explain *pExplain; /* The explainer */ char *zExplain; /* Explanation of data structures */ #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 */ int nOnceFlag; /* Size of array aOnceFlag[] */ u8 *aOnceFlag; /* Flags for OP_Once */ }; /* ** 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 VdbeMemRelease(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(const VdbeCursor *, Mem *); int sqlite3VdbeSorterNext(sqlite3 *, const VdbeCursor *, int *); int sqlite3VdbeSorterRewind(sqlite3 *, const VdbeCursor *, int *); int sqlite3VdbeSorterWrite(sqlite3 *, const VdbeCursor *, Mem *); int sqlite3VdbeSorterCompare(const 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 sqlite3VdbeMemAboutToChange(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 *); #define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0) #else #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK #define ExpandBlob(P) SQLITE_OK #endif #endif /* !defined(_VDBEINT_H_) */