000001 /*
000002 ** 2004 May 26
000003 **
000004 ** The author disclaims copyright to this source code. In place of
000005 ** a legal notice, here is a blessing:
000006 **
000007 ** May you do good and not evil.
000008 ** May you find forgiveness for yourself and forgive others.
000009 ** May you share freely, never taking more than you give.
000010 **
000011 *************************************************************************
000012 **
000013 ** This file contains code use to manipulate "Mem" structure. A "Mem"
000014 ** stores a single value in the VDBE. Mem is an opaque structure visible
000015 ** only within the VDBE. Interface routines refer to a Mem using the
000016 ** name sqlite_value
000017 */
000018 #include "sqliteInt.h"
000019 #include "vdbeInt.h"
000020
000021 /* True if X is a power of two. 0 is considered a power of two here.
000022 ** In other words, return true if X has at most one bit set.
000023 */
000024 #define ISPOWEROF2(X) (((X)&((X)-1))==0)
000025
000026 #ifdef SQLITE_DEBUG
000027 /*
000028 ** Check invariants on a Mem object.
000029 **
000030 ** This routine is intended for use inside of assert() statements, like
000031 ** this: assert( sqlite3VdbeCheckMemInvariants(pMem) );
000032 */
000033 int sqlite3VdbeCheckMemInvariants(Mem *p){
000034 /* If MEM_Dyn is set then Mem.xDel!=0.
000035 ** Mem.xDel might not be initialized if MEM_Dyn is clear.
000036 */
000037 assert( (p->flags & MEM_Dyn)==0 || p->xDel!=0 );
000038
000039 /* MEM_Dyn may only be set if Mem.szMalloc==0. In this way we
000040 ** ensure that if Mem.szMalloc>0 then it is safe to do
000041 ** Mem.z = Mem.zMalloc without having to check Mem.flags&MEM_Dyn.
000042 ** That saves a few cycles in inner loops. */
000043 assert( (p->flags & MEM_Dyn)==0 || p->szMalloc==0 );
000044
000045 /* Cannot have more than one of MEM_Int, MEM_Real, or MEM_IntReal */
000046 assert( ISPOWEROF2(p->flags & (MEM_Int|MEM_Real|MEM_IntReal)) );
000047
000048 if( p->flags & MEM_Null ){
000049 /* Cannot be both MEM_Null and some other type */
000050 assert( (p->flags & (MEM_Int|MEM_Real|MEM_Str|MEM_Blob|MEM_Agg))==0 );
000051
000052 /* If MEM_Null is set, then either the value is a pure NULL (the usual
000053 ** case) or it is a pointer set using sqlite3_bind_pointer() or
000054 ** sqlite3_result_pointer(). If a pointer, then MEM_Term must also be
000055 ** set.
000056 */
000057 if( (p->flags & (MEM_Term|MEM_Subtype))==(MEM_Term|MEM_Subtype) ){
000058 /* This is a pointer type. There may be a flag to indicate what to
000059 ** do with the pointer. */
000060 assert( ((p->flags&MEM_Dyn)!=0 ? 1 : 0) +
000061 ((p->flags&MEM_Ephem)!=0 ? 1 : 0) +
000062 ((p->flags&MEM_Static)!=0 ? 1 : 0) <= 1 );
000063
000064 /* No other bits set */
000065 assert( (p->flags & ~(MEM_Null|MEM_Term|MEM_Subtype|MEM_FromBind
000066 |MEM_Dyn|MEM_Ephem|MEM_Static))==0 );
000067 }else{
000068 /* A pure NULL might have other flags, such as MEM_Static, MEM_Dyn,
000069 ** MEM_Ephem, MEM_Cleared, or MEM_Subtype */
000070 }
000071 }else{
000072 /* The MEM_Cleared bit is only allowed on NULLs */
000073 assert( (p->flags & MEM_Cleared)==0 );
000074 }
000075
000076 /* The szMalloc field holds the correct memory allocation size */
000077 assert( p->szMalloc==0
000078 || (p->flags==MEM_Undefined
000079 && p->szMalloc<=sqlite3DbMallocSize(p->db,p->zMalloc))
000080 || p->szMalloc==sqlite3DbMallocSize(p->db,p->zMalloc));
000081
000082 /* If p holds a string or blob, the Mem.z must point to exactly
000083 ** one of the following:
000084 **
000085 ** (1) Memory in Mem.zMalloc and managed by the Mem object
000086 ** (2) Memory to be freed using Mem.xDel
000087 ** (3) An ephemeral string or blob
000088 ** (4) A static string or blob
000089 */
000090 if( (p->flags & (MEM_Str|MEM_Blob)) && p->n>0 ){
000091 assert(
000092 ((p->szMalloc>0 && p->z==p->zMalloc)? 1 : 0) +
000093 ((p->flags&MEM_Dyn)!=0 ? 1 : 0) +
000094 ((p->flags&MEM_Ephem)!=0 ? 1 : 0) +
000095 ((p->flags&MEM_Static)!=0 ? 1 : 0) == 1
000096 );
000097 }
000098 return 1;
000099 }
000100 #endif
000101
000102 /*
000103 ** Render a Mem object which is one of MEM_Int, MEM_Real, or MEM_IntReal
000104 ** into a buffer.
000105 */
000106 static void vdbeMemRenderNum(int sz, char *zBuf, Mem *p){
000107 StrAccum acc;
000108 assert( p->flags & (MEM_Int|MEM_Real|MEM_IntReal) );
000109 assert( sz>22 );
000110 if( p->flags & MEM_Int ){
000111 #if GCC_VERSION>=7000000
000112 /* Work-around for GCC bug
000113 ** https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96270 */
000114 i64 x;
000115 assert( (p->flags&MEM_Int)*2==sizeof(x) );
000116 memcpy(&x, (char*)&p->u, (p->flags&MEM_Int)*2);
000117 p->n = sqlite3Int64ToText(x, zBuf);
000118 #else
000119 p->n = sqlite3Int64ToText(p->u.i, zBuf);
000120 #endif
000121 }else{
000122 sqlite3StrAccumInit(&acc, 0, zBuf, sz, 0);
000123 sqlite3_str_appendf(&acc, "%!.15g",
000124 (p->flags & MEM_IntReal)!=0 ? (double)p->u.i : p->u.r);
000125 assert( acc.zText==zBuf && acc.mxAlloc<=0 );
000126 zBuf[acc.nChar] = 0; /* Fast version of sqlite3StrAccumFinish(&acc) */
000127 p->n = acc.nChar;
000128 }
000129 }
000130
000131 #ifdef SQLITE_DEBUG
000132 /*
000133 ** Validity checks on pMem. pMem holds a string.
000134 **
000135 ** (1) Check that string value of pMem agrees with its integer or real value.
000136 ** (2) Check that the string is correctly zero terminated
000137 **
000138 ** A single int or real value always converts to the same strings. But
000139 ** many different strings can be converted into the same int or real.
000140 ** If a table contains a numeric value and an index is based on the
000141 ** corresponding string value, then it is important that the string be
000142 ** derived from the numeric value, not the other way around, to ensure
000143 ** that the index and table are consistent. See ticket
000144 ** https://www.sqlite.org/src/info/343634942dd54ab (2018-01-31) for
000145 ** an example.
000146 **
000147 ** This routine looks at pMem to verify that if it has both a numeric
000148 ** representation and a string representation then the string rep has
000149 ** been derived from the numeric and not the other way around. It returns
000150 ** true if everything is ok and false if there is a problem.
000151 **
000152 ** This routine is for use inside of assert() statements only.
000153 */
000154 int sqlite3VdbeMemValidStrRep(Mem *p){
000155 Mem tmp;
000156 char zBuf[100];
000157 char *z;
000158 int i, j, incr;
000159 if( (p->flags & MEM_Str)==0 ) return 1;
000160 if( p->db && p->db->mallocFailed ) return 1;
000161 if( p->flags & MEM_Term ){
000162 /* Insure that the string is properly zero-terminated. Pay particular
000163 ** attention to the case where p->n is odd */
000164 if( p->szMalloc>0 && p->z==p->zMalloc ){
000165 assert( p->enc==SQLITE_UTF8 || p->szMalloc >= ((p->n+1)&~1)+2 );
000166 assert( p->enc!=SQLITE_UTF8 || p->szMalloc >= p->n+1 );
000167 }
000168 assert( p->z[p->n]==0 );
000169 assert( p->enc==SQLITE_UTF8 || p->z[(p->n+1)&~1]==0 );
000170 assert( p->enc==SQLITE_UTF8 || p->z[((p->n+1)&~1)+1]==0 );
000171 }
000172 if( (p->flags & (MEM_Int|MEM_Real|MEM_IntReal))==0 ) return 1;
000173 memcpy(&tmp, p, sizeof(tmp));
000174 vdbeMemRenderNum(sizeof(zBuf), zBuf, &tmp);
000175 z = p->z;
000176 i = j = 0;
000177 incr = 1;
000178 if( p->enc!=SQLITE_UTF8 ){
000179 incr = 2;
000180 if( p->enc==SQLITE_UTF16BE ) z++;
000181 }
000182 while( zBuf[j] ){
000183 if( zBuf[j++]!=z[i] ) return 0;
000184 i += incr;
000185 }
000186 return 1;
000187 }
000188 #endif /* SQLITE_DEBUG */
000189
000190 /*
000191 ** If pMem is an object with a valid string representation, this routine
000192 ** ensures the internal encoding for the string representation is
000193 ** 'desiredEnc', one of SQLITE_UTF8, SQLITE_UTF16LE or SQLITE_UTF16BE.
000194 **
000195 ** If pMem is not a string object, or the encoding of the string
000196 ** representation is already stored using the requested encoding, then this
000197 ** routine is a no-op.
000198 **
000199 ** SQLITE_OK is returned if the conversion is successful (or not required).
000200 ** SQLITE_NOMEM may be returned if a malloc() fails during conversion
000201 ** between formats.
000202 */
000203 int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
000204 #ifndef SQLITE_OMIT_UTF16
000205 int rc;
000206 #endif
000207 assert( pMem!=0 );
000208 assert( !sqlite3VdbeMemIsRowSet(pMem) );
000209 assert( desiredEnc==SQLITE_UTF8 || desiredEnc==SQLITE_UTF16LE
000210 || desiredEnc==SQLITE_UTF16BE );
000211 if( !(pMem->flags&MEM_Str) ){
000212 pMem->enc = desiredEnc;
000213 return SQLITE_OK;
000214 }
000215 if( pMem->enc==desiredEnc ){
000216 return SQLITE_OK;
000217 }
000218 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000219 #ifdef SQLITE_OMIT_UTF16
000220 return SQLITE_ERROR;
000221 #else
000222
000223 /* MemTranslate() may return SQLITE_OK or SQLITE_NOMEM. If NOMEM is returned,
000224 ** then the encoding of the value may not have changed.
000225 */
000226 rc = sqlite3VdbeMemTranslate(pMem, (u8)desiredEnc);
000227 assert(rc==SQLITE_OK || rc==SQLITE_NOMEM);
000228 assert(rc==SQLITE_OK || pMem->enc!=desiredEnc);
000229 assert(rc==SQLITE_NOMEM || pMem->enc==desiredEnc);
000230 return rc;
000231 #endif
000232 }
000233
000234 /*
000235 ** Make sure pMem->z points to a writable allocation of at least n bytes.
000236 **
000237 ** If the bPreserve argument is true, then copy of the content of
000238 ** pMem->z into the new allocation. pMem must be either a string or
000239 ** blob if bPreserve is true. If bPreserve is false, any prior content
000240 ** in pMem->z is discarded.
000241 */
000242 SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
000243 assert( sqlite3VdbeCheckMemInvariants(pMem) );
000244 assert( !sqlite3VdbeMemIsRowSet(pMem) );
000245 testcase( pMem->db==0 );
000246
000247 /* If the bPreserve flag is set to true, then the memory cell must already
000248 ** contain a valid string or blob value. */
000249 assert( bPreserve==0 || pMem->flags&(MEM_Blob|MEM_Str) );
000250 testcase( bPreserve && pMem->z==0 );
000251
000252 assert( pMem->szMalloc==0
000253 || (pMem->flags==MEM_Undefined
000254 && pMem->szMalloc<=sqlite3DbMallocSize(pMem->db,pMem->zMalloc))
000255 || pMem->szMalloc==sqlite3DbMallocSize(pMem->db,pMem->zMalloc));
000256 if( pMem->szMalloc>0 && bPreserve && pMem->z==pMem->zMalloc ){
000257 if( pMem->db ){
000258 pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
000259 }else{
000260 pMem->zMalloc = sqlite3Realloc(pMem->z, n);
000261 if( pMem->zMalloc==0 ) sqlite3_free(pMem->z);
000262 pMem->z = pMem->zMalloc;
000263 }
000264 bPreserve = 0;
000265 }else{
000266 if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc);
000267 pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);
000268 }
000269 if( pMem->zMalloc==0 ){
000270 sqlite3VdbeMemSetNull(pMem);
000271 pMem->z = 0;
000272 pMem->szMalloc = 0;
000273 return SQLITE_NOMEM_BKPT;
000274 }else{
000275 pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);
000276 }
000277
000278 if( bPreserve && pMem->z ){
000279 assert( pMem->z!=pMem->zMalloc );
000280 memcpy(pMem->zMalloc, pMem->z, pMem->n);
000281 }
000282 if( (pMem->flags&MEM_Dyn)!=0 ){
000283 assert( pMem->xDel!=0 && pMem->xDel!=SQLITE_DYNAMIC );
000284 pMem->xDel((void *)(pMem->z));
000285 }
000286
000287 pMem->z = pMem->zMalloc;
000288 pMem->flags &= ~(MEM_Dyn|MEM_Ephem|MEM_Static);
000289 return SQLITE_OK;
000290 }
000291
000292 /*
000293 ** Change the pMem->zMalloc allocation to be at least szNew bytes.
000294 ** If pMem->zMalloc already meets or exceeds the requested size, this
000295 ** routine is a no-op.
000296 **
000297 ** Any prior string or blob content in the pMem object may be discarded.
000298 ** The pMem->xDel destructor is called, if it exists. Though MEM_Str
000299 ** and MEM_Blob values may be discarded, MEM_Int, MEM_Real, MEM_IntReal,
000300 ** and MEM_Null values are preserved.
000301 **
000302 ** Return SQLITE_OK on success or an error code (probably SQLITE_NOMEM)
000303 ** if unable to complete the resizing.
000304 */
000305 int sqlite3VdbeMemClearAndResize(Mem *pMem, int szNew){
000306 assert( CORRUPT_DB || szNew>0 );
000307 assert( (pMem->flags & MEM_Dyn)==0 || pMem->szMalloc==0 );
000308 if( pMem->szMalloc<szNew ){
000309 return sqlite3VdbeMemGrow(pMem, szNew, 0);
000310 }
000311 assert( (pMem->flags & MEM_Dyn)==0 );
000312 pMem->z = pMem->zMalloc;
000313 pMem->flags &= (MEM_Null|MEM_Int|MEM_Real|MEM_IntReal);
000314 return SQLITE_OK;
000315 }
000316
000317 /*
000318 ** If pMem is already a string, detect if it is a zero-terminated
000319 ** string, or make it into one if possible, and mark it as such.
000320 **
000321 ** This is an optimization. Correct operation continues even if
000322 ** this routine is a no-op.
000323 */
000324 void sqlite3VdbeMemZeroTerminateIfAble(Mem *pMem){
000325 if( (pMem->flags & (MEM_Str|MEM_Term|MEM_Ephem|MEM_Static))!=MEM_Str ){
000326 /* pMem must be a string, and it cannot be an ephemeral or static string */
000327 return;
000328 }
000329 if( pMem->enc!=SQLITE_UTF8 ) return;
000330 if( NEVER(pMem->z==0) ) return;
000331 if( pMem->flags & MEM_Dyn ){
000332 if( pMem->xDel==sqlite3_free
000333 && sqlite3_msize(pMem->z) >= (u64)(pMem->n+1)
000334 ){
000335 pMem->z[pMem->n] = 0;
000336 pMem->flags |= MEM_Term;
000337 return;
000338 }
000339 if( pMem->xDel==sqlite3RCStrUnref ){
000340 /* Blindly assume that all RCStr objects are zero-terminated */
000341 pMem->flags |= MEM_Term;
000342 return;
000343 }
000344 }else if( pMem->szMalloc >= pMem->n+1 ){
000345 pMem->z[pMem->n] = 0;
000346 pMem->flags |= MEM_Term;
000347 return;
000348 }
000349 }
000350
000351 /*
000352 ** It is already known that pMem contains an unterminated string.
000353 ** Add the zero terminator.
000354 **
000355 ** Three bytes of zero are added. In this way, there is guaranteed
000356 ** to be a double-zero byte at an even byte boundary in order to
000357 ** terminate a UTF16 string, even if the initial size of the buffer
000358 ** is an odd number of bytes.
000359 */
000360 static SQLITE_NOINLINE int vdbeMemAddTerminator(Mem *pMem){
000361 if( sqlite3VdbeMemGrow(pMem, pMem->n+3, 1) ){
000362 return SQLITE_NOMEM_BKPT;
000363 }
000364 pMem->z[pMem->n] = 0;
000365 pMem->z[pMem->n+1] = 0;
000366 pMem->z[pMem->n+2] = 0;
000367 pMem->flags |= MEM_Term;
000368 return SQLITE_OK;
000369 }
000370
000371 /*
000372 ** Change pMem so that its MEM_Str or MEM_Blob value is stored in
000373 ** MEM.zMalloc, where it can be safely written.
000374 **
000375 ** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
000376 */
000377 int sqlite3VdbeMemMakeWriteable(Mem *pMem){
000378 assert( pMem!=0 );
000379 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000380 assert( !sqlite3VdbeMemIsRowSet(pMem) );
000381 if( (pMem->flags & (MEM_Str|MEM_Blob))!=0 ){
000382 if( ExpandBlob(pMem) ) return SQLITE_NOMEM;
000383 if( pMem->szMalloc==0 || pMem->z!=pMem->zMalloc ){
000384 int rc = vdbeMemAddTerminator(pMem);
000385 if( rc ) return rc;
000386 }
000387 }
000388 pMem->flags &= ~MEM_Ephem;
000389 #ifdef SQLITE_DEBUG
000390 pMem->pScopyFrom = 0;
000391 #endif
000392
000393 return SQLITE_OK;
000394 }
000395
000396 /*
000397 ** If the given Mem* has a zero-filled tail, turn it into an ordinary
000398 ** blob stored in dynamically allocated space.
000399 */
000400 #ifndef SQLITE_OMIT_INCRBLOB
000401 int sqlite3VdbeMemExpandBlob(Mem *pMem){
000402 int nByte;
000403 assert( pMem!=0 );
000404 assert( pMem->flags & MEM_Zero );
000405 assert( (pMem->flags&MEM_Blob)!=0 || MemNullNochng(pMem) );
000406 testcase( sqlite3_value_nochange(pMem) );
000407 assert( !sqlite3VdbeMemIsRowSet(pMem) );
000408 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000409
000410 /* Set nByte to the number of bytes required to store the expanded blob. */
000411 nByte = pMem->n + pMem->u.nZero;
000412 if( nByte<=0 ){
000413 if( (pMem->flags & MEM_Blob)==0 ) return SQLITE_OK;
000414 nByte = 1;
000415 }
000416 if( sqlite3VdbeMemGrow(pMem, nByte, 1) ){
000417 return SQLITE_NOMEM_BKPT;
000418 }
000419 assert( pMem->z!=0 );
000420 assert( sqlite3DbMallocSize(pMem->db,pMem->z) >= nByte );
000421
000422 memset(&pMem->z[pMem->n], 0, pMem->u.nZero);
000423 pMem->n += pMem->u.nZero;
000424 pMem->flags &= ~(MEM_Zero|MEM_Term);
000425 return SQLITE_OK;
000426 }
000427 #endif
000428
000429 /*
000430 ** Make sure the given Mem is \u0000 terminated.
000431 */
000432 int sqlite3VdbeMemNulTerminate(Mem *pMem){
000433 assert( pMem!=0 );
000434 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000435 testcase( (pMem->flags & (MEM_Term|MEM_Str))==(MEM_Term|MEM_Str) );
000436 testcase( (pMem->flags & (MEM_Term|MEM_Str))==0 );
000437 if( (pMem->flags & (MEM_Term|MEM_Str))!=MEM_Str ){
000438 return SQLITE_OK; /* Nothing to do */
000439 }else{
000440 return vdbeMemAddTerminator(pMem);
000441 }
000442 }
000443
000444 /*
000445 ** Add MEM_Str to the set of representations for the given Mem. This
000446 ** routine is only called if pMem is a number of some kind, not a NULL
000447 ** or a BLOB.
000448 **
000449 ** Existing representations MEM_Int, MEM_Real, or MEM_IntReal are invalidated
000450 ** if bForce is true but are retained if bForce is false.
000451 **
000452 ** A MEM_Null value will never be passed to this function. This function is
000453 ** used for converting values to text for returning to the user (i.e. via
000454 ** sqlite3_value_text()), or for ensuring that values to be used as btree
000455 ** keys are strings. In the former case a NULL pointer is returned the
000456 ** user and the latter is an internal programming error.
000457 */
000458 int sqlite3VdbeMemStringify(Mem *pMem, u8 enc, u8 bForce){
000459 const int nByte = 32;
000460
000461 assert( pMem!=0 );
000462 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000463 assert( !(pMem->flags&MEM_Zero) );
000464 assert( !(pMem->flags&(MEM_Str|MEM_Blob)) );
000465 assert( pMem->flags&(MEM_Int|MEM_Real|MEM_IntReal) );
000466 assert( !sqlite3VdbeMemIsRowSet(pMem) );
000467 assert( EIGHT_BYTE_ALIGNMENT(pMem) );
000468
000469
000470 if( sqlite3VdbeMemClearAndResize(pMem, nByte) ){
000471 pMem->enc = 0;
000472 return SQLITE_NOMEM_BKPT;
000473 }
000474
000475 vdbeMemRenderNum(nByte, pMem->z, pMem);
000476 assert( pMem->z!=0 );
000477 assert( pMem->n==(int)sqlite3Strlen30NN(pMem->z) );
000478 pMem->enc = SQLITE_UTF8;
000479 pMem->flags |= MEM_Str|MEM_Term;
000480 if( bForce ) pMem->flags &= ~(MEM_Int|MEM_Real|MEM_IntReal);
000481 sqlite3VdbeChangeEncoding(pMem, enc);
000482 return SQLITE_OK;
000483 }
000484
000485 /*
000486 ** Memory cell pMem contains the context of an aggregate function.
000487 ** This routine calls the finalize method for that function. The
000488 ** result of the aggregate is stored back into pMem.
000489 **
000490 ** Return SQLITE_ERROR if the finalizer reports an error. SQLITE_OK
000491 ** otherwise.
000492 */
000493 int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
000494 sqlite3_context ctx;
000495 Mem t;
000496 assert( pFunc!=0 );
000497 assert( pMem!=0 );
000498 assert( pMem->db!=0 );
000499 assert( pFunc->xFinalize!=0 );
000500 assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef );
000501 assert( sqlite3_mutex_held(pMem->db->mutex) );
000502 memset(&ctx, 0, sizeof(ctx));
000503 memset(&t, 0, sizeof(t));
000504 t.flags = MEM_Null;
000505 t.db = pMem->db;
000506 ctx.pOut = &t;
000507 ctx.pMem = pMem;
000508 ctx.pFunc = pFunc;
000509 ctx.enc = ENC(t.db);
000510 pFunc->xFinalize(&ctx); /* IMP: R-24505-23230 */
000511 assert( (pMem->flags & MEM_Dyn)==0 );
000512 if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc);
000513 memcpy(pMem, &t, sizeof(t));
000514 return ctx.isError;
000515 }
000516
000517 /*
000518 ** Memory cell pAccum contains the context of an aggregate function.
000519 ** This routine calls the xValue method for that function and stores
000520 ** the results in memory cell pMem.
000521 **
000522 ** SQLITE_ERROR is returned if xValue() reports an error. SQLITE_OK
000523 ** otherwise.
000524 */
000525 #ifndef SQLITE_OMIT_WINDOWFUNC
000526 int sqlite3VdbeMemAggValue(Mem *pAccum, Mem *pOut, FuncDef *pFunc){
000527 sqlite3_context ctx;
000528 assert( pFunc!=0 );
000529 assert( pFunc->xValue!=0 );
000530 assert( (pAccum->flags & MEM_Null)!=0 || pFunc==pAccum->u.pDef );
000531 assert( pAccum->db!=0 );
000532 assert( sqlite3_mutex_held(pAccum->db->mutex) );
000533 memset(&ctx, 0, sizeof(ctx));
000534 sqlite3VdbeMemSetNull(pOut);
000535 ctx.pOut = pOut;
000536 ctx.pMem = pAccum;
000537 ctx.pFunc = pFunc;
000538 ctx.enc = ENC(pAccum->db);
000539 pFunc->xValue(&ctx);
000540 return ctx.isError;
000541 }
000542 #endif /* SQLITE_OMIT_WINDOWFUNC */
000543
000544 /*
000545 ** If the memory cell contains a value that must be freed by
000546 ** invoking the external callback in Mem.xDel, then this routine
000547 ** will free that value. It also sets Mem.flags to MEM_Null.
000548 **
000549 ** This is a helper routine for sqlite3VdbeMemSetNull() and
000550 ** for sqlite3VdbeMemRelease(). Use those other routines as the
000551 ** entry point for releasing Mem resources.
000552 */
000553 static SQLITE_NOINLINE void vdbeMemClearExternAndSetNull(Mem *p){
000554 assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
000555 assert( VdbeMemDynamic(p) );
000556 if( p->flags&MEM_Agg ){
000557 sqlite3VdbeMemFinalize(p, p->u.pDef);
000558 assert( (p->flags & MEM_Agg)==0 );
000559 testcase( p->flags & MEM_Dyn );
000560 }
000561 if( p->flags&MEM_Dyn ){
000562 assert( p->xDel!=SQLITE_DYNAMIC && p->xDel!=0 );
000563 p->xDel((void *)p->z);
000564 }
000565 p->flags = MEM_Null;
000566 }
000567
000568 /*
000569 ** Release memory held by the Mem p, both external memory cleared
000570 ** by p->xDel and memory in p->zMalloc.
000571 **
000572 ** This is a helper routine invoked by sqlite3VdbeMemRelease() in
000573 ** the unusual case where there really is memory in p that needs
000574 ** to be freed.
000575 */
000576 static SQLITE_NOINLINE void vdbeMemClear(Mem *p){
000577 if( VdbeMemDynamic(p) ){
000578 vdbeMemClearExternAndSetNull(p);
000579 }
000580 if( p->szMalloc ){
000581 sqlite3DbFreeNN(p->db, p->zMalloc);
000582 p->szMalloc = 0;
000583 }
000584 p->z = 0;
000585 }
000586
000587 /*
000588 ** Release any memory resources held by the Mem. Both the memory that is
000589 ** free by Mem.xDel and the Mem.zMalloc allocation are freed.
000590 **
000591 ** Use this routine prior to clean up prior to abandoning a Mem, or to
000592 ** reset a Mem back to its minimum memory utilization.
000593 **
000594 ** Use sqlite3VdbeMemSetNull() to release just the Mem.xDel space
000595 ** prior to inserting new content into the Mem.
000596 */
000597 void sqlite3VdbeMemRelease(Mem *p){
000598 assert( sqlite3VdbeCheckMemInvariants(p) );
000599 if( VdbeMemDynamic(p) || p->szMalloc ){
000600 vdbeMemClear(p);
000601 }
000602 }
000603
000604 /* Like sqlite3VdbeMemRelease() but faster for cases where we
000605 ** know in advance that the Mem is not MEM_Dyn or MEM_Agg.
000606 */
000607 void sqlite3VdbeMemReleaseMalloc(Mem *p){
000608 assert( !VdbeMemDynamic(p) );
000609 if( p->szMalloc ) vdbeMemClear(p);
000610 }
000611
000612 /*
000613 ** Return some kind of integer value which is the best we can do
000614 ** at representing the value that *pMem describes as an integer.
000615 ** If pMem is an integer, then the value is exact. If pMem is
000616 ** a floating-point then the value returned is the integer part.
000617 ** If pMem is a string or blob, then we make an attempt to convert
000618 ** it into an integer and return that. If pMem represents an
000619 ** an SQL-NULL value, return 0.
000620 **
000621 ** If pMem represents a string value, its encoding might be changed.
000622 */
000623 static SQLITE_NOINLINE i64 memIntValue(const Mem *pMem){
000624 i64 value = 0;
000625 sqlite3Atoi64(pMem->z, &value, pMem->n, pMem->enc);
000626 return value;
000627 }
000628 i64 sqlite3VdbeIntValue(const Mem *pMem){
000629 int flags;
000630 assert( pMem!=0 );
000631 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000632 assert( EIGHT_BYTE_ALIGNMENT(pMem) );
000633 flags = pMem->flags;
000634 if( flags & (MEM_Int|MEM_IntReal) ){
000635 testcase( flags & MEM_IntReal );
000636 return pMem->u.i;
000637 }else if( flags & MEM_Real ){
000638 return sqlite3RealToI64(pMem->u.r);
000639 }else if( (flags & (MEM_Str|MEM_Blob))!=0 && pMem->z!=0 ){
000640 return memIntValue(pMem);
000641 }else{
000642 return 0;
000643 }
000644 }
000645
000646 /*
000647 ** Return the best representation of pMem that we can get into a
000648 ** double. If pMem is already a double or an integer, return its
000649 ** value. If it is a string or blob, try to convert it to a double.
000650 ** If it is a NULL, return 0.0.
000651 */
000652 static SQLITE_NOINLINE double memRealValue(Mem *pMem){
000653 /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
000654 double val = (double)0;
000655 sqlite3AtoF(pMem->z, &val, pMem->n, pMem->enc);
000656 return val;
000657 }
000658 double sqlite3VdbeRealValue(Mem *pMem){
000659 assert( pMem!=0 );
000660 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000661 assert( EIGHT_BYTE_ALIGNMENT(pMem) );
000662 if( pMem->flags & MEM_Real ){
000663 return pMem->u.r;
000664 }else if( pMem->flags & (MEM_Int|MEM_IntReal) ){
000665 testcase( pMem->flags & MEM_IntReal );
000666 return (double)pMem->u.i;
000667 }else if( pMem->flags & (MEM_Str|MEM_Blob) ){
000668 return memRealValue(pMem);
000669 }else{
000670 /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
000671 return (double)0;
000672 }
000673 }
000674
000675 /*
000676 ** Return 1 if pMem represents true, and return 0 if pMem represents false.
000677 ** Return the value ifNull if pMem is NULL.
000678 */
000679 int sqlite3VdbeBooleanValue(Mem *pMem, int ifNull){
000680 testcase( pMem->flags & MEM_IntReal );
000681 if( pMem->flags & (MEM_Int|MEM_IntReal) ) return pMem->u.i!=0;
000682 if( pMem->flags & MEM_Null ) return ifNull;
000683 return sqlite3VdbeRealValue(pMem)!=0.0;
000684 }
000685
000686 /*
000687 ** The MEM structure is already a MEM_Real or MEM_IntReal. Try to
000688 ** make it a MEM_Int if we can.
000689 */
000690 void sqlite3VdbeIntegerAffinity(Mem *pMem){
000691 assert( pMem!=0 );
000692 assert( pMem->flags & (MEM_Real|MEM_IntReal) );
000693 assert( !sqlite3VdbeMemIsRowSet(pMem) );
000694 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000695 assert( EIGHT_BYTE_ALIGNMENT(pMem) );
000696
000697 if( pMem->flags & MEM_IntReal ){
000698 MemSetTypeFlag(pMem, MEM_Int);
000699 }else{
000700 i64 ix = sqlite3RealToI64(pMem->u.r);
000701
000702 /* Only mark the value as an integer if
000703 **
000704 ** (1) the round-trip conversion real->int->real is a no-op, and
000705 ** (2) The integer is neither the largest nor the smallest
000706 ** possible integer (ticket #3922)
000707 **
000708 ** The second and third terms in the following conditional enforces
000709 ** the second condition under the assumption that addition overflow causes
000710 ** values to wrap around.
000711 */
000712 if( pMem->u.r==ix && ix>SMALLEST_INT64 && ix<LARGEST_INT64 ){
000713 pMem->u.i = ix;
000714 MemSetTypeFlag(pMem, MEM_Int);
000715 }
000716 }
000717 }
000718
000719 /*
000720 ** Convert pMem to type integer. Invalidate any prior representations.
000721 */
000722 int sqlite3VdbeMemIntegerify(Mem *pMem){
000723 assert( pMem!=0 );
000724 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000725 assert( !sqlite3VdbeMemIsRowSet(pMem) );
000726 assert( EIGHT_BYTE_ALIGNMENT(pMem) );
000727
000728 pMem->u.i = sqlite3VdbeIntValue(pMem);
000729 MemSetTypeFlag(pMem, MEM_Int);
000730 return SQLITE_OK;
000731 }
000732
000733 /*
000734 ** Convert pMem so that it is of type MEM_Real.
000735 ** Invalidate any prior representations.
000736 */
000737 int sqlite3VdbeMemRealify(Mem *pMem){
000738 assert( pMem!=0 );
000739 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000740 assert( EIGHT_BYTE_ALIGNMENT(pMem) );
000741
000742 pMem->u.r = sqlite3VdbeRealValue(pMem);
000743 MemSetTypeFlag(pMem, MEM_Real);
000744 return SQLITE_OK;
000745 }
000746
000747 /* Compare a floating point value to an integer. Return true if the two
000748 ** values are the same within the precision of the floating point value.
000749 **
000750 ** This function assumes that i was obtained by assignment from r1.
000751 **
000752 ** For some versions of GCC on 32-bit machines, if you do the more obvious
000753 ** comparison of "r1==(double)i" you sometimes get an answer of false even
000754 ** though the r1 and (double)i values are bit-for-bit the same.
000755 */
000756 int sqlite3RealSameAsInt(double r1, sqlite3_int64 i){
000757 double r2 = (double)i;
000758 return r1==0.0
000759 || (memcmp(&r1, &r2, sizeof(r1))==0
000760 && i >= -2251799813685248LL && i < 2251799813685248LL);
000761 }
000762
000763 /* Convert a floating point value to its closest integer. Do so in
000764 ** a way that avoids 'outside the range of representable values' warnings
000765 ** from UBSAN.
000766 */
000767 i64 sqlite3RealToI64(double r){
000768 if( r<-9223372036854774784.0 ) return SMALLEST_INT64;
000769 if( r>+9223372036854774784.0 ) return LARGEST_INT64;
000770 return (i64)r;
000771 }
000772
000773 /*
000774 ** Convert pMem so that it has type MEM_Real or MEM_Int.
000775 ** Invalidate any prior representations.
000776 **
000777 ** Every effort is made to force the conversion, even if the input
000778 ** is a string that does not look completely like a number. Convert
000779 ** as much of the string as we can and ignore the rest.
000780 */
000781 int sqlite3VdbeMemNumerify(Mem *pMem){
000782 assert( pMem!=0 );
000783 testcase( pMem->flags & MEM_Int );
000784 testcase( pMem->flags & MEM_Real );
000785 testcase( pMem->flags & MEM_IntReal );
000786 testcase( pMem->flags & MEM_Null );
000787 if( (pMem->flags & (MEM_Int|MEM_Real|MEM_IntReal|MEM_Null))==0 ){
000788 int rc;
000789 sqlite3_int64 ix;
000790 assert( (pMem->flags & (MEM_Blob|MEM_Str))!=0 );
000791 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
000792 rc = sqlite3AtoF(pMem->z, &pMem->u.r, pMem->n, pMem->enc);
000793 if( ((rc==0 || rc==1) && sqlite3Atoi64(pMem->z, &ix, pMem->n, pMem->enc)<=1)
000794 || sqlite3RealSameAsInt(pMem->u.r, (ix = sqlite3RealToI64(pMem->u.r)))
000795 ){
000796 pMem->u.i = ix;
000797 MemSetTypeFlag(pMem, MEM_Int);
000798 }else{
000799 MemSetTypeFlag(pMem, MEM_Real);
000800 }
000801 }
000802 assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_IntReal|MEM_Null))!=0 );
000803 pMem->flags &= ~(MEM_Str|MEM_Blob|MEM_Zero);
000804 return SQLITE_OK;
000805 }
000806
000807 /*
000808 ** Cast the datatype of the value in pMem according to the affinity
000809 ** "aff". Casting is different from applying affinity in that a cast
000810 ** is forced. In other words, the value is converted into the desired
000811 ** affinity even if that results in loss of data. This routine is
000812 ** used (for example) to implement the SQL "cast()" operator.
000813 */
000814 int sqlite3VdbeMemCast(Mem *pMem, u8 aff, u8 encoding){
000815 if( pMem->flags & MEM_Null ) return SQLITE_OK;
000816 switch( aff ){
000817 case SQLITE_AFF_BLOB: { /* Really a cast to BLOB */
000818 if( (pMem->flags & MEM_Blob)==0 ){
000819 sqlite3ValueApplyAffinity(pMem, SQLITE_AFF_TEXT, encoding);
000820 assert( pMem->flags & MEM_Str || pMem->db->mallocFailed );
000821 if( pMem->flags & MEM_Str ) MemSetTypeFlag(pMem, MEM_Blob);
000822 }else{
000823 pMem->flags &= ~(MEM_TypeMask&~MEM_Blob);
000824 }
000825 break;
000826 }
000827 case SQLITE_AFF_NUMERIC: {
000828 sqlite3VdbeMemNumerify(pMem);
000829 break;
000830 }
000831 case SQLITE_AFF_INTEGER: {
000832 sqlite3VdbeMemIntegerify(pMem);
000833 break;
000834 }
000835 case SQLITE_AFF_REAL: {
000836 sqlite3VdbeMemRealify(pMem);
000837 break;
000838 }
000839 default: {
000840 int rc;
000841 assert( aff==SQLITE_AFF_TEXT );
000842 assert( MEM_Str==(MEM_Blob>>3) );
000843 pMem->flags |= (pMem->flags&MEM_Blob)>>3;
000844 sqlite3ValueApplyAffinity(pMem, SQLITE_AFF_TEXT, encoding);
000845 assert( pMem->flags & MEM_Str || pMem->db->mallocFailed );
000846 pMem->flags &= ~(MEM_Int|MEM_Real|MEM_IntReal|MEM_Blob|MEM_Zero);
000847 if( encoding!=SQLITE_UTF8 ) pMem->n &= ~1;
000848 rc = sqlite3VdbeChangeEncoding(pMem, encoding);
000849 if( rc ) return rc;
000850 sqlite3VdbeMemZeroTerminateIfAble(pMem);
000851 }
000852 }
000853 return SQLITE_OK;
000854 }
000855
000856 /*
000857 ** Initialize bulk memory to be a consistent Mem object.
000858 **
000859 ** The minimum amount of initialization feasible is performed.
000860 */
000861 void sqlite3VdbeMemInit(Mem *pMem, sqlite3 *db, u16 flags){
000862 assert( (flags & ~MEM_TypeMask)==0 );
000863 pMem->flags = flags;
000864 pMem->db = db;
000865 pMem->szMalloc = 0;
000866 }
000867
000868
000869 /*
000870 ** Delete any previous value and set the value stored in *pMem to NULL.
000871 **
000872 ** This routine calls the Mem.xDel destructor to dispose of values that
000873 ** require the destructor. But it preserves the Mem.zMalloc memory allocation.
000874 ** To free all resources, use sqlite3VdbeMemRelease(), which both calls this
000875 ** routine to invoke the destructor and deallocates Mem.zMalloc.
000876 **
000877 ** Use this routine to reset the Mem prior to insert a new value.
000878 **
000879 ** Use sqlite3VdbeMemRelease() to complete erase the Mem prior to abandoning it.
000880 */
000881 void sqlite3VdbeMemSetNull(Mem *pMem){
000882 if( VdbeMemDynamic(pMem) ){
000883 vdbeMemClearExternAndSetNull(pMem);
000884 }else{
000885 pMem->flags = MEM_Null;
000886 }
000887 }
000888 void sqlite3ValueSetNull(sqlite3_value *p){
000889 sqlite3VdbeMemSetNull((Mem*)p);
000890 }
000891
000892 /*
000893 ** Delete any previous value and set the value to be a BLOB of length
000894 ** n containing all zeros.
000895 */
000896 #ifndef SQLITE_OMIT_INCRBLOB
000897 void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){
000898 sqlite3VdbeMemRelease(pMem);
000899 pMem->flags = MEM_Blob|MEM_Zero;
000900 pMem->n = 0;
000901 if( n<0 ) n = 0;
000902 pMem->u.nZero = n;
000903 pMem->enc = SQLITE_UTF8;
000904 pMem->z = 0;
000905 }
000906 #else
000907 int sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){
000908 int nByte = n>0?n:1;
000909 if( sqlite3VdbeMemGrow(pMem, nByte, 0) ){
000910 return SQLITE_NOMEM_BKPT;
000911 }
000912 assert( pMem->z!=0 );
000913 assert( sqlite3DbMallocSize(pMem->db, pMem->z)>=nByte );
000914 memset(pMem->z, 0, nByte);
000915 pMem->n = n>0?n:0;
000916 pMem->flags = MEM_Blob;
000917 pMem->enc = SQLITE_UTF8;
000918 return SQLITE_OK;
000919 }
000920 #endif
000921
000922 /*
000923 ** The pMem is known to contain content that needs to be destroyed prior
000924 ** to a value change. So invoke the destructor, then set the value to
000925 ** a 64-bit integer.
000926 */
000927 static SQLITE_NOINLINE void vdbeReleaseAndSetInt64(Mem *pMem, i64 val){
000928 sqlite3VdbeMemSetNull(pMem);
000929 pMem->u.i = val;
000930 pMem->flags = MEM_Int;
000931 }
000932
000933 /*
000934 ** Delete any previous value and set the value stored in *pMem to val,
000935 ** manifest type INTEGER.
000936 */
000937 void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){
000938 if( VdbeMemDynamic(pMem) ){
000939 vdbeReleaseAndSetInt64(pMem, val);
000940 }else{
000941 pMem->u.i = val;
000942 pMem->flags = MEM_Int;
000943 }
000944 }
000945
000946 /* A no-op destructor */
000947 void sqlite3NoopDestructor(void *p){ UNUSED_PARAMETER(p); }
000948
000949 /*
000950 ** Set the value stored in *pMem should already be a NULL.
000951 ** Also store a pointer to go with it.
000952 */
000953 void sqlite3VdbeMemSetPointer(
000954 Mem *pMem,
000955 void *pPtr,
000956 const char *zPType,
000957 void (*xDestructor)(void*)
000958 ){
000959 assert( pMem->flags==MEM_Null );
000960 vdbeMemClear(pMem);
000961 pMem->u.zPType = zPType ? zPType : "";
000962 pMem->z = pPtr;
000963 pMem->flags = MEM_Null|MEM_Dyn|MEM_Subtype|MEM_Term;
000964 pMem->eSubtype = 'p';
000965 pMem->xDel = xDestructor ? xDestructor : sqlite3NoopDestructor;
000966 }
000967
000968 #ifndef SQLITE_OMIT_FLOATING_POINT
000969 /*
000970 ** Delete any previous value and set the value stored in *pMem to val,
000971 ** manifest type REAL.
000972 */
000973 void sqlite3VdbeMemSetDouble(Mem *pMem, double val){
000974 sqlite3VdbeMemSetNull(pMem);
000975 if( !sqlite3IsNaN(val) ){
000976 pMem->u.r = val;
000977 pMem->flags = MEM_Real;
000978 }
000979 }
000980 #endif
000981
000982 #ifdef SQLITE_DEBUG
000983 /*
000984 ** Return true if the Mem holds a RowSet object. This routine is intended
000985 ** for use inside of assert() statements.
000986 */
000987 int sqlite3VdbeMemIsRowSet(const Mem *pMem){
000988 return (pMem->flags&(MEM_Blob|MEM_Dyn))==(MEM_Blob|MEM_Dyn)
000989 && pMem->xDel==sqlite3RowSetDelete;
000990 }
000991 #endif
000992
000993 /*
000994 ** Delete any previous value and set the value of pMem to be an
000995 ** empty boolean index.
000996 **
000997 ** Return SQLITE_OK on success and SQLITE_NOMEM if a memory allocation
000998 ** error occurs.
000999 */
001000 int sqlite3VdbeMemSetRowSet(Mem *pMem){
001001 sqlite3 *db = pMem->db;
001002 RowSet *p;
001003 assert( db!=0 );
001004 assert( !sqlite3VdbeMemIsRowSet(pMem) );
001005 sqlite3VdbeMemRelease(pMem);
001006 p = sqlite3RowSetInit(db);
001007 if( p==0 ) return SQLITE_NOMEM;
001008 pMem->z = (char*)p;
001009 pMem->flags = MEM_Blob|MEM_Dyn;
001010 pMem->xDel = sqlite3RowSetDelete;
001011 return SQLITE_OK;
001012 }
001013
001014 /*
001015 ** Return true if the Mem object contains a TEXT or BLOB that is
001016 ** too large - whose size exceeds SQLITE_MAX_LENGTH.
001017 */
001018 int sqlite3VdbeMemTooBig(Mem *p){
001019 assert( p->db!=0 );
001020 if( p->flags & (MEM_Str|MEM_Blob) ){
001021 int n = p->n;
001022 if( p->flags & MEM_Zero ){
001023 n += p->u.nZero;
001024 }
001025 return n>p->db->aLimit[SQLITE_LIMIT_LENGTH];
001026 }
001027 return 0;
001028 }
001029
001030 #ifdef SQLITE_DEBUG
001031 /*
001032 ** This routine prepares a memory cell for modification by breaking
001033 ** its link to a shallow copy and by marking any current shallow
001034 ** copies of this cell as invalid.
001035 **
001036 ** This is used for testing and debugging only - to help ensure that shallow
001037 ** copies (created by OP_SCopy) are not misused.
001038 */
001039 void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
001040 int i;
001041 Mem *pX;
001042 for(i=1, pX=pVdbe->aMem+1; i<pVdbe->nMem; i++, pX++){
001043 if( pX->pScopyFrom==pMem ){
001044 u16 mFlags;
001045 if( pVdbe->db->flags & SQLITE_VdbeTrace ){
001046 sqlite3DebugPrintf("Invalidate R[%d] due to change in R[%d]\n",
001047 (int)(pX - pVdbe->aMem), (int)(pMem - pVdbe->aMem));
001048 }
001049 /* If pX is marked as a shallow copy of pMem, then try to verify that
001050 ** no significant changes have been made to pX since the OP_SCopy.
001051 ** A significant change would indicated a missed call to this
001052 ** function for pX. Minor changes, such as adding or removing a
001053 ** dual type, are allowed, as long as the underlying value is the
001054 ** same. */
001055 mFlags = pMem->flags & pX->flags & pX->mScopyFlags;
001056 assert( (mFlags&(MEM_Int|MEM_IntReal))==0 || pMem->u.i==pX->u.i );
001057
001058 /* pMem is the register that is changing. But also mark pX as
001059 ** undefined so that we can quickly detect the shallow-copy error */
001060 pX->flags = MEM_Undefined;
001061 pX->pScopyFrom = 0;
001062 }
001063 }
001064 pMem->pScopyFrom = 0;
001065 }
001066 #endif /* SQLITE_DEBUG */
001067
001068 /*
001069 ** Make an shallow copy of pFrom into pTo. Prior contents of
001070 ** pTo are freed. The pFrom->z field is not duplicated. If
001071 ** pFrom->z is used, then pTo->z points to the same thing as pFrom->z
001072 ** and flags gets srcType (either MEM_Ephem or MEM_Static).
001073 */
001074 static SQLITE_NOINLINE void vdbeClrCopy(Mem *pTo, const Mem *pFrom, int eType){
001075 vdbeMemClearExternAndSetNull(pTo);
001076 assert( !VdbeMemDynamic(pTo) );
001077 sqlite3VdbeMemShallowCopy(pTo, pFrom, eType);
001078 }
001079 void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
001080 assert( !sqlite3VdbeMemIsRowSet(pFrom) );
001081 assert( pTo->db==pFrom->db );
001082 if( VdbeMemDynamic(pTo) ){ vdbeClrCopy(pTo,pFrom,srcType); return; }
001083 memcpy(pTo, pFrom, MEMCELLSIZE);
001084 if( (pFrom->flags&MEM_Static)==0 ){
001085 pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
001086 assert( srcType==MEM_Ephem || srcType==MEM_Static );
001087 pTo->flags |= srcType;
001088 }
001089 }
001090
001091 /*
001092 ** Make a full copy of pFrom into pTo. Prior contents of pTo are
001093 ** freed before the copy is made.
001094 */
001095 int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
001096 int rc = SQLITE_OK;
001097
001098 assert( !sqlite3VdbeMemIsRowSet(pFrom) );
001099 if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);
001100 memcpy(pTo, pFrom, MEMCELLSIZE);
001101 pTo->flags &= ~MEM_Dyn;
001102 if( pTo->flags&(MEM_Str|MEM_Blob) ){
001103 if( 0==(pFrom->flags&MEM_Static) ){
001104 pTo->flags |= MEM_Ephem;
001105 rc = sqlite3VdbeMemMakeWriteable(pTo);
001106 }
001107 }
001108
001109 return rc;
001110 }
001111
001112 /*
001113 ** Transfer the contents of pFrom to pTo. Any existing value in pTo is
001114 ** freed. If pFrom contains ephemeral data, a copy is made.
001115 **
001116 ** pFrom contains an SQL NULL when this routine returns.
001117 */
001118 void sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){
001119 assert( pFrom->db==0 || sqlite3_mutex_held(pFrom->db->mutex) );
001120 assert( pTo->db==0 || sqlite3_mutex_held(pTo->db->mutex) );
001121 assert( pFrom->db==0 || pTo->db==0 || pFrom->db==pTo->db );
001122
001123 sqlite3VdbeMemRelease(pTo);
001124 memcpy(pTo, pFrom, sizeof(Mem));
001125 pFrom->flags = MEM_Null;
001126 pFrom->szMalloc = 0;
001127 }
001128
001129 /*
001130 ** Change the value of a Mem to be a string or a BLOB.
001131 **
001132 ** The memory management strategy depends on the value of the xDel
001133 ** parameter. If the value passed is SQLITE_TRANSIENT, then the
001134 ** string is copied into a (possibly existing) buffer managed by the
001135 ** Mem structure. Otherwise, any existing buffer is freed and the
001136 ** pointer copied.
001137 **
001138 ** If the string is too large (if it exceeds the SQLITE_LIMIT_LENGTH
001139 ** size limit) then no memory allocation occurs. If the string can be
001140 ** stored without allocating memory, then it is. If a memory allocation
001141 ** is required to store the string, then value of pMem is unchanged. In
001142 ** either case, SQLITE_TOOBIG is returned.
001143 **
001144 ** The "enc" parameter is the text encoding for the string, or zero
001145 ** to store a blob.
001146 **
001147 ** If n is negative, then the string consists of all bytes up to but
001148 ** excluding the first zero character. The n parameter must be
001149 ** non-negative for blobs.
001150 */
001151 int sqlite3VdbeMemSetStr(
001152 Mem *pMem, /* Memory cell to set to string value */
001153 const char *z, /* String pointer */
001154 i64 n, /* Bytes in string, or negative */
001155 u8 enc, /* Encoding of z. 0 for BLOBs */
001156 void (*xDel)(void*) /* Destructor function */
001157 ){
001158 i64 nByte = n; /* New value for pMem->n */
001159 int iLimit; /* Maximum allowed string or blob size */
001160 u16 flags; /* New value for pMem->flags */
001161
001162 assert( pMem!=0 );
001163 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
001164 assert( !sqlite3VdbeMemIsRowSet(pMem) );
001165 assert( enc!=0 || n>=0 );
001166
001167 /* If z is a NULL pointer, set pMem to contain an SQL NULL. */
001168 if( !z ){
001169 sqlite3VdbeMemSetNull(pMem);
001170 return SQLITE_OK;
001171 }
001172
001173 if( pMem->db ){
001174 iLimit = pMem->db->aLimit[SQLITE_LIMIT_LENGTH];
001175 }else{
001176 iLimit = SQLITE_MAX_LENGTH;
001177 }
001178 if( nByte<0 ){
001179 assert( enc!=0 );
001180 if( enc==SQLITE_UTF8 ){
001181 nByte = strlen(z);
001182 }else{
001183 for(nByte=0; nByte<=iLimit && (z[nByte] | z[nByte+1]); nByte+=2){}
001184 }
001185 flags= MEM_Str|MEM_Term;
001186 }else if( enc==0 ){
001187 flags = MEM_Blob;
001188 enc = SQLITE_UTF8;
001189 }else{
001190 flags = MEM_Str;
001191 }
001192 if( nByte>iLimit ){
001193 if( xDel && xDel!=SQLITE_TRANSIENT ){
001194 if( xDel==SQLITE_DYNAMIC ){
001195 sqlite3DbFree(pMem->db, (void*)z);
001196 }else{
001197 xDel((void*)z);
001198 }
001199 }
001200 sqlite3VdbeMemSetNull(pMem);
001201 return sqlite3ErrorToParser(pMem->db, SQLITE_TOOBIG);
001202 }
001203
001204 /* The following block sets the new values of Mem.z and Mem.xDel. It
001205 ** also sets a flag in local variable "flags" to indicate the memory
001206 ** management (one of MEM_Dyn or MEM_Static).
001207 */
001208 if( xDel==SQLITE_TRANSIENT ){
001209 i64 nAlloc = nByte;
001210 if( flags&MEM_Term ){
001211 nAlloc += (enc==SQLITE_UTF8?1:2);
001212 }
001213 testcase( nAlloc==0 );
001214 testcase( nAlloc==31 );
001215 testcase( nAlloc==32 );
001216 if( sqlite3VdbeMemClearAndResize(pMem, (int)MAX(nAlloc,32)) ){
001217 return SQLITE_NOMEM_BKPT;
001218 }
001219 memcpy(pMem->z, z, nAlloc);
001220 }else{
001221 sqlite3VdbeMemRelease(pMem);
001222 pMem->z = (char *)z;
001223 if( xDel==SQLITE_DYNAMIC ){
001224 pMem->zMalloc = pMem->z;
001225 pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);
001226 }else{
001227 pMem->xDel = xDel;
001228 flags |= ((xDel==SQLITE_STATIC)?MEM_Static:MEM_Dyn);
001229 }
001230 }
001231
001232 pMem->n = (int)(nByte & 0x7fffffff);
001233 pMem->flags = flags;
001234 pMem->enc = enc;
001235
001236 #ifndef SQLITE_OMIT_UTF16
001237 if( enc>SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){
001238 return SQLITE_NOMEM_BKPT;
001239 }
001240 #endif
001241
001242
001243 return SQLITE_OK;
001244 }
001245
001246 /*
001247 ** Move data out of a btree key or data field and into a Mem structure.
001248 ** The data is payload from the entry that pCur is currently pointing
001249 ** to. offset and amt determine what portion of the data or key to retrieve.
001250 ** The result is written into the pMem element.
001251 **
001252 ** The pMem object must have been initialized. This routine will use
001253 ** pMem->zMalloc to hold the content from the btree, if possible. New
001254 ** pMem->zMalloc space will be allocated if necessary. The calling routine
001255 ** is responsible for making sure that the pMem object is eventually
001256 ** destroyed.
001257 **
001258 ** If this routine fails for any reason (malloc returns NULL or unable
001259 ** to read from the disk) then the pMem is left in an inconsistent state.
001260 */
001261 int sqlite3VdbeMemFromBtree(
001262 BtCursor *pCur, /* Cursor pointing at record to retrieve. */
001263 u32 offset, /* Offset from the start of data to return bytes from. */
001264 u32 amt, /* Number of bytes to return. */
001265 Mem *pMem /* OUT: Return data in this Mem structure. */
001266 ){
001267 int rc;
001268 pMem->flags = MEM_Null;
001269 if( sqlite3BtreeMaxRecordSize(pCur)<offset+amt ){
001270 return SQLITE_CORRUPT_BKPT;
001271 }
001272 if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+1)) ){
001273 rc = sqlite3BtreePayload(pCur, offset, amt, pMem->z);
001274 if( rc==SQLITE_OK ){
001275 pMem->z[amt] = 0; /* Overrun area used when reading malformed records */
001276 pMem->flags = MEM_Blob;
001277 pMem->n = (int)amt;
001278 }else{
001279 sqlite3VdbeMemRelease(pMem);
001280 }
001281 }
001282 return rc;
001283 }
001284 int sqlite3VdbeMemFromBtreeZeroOffset(
001285 BtCursor *pCur, /* Cursor pointing at record to retrieve. */
001286 u32 amt, /* Number of bytes to return. */
001287 Mem *pMem /* OUT: Return data in this Mem structure. */
001288 ){
001289 u32 available = 0; /* Number of bytes available on the local btree page */
001290 int rc = SQLITE_OK; /* Return code */
001291
001292 assert( sqlite3BtreeCursorIsValid(pCur) );
001293 assert( !VdbeMemDynamic(pMem) );
001294
001295 /* Note: the calls to BtreeKeyFetch() and DataFetch() below assert()
001296 ** that both the BtShared and database handle mutexes are held. */
001297 assert( !sqlite3VdbeMemIsRowSet(pMem) );
001298 pMem->z = (char *)sqlite3BtreePayloadFetch(pCur, &available);
001299 assert( pMem->z!=0 );
001300
001301 if( amt<=available ){
001302 pMem->flags = MEM_Blob|MEM_Ephem;
001303 pMem->n = (int)amt;
001304 }else{
001305 rc = sqlite3VdbeMemFromBtree(pCur, 0, amt, pMem);
001306 }
001307
001308 return rc;
001309 }
001310
001311 /*
001312 ** The pVal argument is known to be a value other than NULL.
001313 ** Convert it into a string with encoding enc and return a pointer
001314 ** to a zero-terminated version of that string.
001315 */
001316 static SQLITE_NOINLINE const void *valueToText(sqlite3_value* pVal, u8 enc){
001317 assert( pVal!=0 );
001318 assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
001319 assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
001320 assert( !sqlite3VdbeMemIsRowSet(pVal) );
001321 assert( (pVal->flags & (MEM_Null))==0 );
001322 if( pVal->flags & (MEM_Blob|MEM_Str) ){
001323 if( ExpandBlob(pVal) ) return 0;
001324 pVal->flags |= MEM_Str;
001325 if( pVal->enc != (enc & ~SQLITE_UTF16_ALIGNED) ){
001326 sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
001327 }
001328 if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&SQLITE_PTR_TO_INT(pVal->z)) ){
001329 assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );
001330 if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){
001331 return 0;
001332 }
001333 }
001334 sqlite3VdbeMemNulTerminate(pVal); /* IMP: R-31275-44060 */
001335 }else{
001336 sqlite3VdbeMemStringify(pVal, enc, 0);
001337 assert( 0==(1&SQLITE_PTR_TO_INT(pVal->z)) );
001338 }
001339 assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || pVal->db==0
001340 || pVal->db->mallocFailed );
001341 if( pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) ){
001342 assert( sqlite3VdbeMemValidStrRep(pVal) );
001343 return pVal->z;
001344 }else{
001345 return 0;
001346 }
001347 }
001348
001349 /* This function is only available internally, it is not part of the
001350 ** external API. It works in a similar way to sqlite3_value_text(),
001351 ** except the data returned is in the encoding specified by the second
001352 ** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or
001353 ** SQLITE_UTF8.
001354 **
001355 ** (2006-02-16:) The enc value can be or-ed with SQLITE_UTF16_ALIGNED.
001356 ** If that is the case, then the result must be aligned on an even byte
001357 ** boundary.
001358 */
001359 const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
001360 if( !pVal ) return 0;
001361 assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
001362 assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
001363 assert( !sqlite3VdbeMemIsRowSet(pVal) );
001364 if( (pVal->flags&(MEM_Str|MEM_Term))==(MEM_Str|MEM_Term) && pVal->enc==enc ){
001365 assert( sqlite3VdbeMemValidStrRep(pVal) );
001366 return pVal->z;
001367 }
001368 if( pVal->flags&MEM_Null ){
001369 return 0;
001370 }
001371 return valueToText(pVal, enc);
001372 }
001373
001374 /* Return true if sqlit3_value object pVal is a string or blob value
001375 ** that uses the destructor specified in the second argument.
001376 **
001377 ** TODO: Maybe someday promote this interface into a published API so
001378 ** that third-party extensions can get access to it?
001379 */
001380 int sqlite3ValueIsOfClass(const sqlite3_value *pVal, void(*xFree)(void*)){
001381 if( ALWAYS(pVal!=0)
001382 && ALWAYS((pVal->flags & (MEM_Str|MEM_Blob))!=0)
001383 && (pVal->flags & MEM_Dyn)!=0
001384 && pVal->xDel==xFree
001385 ){
001386 return 1;
001387 }else{
001388 return 0;
001389 }
001390 }
001391
001392 /*
001393 ** Create a new sqlite3_value object.
001394 */
001395 sqlite3_value *sqlite3ValueNew(sqlite3 *db){
001396 Mem *p = sqlite3DbMallocZero(db, sizeof(*p));
001397 if( p ){
001398 p->flags = MEM_Null;
001399 p->db = db;
001400 }
001401 return p;
001402 }
001403
001404 /*
001405 ** Context object passed by sqlite3Stat4ProbeSetValue() through to
001406 ** valueNew(). See comments above valueNew() for details.
001407 */
001408 struct ValueNewStat4Ctx {
001409 Parse *pParse;
001410 Index *pIdx;
001411 UnpackedRecord **ppRec;
001412 int iVal;
001413 };
001414
001415 /*
001416 ** Allocate and return a pointer to a new sqlite3_value object. If
001417 ** the second argument to this function is NULL, the object is allocated
001418 ** by calling sqlite3ValueNew().
001419 **
001420 ** Otherwise, if the second argument is non-zero, then this function is
001421 ** being called indirectly by sqlite3Stat4ProbeSetValue(). If it has not
001422 ** already been allocated, allocate the UnpackedRecord structure that
001423 ** that function will return to its caller here. Then return a pointer to
001424 ** an sqlite3_value within the UnpackedRecord.a[] array.
001425 */
001426 static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){
001427 #ifdef SQLITE_ENABLE_STAT4
001428 if( p ){
001429 UnpackedRecord *pRec = p->ppRec[0];
001430
001431 if( pRec==0 ){
001432 Index *pIdx = p->pIdx; /* Index being probed */
001433 int nByte; /* Bytes of space to allocate */
001434 int i; /* Counter variable */
001435 int nCol = pIdx->nColumn; /* Number of index columns including rowid */
001436
001437 nByte = sizeof(Mem) * nCol + ROUND8(sizeof(UnpackedRecord));
001438 pRec = (UnpackedRecord*)sqlite3DbMallocZero(db, nByte);
001439 if( pRec ){
001440 pRec->pKeyInfo = sqlite3KeyInfoOfIndex(p->pParse, pIdx);
001441 if( pRec->pKeyInfo ){
001442 assert( pRec->pKeyInfo->nAllField==nCol );
001443 assert( pRec->pKeyInfo->enc==ENC(db) );
001444 pRec->aMem = (Mem *)((u8*)pRec + ROUND8(sizeof(UnpackedRecord)));
001445 for(i=0; i<nCol; i++){
001446 pRec->aMem[i].flags = MEM_Null;
001447 pRec->aMem[i].db = db;
001448 }
001449 }else{
001450 sqlite3DbFreeNN(db, pRec);
001451 pRec = 0;
001452 }
001453 }
001454 if( pRec==0 ) return 0;
001455 p->ppRec[0] = pRec;
001456 }
001457
001458 pRec->nField = p->iVal+1;
001459 sqlite3VdbeMemSetNull(&pRec->aMem[p->iVal]);
001460 return &pRec->aMem[p->iVal];
001461 }
001462 #else
001463 UNUSED_PARAMETER(p);
001464 #endif /* defined(SQLITE_ENABLE_STAT4) */
001465 return sqlite3ValueNew(db);
001466 }
001467
001468 /*
001469 ** The expression object indicated by the second argument is guaranteed
001470 ** to be a scalar SQL function. If
001471 **
001472 ** * all function arguments are SQL literals,
001473 ** * one of the SQLITE_FUNC_CONSTANT or _SLOCHNG function flags is set, and
001474 ** * the SQLITE_FUNC_NEEDCOLL function flag is not set,
001475 **
001476 ** then this routine attempts to invoke the SQL function. Assuming no
001477 ** error occurs, output parameter (*ppVal) is set to point to a value
001478 ** object containing the result before returning SQLITE_OK.
001479 **
001480 ** Affinity aff is applied to the result of the function before returning.
001481 ** If the result is a text value, the sqlite3_value object uses encoding
001482 ** enc.
001483 **
001484 ** If the conditions above are not met, this function returns SQLITE_OK
001485 ** and sets (*ppVal) to NULL. Or, if an error occurs, (*ppVal) is set to
001486 ** NULL and an SQLite error code returned.
001487 */
001488 #ifdef SQLITE_ENABLE_STAT4
001489 static int valueFromFunction(
001490 sqlite3 *db, /* The database connection */
001491 const Expr *p, /* The expression to evaluate */
001492 u8 enc, /* Encoding to use */
001493 u8 aff, /* Affinity to use */
001494 sqlite3_value **ppVal, /* Write the new value here */
001495 struct ValueNewStat4Ctx *pCtx /* Second argument for valueNew() */
001496 ){
001497 sqlite3_context ctx; /* Context object for function invocation */
001498 sqlite3_value **apVal = 0; /* Function arguments */
001499 int nVal = 0; /* Size of apVal[] array */
001500 FuncDef *pFunc = 0; /* Function definition */
001501 sqlite3_value *pVal = 0; /* New value */
001502 int rc = SQLITE_OK; /* Return code */
001503 ExprList *pList = 0; /* Function arguments */
001504 int i; /* Iterator variable */
001505
001506 assert( pCtx!=0 );
001507 assert( (p->flags & EP_TokenOnly)==0 );
001508 assert( ExprUseXList(p) );
001509 pList = p->x.pList;
001510 if( pList ) nVal = pList->nExpr;
001511 assert( !ExprHasProperty(p, EP_IntValue) );
001512 pFunc = sqlite3FindFunction(db, p->u.zToken, nVal, enc, 0);
001513 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
001514 if( pFunc==0 ) return SQLITE_OK;
001515 #endif
001516 assert( pFunc );
001517 if( (pFunc->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG))==0
001518 || (pFunc->funcFlags & (SQLITE_FUNC_NEEDCOLL|SQLITE_FUNC_RUNONLY))!=0
001519 ){
001520 return SQLITE_OK;
001521 }
001522
001523 if( pList ){
001524 apVal = (sqlite3_value**)sqlite3DbMallocZero(db, sizeof(apVal[0]) * nVal);
001525 if( apVal==0 ){
001526 rc = SQLITE_NOMEM_BKPT;
001527 goto value_from_function_out;
001528 }
001529 for(i=0; i<nVal; i++){
001530 rc = sqlite3ValueFromExpr(db, pList->a[i].pExpr, enc, aff, &apVal[i]);
001531 if( apVal[i]==0 || rc!=SQLITE_OK ) goto value_from_function_out;
001532 }
001533 }
001534
001535 pVal = valueNew(db, pCtx);
001536 if( pVal==0 ){
001537 rc = SQLITE_NOMEM_BKPT;
001538 goto value_from_function_out;
001539 }
001540
001541 memset(&ctx, 0, sizeof(ctx));
001542 ctx.pOut = pVal;
001543 ctx.pFunc = pFunc;
001544 ctx.enc = ENC(db);
001545 pFunc->xSFunc(&ctx, nVal, apVal);
001546 if( ctx.isError ){
001547 rc = ctx.isError;
001548 sqlite3ErrorMsg(pCtx->pParse, "%s", sqlite3_value_text(pVal));
001549 }else{
001550 sqlite3ValueApplyAffinity(pVal, aff, SQLITE_UTF8);
001551 assert( rc==SQLITE_OK );
001552 rc = sqlite3VdbeChangeEncoding(pVal, enc);
001553 if( NEVER(rc==SQLITE_OK && sqlite3VdbeMemTooBig(pVal)) ){
001554 rc = SQLITE_TOOBIG;
001555 pCtx->pParse->nErr++;
001556 }
001557 }
001558
001559 value_from_function_out:
001560 if( rc!=SQLITE_OK ){
001561 pVal = 0;
001562 pCtx->pParse->rc = rc;
001563 }
001564 if( apVal ){
001565 for(i=0; i<nVal; i++){
001566 sqlite3ValueFree(apVal[i]);
001567 }
001568 sqlite3DbFreeNN(db, apVal);
001569 }
001570
001571 *ppVal = pVal;
001572 return rc;
001573 }
001574 #else
001575 # define valueFromFunction(a,b,c,d,e,f) SQLITE_OK
001576 #endif /* defined(SQLITE_ENABLE_STAT4) */
001577
001578 /*
001579 ** Extract a value from the supplied expression in the manner described
001580 ** above sqlite3ValueFromExpr(). Allocate the sqlite3_value object
001581 ** using valueNew().
001582 **
001583 ** If pCtx is NULL and an error occurs after the sqlite3_value object
001584 ** has been allocated, it is freed before returning. Or, if pCtx is not
001585 ** NULL, it is assumed that the caller will free any allocated object
001586 ** in all cases.
001587 */
001588 static int valueFromExpr(
001589 sqlite3 *db, /* The database connection */
001590 const Expr *pExpr, /* The expression to evaluate */
001591 u8 enc, /* Encoding to use */
001592 u8 affinity, /* Affinity to use */
001593 sqlite3_value **ppVal, /* Write the new value here */
001594 struct ValueNewStat4Ctx *pCtx /* Second argument for valueNew() */
001595 ){
001596 int op;
001597 char *zVal = 0;
001598 sqlite3_value *pVal = 0;
001599 int negInt = 1;
001600 const char *zNeg = "";
001601 int rc = SQLITE_OK;
001602
001603 assert( pExpr!=0 );
001604 while( (op = pExpr->op)==TK_UPLUS || op==TK_SPAN ) pExpr = pExpr->pLeft;
001605 if( op==TK_REGISTER ) op = pExpr->op2;
001606
001607 /* Compressed expressions only appear when parsing the DEFAULT clause
001608 ** on a table column definition, and hence only when pCtx==0. This
001609 ** check ensures that an EP_TokenOnly expression is never passed down
001610 ** into valueFromFunction(). */
001611 assert( (pExpr->flags & EP_TokenOnly)==0 || pCtx==0 );
001612
001613 if( op==TK_CAST ){
001614 u8 aff;
001615 assert( !ExprHasProperty(pExpr, EP_IntValue) );
001616 aff = sqlite3AffinityType(pExpr->u.zToken,0);
001617 rc = valueFromExpr(db, pExpr->pLeft, enc, aff, ppVal, pCtx);
001618 testcase( rc!=SQLITE_OK );
001619 if( *ppVal ){
001620 #ifdef SQLITE_ENABLE_STAT4
001621 rc = ExpandBlob(*ppVal);
001622 #else
001623 /* zero-blobs only come from functions, not literal values. And
001624 ** functions are only processed under STAT4 */
001625 assert( (ppVal[0][0].flags & MEM_Zero)==0 );
001626 #endif
001627 sqlite3VdbeMemCast(*ppVal, aff, enc);
001628 sqlite3ValueApplyAffinity(*ppVal, affinity, enc);
001629 }
001630 return rc;
001631 }
001632
001633 /* Handle negative integers in a single step. This is needed in the
001634 ** case when the value is -9223372036854775808.
001635 */
001636 if( op==TK_UMINUS
001637 && (pExpr->pLeft->op==TK_INTEGER || pExpr->pLeft->op==TK_FLOAT) ){
001638 pExpr = pExpr->pLeft;
001639 op = pExpr->op;
001640 negInt = -1;
001641 zNeg = "-";
001642 }
001643
001644 if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){
001645 pVal = valueNew(db, pCtx);
001646 if( pVal==0 ) goto no_mem;
001647 if( ExprHasProperty(pExpr, EP_IntValue) ){
001648 sqlite3VdbeMemSetInt64(pVal, (i64)pExpr->u.iValue*negInt);
001649 }else{
001650 zVal = sqlite3MPrintf(db, "%s%s", zNeg, pExpr->u.zToken);
001651 if( zVal==0 ) goto no_mem;
001652 sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, SQLITE_DYNAMIC);
001653 }
001654 if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_BLOB ){
001655 sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, SQLITE_UTF8);
001656 }else{
001657 sqlite3ValueApplyAffinity(pVal, affinity, SQLITE_UTF8);
001658 }
001659 assert( (pVal->flags & MEM_IntReal)==0 );
001660 if( pVal->flags & (MEM_Int|MEM_IntReal|MEM_Real) ){
001661 testcase( pVal->flags & MEM_Int );
001662 testcase( pVal->flags & MEM_Real );
001663 pVal->flags &= ~MEM_Str;
001664 }
001665 if( enc!=SQLITE_UTF8 ){
001666 rc = sqlite3VdbeChangeEncoding(pVal, enc);
001667 }
001668 }else if( op==TK_UMINUS ) {
001669 /* This branch happens for multiple negative signs. Ex: -(-5) */
001670 if( SQLITE_OK==valueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal,pCtx)
001671 && pVal!=0
001672 ){
001673 sqlite3VdbeMemNumerify(pVal);
001674 if( pVal->flags & MEM_Real ){
001675 pVal->u.r = -pVal->u.r;
001676 }else if( pVal->u.i==SMALLEST_INT64 ){
001677 #ifndef SQLITE_OMIT_FLOATING_POINT
001678 pVal->u.r = -(double)SMALLEST_INT64;
001679 #else
001680 pVal->u.r = LARGEST_INT64;
001681 #endif
001682 MemSetTypeFlag(pVal, MEM_Real);
001683 }else{
001684 pVal->u.i = -pVal->u.i;
001685 }
001686 sqlite3ValueApplyAffinity(pVal, affinity, enc);
001687 }
001688 }else if( op==TK_NULL ){
001689 pVal = valueNew(db, pCtx);
001690 if( pVal==0 ) goto no_mem;
001691 sqlite3VdbeMemSetNull(pVal);
001692 }
001693 #ifndef SQLITE_OMIT_BLOB_LITERAL
001694 else if( op==TK_BLOB ){
001695 int nVal;
001696 assert( !ExprHasProperty(pExpr, EP_IntValue) );
001697 assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
001698 assert( pExpr->u.zToken[1]=='\'' );
001699 pVal = valueNew(db, pCtx);
001700 if( !pVal ) goto no_mem;
001701 zVal = &pExpr->u.zToken[2];
001702 nVal = sqlite3Strlen30(zVal)-1;
001703 assert( zVal[nVal]=='\'' );
001704 sqlite3VdbeMemSetStr(pVal, sqlite3HexToBlob(db, zVal, nVal), nVal/2,
001705 0, SQLITE_DYNAMIC);
001706 }
001707 #endif
001708 #ifdef SQLITE_ENABLE_STAT4
001709 else if( op==TK_FUNCTION && pCtx!=0 ){
001710 rc = valueFromFunction(db, pExpr, enc, affinity, &pVal, pCtx);
001711 }
001712 #endif
001713 else if( op==TK_TRUEFALSE ){
001714 assert( !ExprHasProperty(pExpr, EP_IntValue) );
001715 pVal = valueNew(db, pCtx);
001716 if( pVal ){
001717 pVal->flags = MEM_Int;
001718 pVal->u.i = pExpr->u.zToken[4]==0;
001719 sqlite3ValueApplyAffinity(pVal, affinity, enc);
001720 }
001721 }
001722
001723 *ppVal = pVal;
001724 return rc;
001725
001726 no_mem:
001727 #ifdef SQLITE_ENABLE_STAT4
001728 if( pCtx==0 || NEVER(pCtx->pParse->nErr==0) )
001729 #endif
001730 sqlite3OomFault(db);
001731 sqlite3DbFree(db, zVal);
001732 assert( *ppVal==0 );
001733 #ifdef SQLITE_ENABLE_STAT4
001734 if( pCtx==0 ) sqlite3ValueFree(pVal);
001735 #else
001736 assert( pCtx==0 ); sqlite3ValueFree(pVal);
001737 #endif
001738 return SQLITE_NOMEM_BKPT;
001739 }
001740
001741 /*
001742 ** Create a new sqlite3_value object, containing the value of pExpr.
001743 **
001744 ** This only works for very simple expressions that consist of one constant
001745 ** token (i.e. "5", "5.1", "'a string'"). If the expression can
001746 ** be converted directly into a value, then the value is allocated and
001747 ** a pointer written to *ppVal. The caller is responsible for deallocating
001748 ** the value by passing it to sqlite3ValueFree() later on. If the expression
001749 ** cannot be converted to a value, then *ppVal is set to NULL.
001750 */
001751 int sqlite3ValueFromExpr(
001752 sqlite3 *db, /* The database connection */
001753 const Expr *pExpr, /* The expression to evaluate */
001754 u8 enc, /* Encoding to use */
001755 u8 affinity, /* Affinity to use */
001756 sqlite3_value **ppVal /* Write the new value here */
001757 ){
001758 return pExpr ? valueFromExpr(db, pExpr, enc, affinity, ppVal, 0) : 0;
001759 }
001760
001761 #ifdef SQLITE_ENABLE_STAT4
001762 /*
001763 ** Attempt to extract a value from pExpr and use it to construct *ppVal.
001764 **
001765 ** If pAlloc is not NULL, then an UnpackedRecord object is created for
001766 ** pAlloc if one does not exist and the new value is added to the
001767 ** UnpackedRecord object.
001768 **
001769 ** A value is extracted in the following cases:
001770 **
001771 ** * (pExpr==0). In this case the value is assumed to be an SQL NULL,
001772 **
001773 ** * The expression is a bound variable, and this is a reprepare, or
001774 **
001775 ** * The expression is a literal value.
001776 **
001777 ** On success, *ppVal is made to point to the extracted value. The caller
001778 ** is responsible for ensuring that the value is eventually freed.
001779 */
001780 static int stat4ValueFromExpr(
001781 Parse *pParse, /* Parse context */
001782 Expr *pExpr, /* The expression to extract a value from */
001783 u8 affinity, /* Affinity to use */
001784 struct ValueNewStat4Ctx *pAlloc,/* How to allocate space. Or NULL */
001785 sqlite3_value **ppVal /* OUT: New value object (or NULL) */
001786 ){
001787 int rc = SQLITE_OK;
001788 sqlite3_value *pVal = 0;
001789 sqlite3 *db = pParse->db;
001790
001791 /* Skip over any TK_COLLATE nodes */
001792 pExpr = sqlite3ExprSkipCollate(pExpr);
001793
001794 assert( pExpr==0 || pExpr->op!=TK_REGISTER || pExpr->op2!=TK_VARIABLE );
001795 if( !pExpr ){
001796 pVal = valueNew(db, pAlloc);
001797 if( pVal ){
001798 sqlite3VdbeMemSetNull((Mem*)pVal);
001799 }
001800 }else if( pExpr->op==TK_VARIABLE && (db->flags & SQLITE_EnableQPSG)==0 ){
001801 Vdbe *v;
001802 int iBindVar = pExpr->iColumn;
001803 sqlite3VdbeSetVarmask(pParse->pVdbe, iBindVar);
001804 if( (v = pParse->pReprepare)!=0 ){
001805 pVal = valueNew(db, pAlloc);
001806 if( pVal ){
001807 rc = sqlite3VdbeMemCopy((Mem*)pVal, &v->aVar[iBindVar-1]);
001808 sqlite3ValueApplyAffinity(pVal, affinity, ENC(db));
001809 pVal->db = pParse->db;
001810 }
001811 }
001812 }else{
001813 rc = valueFromExpr(db, pExpr, ENC(db), affinity, &pVal, pAlloc);
001814 }
001815
001816 assert( pVal==0 || pVal->db==db );
001817 *ppVal = pVal;
001818 return rc;
001819 }
001820
001821 /*
001822 ** This function is used to allocate and populate UnpackedRecord
001823 ** structures intended to be compared against sample index keys stored
001824 ** in the sqlite_stat4 table.
001825 **
001826 ** A single call to this function populates zero or more fields of the
001827 ** record starting with field iVal (fields are numbered from left to
001828 ** right starting with 0). A single field is populated if:
001829 **
001830 ** * (pExpr==0). In this case the value is assumed to be an SQL NULL,
001831 **
001832 ** * The expression is a bound variable, and this is a reprepare, or
001833 **
001834 ** * The sqlite3ValueFromExpr() function is able to extract a value
001835 ** from the expression (i.e. the expression is a literal value).
001836 **
001837 ** Or, if pExpr is a TK_VECTOR, one field is populated for each of the
001838 ** vector components that match either of the two latter criteria listed
001839 ** above.
001840 **
001841 ** Before any value is appended to the record, the affinity of the
001842 ** corresponding column within index pIdx is applied to it. Before
001843 ** this function returns, output parameter *pnExtract is set to the
001844 ** number of values appended to the record.
001845 **
001846 ** When this function is called, *ppRec must either point to an object
001847 ** allocated by an earlier call to this function, or must be NULL. If it
001848 ** is NULL and a value can be successfully extracted, a new UnpackedRecord
001849 ** is allocated (and *ppRec set to point to it) before returning.
001850 **
001851 ** Unless an error is encountered, SQLITE_OK is returned. It is not an
001852 ** error if a value cannot be extracted from pExpr. If an error does
001853 ** occur, an SQLite error code is returned.
001854 */
001855 int sqlite3Stat4ProbeSetValue(
001856 Parse *pParse, /* Parse context */
001857 Index *pIdx, /* Index being probed */
001858 UnpackedRecord **ppRec, /* IN/OUT: Probe record */
001859 Expr *pExpr, /* The expression to extract a value from */
001860 int nElem, /* Maximum number of values to append */
001861 int iVal, /* Array element to populate */
001862 int *pnExtract /* OUT: Values appended to the record */
001863 ){
001864 int rc = SQLITE_OK;
001865 int nExtract = 0;
001866
001867 if( pExpr==0 || pExpr->op!=TK_SELECT ){
001868 int i;
001869 struct ValueNewStat4Ctx alloc;
001870
001871 alloc.pParse = pParse;
001872 alloc.pIdx = pIdx;
001873 alloc.ppRec = ppRec;
001874
001875 for(i=0; i<nElem; i++){
001876 sqlite3_value *pVal = 0;
001877 Expr *pElem = (pExpr ? sqlite3VectorFieldSubexpr(pExpr, i) : 0);
001878 u8 aff = sqlite3IndexColumnAffinity(pParse->db, pIdx, iVal+i);
001879 alloc.iVal = iVal+i;
001880 rc = stat4ValueFromExpr(pParse, pElem, aff, &alloc, &pVal);
001881 if( !pVal ) break;
001882 nExtract++;
001883 }
001884 }
001885
001886 *pnExtract = nExtract;
001887 return rc;
001888 }
001889
001890 /*
001891 ** Attempt to extract a value from expression pExpr using the methods
001892 ** as described for sqlite3Stat4ProbeSetValue() above.
001893 **
001894 ** If successful, set *ppVal to point to a new value object and return
001895 ** SQLITE_OK. If no value can be extracted, but no other error occurs
001896 ** (e.g. OOM), return SQLITE_OK and set *ppVal to NULL. Or, if an error
001897 ** does occur, return an SQLite error code. The final value of *ppVal
001898 ** is undefined in this case.
001899 */
001900 int sqlite3Stat4ValueFromExpr(
001901 Parse *pParse, /* Parse context */
001902 Expr *pExpr, /* The expression to extract a value from */
001903 u8 affinity, /* Affinity to use */
001904 sqlite3_value **ppVal /* OUT: New value object (or NULL) */
001905 ){
001906 return stat4ValueFromExpr(pParse, pExpr, affinity, 0, ppVal);
001907 }
001908
001909 /*
001910 ** Extract the iCol-th column from the nRec-byte record in pRec. Write
001911 ** the column value into *ppVal. If *ppVal is initially NULL then a new
001912 ** sqlite3_value object is allocated.
001913 **
001914 ** If *ppVal is initially NULL then the caller is responsible for
001915 ** ensuring that the value written into *ppVal is eventually freed.
001916 */
001917 int sqlite3Stat4Column(
001918 sqlite3 *db, /* Database handle */
001919 const void *pRec, /* Pointer to buffer containing record */
001920 int nRec, /* Size of buffer pRec in bytes */
001921 int iCol, /* Column to extract */
001922 sqlite3_value **ppVal /* OUT: Extracted value */
001923 ){
001924 u32 t = 0; /* a column type code */
001925 int nHdr; /* Size of the header in the record */
001926 int iHdr; /* Next unread header byte */
001927 int iField; /* Next unread data byte */
001928 int szField = 0; /* Size of the current data field */
001929 int i; /* Column index */
001930 u8 *a = (u8*)pRec; /* Typecast byte array */
001931 Mem *pMem = *ppVal; /* Write result into this Mem object */
001932
001933 assert( iCol>0 );
001934 iHdr = getVarint32(a, nHdr);
001935 if( nHdr>nRec || iHdr>=nHdr ) return SQLITE_CORRUPT_BKPT;
001936 iField = nHdr;
001937 for(i=0; i<=iCol; i++){
001938 iHdr += getVarint32(&a[iHdr], t);
001939 testcase( iHdr==nHdr );
001940 testcase( iHdr==nHdr+1 );
001941 if( iHdr>nHdr ) return SQLITE_CORRUPT_BKPT;
001942 szField = sqlite3VdbeSerialTypeLen(t);
001943 iField += szField;
001944 }
001945 testcase( iField==nRec );
001946 testcase( iField==nRec+1 );
001947 if( iField>nRec ) return SQLITE_CORRUPT_BKPT;
001948 if( pMem==0 ){
001949 pMem = *ppVal = sqlite3ValueNew(db);
001950 if( pMem==0 ) return SQLITE_NOMEM_BKPT;
001951 }
001952 sqlite3VdbeSerialGet(&a[iField-szField], t, pMem);
001953 pMem->enc = ENC(db);
001954 return SQLITE_OK;
001955 }
001956
001957 /*
001958 ** Unless it is NULL, the argument must be an UnpackedRecord object returned
001959 ** by an earlier call to sqlite3Stat4ProbeSetValue(). This call deletes
001960 ** the object.
001961 */
001962 void sqlite3Stat4ProbeFree(UnpackedRecord *pRec){
001963 if( pRec ){
001964 int i;
001965 int nCol = pRec->pKeyInfo->nAllField;
001966 Mem *aMem = pRec->aMem;
001967 sqlite3 *db = aMem[0].db;
001968 for(i=0; i<nCol; i++){
001969 sqlite3VdbeMemRelease(&aMem[i]);
001970 }
001971 sqlite3KeyInfoUnref(pRec->pKeyInfo);
001972 sqlite3DbFreeNN(db, pRec);
001973 }
001974 }
001975 #endif /* ifdef SQLITE_ENABLE_STAT4 */
001976
001977 /*
001978 ** Change the string value of an sqlite3_value object
001979 */
001980 void sqlite3ValueSetStr(
001981 sqlite3_value *v, /* Value to be set */
001982 int n, /* Length of string z */
001983 const void *z, /* Text of the new string */
001984 u8 enc, /* Encoding to use */
001985 void (*xDel)(void*) /* Destructor for the string */
001986 ){
001987 if( v ) sqlite3VdbeMemSetStr((Mem *)v, z, n, enc, xDel);
001988 }
001989
001990 /*
001991 ** Free an sqlite3_value object
001992 */
001993 void sqlite3ValueFree(sqlite3_value *v){
001994 if( !v ) return;
001995 sqlite3VdbeMemRelease((Mem *)v);
001996 sqlite3DbFreeNN(((Mem*)v)->db, v);
001997 }
001998
001999 /*
002000 ** The sqlite3ValueBytes() routine returns the number of bytes in the
002001 ** sqlite3_value object assuming that it uses the encoding "enc".
002002 ** The valueBytes() routine is a helper function.
002003 */
002004 static SQLITE_NOINLINE int valueBytes(sqlite3_value *pVal, u8 enc){
002005 return valueToText(pVal, enc)!=0 ? pVal->n : 0;
002006 }
002007 int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
002008 Mem *p = (Mem*)pVal;
002009 assert( (p->flags & MEM_Null)==0 || (p->flags & (MEM_Str|MEM_Blob))==0 );
002010 if( (p->flags & MEM_Str)!=0 && pVal->enc==enc ){
002011 return p->n;
002012 }
002013 if( (p->flags & MEM_Str)!=0 && enc!=SQLITE_UTF8 && pVal->enc!=SQLITE_UTF8 ){
002014 return p->n;
002015 }
002016 if( (p->flags & MEM_Blob)!=0 ){
002017 if( p->flags & MEM_Zero ){
002018 return p->n + p->u.nZero;
002019 }else{
002020 return p->n;
002021 }
002022 }
002023 if( p->flags & MEM_Null ) return 0;
002024 return valueBytes(pVal, enc);
002025 }