/*
** 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"
/*
** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
** P if required.
*/
#define expandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
/*
** 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){
int rc;
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
** n bytes.
**
** If the memory cell currently contains string or blob data
** and the third argument passed to this function is true, the
** current content of the cell is preserved. Otherwise, it may
** be discarded.
**
** This function sets the MEM_Dyn flag and clears any xDel callback.
** It also clears MEM_Ephem and MEM_Static. If the preserve flag is
** not set, Mem.n is zeroed.
*/
int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve){
assert( 1 >=
((pMem->zMalloc && pMem->zMalloc==pMem->z) ? 1 : 0) +
(((pMem->flags&MEM_Dyn)&&pMem->xDel) ? 1 : 0) +
((pMem->flags&MEM_Ephem) ? 1 : 0) +
((pMem->flags&MEM_Static) ? 1 : 0)
);
assert( (pMem->flags&MEM_RowSet)==0 );
if( n<32 ) n = 32;
if( sqlite3DbMallocSize(pMem->db, pMem->zMalloc)<n ){
if( preserve && pMem->z==pMem->zMalloc ){
pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
preserve = 0;
}else{
sqlite3DbFree(pMem->db, pMem->zMalloc);
pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);
}
}
if( pMem->z && preserve && pMem->zMalloc && pMem->z!=pMem->zMalloc ){
memcpy(pMem->zMalloc, pMem->z, pMem->n);
}
if( pMem->flags&MEM_Dyn && pMem->xDel ){
pMem->xDel((void *)(pMem->z));
}
pMem->z = pMem->zMalloc;
if( pMem->z==0 ){
pMem->flags = MEM_Null;
}else{
pMem->flags &= ~(MEM_Ephem|MEM_Static);
}
pMem->xDel = 0;
return (pMem->z ? SQLITE_OK : SQLITE_NOMEM);
}
/*
** 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 && p->xDel ){
assert( (p->flags&MEM_RowSet)==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.type==SQLITE_TEXT).
*/
void sqlite3VdbeMemRelease(Mem *p){
MemReleaseExt(p);
sqlite3DbFree(p->db, p->zMalloc);
p->z = 0;
p->zMalloc = 0;
p->xDel = 0;
}
/*
** Convert a 64-bit IEEE double into a 64-bit signed integer.
** If the double is too large, return 0x8000000000000000.
**
** Most systems appear to do this simply by assigning
** variables and without the extra range tests. But
** there are reports that windows throws an expection
** if the floating point value is out of range. (See ticket #2880.)
** Because we do not completely understand the problem, we will
** take the conservative approach and always do range tests
** before attempting the conversion.
*/
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 ){
/* minInt is correct here - not maxInt. It turns out that assigning
** a very large positive number to an integer results in a very large
** negative integer. This makes no sense, but it is what x86 hardware
** does so for compatibility we will do the same in software. */
return minInt;
}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. On x86 hardware, the third term is always
** true and could be omitted. But we leave it in because other
** architectures might behave differently.
*/
if( pMem->r==(double)pMem->u.i && pMem->u.i>SMALLEST_INT64
&& ALWAYS(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);
pMem->type = SQLITE_NULL;
}
/*
** 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->type = SQLITE_BLOB;
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;
pMem->type = SQLITE_INTEGER;
}
#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;
pMem->type = SQLITE_FLOAT;
}
}
#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 sqlite3VdbeMemPrepareToChange(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_Invalid;
pX->pScopyFrom = 0;
}
}
pMem->pScopyFrom = 0;
}
#endif /* SQLITE_DEBUG */
/*
** Size of struct Mem not including the Mem.zMalloc member.
*/
#define MEMCELLSIZE (size_t)(&(((Mem *)0)->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 );
MemReleaseExt(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 );
MemReleaseExt(pTo);
memcpy(pTo, pFrom, MEMCELLSIZE);
pTo->flags &= ~MEM_Dyn;
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);
pMem->type = (enc==0 ? SQLITE_BLOB : SQLITE_TEXT);
#ifndef SQLITE_OMIT_UTF16
if( pMem->enc!=SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){
return SQLITE_NOMEM;
}
#endif
if( nByte>iLimit ){
return SQLITE_TOOBIG;
}
return SQLITE_OK;
}
/*
** Compare the values contained by the two memory cells, returning
** negative, zero or positive if pMem1 is less than, equal to, or greater
** than pMem2. Sorting order is NULL's first, followed by numbers (integers
** and reals) sorted numerically, followed by text ordered by the collating
** sequence pColl and finally blob's ordered by memcmp().
**
** Two NULL values are considered equal by this function.
*/
int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
int rc;
int f1, f2;
int combined_flags;
f1 = pMem1->flags;
f2 = pMem2->flags;
combined_flags = f1|f2;
assert( (combined_flags & MEM_RowSet)==0 );
/* If one value is NULL, it is less than the other. If both values
** are NULL, return 0.
*/
if( combined_flags&MEM_Null ){
return (f2&MEM_Null) - (f1&MEM_Null);
}
/* If one value is a number and the other is not, the number is less.
** If both are numbers, compare as reals if one is a real, or as integers
** if both values are integers.
*/
if( combined_flags&(MEM_Int|MEM_Real) ){
if( !(f1&(MEM_Int|MEM_Real)) ){
return 1;
}
if( !(f2&(MEM_Int|MEM_Real)) ){
return -1;
}
if( (f1 & f2 & MEM_Int)==0 ){
double r1, r2;
if( (f1&MEM_Real)==0 ){
r1 = (double)pMem1->u.i;
}else{
r1 = pMem1->r;
}
if( (f2&MEM_Real)==0 ){
r2 = (double)pMem2->u.i;
}else{
r2 = pMem2->r;
}
if( r1<r2 ) return -1;
if( r1>r2 ) return 1;
return 0;
}else{
assert( f1&MEM_Int );
assert( f2&MEM_Int );
if( pMem1->u.i < pMem2->u.i ) return -1;
if( pMem1->u.i > pMem2->u.i ) return 1;
return 0;
}
}
/* If one value is a string and the other is a blob, the string is less.
** If both are strings, compare using the collating functions.
*/
if( combined_flags&MEM_Str ){
if( (f1 & MEM_Str)==0 ){
return 1;
}
if( (f2 & MEM_Str)==0 ){
return -1;
}
assert( pMem1->enc==pMem2->enc );
assert( pMem1->enc==SQLITE_UTF8 ||
pMem1->enc==SQLITE_UTF16LE || pMem1->enc==SQLITE_UTF16BE );
/* The collation sequence must be defined at this point, even if
** the user deletes the collation sequence after the vdbe program is
** compiled (this was not always the case).
*/
assert( !pColl || pColl->xCmp );
if( pColl ){
if( pMem1->enc==pColl->enc ){
/* The strings are already in the correct encoding. Call the
** comparison function directly */
return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
}else{
const void *v1, *v2;
int n1, n2;
Mem c1;
Mem c2;
memset(&c1, 0, sizeof(c1));
memset(&c2, 0, sizeof(c2));
sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);
sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);
v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);
n1 = v1==0 ? 0 : c1.n;
v2 = sqlite3ValueText((sqlite3_value*)&c2, pColl->enc);
n2 = v2==0 ? 0 : c2.n;
rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
sqlite3VdbeMemRelease(&c1);
sqlite3VdbeMemRelease(&c2);
return rc;
}
}
/* If a NULL pointer was passed as the collate function, fall through
** to the blob case and use memcmp(). */
}
/* Both values must be blobs. Compare using memcmp(). */
rc = memcmp(pMem1->z, pMem2->z, (pMem1->n>pMem2->n)?pMem2->n:pMem1->n);
if( rc==0 ){
rc = pMem1->n - pMem2->n;
}
return rc;
}
/*
** 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. */
int offset, /* Offset from the start of data to return bytes from. */
int 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 */
int 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 && (pMem->flags&MEM_Dyn)==0 ){
sqlite3VdbeMemRelease(pMem);
pMem->z = &zData[offset];
pMem->flags = MEM_Blob|MEM_Ephem;
}else if( SQLITE_OK==(rc = sqlite3VdbeMemGrow(pMem, amt+2, 0)) ){
pMem->flags = MEM_Blob|MEM_Dyn|MEM_Term;
pMem->enc = 0;
pMem->type = SQLITE_BLOB;
if( key ){
rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
}else{
rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
}
pMem->z[amt] = 0;
pMem->z[amt+1] = 0;
if( rc!=SQLITE_OK ){
sqlite3VdbeMemRelease(pMem);
}
}
pMem->n = amt;
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-59893-45467 */
}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->type = SQLITE_NULL;
p->db = db;
}
return p;
}
/*
** 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 */
){
int op;
char *zVal = 0;
sqlite3_value *pVal = 0;
int negInt = 1;
const char *zNeg = "";
if( !pExpr ){
*ppVal = 0;
return SQLITE_OK;
}
op = pExpr->op;
/* op can only be TK_REGISTER if we have compiled with SQLITE_ENABLE_STAT2.
** The ifdef here is to enable us to achieve 100% branch test coverage even
** when SQLITE_ENABLE_STAT2 is omitted.
*/
#ifdef SQLITE_ENABLE_STAT2
if( op==TK_REGISTER ) op = pExpr->op2;
#else
if( NEVER(op==TK_REGISTER) ) op = pExpr->op2;
#endif
/* 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 = sqlite3ValueNew(db);
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_FLOAT ) pVal->type = SQLITE_FLOAT;
}
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 ){
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) ){
sqlite3VdbeMemNumerify(pVal);
if( pVal->u.i==SMALLEST_INT64 ){
pVal->flags &= MEM_Int;
pVal->flags |= MEM_Real;
pVal->r = (double)LARGEST_INT64;
}else{
pVal->u.i = -pVal->u.i;
}
pVal->r = -pVal->r;
sqlite3ValueApplyAffinity(pVal, affinity, enc);
}
}else if( op==TK_NULL ){
pVal = sqlite3ValueNew(db);
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 = sqlite3ValueNew(db);
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
if( pVal ){
sqlite3VdbeMemStoreType(pVal);
}
*ppVal = pVal;
return SQLITE_OK;
no_mem:
db->mallocFailed = 1;
sqlite3DbFree(db, zVal);
sqlite3ValueFree(pVal);
*ppVal = 0;
return SQLITE_NOMEM;
}
/*
** 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;
}