Files correlati : sqlite Ricompilazione Demo : [ ] Commento : Passaggio da Sqlite 2 a Sqlite 3.3.5 git-svn-id: svn://10.65.10.50/trunk@13902 c028cbd2-c16b-5b4b-a496-9718f37d4682
		
			
				
	
	
		
			393 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			393 lines
		
	
	
		
			17 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
/*
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** 2003 September 6
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**
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** The author disclaims copyright to this source code.  In place of
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** a legal notice, here is a blessing:
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**
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**    May you do good and not evil.
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**    May you find forgiveness for yourself and forgive others.
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**    May you share freely, never taking more than you give.
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**
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*************************************************************************
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** This is the header file for information that is private to the
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** VDBE.  This information used to all be at the top of the single
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** source code file "vdbe.c".  When that file became too big (over
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** 6000 lines long) it was split up into several smaller files and
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** this header information was factored out.
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*/
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/*
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** intToKey() and keyToInt() used to transform the rowid.  But with
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** the latest versions of the design they are no-ops.
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*/
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#define keyToInt(X)   (X)
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#define intToKey(X)   (X)
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/*
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** The makefile scans the vdbe.c source file and creates the following
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** array of string constants which are the names of all VDBE opcodes.  This
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** array is defined in a separate source code file named opcode.c which is
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** automatically generated by the makefile.
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*/
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extern char *sqlite3OpcodeNames[];
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/*
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** SQL is translated into a sequence of instructions to be
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** executed by a virtual machine.  Each instruction is an instance
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** of the following structure.
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*/
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typedef struct VdbeOp Op;
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/*
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** Boolean values
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*/
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typedef unsigned char Bool;
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/*
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** A cursor is a pointer into a single BTree within a database file.
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** The cursor can seek to a BTree entry with a particular key, or
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** loop over all entries of the Btree.  You can also insert new BTree
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** entries or retrieve the key or data from the entry that the cursor
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** is currently pointing to.
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** 
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** Every cursor that the virtual machine has open is represented by an
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** instance of the following structure.
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**
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** If the Cursor.isTriggerRow flag is set it means that this cursor is
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** really a single row that represents the NEW or OLD pseudo-table of
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** a row trigger.  The data for the row is stored in Cursor.pData and
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** the rowid is in Cursor.iKey.
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*/
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struct Cursor {
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  BtCursor *pCursor;    /* The cursor structure of the backend */
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  int iDb;              /* Index of cursor database in db->aDb[] (or -1) */
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  i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */
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  i64 nextRowid;        /* Next rowid returned by OP_NewRowid */
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  Bool zeroed;          /* True if zeroed out and ready for reuse */
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  Bool rowidIsValid;    /* True if lastRowid is valid */
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  Bool atFirst;         /* True if pointing to first entry */
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  Bool useRandomRowid;  /* Generate new record numbers semi-randomly */
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  Bool nullRow;         /* True if pointing to a row with no data */
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  Bool nextRowidValid;  /* True if the nextRowid field is valid */
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  Bool pseudoTable;     /* This is a NEW or OLD pseudo-tables of a trigger */
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  Bool deferredMoveto;  /* A call to sqlite3BtreeMoveto() is needed */
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  Bool isTable;         /* True if a table requiring integer keys */
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  Bool isIndex;         /* True if an index containing keys only - no data */
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  u8 bogusIncrKey;      /* Something for pIncrKey to point to if pKeyInfo==0 */
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  i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
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  Btree *pBt;           /* Separate file holding temporary table */
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  int nData;            /* Number of bytes in pData */
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  char *pData;          /* Data for a NEW or OLD pseudo-table */
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  i64 iKey;             /* Key for the NEW or OLD pseudo-table row */
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  u8 *pIncrKey;         /* Pointer to pKeyInfo->incrKey */
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  KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
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  int nField;           /* Number of fields in the header */
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  i64 seqCount;         /* Sequence counter */
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  /* Cached information about the header for the data record that the
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  ** cursor is currently pointing to.  Only valid if cacheValid is true.
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  ** aRow might point to (ephemeral) data for the current row, or it might
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  ** be NULL.
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  */
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  int cacheStatus;      /* Cache is valid if this matches Vdbe.cacheCtr */
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  int payloadSize;      /* Total number of bytes in the record */
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  u32 *aType;           /* Type values for all entries in the record */
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  u32 *aOffset;         /* Cached offsets to the start of each columns data */
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  u8 *aRow;             /* Data for the current row, if all on one page */
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};
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typedef struct Cursor Cursor;
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/*
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** Number of bytes of string storage space available to each stack
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** layer without having to malloc.  NBFS is short for Number of Bytes
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** For Strings.
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*/
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#define NBFS 32
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/*
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** A value for Cursor.cacheValid that means the cache is always invalid.
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*/
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#define CACHE_STALE 0
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/*
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** Internally, the vdbe manipulates nearly all SQL values as Mem
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** structures. Each Mem struct may cache multiple representations (string,
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** integer etc.) of the same value.  A value (and therefore Mem structure)
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** has the following properties:
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**
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** Each value has a manifest type. The manifest type of the value stored
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** in a Mem struct is returned by the MemType(Mem*) macro. The type is
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** one of SQLITE_NULL, SQLITE_INTEGER, SQLITE_REAL, SQLITE_TEXT or
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** SQLITE_BLOB.
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*/
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struct Mem {
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  i64 i;              /* Integer value. Or FuncDef* when flags==MEM_Agg */
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  double r;           /* Real value */
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  char *z;            /* String or BLOB value */
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  int n;              /* Number of characters in string value, including '\0' */
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  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
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  u8  type;           /* One of MEM_Null, MEM_Str, etc. */
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  u8  enc;            /* TEXT_Utf8, TEXT_Utf16le, or TEXT_Utf16be */
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  void (*xDel)(void *);  /* If not null, call this function to delete Mem.z */
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  char zShort[NBFS];  /* Space for short strings */
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};
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typedef struct Mem Mem;
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/* One or more of the following flags are set to indicate the validOK
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** representations of the value stored in the Mem struct.
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**
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** If the MEM_Null flag is set, then the value is an SQL NULL value.
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** No other flags may be set in this case.
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**
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** If the MEM_Str flag is set then Mem.z points at a string representation.
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** Usually this is encoded in the same unicode encoding as the main
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** database (see below for exceptions). If the MEM_Term flag is also
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** set, then the string is nul terminated. The MEM_Int and MEM_Real 
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** flags may coexist with the MEM_Str flag.
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**
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** Multiple of these values can appear in Mem.flags.  But only one
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** at a time can appear in Mem.type.
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*/
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#define MEM_Null      0x0001   /* Value is NULL */
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#define MEM_Str       0x0002   /* Value is a string */
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#define MEM_Int       0x0004   /* Value is an integer */
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#define MEM_Real      0x0008   /* Value is a real number */
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#define MEM_Blob      0x0010   /* Value is a BLOB */
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/* Whenever Mem contains a valid string or blob representation, one of
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** the following flags must be set to determine the memory management
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** policy for Mem.z.  The MEM_Term flag tells us whether or not the
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** string is \000 or \u0000 terminated
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*/
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#define MEM_Term      0x0020   /* String rep is nul terminated */
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#define MEM_Dyn       0x0040   /* Need to call sqliteFree() on Mem.z */
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#define MEM_Static    0x0080   /* Mem.z points to a static string */
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#define MEM_Ephem     0x0100   /* Mem.z points to an ephemeral string */
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#define MEM_Short     0x0200   /* Mem.z points to Mem.zShort */
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#define MEM_Agg       0x0400   /* Mem.z points to an agg function context */
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/* A VdbeFunc is just a FuncDef (defined in sqliteInt.h) that contains
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** additional information about auxiliary information bound to arguments
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** of the function.  This is used to implement the sqlite3_get_auxdata()
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** and sqlite3_set_auxdata() APIs.  The "auxdata" is some auxiliary data
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** that can be associated with a constant argument to a function.  This
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** allows functions such as "regexp" to compile their constant regular
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** expression argument once and reused the compiled code for multiple
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** invocations.
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*/
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struct VdbeFunc {
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  FuncDef *pFunc;               /* The definition of the function */
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  int nAux;                     /* Number of entries allocated for apAux[] */
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  struct AuxData {
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    void *pAux;                   /* Aux data for the i-th argument */
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    void (*xDelete)(void *);      /* Destructor for the aux data */
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  } apAux[1];                   /* One slot for each function argument */
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};
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typedef struct VdbeFunc VdbeFunc;
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/*
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** The "context" argument for a installable function.  A pointer to an
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** instance of this structure is the first argument to the routines used
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** implement the SQL functions.
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**
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** There is a typedef for this structure in sqlite.h.  So all routines,
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** even the public interface to SQLite, can use a pointer to this structure.
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** But this file is the only place where the internal details of this
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** structure are known.
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**
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** This structure is defined inside of vdbeInt.h because it uses substructures
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** (Mem) which are only defined there.
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*/
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struct sqlite3_context {
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  FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
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  VdbeFunc *pVdbeFunc;  /* Auxilary data, if created. */
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  Mem s;                /* The return value is stored here */
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  Mem *pMem;            /* Memory cell used to store aggregate context */
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  u8 isError;           /* Set to true for an error */
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  CollSeq *pColl;       /* Collating sequence */
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};
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/*
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** A Set structure is used for quick testing to see if a value
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** is part of a small set.  Sets are used to implement code like
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** this:
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**            x.y IN ('hi','hoo','hum')
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*/
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typedef struct Set Set;
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struct Set {
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  Hash hash;             /* A set is just a hash table */
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  HashElem *prev;        /* Previously accessed hash elemen */
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};
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/*
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** A FifoPage structure holds a single page of valves.  Pages are arranged
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** in a list.
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*/
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typedef struct FifoPage FifoPage;
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struct FifoPage {
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  int nSlot;         /* Number of entries aSlot[] */
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  int iWrite;        /* Push the next value into this entry in aSlot[] */
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  int iRead;         /* Read the next value from this entry in aSlot[] */
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  FifoPage *pNext;   /* Next page in the fifo */
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  i64 aSlot[1];      /* One or more slots for rowid values */
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};
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/*
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** The Fifo structure is typedef-ed in vdbeInt.h.  But the implementation
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** of that structure is private to this file.
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**
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** The Fifo structure describes the entire fifo.  
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*/
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typedef struct Fifo Fifo;
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struct Fifo {
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  int nEntry;         /* Total number of entries */
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  FifoPage *pFirst;   /* First page on the list */
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  FifoPage *pLast;    /* Last page on the list */
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};
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/*
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** A Context stores the last insert rowid, the last statement change count,
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** and the current statement change count (i.e. changes since last statement).
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** The current keylist is also stored in the context.
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** Elements of Context structure type make up the ContextStack, which is
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** updated by the ContextPush and ContextPop opcodes (used by triggers).
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** The context is pushed before executing a trigger a popped when the
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** trigger finishes.
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*/
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typedef struct Context Context;
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struct Context {
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  i64 lastRowid;    /* Last insert rowid (sqlite3.lastRowid) */
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  int nChange;      /* Statement changes (Vdbe.nChanges)     */
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  Fifo sFifo;       /* Records that will participate in a DELETE or UPDATE */
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};
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/*
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** An instance of the virtual machine.  This structure contains the complete
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** state of the virtual machine.
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**
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** The "sqlite3_stmt" structure pointer that is returned by sqlite3_compile()
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** is really a pointer to an instance of this structure.
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*/
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struct Vdbe {
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  sqlite3 *db;        /* The whole database */
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  Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */
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  FILE *trace;        /* Write an execution trace here, if not NULL */
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  int nOp;            /* Number of instructions in the program */
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  int nOpAlloc;       /* Number of slots allocated for aOp[] */
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  Op *aOp;            /* Space to hold the virtual machine's program */
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  int nLabel;         /* Number of labels used */
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  int nLabelAlloc;    /* Number of slots allocated in aLabel[] */
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  int *aLabel;        /* Space to hold the labels */
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  Mem *aStack;        /* The operand stack, except string values */
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  Mem *pTos;          /* Top entry in the operand stack */
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  Mem **apArg;        /* Arguments to currently executing user function */
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  Mem *aColName;      /* Column names to return */
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  int nCursor;        /* Number of slots in apCsr[] */
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  Cursor **apCsr;     /* One element of this array for each open cursor */
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  int nVar;           /* Number of entries in aVar[] */
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  Mem *aVar;          /* Values for the OP_Variable opcode. */
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  char **azVar;       /* Name of variables */
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  int okVar;          /* True if azVar[] has been initialized */
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  int magic;              /* Magic number for sanity checking */
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  int nMem;               /* Number of memory locations currently allocated */
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  Mem *aMem;              /* The memory locations */
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  int nCallback;          /* Number of callbacks invoked so far */
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  int cacheCtr;           /* Cursor row cache generation counter */
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  Fifo sFifo;             /* A list of ROWIDs */
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  int contextStackTop;    /* Index of top element in the context stack */
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  int contextStackDepth;  /* The size of the "context" stack */
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  Context *contextStack;  /* Stack used by opcodes ContextPush & ContextPop*/
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  int pc;                 /* The program counter */
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  int rc;                 /* Value to return */
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  unsigned uniqueCnt;     /* Used by OP_MakeRecord when P2!=0 */
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  int errorAction;        /* Recovery action to do in case of an error */
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  int inTempTrans;        /* True if temp database is transactioned */
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  int returnStack[100];   /* Return address stack for OP_Gosub & OP_Return */
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  int returnDepth;        /* Next unused element in returnStack[] */
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  int nResColumn;         /* Number of columns in one row of the result set */
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  char **azResColumn;     /* Values for one row of result */ 
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  int popStack;           /* Pop the stack this much on entry to VdbeExec() */
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  char *zErrMsg;          /* Error message written here */
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  u8 resOnStack;          /* True if there are result values on the stack */
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  u8 explain;             /* True if EXPLAIN present on SQL command */
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  u8 changeCntOn;         /* True to update the change-counter */
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  u8 aborted;             /* True if ROLLBACK in another VM causes an abort */
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  u8 expired;             /* True if the VM needs to be recompiled */
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  u8 minWriteFileFormat;  /* Minimum file format for writable database files */
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  int nChange;            /* Number of db changes made since last reset */
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  i64 startTime;          /* Time when query started - used for profiling */
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#ifdef SQLITE_SSE
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  int fetchId;          /* Statement number used by sqlite3_fetch_statement */
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  int lru;              /* Counter used for LRU cache replacement */
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#endif
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};
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/*
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** The following are allowed values for Vdbe.magic
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*/
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#define VDBE_MAGIC_INIT     0x26bceaa5    /* Building a VDBE program */
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#define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */
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#define VDBE_MAGIC_HALT     0x519c2973    /* VDBE has completed execution */
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#define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */
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/*
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** Function prototypes
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*/
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void sqlite3VdbeFreeCursor(Cursor*);
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void sqliteVdbePopStack(Vdbe*,int);
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int sqlite3VdbeCursorMoveto(Cursor*);
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#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
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void sqlite3VdbePrintOp(FILE*, int, Op*);
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#endif
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#ifdef SQLITE_DEBUG
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void sqlite3VdbePrintSql(Vdbe*);
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#endif
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int sqlite3VdbeSerialTypeLen(u32);
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u32 sqlite3VdbeSerialType(Mem*, int);
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int sqlite3VdbeSerialPut(unsigned char*, Mem*, int);
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int sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
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void sqlite3VdbeDeleteAuxData(VdbeFunc*, int);
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int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
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int sqlite3VdbeIdxKeyCompare(Cursor*, int , const unsigned char*, int*);
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int sqlite3VdbeIdxRowid(BtCursor *, i64 *);
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int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
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int sqlite3VdbeRecordCompare(void*,int,const void*,int, const void*);
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int sqlite3VdbeIdxRowidLen(const u8*);
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int sqlite3VdbeExec(Vdbe*);
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int sqlite3VdbeList(Vdbe*);
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int sqlite3VdbeHalt(Vdbe*);
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int sqlite3VdbeChangeEncoding(Mem *, int);
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int sqlite3VdbeMemCopy(Mem*, const Mem*);
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void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int);
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int sqlite3VdbeMemMove(Mem*, Mem*);
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int sqlite3VdbeMemNulTerminate(Mem*);
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int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*));
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void sqlite3VdbeMemSetInt64(Mem*, i64);
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void sqlite3VdbeMemSetDouble(Mem*, double);
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void sqlite3VdbeMemSetNull(Mem*);
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int sqlite3VdbeMemMakeWriteable(Mem*);
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int sqlite3VdbeMemDynamicify(Mem*);
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int sqlite3VdbeMemStringify(Mem*, int);
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i64 sqlite3VdbeIntValue(Mem*);
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int sqlite3VdbeMemIntegerify(Mem*);
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double sqlite3VdbeRealValue(Mem*);
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void sqlite3VdbeIntegerAffinity(Mem*);
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int sqlite3VdbeMemRealify(Mem*);
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int sqlite3VdbeMemNumerify(Mem*);
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int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
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void sqlite3VdbeMemRelease(Mem *p);
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int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
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#ifndef NDEBUG
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void sqlite3VdbeMemSanity(Mem*);
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int sqlite3VdbeOpcodeNoPush(u8);
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#endif
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int sqlite3VdbeMemTranslate(Mem*, u8);
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void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
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int sqlite3VdbeMemHandleBom(Mem *pMem);
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void sqlite3VdbeFifoInit(Fifo*);
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int sqlite3VdbeFifoPush(Fifo*, i64);
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int sqlite3VdbeFifoPop(Fifo*, i64*);
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void sqlite3VdbeFifoClear(Fifo*);
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