/*
** 2004 May 26
**
** 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 file contains code use to manipulate "Mem" structure. A "Mem"
** stores a single value in the VDBE. Mem is an opaque structure visible
** only within the VDBE. Interface routines refer to a Mem using the
** name sqlite_value
*/
#include "sqliteInt.h"
#include "vdbeInt.h"
#ifdef SQLITE_DEBUG
/*
** Check invariants on a Mem object.
**
** This routine is intended for use inside of assert() statements, like
** this: assert( sqlite3VdbeCheckMemInvariants(pMem) );
*/
int sqlite3VdbeCheckMemInvariants(Mem *p){
/* The MEM_Dyn bit is set if and only if Mem.xDel is a non-NULL destructor
** function for Mem.z
*/
assert( (p->flags & MEM_Dyn)==0 || p->xDel!=0 );
assert( (p->flags & MEM_Dyn)!=0 || p->xDel==0 );
/* If p holds a string or blob, the Mem.z must point to exactly
** one of the following:
**
** (1) Memory in Mem.zMalloc and managed by the Mem object
** (2) Memory to be freed using Mem.xDel
** (3) An ephermal string or blob
** (4) A static string or blob
*/
if( (p->flags & (MEM_Str|MEM_Blob)) && p->z!=0 ){
assert(
((p->z==p->zMalloc)? 1 : 0) +
((p->flags&MEM_Dyn)!=0 ? 1 : 0) +
((p->flags&MEM_Ephem)!=0 ? 1 : 0) +
((p->flags&MEM_Static)!=0 ? 1 : 0) == 1
);
}
return 1;
}
#endif
/*
** If pMem is an object with a valid string representation, this routine
** ensures the internal encoding for the string representation is
** 'desiredEnc', one of SQLITE_UTF8, SQLITE_UTF16LE or SQLITE_UTF16BE.
**
** If pMem is not a string object, or the encoding of the string
** representation is already stored using the requested encoding, then this
** routine is a no-op.
**
** SQLITE_OK is returned if the conversion is successful (or not required).
** SQLITE_NOMEM may be returned if a malloc() fails during conversion
** between formats.
*/
int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
#ifndef SQLITE_OMIT_UTF16
int rc;
#endif
assert( (pMem->flags&MEM_RowSet)==0 );
assert( desiredEnc==SQLITE_UTF8 || desiredEnc==SQLITE_UTF16LE
|| desiredEnc==SQLITE_UTF16BE );
if( !(pMem->flags&MEM_Str) || pMem->enc==desiredEnc ){
return SQLITE_OK;
}
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
#ifdef SQLITE_OMIT_UTF16
return SQLITE_ERROR;
#else
/* MemTranslate() may return SQLITE_OK or SQLITE_NOMEM. If NOMEM is returned,
** then the encoding of the value may not have changed.
*/
rc = sqlite3VdbeMemTranslate(pMem, (u8)desiredEnc);
assert(rc==SQLITE_OK || rc==SQLITE_NOMEM);
assert(rc==SQLITE_OK || pMem->enc!=desiredEnc);
assert(rc==SQLITE_NOMEM || pMem->enc==desiredEnc);
return rc;
#endif
}
/*
** Make sure pMem->z points to a writable allocation of at least
** min(n,32) bytes.
**
** If the bPreserve argument is true, then copy of the content of
** pMem->z into the new allocation. pMem must be either a string or
** blob if bPreserve is true. If bPreserve is false, any prior content
** in pMem->z is discarded.
*/
int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
assert( sqlite3VdbeCheckMemInvariants(pMem) );
assert( (pMem->flags&MEM_RowSet)==0 );
/* If the bPreserve flag is set to true, then the memory cell must already
** contain a valid string or blob value. */
assert( bPreserve==0 || pMem->flags&(MEM_Blob|MEM_Str) );
testcase( bPreserve && pMem->z==0 );
if( pMem->zMalloc==0 || sqlite3DbMallocSize(pMem->db, pMem->zMalloc)<n ){
if( n<32 ) n = 32;
if( bPreserve && pMem->z==pMem->zMalloc ){
pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
bPreserve = 0;
}else{
sqlite3DbFree(pMem->db, pMem->zMalloc);
pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);
}
if( pMem->zMalloc==0 ){
VdbeMemRelease(pMem);
pMem->z = 0;
pMem->flags = MEM_Null;
return SQLITE_NOMEM;
}
}
if( pMem->z && bPreserve && pMem->z!=pMem->zMalloc ){
memcpy(pMem->zMalloc, pMem->z, pMem->n);
}
if( (pMem->flags&MEM_Dyn)!=0 ){
assert( pMem->xDel!=0 && pMem->xDel!=SQLITE_DYNAMIC );
pMem->xDel((void *)(pMem->z));
}
pMem->z = pMem->zMalloc;
pMem->flags &= ~(MEM_Dyn|MEM_Ephem|MEM_Static);
pMem->xDel = 0;
return SQLITE_OK;
}
/*
** Make the given Mem object MEM_Dyn. In other words, make it so
** that any TEXT or BLOB content is stored in memory obtained from
** malloc(). In this way, we know that the memory is safe to be
** overwritten or altered.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemMakeWriteable(Mem *pMem){
int f;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( (pMem->flags&MEM_RowSet)==0 );
ExpandBlob(pMem);
f = pMem->flags;
if( (f&(MEM_Str|MEM_Blob)) && pMem->z!=pMem->zMalloc ){
if( sqlite3VdbeMemGrow(pMem, pMem->n + 2, 1) ){
return SQLITE_NOMEM;
}
pMem->z[pMem->n] = 0;
pMem->z[pMem->n+1] = 0;
pMem->flags |= MEM_Term;
#ifdef SQLITE_DEBUG
pMem->pScopyFrom = 0;
#endif
}
return SQLITE_OK;
}
/*
** If the given Mem* has a zero-filled tail, turn it into an ordinary
** blob stored in dynamically allocated space.
*/
#ifndef SQLITE_OMIT_INCRBLOB
int sqlite3VdbeMemExpandBlob(Mem *pMem){
if( pMem->flags & MEM_Zero ){
int nByte;
assert( pMem->flags&MEM_Blob );
assert( (pMem->flags&MEM_RowSet)==0 );
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
/* Set nByte to the number of bytes required to store the expanded blob. */
nByte = pMem->n + pMem->u.nZero;
if( nByte<=0 ){
nByte = 1;
}
if( sqlite3VdbeMemGrow(pMem, nByte, 1) ){
return SQLITE_NOMEM;
}
memset(&pMem->z[pMem->n], 0, pMem->u.nZero);
pMem->n += pMem->u.nZero;
pMem->flags &= ~(MEM_Zero|MEM_Term);
}
return SQLITE_OK;
}
#endif
/*
** Make sure the given Mem is \u0000 terminated.
*/
int sqlite3VdbeMemNulTerminate(Mem *pMem){
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
if( (pMem->flags & MEM_Term)!=0 || (pMem->flags & MEM_Str)==0 ){
return SQLITE_OK; /* Nothing to do */
}
if( sqlite3VdbeMemGrow(pMem, pMem->n+2, 1) ){
return SQLITE_NOMEM;
}
pMem->z[pMem->n] = 0;
pMem->z[pMem->n+1] = 0;
pMem->flags |= MEM_Term;
return SQLITE_OK;
}
/*
** Add MEM_Str to the set of representations for the given Mem. Numbers
** are converted using sqlite3_snprintf(). Converting a BLOB to a string
** is a no-op.
**
** Existing representations MEM_Int and MEM_Real are *not* invalidated.
**
** A MEM_Null value will never be passed to this function. This function is
** used for converting values to text for returning to the user (i.e. via
** sqlite3_value_text()), or for ensuring that values to be used as btree
** keys are strings. In the former case a NULL pointer is returned the
** user and the later is an internal programming error.
*/
int sqlite3VdbeMemStringify(Mem *pMem, int enc){
int rc = SQLITE_OK;
int fg = pMem->flags;
const int nByte = 32;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( !(fg&MEM_Zero) );
assert( !(fg&(MEM_Str|MEM_Blob)) );
assert( fg&(MEM_Int|MEM_Real) );
assert( (pMem->flags&MEM_RowSet)==0 );
assert( EIGHT_BYTE_ALIGNMENT(pMem) );
if( sqlite3VdbeMemGrow(pMem, nByte, 0) ){
return SQLITE_NOMEM;
}
/* For a Real or Integer, use sqlite3_mprintf() to produce the UTF-8
** string representation of the value. Then, if the required encoding
** is UTF-16le or UTF-16be do a translation.
**
** FIX ME: It would be better if sqlite3_snprintf() could do UTF-16.
*/
if( fg & MEM_Int ){
sqlite3_snprintf(nByte, pMem->z, "%lld", pMem->u.i);
}else{
assert( fg & MEM_Real );
sqlite3_snprintf(nByte, pMem->z, "%!.15g", pMem->r);
}
pMem->n = sqlite3Strlen30(pMem->z);
pMem->enc = SQLITE_UTF8;
pMem->flags |= MEM_Str|MEM_Term;
sqlite3VdbeChangeEncoding(pMem, enc);
return rc;
}
/*
** Memory cell pMem contains the context of an aggregate function.
** This routine calls the finalize method for that function. The
** result of the aggregate is stored back into pMem.
**
** Return SQLITE_ERROR if the finalizer reports an error. SQLITE_OK
** otherwise.
*/
int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
int rc = SQLITE_OK;
if( ALWAYS(pFunc && pFunc->xFinalize) ){
sqlite3_context ctx;
assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef );
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
memset(&ctx, 0, sizeof(ctx));
ctx.s.flags = MEM_Null;
ctx.s.db = pMem->db;
ctx.pMem = pMem;
ctx.pFunc = pFunc;
pFunc->xFinalize(&ctx); /* IMP: R-24505-23230 */
assert( 0==(pMem->flags&MEM_Dyn) && !pMem->xDel );
sqlite3DbFree(pMem->db, pMem->zMalloc);
memcpy(pMem, &ctx.s, sizeof(ctx.s));
rc = ctx.isError;
}
return rc;
}
/*
** If the memory cell contains a string value that must be freed by
** invoking an external callback, free it now. Calling this function
** does not free any Mem.zMalloc buffer.
*/
void sqlite3VdbeMemReleaseExternal(Mem *p){
assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
if( p->flags&MEM_Agg ){
sqlite3VdbeMemFinalize(p, p->u.pDef);
assert( (p->flags & MEM_Agg)==0 );
sqlite3VdbeMemRelease(p);
}else if( p->flags&MEM_Dyn ){
assert( (p->flags&MEM_RowSet)==0 );
assert( p->xDel!=SQLITE_DYNAMIC && p->xDel!=0 );
p->xDel((void *)p->z);
p->xDel = 0;
}else if( p->flags&MEM_RowSet ){
sqlite3RowSetClear(p->u.pRowSet);
}else if( p->flags&MEM_Frame ){
sqlite3VdbeMemSetNull(p);
}
}
/*
** Release any memory held by the Mem. This may leave the Mem in an
** inconsistent state, for example with (Mem.z==0) and
** (Mem.flags==MEM_Str).
*/
void sqlite3VdbeMemRelease(Mem *p){
assert( sqlite3VdbeCheckMemInvariants(p) );
VdbeMemRelease(p);
if( p->zMalloc ){
sqlite3DbFree(p->db, p->zMalloc);
p->zMalloc = 0;
}
p->z = 0;
assert( p->xDel==0 ); /* Zeroed by VdbeMemRelease() above */
}
/*
** Convert a 64-bit IEEE double into a 64-bit signed integer.
** If the double is out of range of a 64-bit signed integer then
** return the closest available 64-bit signed integer.
*/
static i64 doubleToInt64(double r){
#ifdef SQLITE_OMIT_FLOATING_POINT
/* When floating-point is omitted, double and int64 are the same thing */
return r;
#else
/*
** Many compilers we encounter do not define constants for the
** minimum and maximum 64-bit integers, or they define them
** inconsistently. And many do not understand the "LL" notation.
** So we define our own static constants here using nothing
** larger than a 32-bit integer constant.
*/
static const i64 maxInt = LARGEST_INT64;
static const i64 minInt = SMALLEST_INT64;
if( r<=(double)minInt ){
return minInt;
}else if( r>=(double)maxInt ){
return maxInt;
}else{
return (i64)r;
}
#endif
}
/*
** Return some kind of integer value which is the best we can do
** at representing the value that *pMem describes as an integer.
** If pMem is an integer, then the value is exact. If pMem is
** a floating-point then the value returned is the integer part.
** If pMem is a string or blob, then we make an attempt to convert
** it into a integer and return that. If pMem represents an
** an SQL-NULL value, return 0.
**
** If pMem represents a string value, its encoding might be changed.
*/
i64 sqlite3VdbeIntValue(Mem *pMem){
int flags;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( EIGHT_BYTE_ALIGNMENT(pMem) );
flags = pMem->flags;
if( flags & MEM_Int ){
return pMem->u.i;
}else if( flags & MEM_Real ){
return doubleToInt64(pMem->r);
}else if( flags & (MEM_Str|MEM_Blob) ){
i64 value = 0;
assert( pMem->z || pMem->n==0 );
testcase( pMem->z==0 );
sqlite3Atoi64(pMem->z, &value, pMem->n, pMem->enc);
return value;
}else{
return 0;
}
}
/*
** Return the best representation of pMem that we can get into a
** double. If pMem is already a double or an integer, return its
** value. If it is a string or blob, try to convert it to a double.
** If it is a NULL, return 0.0.
*/
double sqlite3VdbeRealValue(Mem *pMem){
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( EIGHT_BYTE_ALIGNMENT(pMem) );
if( pMem->flags & MEM_Real ){
return pMem->r;
}else if( pMem->flags & MEM_Int ){
return (double)pMem->u.i;
}else if( pMem->flags & (MEM_Str|MEM_Blob) ){
/* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
double val = (double)0;
sqlite3AtoF(pMem->z, &val, pMem->n, pMem->enc);
return val;
}else{
/* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
return (double)0;
}
}
/*
** The MEM structure is already a MEM_Real. Try to also make it a
** MEM_Int if we can.
*/
void sqlite3VdbeIntegerAffinity(Mem *pMem){
assert( pMem->flags & MEM_Real );
assert( (pMem->flags & MEM_RowSet)==0 );
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( EIGHT_BYTE_ALIGNMENT(pMem) );
pMem->u.i = doubleToInt64(pMem->r);
/* Only mark the value as an integer if
**
** (1) the round-trip conversion real->int->real is a no-op, and
** (2) The integer is neither the largest nor the smallest
** possible integer (ticket #3922)
**
** The second and third terms in the following conditional enforces
** the second condition under the assumption that addition overflow causes
** values to wrap around.
*/
if( pMem->r==(double)pMem->u.i
&& pMem->u.i>SMALLEST_INT64
&& pMem->u.i<LARGEST_INT64
){
pMem->flags |= MEM_Int;
}
}
/*
** Convert pMem to type integer. Invalidate any prior representations.
*/
int sqlite3VdbeMemIntegerify(Mem *pMem){
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( (pMem->flags & MEM_RowSet)==0 );
assert( EIGHT_BYTE_ALIGNMENT(pMem) );
pMem->u.i = sqlite3VdbeIntValue(pMem);
MemSetTypeFlag(pMem, MEM_Int);
return SQLITE_OK;
}
/*
** Convert pMem so that it is of type MEM_Real.
** Invalidate any prior representations.
*/
int sqlite3VdbeMemRealify(Mem *pMem){
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( EIGHT_BYTE_ALIGNMENT(pMem) );
pMem->r = sqlite3VdbeRealValue(pMem);
MemSetTypeFlag(pMem, MEM_Real);
return SQLITE_OK;
}
/*
** Convert pMem so that it has types MEM_Real or MEM_Int or both.
** Invalidate any prior representations.
**
** Every effort is made to force the conversion, even if the input
** is a string that does not look completely like a number. Convert
** as much of the string as we can and ignore the rest.
*/
int sqlite3VdbeMemNumerify(Mem *pMem){
if( (pMem->flags & (MEM_Int|MEM_Real|MEM_Null))==0 ){
assert( (pMem->flags & (MEM_Blob|MEM_Str))!=0 );
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
if( 0==sqlite3Atoi64(pMem->z, &pMem->u.i, pMem->n, pMem->enc) ){
MemSetTypeFlag(pMem, MEM_Int);
}else{
pMem->r = sqlite3VdbeRealValue(pMem);
MemSetTypeFlag(pMem, MEM_Real);
sqlite3VdbeIntegerAffinity(pMem);
}
}
assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_Null))!=0 );
pMem->flags &= ~(MEM_Str|MEM_Blob);
return SQLITE_OK;
}
/*
** Delete any previous value and set the value stored in *pMem to NULL.
*/
void sqlite3VdbeMemSetNull(Mem *pMem){
if( pMem->flags & MEM_Frame ){
VdbeFrame *pFrame = pMem->u.pFrame;
pFrame->pParent = pFrame->v->pDelFrame;
pFrame->v->pDelFrame = pFrame;
}
if( pMem->flags & MEM_RowSet ){
sqlite3RowSetClear(pMem->u.pRowSet);
}
MemSetTypeFlag(pMem, MEM_Null);
}
void sqlite3ValueSetNull(sqlite3_value *p){
sqlite3VdbeMemSetNull((Mem*)p);
}
/*
** Delete any previous value and set the value to be a BLOB of length
** n containing all zeros.
*/
void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){
sqlite3VdbeMemRelease(pMem);
pMem->flags = MEM_Blob|MEM_Zero;
pMem->n = 0;
if( n<0 ) n = 0;
pMem->u.nZero = n;
pMem->enc = SQLITE_UTF8;
#ifdef SQLITE_OMIT_INCRBLOB
sqlite3VdbeMemGrow(pMem, n, 0);
if( pMem->z ){
pMem->n = n;
memset(pMem->z, 0, n);
}
#endif
}
/*
** Delete any previous value and set the value stored in *pMem to val,
** manifest type INTEGER.
*/
void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){
sqlite3VdbeMemRelease(pMem);
pMem->u.i = val;
pMem->flags = MEM_Int;
}
#ifndef SQLITE_OMIT_FLOATING_POINT
/*
** Delete any previous value and set the value stored in *pMem to val,
** manifest type REAL.
*/
void sqlite3VdbeMemSetDouble(Mem *pMem, double val){
if( sqlite3IsNaN(val) ){
sqlite3VdbeMemSetNull(pMem);
}else{
sqlite3VdbeMemRelease(pMem);
pMem->r = val;
pMem->flags = MEM_Real;
}
}
#endif
/*
** Delete any previous value and set the value of pMem to be an
** empty boolean index.
*/
void sqlite3VdbeMemSetRowSet(Mem *pMem){
sqlite3 *db = pMem->db;
assert( db!=0 );
assert( (pMem->flags & MEM_RowSet)==0 );
sqlite3VdbeMemRelease(pMem);
pMem->zMalloc = sqlite3DbMallocRaw(db, 64);
if( db->mallocFailed ){
pMem->flags = MEM_Null;
}else{
assert( pMem->zMalloc );
pMem->u.pRowSet = sqlite3RowSetInit(db, pMem->zMalloc,
sqlite3DbMallocSize(db, pMem->zMalloc));
assert( pMem->u.pRowSet!=0 );
pMem->flags = MEM_RowSet;
}
}
/*
** Return true if the Mem object contains a TEXT or BLOB that is
** too large - whose size exceeds SQLITE_MAX_LENGTH.
*/
int sqlite3VdbeMemTooBig(Mem *p){
assert( p->db!=0 );
if( p->flags & (MEM_Str|MEM_Blob) ){
int n = p->n;
if( p->flags & MEM_Zero ){
n += p->u.nZero;
}
return n>p->db->aLimit[SQLITE_LIMIT_LENGTH];
}
return 0;
}
#ifdef SQLITE_DEBUG
/*
** This routine prepares a memory cell for modication by breaking
** its link to a shallow copy and by marking any current shallow
** copies of this cell as invalid.
**
** This is used for testing and debugging only - to make sure shallow
** copies are not misused.
*/
void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
int i;
Mem *pX;
for(i=1, pX=&pVdbe->aMem[1]; i<=pVdbe->nMem; i++, pX++){
if( pX->pScopyFrom==pMem ){
pX->flags |= MEM_Undefined;
pX->pScopyFrom = 0;
}
}
pMem->pScopyFrom = 0;
}
#endif /* SQLITE_DEBUG */
/*
** Size of struct Mem not including the Mem.zMalloc member.
*/
#define MEMCELLSIZE offsetof(Mem,zMalloc)
/*
** Make an shallow copy of pFrom into pTo. Prior contents of
** pTo are freed. The pFrom->z field is not duplicated. If
** pFrom->z is used, then pTo->z points to the same thing as pFrom->z
** and flags gets srcType (either MEM_Ephem or MEM_Static).
*/
void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
assert( (pFrom->flags & MEM_RowSet)==0 );
VdbeMemRelease(pTo);
memcpy(pTo, pFrom, MEMCELLSIZE);
pTo->xDel = 0;
if( (pFrom->flags&MEM_Static)==0 ){
pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
assert( srcType==MEM_Ephem || srcType==MEM_Static );
pTo->flags |= srcType;
}
}
/*
** Make a full copy of pFrom into pTo. Prior contents of pTo are
** freed before the copy is made.
*/
int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
int rc = SQLITE_OK;
assert( (pFrom->flags & MEM_RowSet)==0 );
VdbeMemRelease(pTo);
memcpy(pTo, pFrom, MEMCELLSIZE);
pTo->flags &= ~MEM_Dyn;
pTo->xDel = 0;
if( pTo->flags&(MEM_Str|MEM_Blob) ){
if( 0==(pFrom->flags&MEM_Static) ){
pTo->flags |= MEM_Ephem;
rc = sqlite3VdbeMemMakeWriteable(pTo);
}
}
return rc;
}
/*
** Transfer the contents of pFrom to pTo. Any existing value in pTo is
** freed. If pFrom contains ephemeral data, a copy is made.
**
** pFrom contains an SQL NULL when this routine returns.
*/
void sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){
assert( pFrom->db==0 || sqlite3_mutex_held(pFrom->db->mutex) );
assert( pTo->db==0 || sqlite3_mutex_held(pTo->db->mutex) );
assert( pFrom->db==0 || pTo->db==0 || pFrom->db==pTo->db );
sqlite3VdbeMemRelease(pTo);
memcpy(pTo, pFrom, sizeof(Mem));
pFrom->flags = MEM_Null;
pFrom->xDel = 0;
pFrom->zMalloc = 0;
}
/*
** Change the value of a Mem to be a string or a BLOB.
**
** The memory management strategy depends on the value of the xDel
** parameter. If the value passed is SQLITE_TRANSIENT, then the
** string is copied into a (possibly existing) buffer managed by the
** Mem structure. Otherwise, any existing buffer is freed and the
** pointer copied.
**
** If the string is too large (if it exceeds the SQLITE_LIMIT_LENGTH
** size limit) then no memory allocation occurs. If the string can be
** stored without allocating memory, then it is. If a memory allocation
** is required to store the string, then value of pMem is unchanged. In
** either case, SQLITE_TOOBIG is returned.
*/
int sqlite3VdbeMemSetStr(
Mem *pMem, /* Memory cell to set to string value */
const char *z, /* String pointer */
int n, /* Bytes in string, or negative */
u8 enc, /* Encoding of z. 0 for BLOBs */
void (*xDel)(void*) /* Destructor function */
){
int nByte = n; /* New value for pMem->n */
int iLimit; /* Maximum allowed string or blob size */
u16 flags = 0; /* New value for pMem->flags */
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
assert( (pMem->flags & MEM_RowSet)==0 );
/* If z is a NULL pointer, set pMem to contain an SQL NULL. */
if( !z ){
sqlite3VdbeMemSetNull(pMem);
return SQLITE_OK;
}
if( pMem->db ){
iLimit = pMem->db->aLimit[SQLITE_LIMIT_LENGTH];
}else{
iLimit = SQLITE_MAX_LENGTH;
}
flags = (enc==0?MEM_Blob:MEM_Str);
if( nByte<0 ){
assert( enc!=0 );
if( enc==SQLITE_UTF8 ){
for(nByte=0; nByte<=iLimit && z[nByte]; nByte++){}
}else{
for(nByte=0; nByte<=iLimit && (z[nByte] | z[nByte+1]); nByte+=2){}
}
flags |= MEM_Term;
}
/* The following block sets the new values of Mem.z and Mem.xDel. It
** also sets a flag in local variable "flags" to indicate the memory
** management (one of MEM_Dyn or MEM_Static).
*/
if( xDel==SQLITE_TRANSIENT ){
int nAlloc = nByte;
if( flags&MEM_Term ){
nAlloc += (enc==SQLITE_UTF8?1:2);
}
if( nByte>iLimit ){
return SQLITE_TOOBIG;
}
if( sqlite3VdbeMemGrow(pMem, nAlloc, 0) ){
return SQLITE_NOMEM;
}
memcpy(pMem->z, z, nAlloc);
}else if( xDel==SQLITE_DYNAMIC ){
sqlite3VdbeMemRelease(pMem);
pMem->zMalloc = pMem->z = (char *)z;
pMem->xDel = 0;
}else{
sqlite3VdbeMemRelease(pMem);
pMem->z = (char *)z;
pMem->xDel = xDel;
flags |= ((xDel==SQLITE_STATIC)?MEM_Static:MEM_Dyn);
}
pMem->n = nByte;
pMem->flags = flags;
pMem->enc = (enc==0 ? SQLITE_UTF8 : enc);
#ifndef SQLITE_OMIT_UTF16
if( pMem->enc!=SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){
return SQLITE_NOMEM;
}
#endif
if( nByte>iLimit ){
return SQLITE_TOOBIG;
}
return SQLITE_OK;
}
/*
** Move data out of a btree key or data field and into a Mem structure.
** The data or key is taken from the entry that pCur is currently pointing
** to. offset and amt determine what portion of the data or key to retrieve.
** key is true to get the key or false to get data. The result is written
** into the pMem element.
**
** The pMem structure is assumed to be uninitialized. Any prior content
** is overwritten without being freed.
**
** If this routine fails for any reason (malloc returns NULL or unable
** to read from the disk) then the pMem is left in an inconsistent state.
*/
int sqlite3VdbeMemFromBtree(
BtCursor *pCur, /* Cursor pointing at record to retrieve. */
u32 offset, /* Offset from the start of data to return bytes from. */
u32 amt, /* Number of bytes to return. */
int key, /* If true, retrieve from the btree key, not data. */
Mem *pMem /* OUT: Return data in this Mem structure. */
){
char *zData; /* Data from the btree layer */
u32 available = 0; /* Number of bytes available on the local btree page */
int rc = SQLITE_OK; /* Return code */
assert( sqlite3BtreeCursorIsValid(pCur) );
/* Note: the calls to BtreeKeyFetch() and DataFetch() below assert()
** that both the BtShared and database handle mutexes are held. */
assert( (pMem->flags & MEM_RowSet)==0 );
if( key ){
zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
}else{
zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
}
assert( zData!=0 );
if( offset+amt<=available ){
sqlite3VdbeMemRelease(pMem);
pMem->z = &zData[offset];
pMem->flags = MEM_Blob|MEM_Ephem;
pMem->n = (int)amt;
}else if( SQLITE_OK==(rc = sqlite3VdbeMemGrow(pMem, amt+2, 0)) ){
if( key ){
rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
}else{
rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
}
if( rc==SQLITE_OK ){
pMem->z[amt] = 0;
pMem->z[amt+1] = 0;
pMem->flags = MEM_Blob|MEM_Term;
pMem->n = (int)amt;
}else{
sqlite3VdbeMemRelease(pMem);
}
}
return rc;
}
/* This function is only available internally, it is not part of the
** external API. It works in a similar way to sqlite3_value_text(),
** except the data returned is in the encoding specified by the second
** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or
** SQLITE_UTF8.
**
** (2006-02-16:) The enc value can be or-ed with SQLITE_UTF16_ALIGNED.
** If that is the case, then the result must be aligned on an even byte
** boundary.
*/
const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
if( !pVal ) return 0;
assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
assert( (pVal->flags & MEM_RowSet)==0 );
if( pVal->flags&MEM_Null ){
return 0;
}
assert( (MEM_Blob>>3) == MEM_Str );
pVal->flags |= (pVal->flags & MEM_Blob)>>3;
ExpandBlob(pVal);
if( pVal->flags&MEM_Str ){
sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&SQLITE_PTR_TO_INT(pVal->z)) ){
assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );
if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){
return 0;
}
}
sqlite3VdbeMemNulTerminate(pVal); /* IMP: R-31275-44060 */
}else{
assert( (pVal->flags&MEM_Blob)==0 );
sqlite3VdbeMemStringify(pVal, enc);
assert( 0==(1&SQLITE_PTR_TO_INT(pVal->z)) );
}
assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || pVal->db==0
|| pVal->db->mallocFailed );
if( pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) ){
return pVal->z;
}else{
return 0;
}
}
/*
** Create a new sqlite3_value object.
*/
sqlite3_value *sqlite3ValueNew(sqlite3 *db){
Mem *p = sqlite3DbMallocZero(db, sizeof(*p));
if( p ){
p->flags = MEM_Null;
p->db = db;
}
return p;
}
/*
** Context object passed by sqlite3Stat4ProbeSetValue() through to
** valueNew(). See comments above valueNew() for details.
*/
struct ValueNewStat4Ctx {
Parse *pParse;
Index *pIdx;
UnpackedRecord **ppRec;
int iVal;
};
/*
** Allocate and return a pointer to a new sqlite3_value object. If
** the second argument to this function is NULL, the object is allocated
** by calling sqlite3ValueNew().
**
** Otherwise, if the second argument is non-zero, then this function is
** being called indirectly by sqlite3Stat4ProbeSetValue(). If it has not
** already been allocated, allocate the UnpackedRecord structure that
** that function will return to its caller here. Then return a pointer
** an sqlite3_value within the UnpackedRecord.a[] array.
*/
static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
if( p ){
UnpackedRecord *pRec = p->ppRec[0];
if( pRec==0 ){
Index *pIdx = p->pIdx; /* Index being probed */
int nByte; /* Bytes of space to allocate */
int i; /* Counter variable */
int nCol = pIdx->nColumn; /* Number of index columns including rowid */
nByte = sizeof(Mem) * nCol + ROUND8(sizeof(UnpackedRecord));
pRec = (UnpackedRecord*)sqlite3DbMallocZero(db, nByte);
if( pRec ){
pRec->pKeyInfo = sqlite3KeyInfoOfIndex(p->pParse, pIdx);
if( pRec->pKeyInfo ){
assert( pRec->pKeyInfo->nField+pRec->pKeyInfo->nXField==nCol );
assert( pRec->pKeyInfo->enc==ENC(db) );
pRec->aMem = (Mem *)((u8*)pRec + ROUND8(sizeof(UnpackedRecord)));
for(i=0; i<nCol; i++){
pRec->aMem[i].flags = MEM_Null;
pRec->aMem[i].db = db;
}
}else{
sqlite3DbFree(db, pRec);
pRec = 0;
}
}
if( pRec==0 ) return 0;
p->ppRec[0] = pRec;
}
pRec->nField = p->iVal+1;
return &pRec->aMem[p->iVal];
}
#else
UNUSED_PARAMETER(p);
#endif /* defined(SQLITE_ENABLE_STAT3_OR_STAT4) */
return sqlite3ValueNew(db);
}
/*
** Extract a value from the supplied expression in the manner described
** above sqlite3ValueFromExpr(). Allocate the sqlite3_value object
** using valueNew().
**
** If pCtx is NULL and an error occurs after the sqlite3_value object
** has been allocated, it is freed before returning. Or, if pCtx is not
** NULL, it is assumed that the caller will free any allocated object
** in all cases.
*/
static int valueFromExpr(
sqlite3 *db, /* The database connection */
Expr *pExpr, /* The expression to evaluate */
u8 enc, /* Encoding to use */
u8 affinity, /* Affinity to use */
sqlite3_value **ppVal, /* Write the new value here */
struct ValueNewStat4Ctx *pCtx /* Second argument for valueNew() */
){
int op;
char *zVal = 0;
sqlite3_value *pVal = 0;
int negInt = 1;
const char *zNeg = "";
int rc = SQLITE_OK;
if( !pExpr ){
*ppVal = 0;
return SQLITE_OK;
}
op = pExpr->op;
if( NEVER(op==TK_REGISTER) ) op = pExpr->op2;
/* Handle negative integers in a single step. This is needed in the
** case when the value is -9223372036854775808.
*/
if( op==TK_UMINUS
&& (pExpr->pLeft->op==TK_INTEGER || pExpr->pLeft->op==TK_FLOAT) ){
pExpr = pExpr->pLeft;
op = pExpr->op;
negInt = -1;
zNeg = "-";
}
if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){
pVal = valueNew(db, pCtx);
if( pVal==0 ) goto no_mem;
if( ExprHasProperty(pExpr, EP_IntValue) ){
sqlite3VdbeMemSetInt64(pVal, (i64)pExpr->u.iValue*negInt);
}else{
zVal = sqlite3MPrintf(db, "%s%s", zNeg, pExpr->u.zToken);
if( zVal==0 ) goto no_mem;
sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, SQLITE_DYNAMIC);
}
if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_NONE ){
sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, SQLITE_UTF8);
}else{
sqlite3ValueApplyAffinity(pVal, affinity, SQLITE_UTF8);
}
if( pVal->flags & (MEM_Int|MEM_Real) ) pVal->flags &= ~MEM_Str;
if( enc!=SQLITE_UTF8 ){
rc = sqlite3VdbeChangeEncoding(pVal, enc);
}
}else if( op==TK_UMINUS ) {
/* This branch happens for multiple negative signs. Ex: -(-5) */
if( SQLITE_OK==sqlite3ValueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal)
&& pVal!=0
){
sqlite3VdbeMemNumerify(pVal);
if( pVal->u.i==SMALLEST_INT64 ){
pVal->flags &= ~MEM_Int;
pVal->flags |= MEM_Real;
pVal->r = (double)SMALLEST_INT64;
}else{
pVal->u.i = -pVal->u.i;
}
pVal->r = -pVal->r;
sqlite3ValueApplyAffinity(pVal, affinity, enc);
}
}else if( op==TK_NULL ){
pVal = valueNew(db, pCtx);
if( pVal==0 ) goto no_mem;
}
#ifndef SQLITE_OMIT_BLOB_LITERAL
else if( op==TK_BLOB ){
int nVal;
assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
assert( pExpr->u.zToken[1]=='\'' );
pVal = valueNew(db, pCtx);
if( !pVal ) goto no_mem;
zVal = &pExpr->u.zToken[2];
nVal = sqlite3Strlen30(zVal)-1;
assert( zVal[nVal]=='\'' );
sqlite3VdbeMemSetStr(pVal, sqlite3HexToBlob(db, zVal, nVal), nVal/2,
0, SQLITE_DYNAMIC);
}
#endif
*ppVal = pVal;
return rc;
no_mem:
db->mallocFailed = 1;
sqlite3DbFree(db, zVal);
assert( *ppVal==0 );
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
if( pCtx==0 ) sqlite3ValueFree(pVal);
#else
assert( pCtx==0 ); sqlite3ValueFree(pVal);
#endif
return SQLITE_NOMEM;
}
/*
** Create a new sqlite3_value object, containing the value of pExpr.
**
** This only works for very simple expressions that consist of one constant
** token (i.e. "5", "5.1", "'a string'"). If the expression can
** be converted directly into a value, then the value is allocated and
** a pointer written to *ppVal. The caller is responsible for deallocating
** the value by passing it to sqlite3ValueFree() later on. If the expression
** cannot be converted to a value, then *ppVal is set to NULL.
*/
int sqlite3ValueFromExpr(
sqlite3 *db, /* The database connection */
Expr *pExpr, /* The expression to evaluate */
u8 enc, /* Encoding to use */
u8 affinity, /* Affinity to use */
sqlite3_value **ppVal /* Write the new value here */
){
return valueFromExpr(db, pExpr, enc, affinity, ppVal, 0);
}
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** The implementation of the sqlite_record() function. This function accepts
** a single argument of any type. The return value is a formatted database
** record (a blob) containing the argument value.
**
** This is used to convert the value stored in the 'sample' column of the
** sqlite_stat3 table to the record format SQLite uses internally.
*/
static void recordFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const int file_format = 1;
int iSerial; /* Serial type */
int nSerial; /* Bytes of space for iSerial as varint */
int nVal; /* Bytes of space required for argv[0] */
int nRet;
sqlite3 *db;
u8 *aRet;
UNUSED_PARAMETER( argc );
iSerial = sqlite3VdbeSerialType(argv[0], file_format);
nSerial = sqlite3VarintLen(iSerial);
nVal = sqlite3VdbeSerialTypeLen(iSerial);
db = sqlite3_context_db_handle(context);
nRet = 1 + nSerial + nVal;
aRet = sqlite3DbMallocRaw(db, nRet);
if( aRet==0 ){
sqlite3_result_error_nomem(context);
}else{
aRet[0] = nSerial+1;
sqlite3PutVarint(&aRet[1], iSerial);
sqlite3VdbeSerialPut(&aRet[1+nSerial], argv[0], iSerial);
sqlite3_result_blob(context, aRet, nRet, SQLITE_TRANSIENT);
sqlite3DbFree(db, aRet);
}
}
/*
** Register built-in functions used to help read ANALYZE data.
*/
void sqlite3AnalyzeFunctions(void){
static SQLITE_WSD FuncDef aAnalyzeTableFuncs[] = {
FUNCTION(sqlite_record, 1, 0, 0, recordFunc),
};
int i;
FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aAnalyzeTableFuncs);
for(i=0; i<ArraySize(aAnalyzeTableFuncs); i++){
sqlite3FuncDefInsert(pHash, &aFunc[i]);
}
}
/*
** This function is used to allocate and populate UnpackedRecord
** structures intended to be compared against sample index keys stored
** in the sqlite_stat4 table.
**
** A single call to this function attempts to populates field iVal (leftmost
** is 0 etc.) of the unpacked record with a value extracted from expression
** pExpr. Extraction of values is possible if:
**
** * (pExpr==0). In this case the value is assumed to be an SQL NULL,
**
** * The expression is a bound variable, and this is a reprepare, or
**
** * The sqlite3ValueFromExpr() function is able to extract a value
** from the expression (i.e. the expression is a literal value).
**
** If a value can be extracted, the affinity passed as the 5th argument
** is applied to it before it is copied into the UnpackedRecord. Output
** parameter *pbOk is set to true if a value is extracted, or false
** otherwise.
**
** When this function is called, *ppRec must either point to an object
** allocated by an earlier call to this function, or must be NULL. If it
** is NULL and a value can be successfully extracted, a new UnpackedRecord
** is allocated (and *ppRec set to point to it) before returning.
**
** Unless an error is encountered, SQLITE_OK is returned. It is not an
** error if a value cannot be extracted from pExpr. If an error does
** occur, an SQLite error code is returned.
*/
int sqlite3Stat4ProbeSetValue(
Parse *pParse, /* Parse context */
Index *pIdx, /* Index being probed */
UnpackedRecord **ppRec, /* IN/OUT: Probe record */
Expr *pExpr, /* The expression to extract a value from */
u8 affinity, /* Affinity to use */
int iVal, /* Array element to populate */
int *pbOk /* OUT: True if value was extracted */
){
int rc = SQLITE_OK;
sqlite3_value *pVal = 0;
sqlite3 *db = pParse->db;
struct ValueNewStat4Ctx alloc;
alloc.pParse = pParse;
alloc.pIdx = pIdx;
alloc.ppRec = ppRec;
alloc.iVal = iVal;
/* Skip over any TK_COLLATE nodes */
pExpr = sqlite3ExprSkipCollate(pExpr);
if( !pExpr ){
pVal = valueNew(db, &alloc);
if( pVal ){
sqlite3VdbeMemSetNull((Mem*)pVal);
}
}else if( pExpr->op==TK_VARIABLE
|| NEVER(pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE)
){
Vdbe *v;
int iBindVar = pExpr->iColumn;
sqlite3VdbeSetVarmask(pParse->pVdbe, iBindVar);
if( (v = pParse->pReprepare)!=0 ){
pVal = valueNew(db, &alloc);
if( pVal ){
rc = sqlite3VdbeMemCopy((Mem*)pVal, &v->aVar[iBindVar-1]);
if( rc==SQLITE_OK ){
sqlite3ValueApplyAffinity(pVal, affinity, ENC(db));
}
pVal->db = pParse->db;
}
}
}else{
rc = valueFromExpr(db, pExpr, ENC(db), affinity, &pVal, &alloc);
}
*pbOk = (pVal!=0);
assert( pVal==0 || pVal->db==db );
return rc;
}
/*
** Unless it is NULL, the argument must be an UnpackedRecord object returned
** by an earlier call to sqlite3Stat4ProbeSetValue(). This call deletes
** the object.
*/
void sqlite3Stat4ProbeFree(UnpackedRecord *pRec){
if( pRec ){
int i;
int nCol = pRec->pKeyInfo->nField+pRec->pKeyInfo->nXField;
Mem *aMem = pRec->aMem;
sqlite3 *db = aMem[0].db;
for(i=0; i<nCol; i++){
sqlite3DbFree(db, aMem[i].zMalloc);
}
sqlite3KeyInfoUnref(pRec->pKeyInfo);
sqlite3DbFree(db, pRec);
}
}
#endif /* ifdef SQLITE_ENABLE_STAT4 */
/*
** Change the string value of an sqlite3_value object
*/
void sqlite3ValueSetStr(
sqlite3_value *v, /* Value to be set */
int n, /* Length of string z */
const void *z, /* Text of the new string */
u8 enc, /* Encoding to use */
void (*xDel)(void*) /* Destructor for the string */
){
if( v ) sqlite3VdbeMemSetStr((Mem *)v, z, n, enc, xDel);
}
/*
** Free an sqlite3_value object
*/
void sqlite3ValueFree(sqlite3_value *v){
if( !v ) return;
sqlite3VdbeMemRelease((Mem *)v);
sqlite3DbFree(((Mem*)v)->db, v);
}
/*
** Return the number of bytes in the sqlite3_value object assuming
** that it uses the encoding "enc"
*/
int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
Mem *p = (Mem*)pVal;
if( (p->flags & MEM_Blob)!=0 || sqlite3ValueText(pVal, enc) ){
if( p->flags & MEM_Zero ){
return p->n + p->u.nZero;
}else{
return p->n;
}
}
return 0;
}