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Diffstat (limited to 'src/libs/sqlite2/vdbeInt.h')
-rw-r--r-- | src/libs/sqlite2/vdbeInt.h | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/src/libs/sqlite2/vdbeInt.h b/src/libs/sqlite2/vdbeInt.h new file mode 100644 index 00000000..79b6b51a --- /dev/null +++ b/src/libs/sqlite2/vdbeInt.h @@ -0,0 +1,303 @@ +/* +** 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. +*/ + +/* +** When converting from the native format to the key format and back +** again, in addition to changing the byte order we invert the high-order +** bit of the most significant byte. This causes negative numbers to +** sort before positive numbers in the memcmp() function. +*/ +#define keyToInt(X) (sqliteVdbeByteSwap(X) ^ 0x80000000) +#define intToKey(X) (sqliteVdbeByteSwap((X) ^ 0x80000000)) + +/* +** The makefile scans this 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 *sqliteOpcodeNames[]; + +/* +** 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 */ + int lastRecno; /* Last recno from a Next or NextIdx operation */ + int nextRowid; /* Next rowid returned by OP_NewRowid */ + Bool recnoIsValid; /* True if lastRecno is valid */ + Bool keyAsData; /* The OP_Column command works on key instead of data */ + 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 sqliteBtreeMoveto() is needed */ + int movetoTarget; /* Argument to the deferred sqliteBtreeMoveto() */ + Btree *pBt; /* Separate file holding temporary table */ + int nData; /* Number of bytes in pData */ + char *pData; /* Data for a NEW or OLD pseudo-table */ + int iKey; /* Key for the NEW or OLD pseudo-table row */ +}; +typedef struct Cursor Cursor; + +/* +** A sorter builds a list of elements to be sorted. Each element of +** the list is an instance of the following structure. +*/ +typedef struct Sorter Sorter; +struct Sorter { + int nKey; /* Number of bytes in the key */ + char *zKey; /* The key by which we will sort */ + int nData; /* Number of bytes in the data */ + char *pData; /* The data associated with this key */ + Sorter *pNext; /* Next in the list */ +}; + +/* +** Number of buckets used for merge-sort. +*/ +#define NSORT 30 + +/* +** 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 + +/* +** A single level of the stack or a single memory cell +** is an instance of the following structure. +*/ +struct Mem { + int i; /* Integer value */ + int n; /* Number of characters in string value, including '\0' */ + int flags; /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */ + double r; /* Real value */ + char *z; /* String value */ + char zShort[NBFS]; /* Space for short strings */ +}; +typedef struct Mem Mem; + +/* +** Allowed values for Mem.flags +*/ +#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_Dyn 0x0010 /* Need to call sqliteFree() on Mem.z */ +#define MEM_Static 0x0020 /* Mem.z points to a static string */ +#define MEM_Ephem 0x0040 /* Mem.z points to an ephemeral string */ +#define MEM_Short 0x0080 /* Mem.z points to Mem.zShort */ + +/* The following MEM_ value appears only in AggElem.aMem.s.flag fields. +** It indicates that the corresponding AggElem.aMem.z points to a +** aggregate function context that needs to be finalized. +*/ +#define MEM_AggCtx 0x0100 /* Mem.z points to an agg function context */ + +/* +** 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 vdbe.c because it uses substructures +** (Mem) which are only defined there. +*/ +struct sqlite_func { + FuncDef *pFunc; /* Pointer to function information. MUST BE FIRST */ + Mem s; /* The return value is stored here */ + void *pAgg; /* Aggregate context */ + u8 isError; /* Set to true for an error */ + u8 isStep; /* Current in the step function */ + int cnt; /* Number of times that the step function has been called */ +}; + +/* +** An Agg structure describes an Aggregator. Each Agg consists of +** zero or more Aggregator elements (AggElem). Each AggElem contains +** a key and one or more values. The values are used in processing +** aggregate functions in a SELECT. The key is used to implement +** the GROUP BY clause of a select. +*/ +typedef struct Agg Agg; +typedef struct AggElem AggElem; +struct Agg { + int nMem; /* Number of values stored in each AggElem */ + AggElem *pCurrent; /* The AggElem currently in focus */ + HashElem *pSearch; /* The hash element for pCurrent */ + Hash hash; /* Hash table of all aggregate elements */ + FuncDef **apFunc; /* Information about aggregate functions */ +}; +struct AggElem { + char *zKey; /* The key to this AggElem */ + int nKey; /* Number of bytes in the key, including '\0' at end */ + Mem aMem[1]; /* The values for this AggElem */ +}; + +/* +** 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 Keylist is a bunch of keys into a table. The keylist can +** grow without bound. The keylist stores the ROWIDs of database +** records that need to be deleted or updated. +*/ +typedef struct Keylist Keylist; +struct Keylist { + int nKey; /* Number of slots in aKey[] */ + int nUsed; /* Next unwritten slot in aKey[] */ + int nRead; /* Next unread slot in aKey[] */ + Keylist *pNext; /* Next block of keys */ + int aKey[1]; /* One or more keys. Extra space allocated as needed */ +}; + +/* +** A Context stores the last insert rowid, the last statement change count, +** and the current statement change count (i.e. changes since last statement). +** Elements of Context structure type make up the ContextStack, which is +** updated by the ContextPush and ContextPop opcodes (used by triggers) +*/ +typedef struct Context Context; +struct Context { + int lastRowid; /* Last insert rowid (from db->lastRowid) */ + int lsChange; /* Last statement change count (from db->lsChange) */ + int csChange; /* Current statement change count (from db->csChange) */ +}; + +/* +** An instance of the virtual machine. This structure contains the complete +** state of the virtual machine. +** +** The "sqlite_vm" structure pointer that is returned by sqlite_compile() +** is really a pointer to an instance of this structure. +*/ +struct Vdbe { + sqlite *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 */ + char **zArgv; /* Text values used by the callback */ + char **azColName; /* Becomes the 4th parameter to callbacks */ + int nCursor; /* Number of slots in aCsr[] */ + Cursor *aCsr; /* One element of this array for each open cursor */ + Sorter *pSort; /* A linked list of objects to be sorted */ + FILE *pFile; /* At most one open file handler */ + int nField; /* Number of file fields */ + char **azField; /* Data for each file field */ + int nVar; /* Number of entries in azVariable[] */ + char **azVar; /* Values for the OP_Variable opcode */ + int *anVar; /* Length of each value in azVariable[] */ + u8 *abVar; /* TRUE if azVariable[i] needs to be sqliteFree()ed */ + char *zLine; /* A single line from the input file */ + int nLineAlloc; /* Number of spaces allocated for zLine */ + int magic; /* Magic number for sanity checking */ + int nMem; /* Number of memory locations currently allocated */ + Mem *aMem; /* The memory locations */ + Agg agg; /* Aggregate information */ + int nSet; /* Number of sets allocated */ + Set *aSet; /* An array of sets */ + int nCallback; /* Number of callbacks invoked so far */ + Keylist *pList; /* A list of ROWIDs */ + int keylistStackDepth; /* The size of the "keylist" stack */ + Keylist **keylistStack; /* The stack used by opcodes ListPush & ListPop */ + 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 undoTransOnError; /* If error, either ROLLBACK or COMMIT */ + 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 explain; /* True if EXPLAIN present on SQL command */ +}; + +/* +** 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 sqliteVdbeCleanupCursor(Cursor*); +void sqliteVdbeSorterReset(Vdbe*); +void sqliteVdbeAggReset(Agg*); +void sqliteVdbeKeylistFree(Keylist*); +void sqliteVdbePopStack(Vdbe*,int); +int sqliteVdbeCursorMoveto(Cursor*); +int sqliteVdbeByteSwap(int); +#if !defined(NDEBUG) || defined(VDBE_PROFILE) +void sqliteVdbePrintOp(FILE*, int, Op*); +#endif |