diff options
Diffstat (limited to 'src/vdbemem.c')
| -rw-r--r-- | src/vdbemem.c | 1153 |
1 files changed, 1153 insertions, 0 deletions
diff --git a/src/vdbemem.c b/src/vdbemem.c new file mode 100644 index 0000000..e6e9156 --- /dev/null +++ b/src/vdbemem.c @@ -0,0 +1,1153 @@ +/* +** 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_STAT3. + ** The ifdef here is to enable us to achieve 100% branch test coverage even + ** when SQLITE_ENABLE_STAT3 is omitted. + */ +#ifdef SQLITE_ENABLE_STAT3 + 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; +} |