--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/engine/sqlite/src/vdbemem.cpp Thu Feb 25 14:29:19 2010 +0000
@@ -0,0 +1,1016 @@
+/*
+** 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;
+}