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 /*
000947 ** Set the iIdx'th entry of array aMem[] to contain integer value val.
000948 */
000949 void sqlite3MemSetArrayInt64(sqlite3_value *aMem, int iIdx, i64 val){
000950 sqlite3VdbeMemSetInt64(&aMem[iIdx], val);
000951 }
000952
000953 /* A no-op destructor */
000954 void sqlite3NoopDestructor(void *p){ UNUSED_PARAMETER(p); }
000955
000956 /*
000957 ** Set the value stored in *pMem should already be a NULL.
000958 ** Also store a pointer to go with it.
000959 */
000960 void sqlite3VdbeMemSetPointer(
000961 Mem *pMem,
000962 void *pPtr,
000963 const char *zPType,
000964 void (*xDestructor)(void*)
000965 ){
000966 assert( pMem->flags==MEM_Null );
000967 vdbeMemClear(pMem);
000968 pMem->u.zPType = zPType ? zPType : "";
000969 pMem->z = pPtr;
000970 pMem->flags = MEM_Null|MEM_Dyn|MEM_Subtype|MEM_Term;
000971 pMem->eSubtype = 'p';
000972 pMem->xDel = xDestructor ? xDestructor : sqlite3NoopDestructor;
000973 }
000974
000975 #ifndef SQLITE_OMIT_FLOATING_POINT
000976 /*
000977 ** Delete any previous value and set the value stored in *pMem to val,
000978 ** manifest type REAL.
000979 */
000980 void sqlite3VdbeMemSetDouble(Mem *pMem, double val){
000981 sqlite3VdbeMemSetNull(pMem);
000982 if( !sqlite3IsNaN(val) ){
000983 pMem->u.r = val;
000984 pMem->flags = MEM_Real;
000985 }
000986 }
000987 #endif
000988
000989 #ifdef SQLITE_DEBUG
000990 /*
000991 ** Return true if the Mem holds a RowSet object. This routine is intended
000992 ** for use inside of assert() statements.
000993 */
000994 int sqlite3VdbeMemIsRowSet(const Mem *pMem){
000995 return (pMem->flags&(MEM_Blob|MEM_Dyn))==(MEM_Blob|MEM_Dyn)
000996 && pMem->xDel==sqlite3RowSetDelete;
000997 }
000998 #endif
000999
001000 /*
001001 ** Delete any previous value and set the value of pMem to be an
001002 ** empty boolean index.
001003 **
001004 ** Return SQLITE_OK on success and SQLITE_NOMEM if a memory allocation
001005 ** error occurs.
001006 */
001007 int sqlite3VdbeMemSetRowSet(Mem *pMem){
001008 sqlite3 *db = pMem->db;
001009 RowSet *p;
001010 assert( db!=0 );
001011 assert( !sqlite3VdbeMemIsRowSet(pMem) );
001012 sqlite3VdbeMemRelease(pMem);
001013 p = sqlite3RowSetInit(db);
001014 if( p==0 ) return SQLITE_NOMEM;
001015 pMem->z = (char*)p;
001016 pMem->flags = MEM_Blob|MEM_Dyn;
001017 pMem->xDel = sqlite3RowSetDelete;
001018 return SQLITE_OK;
001019 }
001020
001021 /*
001022 ** Return true if the Mem object contains a TEXT or BLOB that is
001023 ** too large - whose size exceeds SQLITE_MAX_LENGTH.
001024 */
001025 int sqlite3VdbeMemTooBig(Mem *p){
001026 assert( p->db!=0 );
001027 if( p->flags & (MEM_Str|MEM_Blob) ){
001028 int n = p->n;
001029 if( p->flags & MEM_Zero ){
001030 n += p->u.nZero;
001031 }
001032 return n>p->db->aLimit[SQLITE_LIMIT_LENGTH];
001033 }
001034 return 0;
001035 }
001036
001037 #ifdef SQLITE_DEBUG
001038 /*
001039 ** This routine prepares a memory cell for modification by breaking
001040 ** its link to a shallow copy and by marking any current shallow
001041 ** copies of this cell as invalid.
001042 **
001043 ** This is used for testing and debugging only - to help ensure that shallow
001044 ** copies (created by OP_SCopy) are not misused.
001045 */
001046 void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
001047 int i;
001048 Mem *pX;
001049 for(i=1, pX=pVdbe->aMem+1; i<pVdbe->nMem; i++, pX++){
001050 if( pX->pScopyFrom==pMem ){
001051 u16 mFlags;
001052 if( pVdbe->db->flags & SQLITE_VdbeTrace ){
001053 sqlite3DebugPrintf("Invalidate R[%d] due to change in R[%d]\n",
001054 (int)(pX - pVdbe->aMem), (int)(pMem - pVdbe->aMem));
001055 }
001056 /* If pX is marked as a shallow copy of pMem, then try to verify that
001057 ** no significant changes have been made to pX since the OP_SCopy.
001058 ** A significant change would indicated a missed call to this
001059 ** function for pX. Minor changes, such as adding or removing a
001060 ** dual type, are allowed, as long as the underlying value is the
001061 ** same. */
001062 mFlags = pMem->flags & pX->flags & pX->mScopyFlags;
001063 assert( (mFlags&(MEM_Int|MEM_IntReal))==0 || pMem->u.i==pX->u.i );
001064
001065 /* pMem is the register that is changing. But also mark pX as
001066 ** undefined so that we can quickly detect the shallow-copy error */
001067 pX->flags = MEM_Undefined;
001068 pX->pScopyFrom = 0;
001069 }
001070 }
001071 pMem->pScopyFrom = 0;
001072 }
001073 #endif /* SQLITE_DEBUG */
001074
001075 /*
001076 ** Make an shallow copy of pFrom into pTo. Prior contents of
001077 ** pTo are freed. The pFrom->z field is not duplicated. If
001078 ** pFrom->z is used, then pTo->z points to the same thing as pFrom->z
001079 ** and flags gets srcType (either MEM_Ephem or MEM_Static).
001080 */
001081 static SQLITE_NOINLINE void vdbeClrCopy(Mem *pTo, const Mem *pFrom, int eType){
001082 vdbeMemClearExternAndSetNull(pTo);
001083 assert( !VdbeMemDynamic(pTo) );
001084 sqlite3VdbeMemShallowCopy(pTo, pFrom, eType);
001085 }
001086 void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
001087 assert( !sqlite3VdbeMemIsRowSet(pFrom) );
001088 assert( pTo->db==pFrom->db );
001089 if( VdbeMemDynamic(pTo) ){ vdbeClrCopy(pTo,pFrom,srcType); return; }
001090 memcpy(pTo, pFrom, MEMCELLSIZE);
001091 if( (pFrom->flags&MEM_Static)==0 ){
001092 pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
001093 assert( srcType==MEM_Ephem || srcType==MEM_Static );
001094 pTo->flags |= srcType;
001095 }
001096 }
001097
001098 /*
001099 ** Make a full copy of pFrom into pTo. Prior contents of pTo are
001100 ** freed before the copy is made.
001101 */
001102 int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
001103 int rc = SQLITE_OK;
001104
001105 assert( !sqlite3VdbeMemIsRowSet(pFrom) );
001106 if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);
001107 memcpy(pTo, pFrom, MEMCELLSIZE);
001108 pTo->flags &= ~MEM_Dyn;
001109 if( pTo->flags&(MEM_Str|MEM_Blob) ){
001110 if( 0==(pFrom->flags&MEM_Static) ){
001111 pTo->flags |= MEM_Ephem;
001112 rc = sqlite3VdbeMemMakeWriteable(pTo);
001113 }
001114 }
001115
001116 return rc;
001117 }
001118
001119 /*
001120 ** Transfer the contents of pFrom to pTo. Any existing value in pTo is
001121 ** freed. If pFrom contains ephemeral data, a copy is made.
001122 **
001123 ** pFrom contains an SQL NULL when this routine returns.
001124 */
001125 void sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){
001126 assert( pFrom->db==0 || sqlite3_mutex_held(pFrom->db->mutex) );
001127 assert( pTo->db==0 || sqlite3_mutex_held(pTo->db->mutex) );
001128 assert( pFrom->db==0 || pTo->db==0 || pFrom->db==pTo->db );
001129
001130 sqlite3VdbeMemRelease(pTo);
001131 memcpy(pTo, pFrom, sizeof(Mem));
001132 pFrom->flags = MEM_Null;
001133 pFrom->szMalloc = 0;
001134 }
001135
001136 /*
001137 ** Change the value of a Mem to be a string or a BLOB.
001138 **
001139 ** The memory management strategy depends on the value of the xDel
001140 ** parameter. If the value passed is SQLITE_TRANSIENT, then the
001141 ** string is copied into a (possibly existing) buffer managed by the
001142 ** Mem structure. Otherwise, any existing buffer is freed and the
001143 ** pointer copied.
001144 **
001145 ** If the string is too large (if it exceeds the SQLITE_LIMIT_LENGTH
001146 ** size limit) then no memory allocation occurs. If the string can be
001147 ** stored without allocating memory, then it is. If a memory allocation
001148 ** is required to store the string, then value of pMem is unchanged. In
001149 ** either case, SQLITE_TOOBIG is returned.
001150 **
001151 ** The "enc" parameter is the text encoding for the string, or zero
001152 ** to store a blob.
001153 **
001154 ** If n is negative, then the string consists of all bytes up to but
001155 ** excluding the first zero character. The n parameter must be
001156 ** non-negative for blobs.
001157 */
001158 int sqlite3VdbeMemSetStr(
001159 Mem *pMem, /* Memory cell to set to string value */
001160 const char *z, /* String pointer */
001161 i64 n, /* Bytes in string, or negative */
001162 u8 enc, /* Encoding of z. 0 for BLOBs */
001163 void (*xDel)(void*) /* Destructor function */
001164 ){
001165 i64 nByte = n; /* New value for pMem->n */
001166 int iLimit; /* Maximum allowed string or blob size */
001167 u16 flags; /* New value for pMem->flags */
001168
001169 assert( pMem!=0 );
001170 assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
001171 assert( !sqlite3VdbeMemIsRowSet(pMem) );
001172 assert( enc!=0 || n>=0 );
001173
001174 /* If z is a NULL pointer, set pMem to contain an SQL NULL. */
001175 if( !z ){
001176 sqlite3VdbeMemSetNull(pMem);
001177 return SQLITE_OK;
001178 }
001179
001180 if( pMem->db ){
001181 iLimit = pMem->db->aLimit[SQLITE_LIMIT_LENGTH];
001182 }else{
001183 iLimit = SQLITE_MAX_LENGTH;
001184 }
001185 if( nByte<0 ){
001186 assert( enc!=0 );
001187 if( enc==SQLITE_UTF8 ){
001188 nByte = strlen(z);
001189 }else{
001190 for(nByte=0; nByte<=iLimit && (z[nByte] | z[nByte+1]); nByte+=2){}
001191 }
001192 flags= MEM_Str|MEM_Term;
001193 }else if( enc==0 ){
001194 flags = MEM_Blob;
001195 enc = SQLITE_UTF8;
001196 }else{
001197 flags = MEM_Str;
001198 }
001199 if( nByte>iLimit ){
001200 if( xDel && xDel!=SQLITE_TRANSIENT ){
001201 if( xDel==SQLITE_DYNAMIC ){
001202 sqlite3DbFree(pMem->db, (void*)z);
001203 }else{
001204 xDel((void*)z);
001205 }
001206 }
001207 sqlite3VdbeMemSetNull(pMem);
001208 return sqlite3ErrorToParser(pMem->db, SQLITE_TOOBIG);
001209 }
001210
001211 /* The following block sets the new values of Mem.z and Mem.xDel. It
001212 ** also sets a flag in local variable "flags" to indicate the memory
001213 ** management (one of MEM_Dyn or MEM_Static).
001214 */
001215 if( xDel==SQLITE_TRANSIENT ){
001216 i64 nAlloc = nByte;
001217 if( flags&MEM_Term ){
001218 nAlloc += (enc==SQLITE_UTF8?1:2);
001219 }
001220 testcase( nAlloc==0 );
001221 testcase( nAlloc==31 );
001222 testcase( nAlloc==32 );
001223 if( sqlite3VdbeMemClearAndResize(pMem, (int)MAX(nAlloc,32)) ){
001224 return SQLITE_NOMEM_BKPT;
001225 }
001226 memcpy(pMem->z, z, nAlloc);
001227 }else{
001228 sqlite3VdbeMemRelease(pMem);
001229 pMem->z = (char *)z;
001230 if( xDel==SQLITE_DYNAMIC ){
001231 pMem->zMalloc = pMem->z;
001232 pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);
001233 }else{
001234 pMem->xDel = xDel;
001235 flags |= ((xDel==SQLITE_STATIC)?MEM_Static:MEM_Dyn);
001236 }
001237 }
001238
001239 pMem->n = (int)(nByte & 0x7fffffff);
001240 pMem->flags = flags;
001241 pMem->enc = enc;
001242
001243 #ifndef SQLITE_OMIT_UTF16
001244 if( enc>SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){
001245 return SQLITE_NOMEM_BKPT;
001246 }
001247 #endif
001248
001249
001250 return SQLITE_OK;
001251 }
001252
001253 /*
001254 ** Move data out of a btree key or data field and into a Mem structure.
001255 ** The data is payload from the entry that pCur is currently pointing
001256 ** to. offset and amt determine what portion of the data or key to retrieve.
001257 ** The result is written into the pMem element.
001258 **
001259 ** The pMem object must have been initialized. This routine will use
001260 ** pMem->zMalloc to hold the content from the btree, if possible. New
001261 ** pMem->zMalloc space will be allocated if necessary. The calling routine
001262 ** is responsible for making sure that the pMem object is eventually
001263 ** destroyed.
001264 **
001265 ** If this routine fails for any reason (malloc returns NULL or unable
001266 ** to read from the disk) then the pMem is left in an inconsistent state.
001267 */
001268 int sqlite3VdbeMemFromBtree(
001269 BtCursor *pCur, /* Cursor pointing at record to retrieve. */
001270 u32 offset, /* Offset from the start of data to return bytes from. */
001271 u32 amt, /* Number of bytes to return. */
001272 Mem *pMem /* OUT: Return data in this Mem structure. */
001273 ){
001274 int rc;
001275 pMem->flags = MEM_Null;
001276 if( sqlite3BtreeMaxRecordSize(pCur)<offset+amt ){
001277 return SQLITE_CORRUPT_BKPT;
001278 }
001279 if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+1)) ){
001280 rc = sqlite3BtreePayload(pCur, offset, amt, pMem->z);
001281 if( rc==SQLITE_OK ){
001282 pMem->z[amt] = 0; /* Overrun area used when reading malformed records */
001283 pMem->flags = MEM_Blob;
001284 pMem->n = (int)amt;
001285 }else{
001286 sqlite3VdbeMemRelease(pMem);
001287 }
001288 }
001289 return rc;
001290 }
001291 int sqlite3VdbeMemFromBtreeZeroOffset(
001292 BtCursor *pCur, /* Cursor pointing at record to retrieve. */
001293 u32 amt, /* Number of bytes to return. */
001294 Mem *pMem /* OUT: Return data in this Mem structure. */
001295 ){
001296 u32 available = 0; /* Number of bytes available on the local btree page */
001297 int rc = SQLITE_OK; /* Return code */
001298
001299 assert( sqlite3BtreeCursorIsValid(pCur) );
001300 assert( !VdbeMemDynamic(pMem) );
001301
001302 /* Note: the calls to BtreeKeyFetch() and DataFetch() below assert()
001303 ** that both the BtShared and database handle mutexes are held. */
001304 assert( !sqlite3VdbeMemIsRowSet(pMem) );
001305 pMem->z = (char *)sqlite3BtreePayloadFetch(pCur, &available);
001306 assert( pMem->z!=0 );
001307
001308 if( amt<=available ){
001309 pMem->flags = MEM_Blob|MEM_Ephem;
001310 pMem->n = (int)amt;
001311 }else{
001312 rc = sqlite3VdbeMemFromBtree(pCur, 0, amt, pMem);
001313 }
001314
001315 return rc;
001316 }
001317
001318 /*
001319 ** The pVal argument is known to be a value other than NULL.
001320 ** Convert it into a string with encoding enc and return a pointer
001321 ** to a zero-terminated version of that string.
001322 */
001323 static SQLITE_NOINLINE const void *valueToText(sqlite3_value* pVal, u8 enc){
001324 assert( pVal!=0 );
001325 assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
001326 assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
001327 assert( !sqlite3VdbeMemIsRowSet(pVal) );
001328 assert( (pVal->flags & (MEM_Null))==0 );
001329 if( pVal->flags & (MEM_Blob|MEM_Str) ){
001330 if( ExpandBlob(pVal) ) return 0;
001331 pVal->flags |= MEM_Str;
001332 if( pVal->enc != (enc & ~SQLITE_UTF16_ALIGNED) ){
001333 sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
001334 }
001335 if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&SQLITE_PTR_TO_INT(pVal->z)) ){
001336 assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );
001337 if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){
001338 return 0;
001339 }
001340 }
001341 sqlite3VdbeMemNulTerminate(pVal); /* IMP: R-31275-44060 */
001342 }else{
001343 sqlite3VdbeMemStringify(pVal, enc, 0);
001344 assert( 0==(1&SQLITE_PTR_TO_INT(pVal->z)) );
001345 }
001346 assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || pVal->db==0
001347 || pVal->db->mallocFailed );
001348 if( pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) ){
001349 assert( sqlite3VdbeMemValidStrRep(pVal) );
001350 return pVal->z;
001351 }else{
001352 return 0;
001353 }
001354 }
001355
001356 /* This function is only available internally, it is not part of the
001357 ** external API. It works in a similar way to sqlite3_value_text(),
001358 ** except the data returned is in the encoding specified by the second
001359 ** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or
001360 ** SQLITE_UTF8.
001361 **
001362 ** (2006-02-16:) The enc value can be or-ed with SQLITE_UTF16_ALIGNED.
001363 ** If that is the case, then the result must be aligned on an even byte
001364 ** boundary.
001365 */
001366 const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
001367 if( !pVal ) return 0;
001368 assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
001369 assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
001370 assert( !sqlite3VdbeMemIsRowSet(pVal) );
001371 if( (pVal->flags&(MEM_Str|MEM_Term))==(MEM_Str|MEM_Term) && pVal->enc==enc ){
001372 assert( sqlite3VdbeMemValidStrRep(pVal) );
001373 return pVal->z;
001374 }
001375 if( pVal->flags&MEM_Null ){
001376 return 0;
001377 }
001378 return valueToText(pVal, enc);
001379 }
001380
001381 /* Return true if sqlit3_value object pVal is a string or blob value
001382 ** that uses the destructor specified in the second argument.
001383 **
001384 ** TODO: Maybe someday promote this interface into a published API so
001385 ** that third-party extensions can get access to it?
001386 */
001387 int sqlite3ValueIsOfClass(const sqlite3_value *pVal, void(*xFree)(void*)){
001388 if( ALWAYS(pVal!=0)
001389 && ALWAYS((pVal->flags & (MEM_Str|MEM_Blob))!=0)
001390 && (pVal->flags & MEM_Dyn)!=0
001391 && pVal->xDel==xFree
001392 ){
001393 return 1;
001394 }else{
001395 return 0;
001396 }
001397 }
001398
001399 /*
001400 ** Create a new sqlite3_value object.
001401 */
001402 sqlite3_value *sqlite3ValueNew(sqlite3 *db){
001403 Mem *p = sqlite3DbMallocZero(db, sizeof(*p));
001404 if( p ){
001405 p->flags = MEM_Null;
001406 p->db = db;
001407 }
001408 return p;
001409 }
001410
001411 /*
001412 ** Context object passed by sqlite3Stat4ProbeSetValue() through to
001413 ** valueNew(). See comments above valueNew() for details.
001414 */
001415 struct ValueNewStat4Ctx {
001416 Parse *pParse;
001417 Index *pIdx;
001418 UnpackedRecord **ppRec;
001419 int iVal;
001420 };
001421
001422 /*
001423 ** Allocate and return a pointer to a new sqlite3_value object. If
001424 ** the second argument to this function is NULL, the object is allocated
001425 ** by calling sqlite3ValueNew().
001426 **
001427 ** Otherwise, if the second argument is non-zero, then this function is
001428 ** being called indirectly by sqlite3Stat4ProbeSetValue(). If it has not
001429 ** already been allocated, allocate the UnpackedRecord structure that
001430 ** that function will return to its caller here. Then return a pointer to
001431 ** an sqlite3_value within the UnpackedRecord.a[] array.
001432 */
001433 static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){
001434 #ifdef SQLITE_ENABLE_STAT4
001435 if( p ){
001436 UnpackedRecord *pRec = p->ppRec[0];
001437
001438 if( pRec==0 ){
001439 Index *pIdx = p->pIdx; /* Index being probed */
001440 int nByte; /* Bytes of space to allocate */
001441 int i; /* Counter variable */
001442 int nCol = pIdx->nColumn; /* Number of index columns including rowid */
001443
001444 nByte = sizeof(Mem) * nCol + ROUND8(sizeof(UnpackedRecord));
001445 pRec = (UnpackedRecord*)sqlite3DbMallocZero(db, nByte);
001446 if( pRec ){
001447 pRec->pKeyInfo = sqlite3KeyInfoOfIndex(p->pParse, pIdx);
001448 if( pRec->pKeyInfo ){
001449 assert( pRec->pKeyInfo->nAllField==nCol );
001450 assert( pRec->pKeyInfo->enc==ENC(db) );
001451 pRec->aMem = (Mem *)((u8*)pRec + ROUND8(sizeof(UnpackedRecord)));
001452 for(i=0; i<nCol; i++){
001453 pRec->aMem[i].flags = MEM_Null;
001454 pRec->aMem[i].db = db;
001455 }
001456 }else{
001457 sqlite3DbFreeNN(db, pRec);
001458 pRec = 0;
001459 }
001460 }
001461 if( pRec==0 ) return 0;
001462 p->ppRec[0] = pRec;
001463 }
001464
001465 pRec->nField = p->iVal+1;
001466 sqlite3VdbeMemSetNull(&pRec->aMem[p->iVal]);
001467 return &pRec->aMem[p->iVal];
001468 }
001469 #else
001470 UNUSED_PARAMETER(p);
001471 #endif /* defined(SQLITE_ENABLE_STAT4) */
001472 return sqlite3ValueNew(db);
001473 }
001474
001475 /*
001476 ** The expression object indicated by the second argument is guaranteed
001477 ** to be a scalar SQL function. If
001478 **
001479 ** * all function arguments are SQL literals,
001480 ** * one of the SQLITE_FUNC_CONSTANT or _SLOCHNG function flags is set, and
001481 ** * the SQLITE_FUNC_NEEDCOLL function flag is not set,
001482 **
001483 ** then this routine attempts to invoke the SQL function. Assuming no
001484 ** error occurs, output parameter (*ppVal) is set to point to a value
001485 ** object containing the result before returning SQLITE_OK.
001486 **
001487 ** Affinity aff is applied to the result of the function before returning.
001488 ** If the result is a text value, the sqlite3_value object uses encoding
001489 ** enc.
001490 **
001491 ** If the conditions above are not met, this function returns SQLITE_OK
001492 ** and sets (*ppVal) to NULL. Or, if an error occurs, (*ppVal) is set to
001493 ** NULL and an SQLite error code returned.
001494 */
001495 #ifdef SQLITE_ENABLE_STAT4
001496 static int valueFromFunction(
001497 sqlite3 *db, /* The database connection */
001498 const Expr *p, /* The expression to evaluate */
001499 u8 enc, /* Encoding to use */
001500 u8 aff, /* Affinity to use */
001501 sqlite3_value **ppVal, /* Write the new value here */
001502 struct ValueNewStat4Ctx *pCtx /* Second argument for valueNew() */
001503 ){
001504 sqlite3_context ctx; /* Context object for function invocation */
001505 sqlite3_value **apVal = 0; /* Function arguments */
001506 int nVal = 0; /* Size of apVal[] array */
001507 FuncDef *pFunc = 0; /* Function definition */
001508 sqlite3_value *pVal = 0; /* New value */
001509 int rc = SQLITE_OK; /* Return code */
001510 ExprList *pList = 0; /* Function arguments */
001511 int i; /* Iterator variable */
001512
001513 assert( pCtx!=0 );
001514 assert( (p->flags & EP_TokenOnly)==0 );
001515 assert( ExprUseXList(p) );
001516 pList = p->x.pList;
001517 if( pList ) nVal = pList->nExpr;
001518 assert( !ExprHasProperty(p, EP_IntValue) );
001519 pFunc = sqlite3FindFunction(db, p->u.zToken, nVal, enc, 0);
001520 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
001521 if( pFunc==0 ) return SQLITE_OK;
001522 #endif
001523 assert( pFunc );
001524 if( (pFunc->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG))==0
001525 || (pFunc->funcFlags & (SQLITE_FUNC_NEEDCOLL|SQLITE_FUNC_RUNONLY))!=0
001526 ){
001527 return SQLITE_OK;
001528 }
001529
001530 if( pList ){
001531 apVal = (sqlite3_value**)sqlite3DbMallocZero(db, sizeof(apVal[0]) * nVal);
001532 if( apVal==0 ){
001533 rc = SQLITE_NOMEM_BKPT;
001534 goto value_from_function_out;
001535 }
001536 for(i=0; i<nVal; i++){
001537 rc = sqlite3ValueFromExpr(db, pList->a[i].pExpr, enc, aff, &apVal[i]);
001538 if( apVal[i]==0 || rc!=SQLITE_OK ) goto value_from_function_out;
001539 }
001540 }
001541
001542 pVal = valueNew(db, pCtx);
001543 if( pVal==0 ){
001544 rc = SQLITE_NOMEM_BKPT;
001545 goto value_from_function_out;
001546 }
001547
001548 memset(&ctx, 0, sizeof(ctx));
001549 ctx.pOut = pVal;
001550 ctx.pFunc = pFunc;
001551 ctx.enc = ENC(db);
001552 pFunc->xSFunc(&ctx, nVal, apVal);
001553 if( ctx.isError ){
001554 rc = ctx.isError;
001555 sqlite3ErrorMsg(pCtx->pParse, "%s", sqlite3_value_text(pVal));
001556 }else{
001557 sqlite3ValueApplyAffinity(pVal, aff, SQLITE_UTF8);
001558 assert( rc==SQLITE_OK );
001559 rc = sqlite3VdbeChangeEncoding(pVal, enc);
001560 if( NEVER(rc==SQLITE_OK && sqlite3VdbeMemTooBig(pVal)) ){
001561 rc = SQLITE_TOOBIG;
001562 pCtx->pParse->nErr++;
001563 }
001564 }
001565
001566 value_from_function_out:
001567 if( rc!=SQLITE_OK ){
001568 pVal = 0;
001569 pCtx->pParse->rc = rc;
001570 }
001571 if( apVal ){
001572 for(i=0; i<nVal; i++){
001573 sqlite3ValueFree(apVal[i]);
001574 }
001575 sqlite3DbFreeNN(db, apVal);
001576 }
001577
001578 *ppVal = pVal;
001579 return rc;
001580 }
001581 #else
001582 # define valueFromFunction(a,b,c,d,e,f) SQLITE_OK
001583 #endif /* defined(SQLITE_ENABLE_STAT4) */
001584
001585 /*
001586 ** Extract a value from the supplied expression in the manner described
001587 ** above sqlite3ValueFromExpr(). Allocate the sqlite3_value object
001588 ** using valueNew().
001589 **
001590 ** If pCtx is NULL and an error occurs after the sqlite3_value object
001591 ** has been allocated, it is freed before returning. Or, if pCtx is not
001592 ** NULL, it is assumed that the caller will free any allocated object
001593 ** in all cases.
001594 */
001595 static int valueFromExpr(
001596 sqlite3 *db, /* The database connection */
001597 const Expr *pExpr, /* The expression to evaluate */
001598 u8 enc, /* Encoding to use */
001599 u8 affinity, /* Affinity to use */
001600 sqlite3_value **ppVal, /* Write the new value here */
001601 struct ValueNewStat4Ctx *pCtx /* Second argument for valueNew() */
001602 ){
001603 int op;
001604 char *zVal = 0;
001605 sqlite3_value *pVal = 0;
001606 int negInt = 1;
001607 const char *zNeg = "";
001608 int rc = SQLITE_OK;
001609
001610 assert( pExpr!=0 );
001611 while( (op = pExpr->op)==TK_UPLUS || op==TK_SPAN ) pExpr = pExpr->pLeft;
001612 if( op==TK_REGISTER ) op = pExpr->op2;
001613
001614 /* Compressed expressions only appear when parsing the DEFAULT clause
001615 ** on a table column definition, and hence only when pCtx==0. This
001616 ** check ensures that an EP_TokenOnly expression is never passed down
001617 ** into valueFromFunction(). */
001618 assert( (pExpr->flags & EP_TokenOnly)==0 || pCtx==0 );
001619
001620 if( op==TK_CAST ){
001621 u8 aff;
001622 assert( !ExprHasProperty(pExpr, EP_IntValue) );
001623 aff = sqlite3AffinityType(pExpr->u.zToken,0);
001624 rc = valueFromExpr(db, pExpr->pLeft, enc, aff, ppVal, pCtx);
001625 testcase( rc!=SQLITE_OK );
001626 if( *ppVal ){
001627 #ifdef SQLITE_ENABLE_STAT4
001628 rc = ExpandBlob(*ppVal);
001629 #else
001630 /* zero-blobs only come from functions, not literal values. And
001631 ** functions are only processed under STAT4 */
001632 assert( (ppVal[0][0].flags & MEM_Zero)==0 );
001633 #endif
001634 sqlite3VdbeMemCast(*ppVal, aff, enc);
001635 sqlite3ValueApplyAffinity(*ppVal, affinity, enc);
001636 }
001637 return rc;
001638 }
001639
001640 /* Handle negative integers in a single step. This is needed in the
001641 ** case when the value is -9223372036854775808. Except - do not do this
001642 ** for hexadecimal literals. */
001643 if( op==TK_UMINUS ){
001644 Expr *pLeft = pExpr->pLeft;
001645 if( (pLeft->op==TK_INTEGER || pLeft->op==TK_FLOAT) ){
001646 if( ExprHasProperty(pLeft, EP_IntValue)
001647 || pLeft->u.zToken[0]!='0' || (pLeft->u.zToken[1] & ~0x20)!='X'
001648 ){
001649 pExpr = pLeft;
001650 op = pExpr->op;
001651 negInt = -1;
001652 zNeg = "-";
001653 }
001654 }
001655 }
001656
001657 if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){
001658 pVal = valueNew(db, pCtx);
001659 if( pVal==0 ) goto no_mem;
001660 if( ExprHasProperty(pExpr, EP_IntValue) ){
001661 sqlite3VdbeMemSetInt64(pVal, (i64)pExpr->u.iValue*negInt);
001662 }else{
001663 i64 iVal;
001664 if( op==TK_INTEGER && 0==sqlite3DecOrHexToI64(pExpr->u.zToken, &iVal) ){
001665 sqlite3VdbeMemSetInt64(pVal, iVal*negInt);
001666 }else{
001667 zVal = sqlite3MPrintf(db, "%s%s", zNeg, pExpr->u.zToken);
001668 if( zVal==0 ) goto no_mem;
001669 sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, SQLITE_DYNAMIC);
001670 }
001671 }
001672 if( affinity==SQLITE_AFF_BLOB ){
001673 if( op==TK_FLOAT ){
001674 assert( pVal && pVal->z && pVal->flags==(MEM_Str|MEM_Term) );
001675 sqlite3AtoF(pVal->z, &pVal->u.r, pVal->n, SQLITE_UTF8);
001676 pVal->flags = MEM_Real;
001677 }else if( op==TK_INTEGER ){
001678 /* This case is required by -9223372036854775808 and other strings
001679 ** that look like integers but cannot be handled by the
001680 ** sqlite3DecOrHexToI64() call above. */
001681 sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, SQLITE_UTF8);
001682 }
001683 }else{
001684 sqlite3ValueApplyAffinity(pVal, affinity, SQLITE_UTF8);
001685 }
001686 assert( (pVal->flags & MEM_IntReal)==0 );
001687 if( pVal->flags & (MEM_Int|MEM_IntReal|MEM_Real) ){
001688 testcase( pVal->flags & MEM_Int );
001689 testcase( pVal->flags & MEM_Real );
001690 pVal->flags &= ~MEM_Str;
001691 }
001692 if( enc!=SQLITE_UTF8 ){
001693 rc = sqlite3VdbeChangeEncoding(pVal, enc);
001694 }
001695 }else if( op==TK_UMINUS ) {
001696 /* This branch happens for multiple negative signs. Ex: -(-5) */
001697 if( SQLITE_OK==valueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal,pCtx)
001698 && pVal!=0
001699 ){
001700 sqlite3VdbeMemNumerify(pVal);
001701 if( pVal->flags & MEM_Real ){
001702 pVal->u.r = -pVal->u.r;
001703 }else if( pVal->u.i==SMALLEST_INT64 ){
001704 #ifndef SQLITE_OMIT_FLOATING_POINT
001705 pVal->u.r = -(double)SMALLEST_INT64;
001706 #else
001707 pVal->u.r = LARGEST_INT64;
001708 #endif
001709 MemSetTypeFlag(pVal, MEM_Real);
001710 }else{
001711 pVal->u.i = -pVal->u.i;
001712 }
001713 sqlite3ValueApplyAffinity(pVal, affinity, enc);
001714 }
001715 }else if( op==TK_NULL ){
001716 pVal = valueNew(db, pCtx);
001717 if( pVal==0 ) goto no_mem;
001718 sqlite3VdbeMemSetNull(pVal);
001719 }
001720 #ifndef SQLITE_OMIT_BLOB_LITERAL
001721 else if( op==TK_BLOB ){
001722 int nVal;
001723 assert( !ExprHasProperty(pExpr, EP_IntValue) );
001724 assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
001725 assert( pExpr->u.zToken[1]=='\'' );
001726 pVal = valueNew(db, pCtx);
001727 if( !pVal ) goto no_mem;
001728 zVal = &pExpr->u.zToken[2];
001729 nVal = sqlite3Strlen30(zVal)-1;
001730 assert( zVal[nVal]=='\'' );
001731 sqlite3VdbeMemSetStr(pVal, sqlite3HexToBlob(db, zVal, nVal), nVal/2,
001732 0, SQLITE_DYNAMIC);
001733 }
001734 #endif
001735 #ifdef SQLITE_ENABLE_STAT4
001736 else if( op==TK_FUNCTION && pCtx!=0 ){
001737 rc = valueFromFunction(db, pExpr, enc, affinity, &pVal, pCtx);
001738 }
001739 #endif
001740 else if( op==TK_TRUEFALSE ){
001741 assert( !ExprHasProperty(pExpr, EP_IntValue) );
001742 pVal = valueNew(db, pCtx);
001743 if( pVal ){
001744 pVal->flags = MEM_Int;
001745 pVal->u.i = pExpr->u.zToken[4]==0;
001746 sqlite3ValueApplyAffinity(pVal, affinity, enc);
001747 }
001748 }
001749
001750 *ppVal = pVal;
001751 return rc;
001752
001753 no_mem:
001754 #ifdef SQLITE_ENABLE_STAT4
001755 if( pCtx==0 || NEVER(pCtx->pParse->nErr==0) )
001756 #endif
001757 sqlite3OomFault(db);
001758 sqlite3DbFree(db, zVal);
001759 assert( *ppVal==0 );
001760 #ifdef SQLITE_ENABLE_STAT4
001761 if( pCtx==0 ) sqlite3ValueFree(pVal);
001762 #else
001763 assert( pCtx==0 ); sqlite3ValueFree(pVal);
001764 #endif
001765 return SQLITE_NOMEM_BKPT;
001766 }
001767
001768 /*
001769 ** Create a new sqlite3_value object, containing the value of pExpr.
001770 **
001771 ** This only works for very simple expressions that consist of one constant
001772 ** token (i.e. "5", "5.1", "'a string'"). If the expression can
001773 ** be converted directly into a value, then the value is allocated and
001774 ** a pointer written to *ppVal. The caller is responsible for deallocating
001775 ** the value by passing it to sqlite3ValueFree() later on. If the expression
001776 ** cannot be converted to a value, then *ppVal is set to NULL.
001777 */
001778 int sqlite3ValueFromExpr(
001779 sqlite3 *db, /* The database connection */
001780 const Expr *pExpr, /* The expression to evaluate */
001781 u8 enc, /* Encoding to use */
001782 u8 affinity, /* Affinity to use */
001783 sqlite3_value **ppVal /* Write the new value here */
001784 ){
001785 return pExpr ? valueFromExpr(db, pExpr, enc, affinity, ppVal, 0) : 0;
001786 }
001787
001788 #ifdef SQLITE_ENABLE_STAT4
001789 /*
001790 ** Attempt to extract a value from pExpr and use it to construct *ppVal.
001791 **
001792 ** If pAlloc is not NULL, then an UnpackedRecord object is created for
001793 ** pAlloc if one does not exist and the new value is added to the
001794 ** UnpackedRecord object.
001795 **
001796 ** A value is extracted in the following cases:
001797 **
001798 ** * (pExpr==0). In this case the value is assumed to be an SQL NULL,
001799 **
001800 ** * The expression is a bound variable, and this is a reprepare, or
001801 **
001802 ** * The expression is a literal value.
001803 **
001804 ** On success, *ppVal is made to point to the extracted value. The caller
001805 ** is responsible for ensuring that the value is eventually freed.
001806 */
001807 static int stat4ValueFromExpr(
001808 Parse *pParse, /* Parse context */
001809 Expr *pExpr, /* The expression to extract a value from */
001810 u8 affinity, /* Affinity to use */
001811 struct ValueNewStat4Ctx *pAlloc,/* How to allocate space. Or NULL */
001812 sqlite3_value **ppVal /* OUT: New value object (or NULL) */
001813 ){
001814 int rc = SQLITE_OK;
001815 sqlite3_value *pVal = 0;
001816 sqlite3 *db = pParse->db;
001817
001818 /* Skip over any TK_COLLATE nodes */
001819 pExpr = sqlite3ExprSkipCollate(pExpr);
001820
001821 assert( pExpr==0 || pExpr->op!=TK_REGISTER || pExpr->op2!=TK_VARIABLE );
001822 if( !pExpr ){
001823 pVal = valueNew(db, pAlloc);
001824 if( pVal ){
001825 sqlite3VdbeMemSetNull((Mem*)pVal);
001826 }
001827 }else if( pExpr->op==TK_VARIABLE && (db->flags & SQLITE_EnableQPSG)==0 ){
001828 Vdbe *v;
001829 int iBindVar = pExpr->iColumn;
001830 sqlite3VdbeSetVarmask(pParse->pVdbe, iBindVar);
001831 if( (v = pParse->pReprepare)!=0 ){
001832 pVal = valueNew(db, pAlloc);
001833 if( pVal ){
001834 rc = sqlite3VdbeMemCopy((Mem*)pVal, &v->aVar[iBindVar-1]);
001835 sqlite3ValueApplyAffinity(pVal, affinity, ENC(db));
001836 pVal->db = pParse->db;
001837 }
001838 }
001839 }else{
001840 rc = valueFromExpr(db, pExpr, ENC(db), affinity, &pVal, pAlloc);
001841 }
001842
001843 assert( pVal==0 || pVal->db==db );
001844 *ppVal = pVal;
001845 return rc;
001846 }
001847
001848 /*
001849 ** This function is used to allocate and populate UnpackedRecord
001850 ** structures intended to be compared against sample index keys stored
001851 ** in the sqlite_stat4 table.
001852 **
001853 ** A single call to this function populates zero or more fields of the
001854 ** record starting with field iVal (fields are numbered from left to
001855 ** right starting with 0). A single field is populated if:
001856 **
001857 ** * (pExpr==0). In this case the value is assumed to be an SQL NULL,
001858 **
001859 ** * The expression is a bound variable, and this is a reprepare, or
001860 **
001861 ** * The sqlite3ValueFromExpr() function is able to extract a value
001862 ** from the expression (i.e. the expression is a literal value).
001863 **
001864 ** Or, if pExpr is a TK_VECTOR, one field is populated for each of the
001865 ** vector components that match either of the two latter criteria listed
001866 ** above.
001867 **
001868 ** Before any value is appended to the record, the affinity of the
001869 ** corresponding column within index pIdx is applied to it. Before
001870 ** this function returns, output parameter *pnExtract is set to the
001871 ** number of values appended to the record.
001872 **
001873 ** When this function is called, *ppRec must either point to an object
001874 ** allocated by an earlier call to this function, or must be NULL. If it
001875 ** is NULL and a value can be successfully extracted, a new UnpackedRecord
001876 ** is allocated (and *ppRec set to point to it) before returning.
001877 **
001878 ** Unless an error is encountered, SQLITE_OK is returned. It is not an
001879 ** error if a value cannot be extracted from pExpr. If an error does
001880 ** occur, an SQLite error code is returned.
001881 */
001882 int sqlite3Stat4ProbeSetValue(
001883 Parse *pParse, /* Parse context */
001884 Index *pIdx, /* Index being probed */
001885 UnpackedRecord **ppRec, /* IN/OUT: Probe record */
001886 Expr *pExpr, /* The expression to extract a value from */
001887 int nElem, /* Maximum number of values to append */
001888 int iVal, /* Array element to populate */
001889 int *pnExtract /* OUT: Values appended to the record */
001890 ){
001891 int rc = SQLITE_OK;
001892 int nExtract = 0;
001893
001894 if( pExpr==0 || pExpr->op!=TK_SELECT ){
001895 int i;
001896 struct ValueNewStat4Ctx alloc;
001897
001898 alloc.pParse = pParse;
001899 alloc.pIdx = pIdx;
001900 alloc.ppRec = ppRec;
001901
001902 for(i=0; i<nElem; i++){
001903 sqlite3_value *pVal = 0;
001904 Expr *pElem = (pExpr ? sqlite3VectorFieldSubexpr(pExpr, i) : 0);
001905 u8 aff = sqlite3IndexColumnAffinity(pParse->db, pIdx, iVal+i);
001906 alloc.iVal = iVal+i;
001907 rc = stat4ValueFromExpr(pParse, pElem, aff, &alloc, &pVal);
001908 if( !pVal ) break;
001909 nExtract++;
001910 }
001911 }
001912
001913 *pnExtract = nExtract;
001914 return rc;
001915 }
001916
001917 /*
001918 ** Attempt to extract a value from expression pExpr using the methods
001919 ** as described for sqlite3Stat4ProbeSetValue() above.
001920 **
001921 ** If successful, set *ppVal to point to a new value object and return
001922 ** SQLITE_OK. If no value can be extracted, but no other error occurs
001923 ** (e.g. OOM), return SQLITE_OK and set *ppVal to NULL. Or, if an error
001924 ** does occur, return an SQLite error code. The final value of *ppVal
001925 ** is undefined in this case.
001926 */
001927 int sqlite3Stat4ValueFromExpr(
001928 Parse *pParse, /* Parse context */
001929 Expr *pExpr, /* The expression to extract a value from */
001930 u8 affinity, /* Affinity to use */
001931 sqlite3_value **ppVal /* OUT: New value object (or NULL) */
001932 ){
001933 return stat4ValueFromExpr(pParse, pExpr, affinity, 0, ppVal);
001934 }
001935
001936 /*
001937 ** Extract the iCol-th column from the nRec-byte record in pRec. Write
001938 ** the column value into *ppVal. If *ppVal is initially NULL then a new
001939 ** sqlite3_value object is allocated.
001940 **
001941 ** If *ppVal is initially NULL then the caller is responsible for
001942 ** ensuring that the value written into *ppVal is eventually freed.
001943 */
001944 int sqlite3Stat4Column(
001945 sqlite3 *db, /* Database handle */
001946 const void *pRec, /* Pointer to buffer containing record */
001947 int nRec, /* Size of buffer pRec in bytes */
001948 int iCol, /* Column to extract */
001949 sqlite3_value **ppVal /* OUT: Extracted value */
001950 ){
001951 u32 t = 0; /* a column type code */
001952 u32 nHdr; /* Size of the header in the record */
001953 u32 iHdr; /* Next unread header byte */
001954 i64 iField; /* Next unread data byte */
001955 u32 szField = 0; /* Size of the current data field */
001956 int i; /* Column index */
001957 u8 *a = (u8*)pRec; /* Typecast byte array */
001958 Mem *pMem = *ppVal; /* Write result into this Mem object */
001959
001960 assert( iCol>0 );
001961 iHdr = getVarint32(a, nHdr);
001962 if( nHdr>(u32)nRec || iHdr>=nHdr ) return SQLITE_CORRUPT_BKPT;
001963 iField = nHdr;
001964 for(i=0; i<=iCol; i++){
001965 iHdr += getVarint32(&a[iHdr], t);
001966 testcase( iHdr==nHdr );
001967 testcase( iHdr==nHdr+1 );
001968 if( iHdr>nHdr ) return SQLITE_CORRUPT_BKPT;
001969 szField = sqlite3VdbeSerialTypeLen(t);
001970 iField += szField;
001971 }
001972 testcase( iField==nRec );
001973 testcase( iField==nRec+1 );
001974 if( iField>nRec ) return SQLITE_CORRUPT_BKPT;
001975 if( pMem==0 ){
001976 pMem = *ppVal = sqlite3ValueNew(db);
001977 if( pMem==0 ) return SQLITE_NOMEM_BKPT;
001978 }
001979 sqlite3VdbeSerialGet(&a[iField-szField], t, pMem);
001980 pMem->enc = ENC(db);
001981 return SQLITE_OK;
001982 }
001983
001984 /*
001985 ** Unless it is NULL, the argument must be an UnpackedRecord object returned
001986 ** by an earlier call to sqlite3Stat4ProbeSetValue(). This call deletes
001987 ** the object.
001988 */
001989 void sqlite3Stat4ProbeFree(UnpackedRecord *pRec){
001990 if( pRec ){
001991 int i;
001992 int nCol = pRec->pKeyInfo->nAllField;
001993 Mem *aMem = pRec->aMem;
001994 sqlite3 *db = aMem[0].db;
001995 for(i=0; i<nCol; i++){
001996 sqlite3VdbeMemRelease(&aMem[i]);
001997 }
001998 sqlite3KeyInfoUnref(pRec->pKeyInfo);
001999 sqlite3DbFreeNN(db, pRec);
002000 }
002001 }
002002 #endif /* ifdef SQLITE_ENABLE_STAT4 */
002003
002004 /*
002005 ** Change the string value of an sqlite3_value object
002006 */
002007 void sqlite3ValueSetStr(
002008 sqlite3_value *v, /* Value to be set */
002009 int n, /* Length of string z */
002010 const void *z, /* Text of the new string */
002011 u8 enc, /* Encoding to use */
002012 void (*xDel)(void*) /* Destructor for the string */
002013 ){
002014 if( v ) sqlite3VdbeMemSetStr((Mem *)v, z, n, enc, xDel);
002015 }
002016
002017 /*
002018 ** Free an sqlite3_value object
002019 */
002020 void sqlite3ValueFree(sqlite3_value *v){
002021 if( !v ) return;
002022 sqlite3VdbeMemRelease((Mem *)v);
002023 sqlite3DbFreeNN(((Mem*)v)->db, v);
002024 }
002025
002026 /*
002027 ** The sqlite3ValueBytes() routine returns the number of bytes in the
002028 ** sqlite3_value object assuming that it uses the encoding "enc".
002029 ** The valueBytes() routine is a helper function.
002030 */
002031 static SQLITE_NOINLINE int valueBytes(sqlite3_value *pVal, u8 enc){
002032 return valueToText(pVal, enc)!=0 ? pVal->n : 0;
002033 }
002034 int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
002035 Mem *p = (Mem*)pVal;
002036 assert( (p->flags & MEM_Null)==0 || (p->flags & (MEM_Str|MEM_Blob))==0 );
002037 if( (p->flags & MEM_Str)!=0 && pVal->enc==enc ){
002038 return p->n;
002039 }
002040 if( (p->flags & MEM_Str)!=0 && enc!=SQLITE_UTF8 && pVal->enc!=SQLITE_UTF8 ){
002041 return p->n;
002042 }
002043 if( (p->flags & MEM_Blob)!=0 ){
002044 if( p->flags & MEM_Zero ){
002045 return p->n + p->u.nZero;
002046 }else{
002047 return p->n;
002048 }
002049 }
002050 if( p->flags & MEM_Null ) return 0;
002051 return valueBytes(pVal, enc);
002052 }