/*
** 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 <ctype.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;
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, 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 the given Mem object MEM_Dyn.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemDynamicify(Mem *pMem){
int n;
u8 *z;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
expandBlob(pMem);
if( (pMem->flags & (MEM_Ephem|MEM_Static|MEM_Short))==0 ){
return SQLITE_OK;
}
assert( (pMem->flags & MEM_Dyn)==0 );
n = pMem->n;
assert( pMem->flags & (MEM_Str|MEM_Blob) );
z = (u8*)sqlite3DbMallocRaw(pMem->db, n+2 );
if( z==0 ){
return SQLITE_NOMEM;
}
pMem->flags |= MEM_Dyn|MEM_Term;
pMem->xDel = 0;
memcpy(z, pMem->z, n );
z[n] = 0;
z[n+1] = 0;
pMem->z = (char*)z;
pMem->flags &= ~(MEM_Ephem|MEM_Static|MEM_Short);
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 ){
char *pNew;
int nByte;
assert( (pMem->flags & MEM_Blob)!=0 );
nByte = pMem->n + pMem->u.i;
if( nByte<=0 ) nByte = 1;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
pNew = (char*)sqlite3DbMallocRaw(pMem->db, nByte);
if( pNew==0 ){
return SQLITE_NOMEM;
}
memcpy(pNew, pMem->z, pMem->n);
memset(&pNew[pMem->n], 0, pMem->u.i);
sqlite3VdbeMemRelease(pMem);
pMem->z = pNew;
pMem->n += pMem->u.i;
pMem->u.i = 0;
pMem->flags &= ~(MEM_Zero|MEM_Static|MEM_Ephem|MEM_Short|MEM_Term);
pMem->flags |= MEM_Dyn;
}
return SQLITE_OK;
}
#endif
/*
** Make the given Mem object either MEM_Short or MEM_Dyn so that bytes
** of the Mem.z[] array can be modified.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemMakeWriteable(Mem *pMem){
int n;
u8 *z;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
expandBlob(pMem);
if( (pMem->flags & (MEM_Ephem|MEM_Static))==0 ){
return SQLITE_OK;
}
assert( (pMem->flags & MEM_Dyn)==0 );
assert( pMem->flags & (MEM_Str|MEM_Blob) );
if( (n = pMem->n)+2<sizeof(pMem->zShort) ){
z = (u8*)pMem->zShort;
pMem->flags |= MEM_Short|MEM_Term;
}else{
z = (u8*)sqlite3DbMallocRaw(pMem->db, n+2 );
if( z==0 ){
return SQLITE_NOMEM;
}
pMem->flags |= MEM_Dyn|MEM_Term;
pMem->xDel = 0;
}
memcpy(z, pMem->z, n );
z[n] = 0;
z[n+1] = 0;
pMem->z = (char*)z;
pMem->flags &= ~(MEM_Ephem|MEM_Static);
assert(0==(1&(int)pMem->z));
return SQLITE_OK;
}
/*
** 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( pMem->flags & (MEM_Static|MEM_Ephem) ){
return sqlite3VdbeMemMakeWriteable(pMem);
}else{
char *z;
sqlite3VdbeMemExpandBlob(pMem);
z = (char*)sqlite3DbMallocRaw(pMem->db, pMem->n+2);
if( !z ){
return SQLITE_NOMEM;
}
memcpy(z, pMem->z, pMem->n);
z[pMem->n] = 0;
z[pMem->n+1] = 0;
if( pMem->xDel ){
pMem->xDel(pMem->z);
}else{
sqlite3_free(pMem->z);
}
pMem->xDel = 0;
pMem->z = z;
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;
char *z = pMem->zShort;
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) );
/* For a Real or Integer, use sqlite3_snprintf() 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(NBFS, z, "%lld", pMem->u.i);
}else{
assert( fg & MEM_Real );
sqlite3_snprintf(NBFS, z, "%!.15g", pMem->r);
}
pMem->n = strlen(z);
pMem->z = z;
pMem->enc = SQLITE_UTF8;
pMem->flags |= MEM_Str | MEM_Short | 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( 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) );
ctx.s.flags = MEM_Null;
ctx.s.z = pMem->zShort;
ctx.s.db = pMem->db;
ctx.pMem = pMem;
ctx.pFunc = pFunc;
ctx.isError = 0;
pFunc->xFinalize(&ctx);
if( pMem->z && pMem->z!=pMem->zShort ){
sqlite3_free( pMem->z );
}
*pMem = ctx.s;
if( pMem->flags & MEM_Short ){
pMem->z = pMem->zShort;
}
rc = (ctx.isError?SQLITE_ERROR:SQLITE_OK);
}
return rc;
}
/*
** 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){
assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
if( p->flags & (MEM_Dyn|MEM_Agg) ){
if( p->xDel ){
if( p->flags & MEM_Agg ){
sqlite3VdbeMemFinalize(p, p->u.pDef);
assert( (p->flags & MEM_Agg)==0 );
sqlite3VdbeMemRelease(p);
}else{
p->xDel((void *)p->z);
}
}else{
sqlite3_free(p->z);
}
p->z = 0;
p->xDel = 0;
}
}
/*
** 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 is NULL, return 0.
**
** If pMem is a string, its encoding might be changed.
*/
i64 sqlite3VdbeIntValue(Mem *pMem){
int flags;
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
flags = pMem->flags;
if( flags & MEM_Int ){
return pMem->u.i;
}else if( flags & MEM_Real ){
return (i64)pMem->r;
}else if( flags & (MEM_Str|MEM_Blob) ){
i64 value;
pMem->flags |= MEM_Str;
if( sqlite3VdbeChangeEncoding(pMem, SQLITE_UTF8)
|| sqlite3VdbeMemNulTerminate(pMem) ){
return 0;
}
assert( pMem->z );
sqlite3Atoi64(pMem->z, &value);
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) );
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 val = 0.0;
pMem->flags |= MEM_Str;
if( sqlite3VdbeChangeEncoding(pMem, SQLITE_UTF8)
|| sqlite3VdbeMemNulTerminate(pMem) ){
return 0.0;
}
assert( pMem->z );
sqlite3AtoF(pMem->z, &val);
return val;
}else{
return 0.0;
}
}
/*
** 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->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
pMem->u.i = pMem->r;
if( ((double)pMem->u.i)==pMem->r ){
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) );
pMem->u.i = sqlite3VdbeIntValue(pMem);
sqlite3VdbeMemRelease(pMem);
pMem->flags = 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) );
pMem->r = sqlite3VdbeRealValue(pMem);
sqlite3VdbeMemRelease(pMem);
pMem->flags = MEM_Real;
return SQLITE_OK;
}
/*
** Convert pMem so that it has types MEM_Real or MEM_Int or both.
** Invalidate any prior representations.
*/
int sqlite3VdbeMemNumerify(Mem *pMem){
double r1, r2;
i64 i;
assert( (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) );
r1 = sqlite3VdbeRealValue(pMem);
i = (i64)r1;
r2 = (double)i;
if( r1==r2 ){
sqlite3VdbeMemIntegerify(pMem);
}else{
pMem->r = r1;
pMem->flags = MEM_Real;
sqlite3VdbeMemRelease(pMem);
}
return SQLITE_OK;
}
/*
** Delete any previous value and set the value stored in *pMem to NULL.
*/
void sqlite3VdbeMemSetNull(Mem *pMem){
sqlite3VdbeMemRelease(pMem);
pMem->flags = MEM_Null;
pMem->type = SQLITE_NULL;
pMem->n = 0;
}
/*
** 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|MEM_Short;
pMem->type = SQLITE_BLOB;
pMem->n = 0;
if( n<0 ) n = 0;
pMem->u.i = n;
pMem->z = pMem->zShort;
pMem->enc = SQLITE_UTF8;
}
/*
** 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;
}
/*
** Delete any previous value and set the value stored in *pMem to val,
** manifest type REAL.
*/
void sqlite3VdbeMemSetDouble(Mem *pMem, double val){
if( sqlite3_isnan(val) ){
sqlite3VdbeMemSetNull(pMem);
}else{
sqlite3VdbeMemRelease(pMem);
pMem->r = val;
pMem->flags = MEM_Real;
pMem->type = SQLITE_FLOAT;
}
}
/*
** 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){
if( p->flags & (MEM_Str|MEM_Blob) ){
int n = p->n;
if( p->flags & MEM_Zero ){
n += p->u.i;
}
return n>SQLITE_MAX_LENGTH;
}
return 0;
}
/*
** Make an shallow copy of pFrom into pTo. Prior contents of
** pTo are overwritten. 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){
memcpy(pTo, pFrom, sizeof(*pFrom)-sizeof(pFrom->zShort));
pTo->xDel = 0;
if( pTo->flags & (MEM_Str|MEM_Blob) ){
pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Short|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;
if( pTo->flags & MEM_Dyn ){
sqlite3VdbeMemRelease(pTo);
}
sqlite3VdbeMemShallowCopy(pTo, pFrom, MEM_Ephem);
if( pTo->flags & MEM_Ephem ){
rc = sqlite3VdbeMemMakeWriteable(pTo);
}else{
rc = SQLITE_OK;
}
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. SQLITE_NOMEM
** might be returned if pFrom held ephemeral data and we were unable
** to allocate enough space to make a copy.
*/
int sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){
int rc;
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 );
if( pTo->flags & MEM_Dyn ){
sqlite3VdbeMemRelease(pTo);
}
memcpy(pTo, pFrom, sizeof(Mem));
if( pFrom->flags & MEM_Short ){
pTo->z = pTo->zShort;
}
pFrom->flags = MEM_Null;
pFrom->xDel = 0;
if( pTo->flags & MEM_Ephem ){
rc = sqlite3VdbeMemMakeWriteable(pTo);
}else{
rc = SQLITE_OK;
}
return rc;
}
/*
** Change the value of a Mem to be a string or a BLOB.
*/
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 */
){
assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
sqlite3VdbeMemRelease(pMem);
if( !z ){
pMem->flags = MEM_Null;
pMem->type = SQLITE_NULL;
return SQLITE_OK;
}
pMem->z = (char *)z;
if( xDel==SQLITE_STATIC ){
pMem->flags = MEM_Static;
}else if( xDel==SQLITE_TRANSIENT ){
pMem->flags = MEM_Ephem;
}else{
pMem->flags = MEM_Dyn;
pMem->xDel = xDel;
}
pMem->enc = enc;
pMem->type = enc==0 ? SQLITE_BLOB : SQLITE_TEXT;
pMem->n = n;
assert( enc==0 || enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE
|| enc==SQLITE_UTF16BE );
switch( enc ){
case 0:
pMem->flags |= MEM_Blob;
pMem->enc = SQLITE_UTF8;
break;
case SQLITE_UTF8:
pMem->flags |= MEM_Str;
if( n<0 ){
pMem->n = strlen(z);
pMem->flags |= MEM_Term;
}
break;
#ifndef SQLITE_OMIT_UTF16
case SQLITE_UTF16LE:
case SQLITE_UTF16BE:
pMem->flags |= MEM_Str;
if( pMem->n<0 ){
pMem->n = sqlite3Utf16ByteLen(pMem->z,-1);
pMem->flags |= MEM_Term;
}
if( sqlite3VdbeMemHandleBom(pMem) ){
return SQLITE_NOMEM;
}
#endif /* SQLITE_OMIT_UTF16 */
}
if( pMem->flags&MEM_Ephem ){
return sqlite3VdbeMemMakeWriteable(pMem);
}
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;
/* Interchange pMem1 and pMem2 if the collating sequence specifies
** DESC order.
*/
f1 = pMem1->flags;
f2 = pMem2->flags;
combined_flags = f1|f2;
/* 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 = pMem1->u.i;
}else{
r1 = pMem1->r;
}
if( (f2&MEM_Real)==0 ){
r2 = 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{
u8 origEnc = pMem1->enc;
const void *v1, *v2;
int n1, n2;
/* Convert the strings into the encoding that the comparison
** function expects */
v1 = sqlite3ValueText((sqlite3_value*)pMem1, pColl->enc);
n1 = v1==0 ? 0 : pMem1->n;
assert( n1==sqlite3ValueBytes((sqlite3_value*)pMem1, pColl->enc) );
v2 = sqlite3ValueText((sqlite3_value*)pMem2, pColl->enc);
n2 = v2==0 ? 0 : pMem2->n;
assert( n2==sqlite3ValueBytes((sqlite3_value*)pMem2, pColl->enc) );
/* Do the comparison */
rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
/* Convert the strings back into the database encoding */
sqlite3ValueText((sqlite3_value*)pMem1, origEnc);
sqlite3ValueText((sqlite3_value*)pMem2, origEnc);
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 */
sqlite3 *db; /* Database connection */
db = sqlite3BtreeCursorDb(pCur);
assert( sqlite3_mutex_held(db->mutex) );
if( key ){
zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
}else{
zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
}
assert( zData!=0 );
pMem->db = db;
pMem->n = amt;
if( offset+amt<=available ){
pMem->z = &zData[offset];
pMem->flags = MEM_Blob|MEM_Ephem;
}else{
int rc;
if( amt>NBFS-2 ){
zData = (char *)sqlite3DbMallocRaw(db, amt+2);
if( !zData ){
return SQLITE_NOMEM;
}
pMem->flags = MEM_Blob|MEM_Dyn|MEM_Term;
pMem->xDel = 0;
}else{
zData = &(pMem->zShort[0]);
pMem->flags = MEM_Blob|MEM_Short|MEM_Term;
}
pMem->z = zData;
pMem->enc = 0;
pMem->type = SQLITE_BLOB;
if( key ){
rc = sqlite3BtreeKey(pCur, offset, amt, zData);
}else{
rc = sqlite3BtreeData(pCur, offset, amt, zData);
}
zData[amt] = 0;
zData[amt+1] = 0;
if( rc!=SQLITE_OK ){
if( amt>NBFS-2 ){
assert( zData!=pMem->zShort );
assert( pMem->flags & MEM_Dyn );
sqlite3_free(zData);
} else {
assert( zData==pMem->zShort );
assert( pMem->flags & MEM_Short );
}
return rc;
}
}
return SQLITE_OK;
}
#ifndef NDEBUG
/*
** Perform various checks on the memory cell pMem. An assert() will
** fail if pMem is internally inconsistent.
*/
void sqlite3VdbeMemSanity(Mem *pMem){
int flags = pMem->flags;
assert( flags!=0 ); /* Must define some type */
if( flags & (MEM_Str|MEM_Blob) ){
int x = flags & (MEM_Static|MEM_Dyn|MEM_Ephem|MEM_Short);
assert( x!=0 ); /* Strings must define a string subtype */
assert( (x & (x-1))==0 ); /* Only one string subtype can be defined */
assert( pMem->z!=0 ); /* Strings must have a value */
/* Mem.z points to Mem.zShort iff the subtype is MEM_Short */
assert( (x & MEM_Short)==0 || pMem->z==pMem->zShort );
assert( (x & MEM_Short)!=0 || pMem->z!=pMem->zShort );
/* No destructor unless there is MEM_Dyn */
assert( pMem->xDel==0 || (pMem->flags & MEM_Dyn)!=0 );
if( (flags & MEM_Str) ){
assert( pMem->enc==SQLITE_UTF8 ||
pMem->enc==SQLITE_UTF16BE ||
pMem->enc==SQLITE_UTF16LE
);
/* If the string is UTF-8 encoded and nul terminated, then pMem->n
** must be the length of the string. (Later:) If the database file
** has been corrupted, '\000' characters might have been inserted
** into the middle of the string. In that case, the strlen() might
** be less.
*/
if( pMem->enc==SQLITE_UTF8 && (flags & MEM_Term) ){
assert( strlen(pMem->z)<=pMem->n );
assert( pMem->z[pMem->n]==0 );
}
}
}else{
/* Cannot define a string subtype for non-string objects */
assert( (pMem->flags & (MEM_Static|MEM_Dyn|MEM_Ephem|MEM_Short))==0 );
assert( pMem->xDel==0 );
}
/* MEM_Null excludes all other types */
assert( (pMem->flags&(MEM_Str|MEM_Int|MEM_Real|MEM_Blob))==0
|| (pMem->flags&MEM_Null)==0 );
/* If the MEM is both real and integer, the values are equal */
assert( (pMem->flags & (MEM_Int|MEM_Real))!=(MEM_Int|MEM_Real)
|| pMem->r==pMem->u.i );
}
#endif
/* 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) );
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&(int)pVal->z) ){
assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );
if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){
return 0;
}
}
sqlite3VdbeMemNulTerminate(pVal);
}else{
assert( (pVal->flags&MEM_Blob)==0 );
sqlite3VdbeMemStringify(pVal, enc);
assert( 0==(1&(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 = (Mem*)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", "NULL", "'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;
if( !pExpr ){
*ppVal = 0;
return SQLITE_OK;
}
op = pExpr->op;
if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){
zVal = sqlite3StrNDup((char*)pExpr->token.z, pExpr->token.n);
pVal = sqlite3ValueNew(db);
if( !zVal || !pVal ) goto no_mem;
sqlite3Dequote(zVal);
sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, sqlite3_free);
if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_NONE ){
sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, enc);
}else{
sqlite3ValueApplyAffinity(pVal, affinity, enc);
}
}else if( op==TK_UMINUS ) {
if( SQLITE_OK==sqlite3ValueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal) ){
pVal->u.i = -1 * pVal->u.i;
pVal->r = -1.0 * pVal->r;
}
}
#ifndef SQLITE_OMIT_BLOB_LITERAL
else if( op==TK_BLOB ){
int nVal;
pVal = sqlite3ValueNew(db);
zVal = sqlite3StrNDup((char*)pExpr->token.z+1, pExpr->token.n-1);
if( !zVal || !pVal ) goto no_mem;
sqlite3Dequote(zVal);
nVal = strlen(zVal)/2;
sqlite3VdbeMemSetStr(pVal, (const char*)sqlite3HexToBlob(db, zVal), nVal,0,sqlite3_free);
sqlite3_free(zVal);
}
#endif
*ppVal = pVal;
return SQLITE_OK;
no_mem:
db->mallocFailed = 1;
sqlite3_free(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, (const char*)z, n, enc, xDel);
}
/*
** Free an sqlite3_value object
*/
void sqlite3ValueFree(sqlite3_value *v){
if( !v ) return;
sqlite3ValueSetStr(v, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
sqlite3_free(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.i;
}else{
return p->n;
}
}
return 0;
}