/* ** 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. */ /* ** intToKey() and keyToInt() used to transform the rowid. But with ** the latest versions of the design they are no-ops. */ #define keyToInt(X) (X) #define intToKey(X) (X) /* ** The makefile scans the vdbe.c source file and creates the following ** array of string constants which are the names of all VDBE opcodes. This ** array is defined in a separate source code file named opcode.c which is ** automatically generated by the makefile. */ extern char *sqlite3OpcodeNames[]; /* ** 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; /* ** 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. ** ** If the Cursor.isTriggerRow flag is set it means that this cursor is ** really a single row that represents the NEW or OLD pseudo-table of ** a row trigger. The data for the row is stored in Cursor.pData and ** the rowid is in Cursor.iKey. */ struct Cursor { BtCursor *pCursor; /* The cursor structure of the backend */ i64 lastRowid; /* Last rowid from a Next or NextIdx operation */ i64 nextRowid; /* Next rowid returned by OP_NewRowid */ 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 nextRowidValid; /* True if the nextRowid field is valid */ Bool pseudoTable; /* This is a NEW or OLD pseudo-tables of a trigger */ 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 */ u8 bogusIncrKey; /* Something for pIncrKey to point to if pKeyInfo==0 */ i64 movetoTarget; /* Argument to the deferred sqlite3BtreeMoveto() */ Btree *pBt; /* Separate file holding temporary table */ int nData; /* Number of bytes in pData */ char *pData; /* Data for a NEW or OLD pseudo-table */ i64 iKey; /* Key for the NEW or OLD pseudo-table row */ u8 *pIncrKey; /* Pointer to pKeyInfo->incrKey */ KeyInfo *pKeyInfo; /* Info about index keys needed by index cursors */ int nField; /* Number of fields in the header */ i64 setqCount; /* Sequence counter */ /* Cached information about the header for the data record that the ** cursor is currently pointing to. Only valid if cacheValid is true. ** zRow might point to (ephemeral) data for the current row, or it might ** be NULL. */ Bool cacheValid; /* True if the cache is valid */ 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 Cursor Cursor; /* ** Number of bytes of string storage space available to each stack ** layer without having to malloc. NBFS is short for Number of Bytes ** For Strings. */ #define NBFS 32 /* ** 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. A value (and therefore Mem structure) ** has the following properties: ** ** Each value has a manifest type. The manifest type of the value stored ** in a Mem struct is returned by the MemType(Mem*) macro. The type is ** one of SQLITE_NULL, SQLITE_INTEGER, SQLITE_REAL, SQLITE_TEXT or ** SQLITE_BLOB. */ struct Mem { i64 i; /* Integer value. Or FuncDef* when flags==MEM_Agg */ double r; /* Real value */ char *z; /* String or BLOB value */ int n; /* Number of characters in string value, including '\0' */ u16 flags; /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */ u8 type; /* One of MEM_Null, MEM_Str, etc. */ u8 enc; /* TEXT_Utf8, TEXT_Utf16le, or TEXT_Utf16be */ void (*xDel)(void *); /* If not null, call this function to delete Mem.z */ char zShort[NBFS]; /* Space for short strings */ }; typedef struct Mem Mem; /* 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. ** ** Multiple of these values can appear in Mem.flags. But only one ** at a time can appear in Mem.type. */ #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 */ /* 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 0x0020 /* String rep is nul terminated */ #define MEM_Dyn 0x0040 /* Need to call sqliteFree() on Mem.z */ #define MEM_Static 0x0080 /* Mem.z points to a static string */ #define MEM_Ephem 0x0100 /* Mem.z points to an ephemeral string */ #define MEM_Short 0x0200 /* Mem.z points to Mem.zShort */ #define MEM_Agg 0x0400 /* Mem.z points to an agg function context */ /* 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 */ }; typedef struct VdbeFunc VdbeFunc; /* ** 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 */ u8 isError; /* Set to true for an error */ CollSeq *pColl; /* Collating sequence */ }; /* ** A Set structure is used for quick testing to see if a value ** is part of a small set. Sets are used to implement code like ** this: ** x.y IN ('hi','hoo','hum') */ typedef struct Set Set; struct Set { Hash hash; /* A set is just a hash table */ HashElem *prev; /* Previously accessed hash elemen */ }; /* ** A FifoPage structure holds a single page of valves. Pages are arranged ** in a list. */ typedef struct FifoPage FifoPage; struct FifoPage { int nSlot; /* Number of entries aSlot[] */ int iWrite; /* Push the next value into this entry in aSlot[] */ int iRead; /* Read the next value from this entry in aSlot[] */ FifoPage *pNext; /* Next page in the fifo */ i64 aSlot[1]; /* One or more slots for rowid values */ }; /* ** The Fifo structure is typedef-ed in vdbeInt.h. But the implementation ** of that structure is private to this file. ** ** The Fifo structure describes the entire fifo. */ typedef struct Fifo Fifo; struct Fifo { int nEntry; /* Total number of entries */ FifoPage *pFirst; /* First page on the list */ FifoPage *pLast; /* Last page on the list */ }; /* ** A Context stores the last insert rowid, the last statement change count, ** and the current statement change count (i.e. changes since last statement). ** The current keylist is also stored in the context. ** Elements of Context structure type make up the ContextStack, which is ** updated by the ContextPush and ContextPop opcodes (used by triggers). ** The context is pushed before executing a trigger a popped when the ** trigger finishes. */ typedef struct Context Context; struct Context { int lastRowid; /* Last insert rowid (sqlite3.lastRowid) */ int nChange; /* Statement changes (Vdbe.nChanges) */ Fifo sFifo; /* Records that will participate in a DELETE or UPDATE */ }; /* ** 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_compile() ** is really a pointer to an instance of this structure. */ struct Vdbe { sqlite3 *db; /* The whole database */ Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */ FILE *trace; /* Write an execution trace here, if not NULL */ int nOp; /* Number of instructions in the program */ int nOpAlloc; /* Number of slots allocated for aOp[] */ Op *aOp; /* Space to hold the virtual machine's program */ int nLabel; /* Number of labels used */ int nLabelAlloc; /* Number of slots allocated in aLabel[] */ int *aLabel; /* Space to hold the labels */ Mem *aStack; /* The operand stack, except string values */ Mem *pTos; /* Top entry in the operand stack */ Mem **apArg; /* Arguments to currently executing user function */ Mem *aColName; /* Column names to return */ int nCursor; /* Number of slots in apCsr[] */ Cursor **apCsr; /* One element of this array for each open cursor */ int nVar; /* Number of entries in aVar[] */ Mem *aVar; /* Values for the OP_Variable opcode. */ char **azVar; /* Name of variables */ int okVar; /* True if azVar[] has been initialized */ int magic; /* Magic number for sanity checking */ int nMem; /* Number of memory locations currently allocated */ Mem *aMem; /* The memory locations */ int nCallback; /* Number of callbacks invoked so far */ Fifo sFifo; /* A list of ROWIDs */ int contextStackTop; /* Index of top element in the context stack */ int contextStackDepth; /* The size of the "context" stack */ Context *contextStack; /* Stack used by opcodes ContextPush & ContextPop*/ int pc; /* The program counter */ int rc; /* Value to return */ unsigned uniqueCnt; /* Used by OP_MakeRecord when P2!=0 */ int errorAction; /* Recovery action to do in case of an error */ int inTempTrans; /* True if temp database is transactioned */ int returnStack[100]; /* Return address stack for OP_Gosub & OP_Return */ int returnDepth; /* Next unused element in returnStack[] */ int nResColumn; /* Number of columns in one row of the result set */ char **azResColumn; /* Values for one row of result */ int popStack; /* Pop the stack this much on entry to VdbeExec() */ char *zErrMsg; /* Error message written here */ u8 resOnStack; /* True if there are result values on the stack */ u8 explain; /* True if EXPLAIN present on SQL command */ u8 changeCntOn; /* True to update the change-counter */ u8 aborted; /* True if ROLLBACK in another VM causes an abort */ u8 expired; /* True if the VM needs to be recompiled */ int nChange; /* Number of db changes made since last reset */ i64 startTime; /* Time when query started - used for profiling */ }; /* ** 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(Cursor*); void sqliteVdbePopStack(Vdbe*,int); int sqlite3VdbeCursorMoveto(Cursor*); #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE) void sqlite3VdbePrintOp(FILE*, int, Op*); #endif #ifdef SQLITE_DEBUG void sqlite3VdbePrintSql(Vdbe*); #endif int sqlite3VdbeSerialTypeLen(u32); u32 sqlite3VdbeSerialType(Mem*); int sqlite3VdbeSerialPut(unsigned char*, Mem*); int sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*); void sqlite3VdbeDeleteAuxData(VdbeFunc*, int); int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *); int sqlite3VdbeIdxKeyCompare(Cursor*, int , const unsigned char*, int*); int sqlite3VdbeIdxRowid(BtCursor *, i64 *); int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*); int sqlite3VdbeRecordCompare(void*,int,const void*,int, const void*); int sqlite3VdbeIdxRowidLen(int,const u8*); int sqlite3VdbeExec(Vdbe*); int sqlite3VdbeList(Vdbe*); int sqlite3VdbeHalt(Vdbe*); int sqlite3VdbeChangeEncoding(Mem *, int); int sqlite3VdbeMemCopy(Mem*, const Mem*); void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int); int sqlite3VdbeMemMove(Mem*, Mem*); int sqlite3VdbeMemNulTerminate(Mem*); int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*)); void sqlite3VdbeMemSetInt64(Mem*, i64); void sqlite3VdbeMemSetDouble(Mem*, double); void sqlite3VdbeMemSetNull(Mem*); int sqlite3VdbeMemMakeWriteable(Mem*); int sqlite3VdbeMemDynamicify(Mem*); int sqlite3VdbeMemStringify(Mem*, int); i64 sqlite3VdbeIntValue(Mem*); int sqlite3VdbeMemIntegerify(Mem*); double sqlite3VdbeRealValue(Mem*); int sqlite3VdbeMemRealify(Mem*); int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*); void sqlite3VdbeMemRelease(Mem *p); void sqlite3VdbeMemFinalize(Mem*, FuncDef*); #ifndef NDEBUG void sqlite3VdbeMemSanity(Mem*, u8); int sqlite3VdbeOpcodeNoPush(u8); #endif int sqlite3VdbeMemTranslate(Mem*, u8); void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf, int nBuf); int sqlite3VdbeMemHandleBom(Mem *pMem); void sqlite3VdbeFifoInit(Fifo*); int sqlite3VdbeFifoPush(Fifo*, i64); int sqlite3VdbeFifoPop(Fifo*, i64*); void sqlite3VdbeFifoClear(Fifo*);