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Diffstat (limited to 'src/vdbemem.c')
| -rw-r--r-- | src/vdbemem.c | 1983 |
1 files changed, 1983 insertions, 0 deletions
diff --git a/src/vdbemem.c b/src/vdbemem.c new file mode 100644 index 0000000..f14599d --- /dev/null +++ b/src/vdbemem.c @@ -0,0 +1,1983 @@ +/* +** 2004 May 26 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** +** This file contains code use to manipulate "Mem" structure. A "Mem" +** stores a single value in the VDBE. Mem is an opaque structure visible +** only within the VDBE. Interface routines refer to a Mem using the +** name sqlite_value +*/ +#include "sqliteInt.h" +#include "vdbeInt.h" + +/* True if X is a power of two. 0 is considered a power of two here. +** In other words, return true if X has at most one bit set. +*/ +#define ISPOWEROF2(X) (((X)&((X)-1))==0) + +#ifdef SQLITE_DEBUG +/* +** Check invariants on a Mem object. +** +** This routine is intended for use inside of assert() statements, like +** this: assert( sqlite3VdbeCheckMemInvariants(pMem) ); +*/ +int sqlite3VdbeCheckMemInvariants(Mem *p){ + /* If MEM_Dyn is set then Mem.xDel!=0. + ** Mem.xDel might not be initialized if MEM_Dyn is clear. + */ + assert( (p->flags & MEM_Dyn)==0 || p->xDel!=0 ); + + /* MEM_Dyn may only be set if Mem.szMalloc==0. In this way we + ** ensure that if Mem.szMalloc>0 then it is safe to do + ** Mem.z = Mem.zMalloc without having to check Mem.flags&MEM_Dyn. + ** That saves a few cycles in inner loops. */ + assert( (p->flags & MEM_Dyn)==0 || p->szMalloc==0 ); + + /* Cannot have more than one of MEM_Int, MEM_Real, or MEM_IntReal */ + assert( ISPOWEROF2(p->flags & (MEM_Int|MEM_Real|MEM_IntReal)) ); + + if( p->flags & MEM_Null ){ + /* Cannot be both MEM_Null and some other type */ + assert( (p->flags & (MEM_Int|MEM_Real|MEM_Str|MEM_Blob|MEM_Agg))==0 ); + + /* If MEM_Null is set, then either the value is a pure NULL (the usual + ** case) or it is a pointer set using sqlite3_bind_pointer() or + ** sqlite3_result_pointer(). If a pointer, then MEM_Term must also be + ** set. + */ + if( (p->flags & (MEM_Term|MEM_Subtype))==(MEM_Term|MEM_Subtype) ){ + /* This is a pointer type. There may be a flag to indicate what to + ** do with the pointer. */ + assert( ((p->flags&MEM_Dyn)!=0 ? 1 : 0) + + ((p->flags&MEM_Ephem)!=0 ? 1 : 0) + + ((p->flags&MEM_Static)!=0 ? 1 : 0) <= 1 ); + + /* No other bits set */ + assert( (p->flags & ~(MEM_Null|MEM_Term|MEM_Subtype|MEM_FromBind + |MEM_Dyn|MEM_Ephem|MEM_Static))==0 ); + }else{ + /* A pure NULL might have other flags, such as MEM_Static, MEM_Dyn, + ** MEM_Ephem, MEM_Cleared, or MEM_Subtype */ + } + }else{ + /* The MEM_Cleared bit is only allowed on NULLs */ + assert( (p->flags & MEM_Cleared)==0 ); + } + + /* The szMalloc field holds the correct memory allocation size */ + assert( p->szMalloc==0 + || (p->flags==MEM_Undefined + && p->szMalloc<=sqlite3DbMallocSize(p->db,p->zMalloc)) + || p->szMalloc==sqlite3DbMallocSize(p->db,p->zMalloc)); + + /* If p holds a string or blob, the Mem.z must point to exactly + ** one of the following: + ** + ** (1) Memory in Mem.zMalloc and managed by the Mem object + ** (2) Memory to be freed using Mem.xDel + ** (3) An ephemeral string or blob + ** (4) A static string or blob + */ + if( (p->flags & (MEM_Str|MEM_Blob)) && p->n>0 ){ + assert( + ((p->szMalloc>0 && p->z==p->zMalloc)? 1 : 0) + + ((p->flags&MEM_Dyn)!=0 ? 1 : 0) + + ((p->flags&MEM_Ephem)!=0 ? 1 : 0) + + ((p->flags&MEM_Static)!=0 ? 1 : 0) == 1 + ); + } + return 1; +} +#endif + +/* +** Render a Mem object which is one of MEM_Int, MEM_Real, or MEM_IntReal +** into a buffer. +*/ +static void vdbeMemRenderNum(int sz, char *zBuf, Mem *p){ + StrAccum acc; + assert( p->flags & (MEM_Int|MEM_Real|MEM_IntReal) ); + assert( sz>22 ); + if( p->flags & MEM_Int ){ +#if GCC_VERSION>=7000000 + /* Work-around for GCC bug + ** https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96270 */ + i64 x; + assert( (p->flags&MEM_Int)*2==sizeof(x) ); + memcpy(&x, (char*)&p->u, (p->flags&MEM_Int)*2); + sqlite3Int64ToText(x, zBuf); +#else + sqlite3Int64ToText(p->u.i, zBuf); +#endif + }else{ + sqlite3StrAccumInit(&acc, 0, zBuf, sz, 0); + sqlite3_str_appendf(&acc, "%!.15g", + (p->flags & MEM_IntReal)!=0 ? (double)p->u.i : p->u.r); + assert( acc.zText==zBuf && acc.mxAlloc<=0 ); + zBuf[acc.nChar] = 0; /* Fast version of sqlite3StrAccumFinish(&acc) */ + } +} + +#ifdef SQLITE_DEBUG +/* +** Validity checks on pMem. pMem holds a string. +** +** (1) Check that string value of pMem agrees with its integer or real value. +** (2) Check that the string is correctly zero terminated +** +** A single int or real value always converts to the same strings. But +** many different strings can be converted into the same int or real. +** If a table contains a numeric value and an index is based on the +** corresponding string value, then it is important that the string be +** derived from the numeric value, not the other way around, to ensure +** that the index and table are consistent. See ticket +** https://www.sqlite.org/src/info/343634942dd54ab (2018-01-31) for +** an example. +** +** This routine looks at pMem to verify that if it has both a numeric +** representation and a string representation then the string rep has +** been derived from the numeric and not the other way around. It returns +** true if everything is ok and false if there is a problem. +** +** This routine is for use inside of assert() statements only. +*/ +int sqlite3VdbeMemValidStrRep(Mem *p){ + char zBuf[100]; + char *z; + int i, j, incr; + if( (p->flags & MEM_Str)==0 ) return 1; + if( p->flags & MEM_Term ){ + /* Insure that the string is properly zero-terminated. Pay particular + ** attention to the case where p->n is odd */ + if( p->szMalloc>0 && p->z==p->zMalloc ){ + assert( p->enc==SQLITE_UTF8 || p->szMalloc >= ((p->n+1)&~1)+2 ); + assert( p->enc!=SQLITE_UTF8 || p->szMalloc >= p->n+1 ); + } + assert( p->z[p->n]==0 ); + assert( p->enc==SQLITE_UTF8 || p->z[(p->n+1)&~1]==0 ); + assert( p->enc==SQLITE_UTF8 || p->z[((p->n+1)&~1)+1]==0 ); + } + if( (p->flags & (MEM_Int|MEM_Real|MEM_IntReal))==0 ) return 1; + vdbeMemRenderNum(sizeof(zBuf), zBuf, p); + z = p->z; + i = j = 0; + incr = 1; + if( p->enc!=SQLITE_UTF8 ){ + incr = 2; + if( p->enc==SQLITE_UTF16BE ) z++; + } + while( zBuf[j] ){ + if( zBuf[j++]!=z[i] ) return 0; + i += incr; + } + return 1; +} +#endif /* SQLITE_DEBUG */ + +/* +** If pMem is an object with a valid string representation, this routine +** ensures the internal encoding for the string representation is +** 'desiredEnc', one of SQLITE_UTF8, SQLITE_UTF16LE or SQLITE_UTF16BE. +** +** If pMem is not a string object, or the encoding of the string +** representation is already stored using the requested encoding, then this +** routine is a no-op. +** +** SQLITE_OK is returned if the conversion is successful (or not required). +** SQLITE_NOMEM may be returned if a malloc() fails during conversion +** between formats. +*/ +int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){ +#ifndef SQLITE_OMIT_UTF16 + int rc; +#endif + assert( pMem!=0 ); + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + assert( desiredEnc==SQLITE_UTF8 || desiredEnc==SQLITE_UTF16LE + || desiredEnc==SQLITE_UTF16BE ); + if( !(pMem->flags&MEM_Str) ){ + pMem->enc = desiredEnc; + return SQLITE_OK; + } + if( pMem->enc==desiredEnc ){ + return SQLITE_OK; + } + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); +#ifdef SQLITE_OMIT_UTF16 + return SQLITE_ERROR; +#else + + /* MemTranslate() may return SQLITE_OK or SQLITE_NOMEM. If NOMEM is returned, + ** then the encoding of the value may not have changed. + */ + rc = sqlite3VdbeMemTranslate(pMem, (u8)desiredEnc); + assert(rc==SQLITE_OK || rc==SQLITE_NOMEM); + assert(rc==SQLITE_OK || pMem->enc!=desiredEnc); + assert(rc==SQLITE_NOMEM || pMem->enc==desiredEnc); + return rc; +#endif +} + +/* +** Make sure pMem->z points to a writable allocation of at least n bytes. +** +** If the bPreserve argument is true, then copy of the content of +** pMem->z into the new allocation. pMem must be either a string or +** blob if bPreserve is true. If bPreserve is false, any prior content +** in pMem->z is discarded. +*/ +SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){ + assert( sqlite3VdbeCheckMemInvariants(pMem) ); + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + testcase( pMem->db==0 ); + + /* If the bPreserve flag is set to true, then the memory cell must already + ** contain a valid string or blob value. */ + assert( bPreserve==0 || pMem->flags&(MEM_Blob|MEM_Str) ); + testcase( bPreserve && pMem->z==0 ); + + assert( pMem->szMalloc==0 + || (pMem->flags==MEM_Undefined + && pMem->szMalloc<=sqlite3DbMallocSize(pMem->db,pMem->zMalloc)) + || pMem->szMalloc==sqlite3DbMallocSize(pMem->db,pMem->zMalloc)); + if( pMem->szMalloc>0 && bPreserve && pMem->z==pMem->zMalloc ){ + if( pMem->db ){ + pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n); + }else{ + pMem->zMalloc = sqlite3Realloc(pMem->z, n); + if( pMem->zMalloc==0 ) sqlite3_free(pMem->z); + pMem->z = pMem->zMalloc; + } + bPreserve = 0; + }else{ + if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc); + pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n); + } + if( pMem->zMalloc==0 ){ + sqlite3VdbeMemSetNull(pMem); + pMem->z = 0; + pMem->szMalloc = 0; + return SQLITE_NOMEM_BKPT; + }else{ + pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc); + } + + if( bPreserve && pMem->z ){ + assert( pMem->z!=pMem->zMalloc ); + memcpy(pMem->zMalloc, pMem->z, pMem->n); + } + if( (pMem->flags&MEM_Dyn)!=0 ){ + assert( pMem->xDel!=0 && pMem->xDel!=SQLITE_DYNAMIC ); + pMem->xDel((void *)(pMem->z)); + } + + pMem->z = pMem->zMalloc; + pMem->flags &= ~(MEM_Dyn|MEM_Ephem|MEM_Static); + return SQLITE_OK; +} + +/* +** Change the pMem->zMalloc allocation to be at least szNew bytes. +** If pMem->zMalloc already meets or exceeds the requested size, this +** routine is a no-op. +** +** Any prior string or blob content in the pMem object may be discarded. +** The pMem->xDel destructor is called, if it exists. Though MEM_Str +** and MEM_Blob values may be discarded, MEM_Int, MEM_Real, MEM_IntReal, +** and MEM_Null values are preserved. +** +** Return SQLITE_OK on success or an error code (probably SQLITE_NOMEM) +** if unable to complete the resizing. +*/ +int sqlite3VdbeMemClearAndResize(Mem *pMem, int szNew){ + assert( CORRUPT_DB || szNew>0 ); + assert( (pMem->flags & MEM_Dyn)==0 || pMem->szMalloc==0 ); + if( pMem->szMalloc<szNew ){ + return sqlite3VdbeMemGrow(pMem, szNew, 0); + } + assert( (pMem->flags & MEM_Dyn)==0 ); + pMem->z = pMem->zMalloc; + pMem->flags &= (MEM_Null|MEM_Int|MEM_Real|MEM_IntReal); + return SQLITE_OK; +} + +/* +** It is already known that pMem contains an unterminated string. +** Add the zero terminator. +** +** Three bytes of zero are added. In this way, there is guaranteed +** to be a double-zero byte at an even byte boundary in order to +** terminate a UTF16 string, even if the initial size of the buffer +** is an odd number of bytes. +*/ +static SQLITE_NOINLINE int vdbeMemAddTerminator(Mem *pMem){ + if( sqlite3VdbeMemGrow(pMem, pMem->n+3, 1) ){ + return SQLITE_NOMEM_BKPT; + } + pMem->z[pMem->n] = 0; + pMem->z[pMem->n+1] = 0; + pMem->z[pMem->n+2] = 0; + pMem->flags |= MEM_Term; + return SQLITE_OK; +} + +/* +** Change pMem so that its MEM_Str or MEM_Blob value is stored in +** MEM.zMalloc, where it can be safely written. +** +** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails. +*/ +int sqlite3VdbeMemMakeWriteable(Mem *pMem){ + assert( pMem!=0 ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + if( (pMem->flags & (MEM_Str|MEM_Blob))!=0 ){ + if( ExpandBlob(pMem) ) return SQLITE_NOMEM; + if( pMem->szMalloc==0 || pMem->z!=pMem->zMalloc ){ + int rc = vdbeMemAddTerminator(pMem); + if( rc ) return rc; + } + } + pMem->flags &= ~MEM_Ephem; +#ifdef SQLITE_DEBUG + pMem->pScopyFrom = 0; +#endif + + return SQLITE_OK; +} + +/* +** If the given Mem* has a zero-filled tail, turn it into an ordinary +** blob stored in dynamically allocated space. +*/ +#ifndef SQLITE_OMIT_INCRBLOB +int sqlite3VdbeMemExpandBlob(Mem *pMem){ + int nByte; + assert( pMem!=0 ); + assert( pMem->flags & MEM_Zero ); + assert( (pMem->flags&MEM_Blob)!=0 || MemNullNochng(pMem) ); + testcase( sqlite3_value_nochange(pMem) ); + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + + /* Set nByte to the number of bytes required to store the expanded blob. */ + nByte = pMem->n + pMem->u.nZero; + if( nByte<=0 ){ + if( (pMem->flags & MEM_Blob)==0 ) return SQLITE_OK; + nByte = 1; + } + if( sqlite3VdbeMemGrow(pMem, nByte, 1) ){ + return SQLITE_NOMEM_BKPT; + } + assert( pMem->z!=0 ); + assert( sqlite3DbMallocSize(pMem->db,pMem->z) >= nByte ); + + memset(&pMem->z[pMem->n], 0, pMem->u.nZero); + pMem->n += pMem->u.nZero; + pMem->flags &= ~(MEM_Zero|MEM_Term); + return SQLITE_OK; +} +#endif + +/* +** Make sure the given Mem is \u0000 terminated. +*/ +int sqlite3VdbeMemNulTerminate(Mem *pMem){ + assert( pMem!=0 ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + testcase( (pMem->flags & (MEM_Term|MEM_Str))==(MEM_Term|MEM_Str) ); + testcase( (pMem->flags & (MEM_Term|MEM_Str))==0 ); + if( (pMem->flags & (MEM_Term|MEM_Str))!=MEM_Str ){ + return SQLITE_OK; /* Nothing to do */ + }else{ + return vdbeMemAddTerminator(pMem); + } +} + +/* +** Add MEM_Str to the set of representations for the given Mem. This +** routine is only called if pMem is a number of some kind, not a NULL +** or a BLOB. +** +** Existing representations MEM_Int, MEM_Real, or MEM_IntReal are invalidated +** if bForce is true but are retained if bForce is false. +** +** A MEM_Null value will never be passed to this function. This function is +** used for converting values to text for returning to the user (i.e. via +** sqlite3_value_text()), or for ensuring that values to be used as btree +** keys are strings. In the former case a NULL pointer is returned the +** user and the latter is an internal programming error. +*/ +int sqlite3VdbeMemStringify(Mem *pMem, u8 enc, u8 bForce){ + const int nByte = 32; + + assert( pMem!=0 ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + assert( !(pMem->flags&MEM_Zero) ); + assert( !(pMem->flags&(MEM_Str|MEM_Blob)) ); + assert( pMem->flags&(MEM_Int|MEM_Real|MEM_IntReal) ); + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + assert( EIGHT_BYTE_ALIGNMENT(pMem) ); + + + if( sqlite3VdbeMemClearAndResize(pMem, nByte) ){ + pMem->enc = 0; + return SQLITE_NOMEM_BKPT; + } + + vdbeMemRenderNum(nByte, pMem->z, pMem); + assert( pMem->z!=0 ); + pMem->n = sqlite3Strlen30NN(pMem->z); + pMem->enc = SQLITE_UTF8; + pMem->flags |= MEM_Str|MEM_Term; + if( bForce ) pMem->flags &= ~(MEM_Int|MEM_Real|MEM_IntReal); + sqlite3VdbeChangeEncoding(pMem, enc); + return SQLITE_OK; +} + +/* +** Memory cell pMem contains the context of an aggregate function. +** This routine calls the finalize method for that function. The +** result of the aggregate is stored back into pMem. +** +** Return SQLITE_ERROR if the finalizer reports an error. SQLITE_OK +** otherwise. +*/ +int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){ + sqlite3_context ctx; + Mem t; + assert( pFunc!=0 ); + assert( pMem!=0 ); + assert( pMem->db!=0 ); + assert( pFunc->xFinalize!=0 ); + assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef ); + assert( sqlite3_mutex_held(pMem->db->mutex) ); + memset(&ctx, 0, sizeof(ctx)); + memset(&t, 0, sizeof(t)); + t.flags = MEM_Null; + t.db = pMem->db; + ctx.pOut = &t; + ctx.pMem = pMem; + ctx.pFunc = pFunc; + ctx.enc = ENC(t.db); + pFunc->xFinalize(&ctx); /* IMP: R-24505-23230 */ + assert( (pMem->flags & MEM_Dyn)==0 ); + if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc); + memcpy(pMem, &t, sizeof(t)); + return ctx.isError; +} + +/* +** Memory cell pAccum contains the context of an aggregate function. +** This routine calls the xValue method for that function and stores +** the results in memory cell pMem. +** +** SQLITE_ERROR is returned if xValue() reports an error. SQLITE_OK +** otherwise. +*/ +#ifndef SQLITE_OMIT_WINDOWFUNC +int sqlite3VdbeMemAggValue(Mem *pAccum, Mem *pOut, FuncDef *pFunc){ + sqlite3_context ctx; + assert( pFunc!=0 ); + assert( pFunc->xValue!=0 ); + assert( (pAccum->flags & MEM_Null)!=0 || pFunc==pAccum->u.pDef ); + assert( pAccum->db!=0 ); + assert( sqlite3_mutex_held(pAccum->db->mutex) ); + memset(&ctx, 0, sizeof(ctx)); + sqlite3VdbeMemSetNull(pOut); + ctx.pOut = pOut; + ctx.pMem = pAccum; + ctx.pFunc = pFunc; + ctx.enc = ENC(pAccum->db); + pFunc->xValue(&ctx); + return ctx.isError; +} +#endif /* SQLITE_OMIT_WINDOWFUNC */ + +/* +** If the memory cell contains a value that must be freed by +** invoking the external callback in Mem.xDel, then this routine +** will free that value. It also sets Mem.flags to MEM_Null. +** +** This is a helper routine for sqlite3VdbeMemSetNull() and +** for sqlite3VdbeMemRelease(). Use those other routines as the +** entry point for releasing Mem resources. +*/ +static SQLITE_NOINLINE void vdbeMemClearExternAndSetNull(Mem *p){ + assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) ); + assert( VdbeMemDynamic(p) ); + if( p->flags&MEM_Agg ){ + sqlite3VdbeMemFinalize(p, p->u.pDef); + assert( (p->flags & MEM_Agg)==0 ); + testcase( p->flags & MEM_Dyn ); + } + if( p->flags&MEM_Dyn ){ + assert( p->xDel!=SQLITE_DYNAMIC && p->xDel!=0 ); + p->xDel((void *)p->z); + } + p->flags = MEM_Null; +} + +/* +** Release memory held by the Mem p, both external memory cleared +** by p->xDel and memory in p->zMalloc. +** +** This is a helper routine invoked by sqlite3VdbeMemRelease() in +** the unusual case where there really is memory in p that needs +** to be freed. +*/ +static SQLITE_NOINLINE void vdbeMemClear(Mem *p){ + if( VdbeMemDynamic(p) ){ + vdbeMemClearExternAndSetNull(p); + } + if( p->szMalloc ){ + sqlite3DbFreeNN(p->db, p->zMalloc); + p->szMalloc = 0; + } + p->z = 0; +} + +/* +** Release any memory resources held by the Mem. Both the memory that is +** free by Mem.xDel and the Mem.zMalloc allocation are freed. +** +** Use this routine prior to clean up prior to abandoning a Mem, or to +** reset a Mem back to its minimum memory utilization. +** +** Use sqlite3VdbeMemSetNull() to release just the Mem.xDel space +** prior to inserting new content into the Mem. +*/ +void sqlite3VdbeMemRelease(Mem *p){ + assert( sqlite3VdbeCheckMemInvariants(p) ); + if( VdbeMemDynamic(p) || p->szMalloc ){ + vdbeMemClear(p); + } +} + +/* Like sqlite3VdbeMemRelease() but faster for cases where we +** know in advance that the Mem is not MEM_Dyn or MEM_Agg. +*/ +void sqlite3VdbeMemReleaseMalloc(Mem *p){ + assert( !VdbeMemDynamic(p) ); + if( p->szMalloc ) vdbeMemClear(p); +} + +/* +** Convert a 64-bit IEEE double into a 64-bit signed integer. +** If the double is out of range of a 64-bit signed integer then +** return the closest available 64-bit signed integer. +*/ +static SQLITE_NOINLINE i64 doubleToInt64(double r){ +#ifdef SQLITE_OMIT_FLOATING_POINT + /* When floating-point is omitted, double and int64 are the same thing */ + return r; +#else + /* + ** Many compilers we encounter do not define constants for the + ** minimum and maximum 64-bit integers, or they define them + ** inconsistently. And many do not understand the "LL" notation. + ** So we define our own static constants here using nothing + ** larger than a 32-bit integer constant. + */ + static const i64 maxInt = LARGEST_INT64; + static const i64 minInt = SMALLEST_INT64; + + if( r<=(double)minInt ){ + return minInt; + }else if( r>=(double)maxInt ){ + return maxInt; + }else{ + return (i64)r; + } +#endif +} + +/* +** Return some kind of integer value which is the best we can do +** at representing the value that *pMem describes as an integer. +** If pMem is an integer, then the value is exact. If pMem is +** a floating-point then the value returned is the integer part. +** If pMem is a string or blob, then we make an attempt to convert +** it into an integer and return that. If pMem represents an +** an SQL-NULL value, return 0. +** +** If pMem represents a string value, its encoding might be changed. +*/ +static SQLITE_NOINLINE i64 memIntValue(const Mem *pMem){ + i64 value = 0; + sqlite3Atoi64(pMem->z, &value, pMem->n, pMem->enc); + return value; +} +i64 sqlite3VdbeIntValue(const Mem *pMem){ + int flags; + assert( pMem!=0 ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + assert( EIGHT_BYTE_ALIGNMENT(pMem) ); + flags = pMem->flags; + if( flags & (MEM_Int|MEM_IntReal) ){ + testcase( flags & MEM_IntReal ); + return pMem->u.i; + }else if( flags & MEM_Real ){ + return doubleToInt64(pMem->u.r); + }else if( (flags & (MEM_Str|MEM_Blob))!=0 && pMem->z!=0 ){ + return memIntValue(pMem); + }else{ + return 0; + } +} + +/* +** Return the best representation of pMem that we can get into a +** double. If pMem is already a double or an integer, return its +** value. If it is a string or blob, try to convert it to a double. +** If it is a NULL, return 0.0. +*/ +static SQLITE_NOINLINE double memRealValue(Mem *pMem){ + /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */ + double val = (double)0; + sqlite3AtoF(pMem->z, &val, pMem->n, pMem->enc); + return val; +} +double sqlite3VdbeRealValue(Mem *pMem){ + assert( pMem!=0 ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + assert( EIGHT_BYTE_ALIGNMENT(pMem) ); + if( pMem->flags & MEM_Real ){ + return pMem->u.r; + }else if( pMem->flags & (MEM_Int|MEM_IntReal) ){ + testcase( pMem->flags & MEM_IntReal ); + return (double)pMem->u.i; + }else if( pMem->flags & (MEM_Str|MEM_Blob) ){ + return memRealValue(pMem); + }else{ + /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */ + return (double)0; + } +} + +/* +** Return 1 if pMem represents true, and return 0 if pMem represents false. +** Return the value ifNull if pMem is NULL. +*/ +int sqlite3VdbeBooleanValue(Mem *pMem, int ifNull){ + testcase( pMem->flags & MEM_IntReal ); + if( pMem->flags & (MEM_Int|MEM_IntReal) ) return pMem->u.i!=0; + if( pMem->flags & MEM_Null ) return ifNull; + return sqlite3VdbeRealValue(pMem)!=0.0; +} + +/* +** The MEM structure is already a MEM_Real. Try to also make it a +** MEM_Int if we can. +*/ +void sqlite3VdbeIntegerAffinity(Mem *pMem){ + i64 ix; + assert( pMem!=0 ); + assert( pMem->flags & MEM_Real ); + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + assert( EIGHT_BYTE_ALIGNMENT(pMem) ); + + ix = doubleToInt64(pMem->u.r); + + /* Only mark the value as an integer if + ** + ** (1) the round-trip conversion real->int->real is a no-op, and + ** (2) The integer is neither the largest nor the smallest + ** possible integer (ticket #3922) + ** + ** The second and third terms in the following conditional enforces + ** the second condition under the assumption that addition overflow causes + ** values to wrap around. + */ + if( pMem->u.r==ix && ix>SMALLEST_INT64 && ix<LARGEST_INT64 ){ + pMem->u.i = ix; + MemSetTypeFlag(pMem, MEM_Int); + } +} + +/* +** Convert pMem to type integer. Invalidate any prior representations. +*/ +int sqlite3VdbeMemIntegerify(Mem *pMem){ + assert( pMem!=0 ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + assert( EIGHT_BYTE_ALIGNMENT(pMem) ); + + pMem->u.i = sqlite3VdbeIntValue(pMem); + MemSetTypeFlag(pMem, MEM_Int); + return SQLITE_OK; +} + +/* +** Convert pMem so that it is of type MEM_Real. +** Invalidate any prior representations. +*/ +int sqlite3VdbeMemRealify(Mem *pMem){ + assert( pMem!=0 ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + assert( EIGHT_BYTE_ALIGNMENT(pMem) ); + + pMem->u.r = sqlite3VdbeRealValue(pMem); + MemSetTypeFlag(pMem, MEM_Real); + return SQLITE_OK; +} + +/* Compare a floating point value to an integer. Return true if the two +** values are the same within the precision of the floating point value. +** +** This function assumes that i was obtained by assignment from r1. +** +** For some versions of GCC on 32-bit machines, if you do the more obvious +** comparison of "r1==(double)i" you sometimes get an answer of false even +** though the r1 and (double)i values are bit-for-bit the same. +*/ +int sqlite3RealSameAsInt(double r1, sqlite3_int64 i){ + double r2 = (double)i; + return r1==0.0 + || (memcmp(&r1, &r2, sizeof(r1))==0 + && i >= -2251799813685248LL && i < 2251799813685248LL); +} + +/* Convert a floating point value to its closest integer. Do so in +** a way that avoids 'outside the range of representable values' warnings +** from UBSAN. +*/ +i64 sqlite3RealToI64(double r){ + if( r<=(double)SMALLEST_INT64 ) return SMALLEST_INT64; + if( r>=(double)LARGEST_INT64) return LARGEST_INT64; + return (i64)r; +} + +/* +** Convert pMem so that it has type MEM_Real or MEM_Int. +** Invalidate any prior representations. +** +** Every effort is made to force the conversion, even if the input +** is a string that does not look completely like a number. Convert +** as much of the string as we can and ignore the rest. +*/ +int sqlite3VdbeMemNumerify(Mem *pMem){ + assert( pMem!=0 ); + testcase( pMem->flags & MEM_Int ); + testcase( pMem->flags & MEM_Real ); + testcase( pMem->flags & MEM_IntReal ); + testcase( pMem->flags & MEM_Null ); + if( (pMem->flags & (MEM_Int|MEM_Real|MEM_IntReal|MEM_Null))==0 ){ + int rc; + sqlite3_int64 ix; + assert( (pMem->flags & (MEM_Blob|MEM_Str))!=0 ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + rc = sqlite3AtoF(pMem->z, &pMem->u.r, pMem->n, pMem->enc); + if( ((rc==0 || rc==1) && sqlite3Atoi64(pMem->z, &ix, pMem->n, pMem->enc)<=1) + || sqlite3RealSameAsInt(pMem->u.r, (ix = sqlite3RealToI64(pMem->u.r))) + ){ + pMem->u.i = ix; + MemSetTypeFlag(pMem, MEM_Int); + }else{ + MemSetTypeFlag(pMem, MEM_Real); + } + } + assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_IntReal|MEM_Null))!=0 ); + pMem->flags &= ~(MEM_Str|MEM_Blob|MEM_Zero); + return SQLITE_OK; +} + +/* +** Cast the datatype of the value in pMem according to the affinity +** "aff". Casting is different from applying affinity in that a cast +** is forced. In other words, the value is converted into the desired +** affinity even if that results in loss of data. This routine is +** used (for example) to implement the SQL "cast()" operator. +*/ +int sqlite3VdbeMemCast(Mem *pMem, u8 aff, u8 encoding){ + if( pMem->flags & MEM_Null ) return SQLITE_OK; + switch( aff ){ + case SQLITE_AFF_BLOB: { /* Really a cast to BLOB */ + if( (pMem->flags & MEM_Blob)==0 ){ + sqlite3ValueApplyAffinity(pMem, SQLITE_AFF_TEXT, encoding); + assert( pMem->flags & MEM_Str || pMem->db->mallocFailed ); + if( pMem->flags & MEM_Str ) MemSetTypeFlag(pMem, MEM_Blob); + }else{ + pMem->flags &= ~(MEM_TypeMask&~MEM_Blob); + } + break; + } + case SQLITE_AFF_NUMERIC: { + sqlite3VdbeMemNumerify(pMem); + break; + } + case SQLITE_AFF_INTEGER: { + sqlite3VdbeMemIntegerify(pMem); + break; + } + case SQLITE_AFF_REAL: { + sqlite3VdbeMemRealify(pMem); + break; + } + default: { + assert( aff==SQLITE_AFF_TEXT ); + assert( MEM_Str==(MEM_Blob>>3) ); + pMem->flags |= (pMem->flags&MEM_Blob)>>3; + sqlite3ValueApplyAffinity(pMem, SQLITE_AFF_TEXT, encoding); + assert( pMem->flags & MEM_Str || pMem->db->mallocFailed ); + pMem->flags &= ~(MEM_Int|MEM_Real|MEM_IntReal|MEM_Blob|MEM_Zero); + if( encoding!=SQLITE_UTF8 ) pMem->n &= ~1; + return sqlite3VdbeChangeEncoding(pMem, encoding); + } + } + return SQLITE_OK; +} + +/* +** Initialize bulk memory to be a consistent Mem object. +** +** The minimum amount of initialization feasible is performed. +*/ +void sqlite3VdbeMemInit(Mem *pMem, sqlite3 *db, u16 flags){ + assert( (flags & ~MEM_TypeMask)==0 ); + pMem->flags = flags; + pMem->db = db; + pMem->szMalloc = 0; +} + + +/* +** Delete any previous value and set the value stored in *pMem to NULL. +** +** This routine calls the Mem.xDel destructor to dispose of values that +** require the destructor. But it preserves the Mem.zMalloc memory allocation. +** To free all resources, use sqlite3VdbeMemRelease(), which both calls this +** routine to invoke the destructor and deallocates Mem.zMalloc. +** +** Use this routine to reset the Mem prior to insert a new value. +** +** Use sqlite3VdbeMemRelease() to complete erase the Mem prior to abandoning it. +*/ +void sqlite3VdbeMemSetNull(Mem *pMem){ + if( VdbeMemDynamic(pMem) ){ + vdbeMemClearExternAndSetNull(pMem); + }else{ + pMem->flags = MEM_Null; + } +} +void sqlite3ValueSetNull(sqlite3_value *p){ + sqlite3VdbeMemSetNull((Mem*)p); +} + +/* +** Delete any previous value and set the value to be a BLOB of length +** n containing all zeros. +*/ +#ifndef SQLITE_OMIT_INCRBLOB +void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){ + sqlite3VdbeMemRelease(pMem); + pMem->flags = MEM_Blob|MEM_Zero; + pMem->n = 0; + if( n<0 ) n = 0; + pMem->u.nZero = n; + pMem->enc = SQLITE_UTF8; + pMem->z = 0; +} +#else +int sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){ + int nByte = n>0?n:1; + if( sqlite3VdbeMemGrow(pMem, nByte, 0) ){ + return SQLITE_NOMEM_BKPT; + } + assert( pMem->z!=0 ); + assert( sqlite3DbMallocSize(pMem->db, pMem->z)>=nByte ); + memset(pMem->z, 0, nByte); + pMem->n = n>0?n:0; + pMem->flags = MEM_Blob; + pMem->enc = SQLITE_UTF8; + return SQLITE_OK; +} +#endif + +/* +** The pMem is known to contain content that needs to be destroyed prior +** to a value change. So invoke the destructor, then set the value to +** a 64-bit integer. +*/ +static SQLITE_NOINLINE void vdbeReleaseAndSetInt64(Mem *pMem, i64 val){ + sqlite3VdbeMemSetNull(pMem); + pMem->u.i = val; + pMem->flags = MEM_Int; +} + +/* +** Delete any previous value and set the value stored in *pMem to val, +** manifest type INTEGER. +*/ +void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){ + if( VdbeMemDynamic(pMem) ){ + vdbeReleaseAndSetInt64(pMem, val); + }else{ + pMem->u.i = val; + pMem->flags = MEM_Int; + } +} + +/* A no-op destructor */ +void sqlite3NoopDestructor(void *p){ UNUSED_PARAMETER(p); } + +/* +** Set the value stored in *pMem should already be a NULL. +** Also store a pointer to go with it. +*/ +void sqlite3VdbeMemSetPointer( + Mem *pMem, + void *pPtr, + const char *zPType, + void (*xDestructor)(void*) +){ + assert( pMem->flags==MEM_Null ); + vdbeMemClear(pMem); + pMem->u.zPType = zPType ? zPType : ""; + pMem->z = pPtr; + pMem->flags = MEM_Null|MEM_Dyn|MEM_Subtype|MEM_Term; + pMem->eSubtype = 'p'; + pMem->xDel = xDestructor ? xDestructor : sqlite3NoopDestructor; +} + +#ifndef SQLITE_OMIT_FLOATING_POINT +/* +** Delete any previous value and set the value stored in *pMem to val, +** manifest type REAL. +*/ +void sqlite3VdbeMemSetDouble(Mem *pMem, double val){ + sqlite3VdbeMemSetNull(pMem); + if( !sqlite3IsNaN(val) ){ + pMem->u.r = val; + pMem->flags = MEM_Real; + } +} +#endif + +#ifdef SQLITE_DEBUG +/* +** Return true if the Mem holds a RowSet object. This routine is intended +** for use inside of assert() statements. +*/ +int sqlite3VdbeMemIsRowSet(const Mem *pMem){ + return (pMem->flags&(MEM_Blob|MEM_Dyn))==(MEM_Blob|MEM_Dyn) + && pMem->xDel==sqlite3RowSetDelete; +} +#endif + +/* +** Delete any previous value and set the value of pMem to be an +** empty boolean index. +** +** Return SQLITE_OK on success and SQLITE_NOMEM if a memory allocation +** error occurs. +*/ +int sqlite3VdbeMemSetRowSet(Mem *pMem){ + sqlite3 *db = pMem->db; + RowSet *p; + assert( db!=0 ); + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + sqlite3VdbeMemRelease(pMem); + p = sqlite3RowSetInit(db); + if( p==0 ) return SQLITE_NOMEM; + pMem->z = (char*)p; + pMem->flags = MEM_Blob|MEM_Dyn; + pMem->xDel = sqlite3RowSetDelete; + return SQLITE_OK; +} + +/* +** Return true if the Mem object contains a TEXT or BLOB that is +** too large - whose size exceeds SQLITE_MAX_LENGTH. +*/ +int sqlite3VdbeMemTooBig(Mem *p){ + assert( p->db!=0 ); + if( p->flags & (MEM_Str|MEM_Blob) ){ + int n = p->n; + if( p->flags & MEM_Zero ){ + n += p->u.nZero; + } + return n>p->db->aLimit[SQLITE_LIMIT_LENGTH]; + } + return 0; +} + +#ifdef SQLITE_DEBUG +/* +** This routine prepares a memory cell for modification by breaking +** its link to a shallow copy and by marking any current shallow +** copies of this cell as invalid. +** +** This is used for testing and debugging only - to help ensure that shallow +** copies (created by OP_SCopy) are not misused. +*/ +void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){ + int i; + Mem *pX; + for(i=1, pX=pVdbe->aMem+1; i<pVdbe->nMem; i++, pX++){ + if( pX->pScopyFrom==pMem ){ + u16 mFlags; + if( pVdbe->db->flags & SQLITE_VdbeTrace ){ + sqlite3DebugPrintf("Invalidate R[%d] due to change in R[%d]\n", + (int)(pX - pVdbe->aMem), (int)(pMem - pVdbe->aMem)); + } + /* If pX is marked as a shallow copy of pMem, then try to verify that + ** no significant changes have been made to pX since the OP_SCopy. + ** A significant change would indicated a missed call to this + ** function for pX. Minor changes, such as adding or removing a + ** dual type, are allowed, as long as the underlying value is the + ** same. */ + mFlags = pMem->flags & pX->flags & pX->mScopyFlags; + assert( (mFlags&(MEM_Int|MEM_IntReal))==0 || pMem->u.i==pX->u.i ); + + /* pMem is the register that is changing. But also mark pX as + ** undefined so that we can quickly detect the shallow-copy error */ + pX->flags = MEM_Undefined; + pX->pScopyFrom = 0; + } + } + pMem->pScopyFrom = 0; +} +#endif /* SQLITE_DEBUG */ + +/* +** Make an shallow copy of pFrom into pTo. Prior contents of +** pTo are freed. The pFrom->z field is not duplicated. If +** pFrom->z is used, then pTo->z points to the same thing as pFrom->z +** and flags gets srcType (either MEM_Ephem or MEM_Static). +*/ +static SQLITE_NOINLINE void vdbeClrCopy(Mem *pTo, const Mem *pFrom, int eType){ + vdbeMemClearExternAndSetNull(pTo); + assert( !VdbeMemDynamic(pTo) ); + sqlite3VdbeMemShallowCopy(pTo, pFrom, eType); +} +void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){ + assert( !sqlite3VdbeMemIsRowSet(pFrom) ); + assert( pTo->db==pFrom->db ); + if( VdbeMemDynamic(pTo) ){ vdbeClrCopy(pTo,pFrom,srcType); return; } + memcpy(pTo, pFrom, MEMCELLSIZE); + if( (pFrom->flags&MEM_Static)==0 ){ + pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem); + assert( srcType==MEM_Ephem || srcType==MEM_Static ); + pTo->flags |= srcType; + } +} + +/* +** Make a full copy of pFrom into pTo. Prior contents of pTo are +** freed before the copy is made. +*/ +int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){ + int rc = SQLITE_OK; + + assert( !sqlite3VdbeMemIsRowSet(pFrom) ); + if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo); + memcpy(pTo, pFrom, MEMCELLSIZE); + pTo->flags &= ~MEM_Dyn; + if( pTo->flags&(MEM_Str|MEM_Blob) ){ + if( 0==(pFrom->flags&MEM_Static) ){ + pTo->flags |= MEM_Ephem; + rc = sqlite3VdbeMemMakeWriteable(pTo); + } + } + + return rc; +} + +/* +** Transfer the contents of pFrom to pTo. Any existing value in pTo is +** freed. If pFrom contains ephemeral data, a copy is made. +** +** pFrom contains an SQL NULL when this routine returns. +*/ +void sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){ + assert( pFrom->db==0 || sqlite3_mutex_held(pFrom->db->mutex) ); + assert( pTo->db==0 || sqlite3_mutex_held(pTo->db->mutex) ); + assert( pFrom->db==0 || pTo->db==0 || pFrom->db==pTo->db ); + + sqlite3VdbeMemRelease(pTo); + memcpy(pTo, pFrom, sizeof(Mem)); + pFrom->flags = MEM_Null; + pFrom->szMalloc = 0; +} + +/* +** Change the value of a Mem to be a string or a BLOB. +** +** The memory management strategy depends on the value of the xDel +** parameter. If the value passed is SQLITE_TRANSIENT, then the +** string is copied into a (possibly existing) buffer managed by the +** Mem structure. Otherwise, any existing buffer is freed and the +** pointer copied. +** +** If the string is too large (if it exceeds the SQLITE_LIMIT_LENGTH +** size limit) then no memory allocation occurs. If the string can be +** stored without allocating memory, then it is. If a memory allocation +** is required to store the string, then value of pMem is unchanged. In +** either case, SQLITE_TOOBIG is returned. +** +** The "enc" parameter is the text encoding for the string, or zero +** to store a blob. +** +** If n is negative, then the string consists of all bytes up to but +** excluding the first zero character. The n parameter must be +** non-negative for blobs. +*/ +int sqlite3VdbeMemSetStr( + Mem *pMem, /* Memory cell to set to string value */ + const char *z, /* String pointer */ + i64 n, /* Bytes in string, or negative */ + u8 enc, /* Encoding of z. 0 for BLOBs */ + void (*xDel)(void*) /* Destructor function */ +){ + i64 nByte = n; /* New value for pMem->n */ + int iLimit; /* Maximum allowed string or blob size */ + u16 flags; /* New value for pMem->flags */ + + assert( pMem!=0 ); + assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) ); + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + assert( enc!=0 || n>=0 ); + + /* If z is a NULL pointer, set pMem to contain an SQL NULL. */ + if( !z ){ + sqlite3VdbeMemSetNull(pMem); + return SQLITE_OK; + } + + if( pMem->db ){ + iLimit = pMem->db->aLimit[SQLITE_LIMIT_LENGTH]; + }else{ + iLimit = SQLITE_MAX_LENGTH; + } + if( nByte<0 ){ + assert( enc!=0 ); + if( enc==SQLITE_UTF8 ){ + nByte = strlen(z); + }else{ + for(nByte=0; nByte<=iLimit && (z[nByte] | z[nByte+1]); nByte+=2){} + } + flags= MEM_Str|MEM_Term; + }else if( enc==0 ){ + flags = MEM_Blob; + enc = SQLITE_UTF8; + }else{ + flags = MEM_Str; + } + if( nByte>iLimit ){ + if( xDel && xDel!=SQLITE_TRANSIENT ){ + if( xDel==SQLITE_DYNAMIC ){ + sqlite3DbFree(pMem->db, (void*)z); + }else{ + xDel((void*)z); + } + } + sqlite3VdbeMemSetNull(pMem); + return sqlite3ErrorToParser(pMem->db, SQLITE_TOOBIG); + } + + /* The following block sets the new values of Mem.z and Mem.xDel. It + ** also sets a flag in local variable "flags" to indicate the memory + ** management (one of MEM_Dyn or MEM_Static). + */ + if( xDel==SQLITE_TRANSIENT ){ + i64 nAlloc = nByte; + if( flags&MEM_Term ){ + nAlloc += (enc==SQLITE_UTF8?1:2); + } + testcase( nAlloc==0 ); + testcase( nAlloc==31 ); + testcase( nAlloc==32 ); + if( sqlite3VdbeMemClearAndResize(pMem, (int)MAX(nAlloc,32)) ){ + return SQLITE_NOMEM_BKPT; + } + memcpy(pMem->z, z, nAlloc); + }else{ + sqlite3VdbeMemRelease(pMem); + pMem->z = (char *)z; + if( xDel==SQLITE_DYNAMIC ){ + pMem->zMalloc = pMem->z; + pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc); + }else{ + pMem->xDel = xDel; + flags |= ((xDel==SQLITE_STATIC)?MEM_Static:MEM_Dyn); + } + } + + pMem->n = (int)(nByte & 0x7fffffff); + pMem->flags = flags; + pMem->enc = enc; + +#ifndef SQLITE_OMIT_UTF16 + if( enc>SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){ + return SQLITE_NOMEM_BKPT; + } +#endif + + + return SQLITE_OK; +} + +/* +** Move data out of a btree key or data field and into a Mem structure. +** The data is payload from the entry that pCur is currently pointing +** to. offset and amt determine what portion of the data or key to retrieve. +** The result is written into the pMem element. +** +** The pMem object must have been initialized. This routine will use +** pMem->zMalloc to hold the content from the btree, if possible. New +** pMem->zMalloc space will be allocated if necessary. The calling routine +** is responsible for making sure that the pMem object is eventually +** destroyed. +** +** If this routine fails for any reason (malloc returns NULL or unable +** to read from the disk) then the pMem is left in an inconsistent state. +*/ +int sqlite3VdbeMemFromBtree( + BtCursor *pCur, /* Cursor pointing at record to retrieve. */ + u32 offset, /* Offset from the start of data to return bytes from. */ + u32 amt, /* Number of bytes to return. */ + Mem *pMem /* OUT: Return data in this Mem structure. */ +){ + int rc; + pMem->flags = MEM_Null; + if( sqlite3BtreeMaxRecordSize(pCur)<offset+amt ){ + return SQLITE_CORRUPT_BKPT; + } + if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+1)) ){ + rc = sqlite3BtreePayload(pCur, offset, amt, pMem->z); + if( rc==SQLITE_OK ){ + pMem->z[amt] = 0; /* Overrun area used when reading malformed records */ + pMem->flags = MEM_Blob; + pMem->n = (int)amt; + }else{ + sqlite3VdbeMemRelease(pMem); + } + } + return rc; +} +int sqlite3VdbeMemFromBtreeZeroOffset( + BtCursor *pCur, /* Cursor pointing at record to retrieve. */ + u32 amt, /* Number of bytes to return. */ + Mem *pMem /* OUT: Return data in this Mem structure. */ +){ + u32 available = 0; /* Number of bytes available on the local btree page */ + int rc = SQLITE_OK; /* Return code */ + + assert( sqlite3BtreeCursorIsValid(pCur) ); + assert( !VdbeMemDynamic(pMem) ); + + /* Note: the calls to BtreeKeyFetch() and DataFetch() below assert() + ** that both the BtShared and database handle mutexes are held. */ + assert( !sqlite3VdbeMemIsRowSet(pMem) ); + pMem->z = (char *)sqlite3BtreePayloadFetch(pCur, &available); + assert( pMem->z!=0 ); + + if( amt<=available ){ + pMem->flags = MEM_Blob|MEM_Ephem; + pMem->n = (int)amt; + }else{ + rc = sqlite3VdbeMemFromBtree(pCur, 0, amt, pMem); + } + + return rc; +} + +/* +** The pVal argument is known to be a value other than NULL. +** Convert it into a string with encoding enc and return a pointer +** to a zero-terminated version of that string. +*/ +static SQLITE_NOINLINE const void *valueToText(sqlite3_value* pVal, u8 enc){ + assert( pVal!=0 ); + assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) ); + assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) ); + assert( !sqlite3VdbeMemIsRowSet(pVal) ); + assert( (pVal->flags & (MEM_Null))==0 ); + if( pVal->flags & (MEM_Blob|MEM_Str) ){ + if( ExpandBlob(pVal) ) return 0; + pVal->flags |= MEM_Str; + if( pVal->enc != (enc & ~SQLITE_UTF16_ALIGNED) ){ + sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED); + } + if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&SQLITE_PTR_TO_INT(pVal->z)) ){ + assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 ); + if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){ + return 0; + } + } + sqlite3VdbeMemNulTerminate(pVal); /* IMP: R-31275-44060 */ + }else{ + sqlite3VdbeMemStringify(pVal, enc, 0); + assert( 0==(1&SQLITE_PTR_TO_INT(pVal->z)) ); + } + assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || pVal->db==0 + || pVal->db->mallocFailed ); + if( pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) ){ + assert( sqlite3VdbeMemValidStrRep(pVal) ); + return pVal->z; + }else{ + return 0; + } +} + +/* This function is only available internally, it is not part of the +** external API. It works in a similar way to sqlite3_value_text(), +** except the data returned is in the encoding specified by the second +** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or +** SQLITE_UTF8. +** +** (2006-02-16:) The enc value can be or-ed with SQLITE_UTF16_ALIGNED. +** If that is the case, then the result must be aligned on an even byte +** boundary. +*/ +const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){ + if( !pVal ) return 0; + assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) ); + assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) ); + assert( !sqlite3VdbeMemIsRowSet(pVal) ); + if( (pVal->flags&(MEM_Str|MEM_Term))==(MEM_Str|MEM_Term) && pVal->enc==enc ){ + assert( sqlite3VdbeMemValidStrRep(pVal) ); + return pVal->z; + } + if( pVal->flags&MEM_Null ){ + return 0; + } + return valueToText(pVal, enc); +} + +/* +** Create a new sqlite3_value object. +*/ +sqlite3_value *sqlite3ValueNew(sqlite3 *db){ + Mem *p = sqlite3DbMallocZero(db, sizeof(*p)); + if( p ){ + p->flags = MEM_Null; + p->db = db; + } + return p; +} + +/* +** Context object passed by sqlite3Stat4ProbeSetValue() through to +** valueNew(). See comments above valueNew() for details. +*/ +struct ValueNewStat4Ctx { + Parse *pParse; + Index *pIdx; + UnpackedRecord **ppRec; + int iVal; +}; + +/* +** Allocate and return a pointer to a new sqlite3_value object. If +** the second argument to this function is NULL, the object is allocated +** by calling sqlite3ValueNew(). +** +** Otherwise, if the second argument is non-zero, then this function is +** being called indirectly by sqlite3Stat4ProbeSetValue(). If it has not +** already been allocated, allocate the UnpackedRecord structure that +** that function will return to its caller here. Then return a pointer to +** an sqlite3_value within the UnpackedRecord.a[] array. +*/ +static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){ +#ifdef SQLITE_ENABLE_STAT4 + if( p ){ + UnpackedRecord *pRec = p->ppRec[0]; + + if( pRec==0 ){ + Index *pIdx = p->pIdx; /* Index being probed */ + int nByte; /* Bytes of space to allocate */ + int i; /* Counter variable */ + int nCol = pIdx->nColumn; /* Number of index columns including rowid */ + + nByte = sizeof(Mem) * nCol + ROUND8(sizeof(UnpackedRecord)); + pRec = (UnpackedRecord*)sqlite3DbMallocZero(db, nByte); + if( pRec ){ + pRec->pKeyInfo = sqlite3KeyInfoOfIndex(p->pParse, pIdx); + if( pRec->pKeyInfo ){ + assert( pRec->pKeyInfo->nAllField==nCol ); + assert( pRec->pKeyInfo->enc==ENC(db) ); + pRec->aMem = (Mem *)((u8*)pRec + ROUND8(sizeof(UnpackedRecord))); + for(i=0; i<nCol; i++){ + pRec->aMem[i].flags = MEM_Null; + pRec->aMem[i].db = db; + } + }else{ + sqlite3DbFreeNN(db, pRec); + pRec = 0; + } + } + if( pRec==0 ) return 0; + p->ppRec[0] = pRec; + } + + pRec->nField = p->iVal+1; + return &pRec->aMem[p->iVal]; + } +#else + UNUSED_PARAMETER(p); +#endif /* defined(SQLITE_ENABLE_STAT4) */ + return sqlite3ValueNew(db); +} + +/* +** The expression object indicated by the second argument is guaranteed +** to be a scalar SQL function. If +** +** * all function arguments are SQL literals, +** * one of the SQLITE_FUNC_CONSTANT or _SLOCHNG function flags is set, and +** * the SQLITE_FUNC_NEEDCOLL function flag is not set, +** +** then this routine attempts to invoke the SQL function. Assuming no +** error occurs, output parameter (*ppVal) is set to point to a value +** object containing the result before returning SQLITE_OK. +** +** Affinity aff is applied to the result of the function before returning. +** If the result is a text value, the sqlite3_value object uses encoding +** enc. +** +** If the conditions above are not met, this function returns SQLITE_OK +** and sets (*ppVal) to NULL. Or, if an error occurs, (*ppVal) is set to +** NULL and an SQLite error code returned. +*/ +#ifdef SQLITE_ENABLE_STAT4 +static int valueFromFunction( + sqlite3 *db, /* The database connection */ + const Expr *p, /* The expression to evaluate */ + u8 enc, /* Encoding to use */ + u8 aff, /* Affinity to use */ + sqlite3_value **ppVal, /* Write the new value here */ + struct ValueNewStat4Ctx *pCtx /* Second argument for valueNew() */ +){ + sqlite3_context ctx; /* Context object for function invocation */ + sqlite3_value **apVal = 0; /* Function arguments */ + int nVal = 0; /* Size of apVal[] array */ + FuncDef *pFunc = 0; /* Function definition */ + sqlite3_value *pVal = 0; /* New value */ + int rc = SQLITE_OK; /* Return code */ + ExprList *pList = 0; /* Function arguments */ + int i; /* Iterator variable */ + + assert( pCtx!=0 ); + assert( (p->flags & EP_TokenOnly)==0 ); + assert( ExprUseXList(p) ); + pList = p->x.pList; + if( pList ) nVal = pList->nExpr; + assert( !ExprHasProperty(p, EP_IntValue) ); + pFunc = sqlite3FindFunction(db, p->u.zToken, nVal, enc, 0); + assert( pFunc ); + if( (pFunc->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG))==0 + || (pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL) + ){ + return SQLITE_OK; + } + + if( pList ){ + apVal = (sqlite3_value**)sqlite3DbMallocZero(db, sizeof(apVal[0]) * nVal); + if( apVal==0 ){ + rc = SQLITE_NOMEM_BKPT; + goto value_from_function_out; + } + for(i=0; i<nVal; i++){ + rc = sqlite3ValueFromExpr(db, pList->a[i].pExpr, enc, aff, &apVal[i]); + if( apVal[i]==0 || rc!=SQLITE_OK ) goto value_from_function_out; + } + } + + pVal = valueNew(db, pCtx); + if( pVal==0 ){ + rc = SQLITE_NOMEM_BKPT; + goto value_from_function_out; + } + + testcase( pCtx->pParse->rc==SQLITE_ERROR ); + testcase( pCtx->pParse->rc==SQLITE_OK ); + memset(&ctx, 0, sizeof(ctx)); + ctx.pOut = pVal; + ctx.pFunc = pFunc; + ctx.enc = ENC(db); + pFunc->xSFunc(&ctx, nVal, apVal); + if( ctx.isError ){ + rc = ctx.isError; + sqlite3ErrorMsg(pCtx->pParse, "%s", sqlite3_value_text(pVal)); + }else{ + sqlite3ValueApplyAffinity(pVal, aff, SQLITE_UTF8); + assert( rc==SQLITE_OK ); + rc = sqlite3VdbeChangeEncoding(pVal, enc); + if( rc==SQLITE_OK && sqlite3VdbeMemTooBig(pVal) ){ + rc = SQLITE_TOOBIG; + pCtx->pParse->nErr++; + } + } + pCtx->pParse->rc = rc; + + value_from_function_out: + if( rc!=SQLITE_OK ){ + pVal = 0; + } + if( apVal ){ + for(i=0; i<nVal; i++){ + sqlite3ValueFree(apVal[i]); + } + sqlite3DbFreeNN(db, apVal); + } + + *ppVal = pVal; + return rc; +} +#else +# define valueFromFunction(a,b,c,d,e,f) SQLITE_OK +#endif /* defined(SQLITE_ENABLE_STAT4) */ + +/* +** Extract a value from the supplied expression in the manner described +** above sqlite3ValueFromExpr(). Allocate the sqlite3_value object +** using valueNew(). +** +** If pCtx is NULL and an error occurs after the sqlite3_value object +** has been allocated, it is freed before returning. Or, if pCtx is not +** NULL, it is assumed that the caller will free any allocated object +** in all cases. +*/ +static int valueFromExpr( + sqlite3 *db, /* The database connection */ + const Expr *pExpr, /* The expression to evaluate */ + u8 enc, /* Encoding to use */ + u8 affinity, /* Affinity to use */ + sqlite3_value **ppVal, /* Write the new value here */ + struct ValueNewStat4Ctx *pCtx /* Second argument for valueNew() */ +){ + int op; + char *zVal = 0; + sqlite3_value *pVal = 0; + int negInt = 1; + const char *zNeg = ""; + int rc = SQLITE_OK; + + assert( pExpr!=0 ); + while( (op = pExpr->op)==TK_UPLUS || op==TK_SPAN ) pExpr = pExpr->pLeft; + if( op==TK_REGISTER ) op = pExpr->op2; + + /* Compressed expressions only appear when parsing the DEFAULT clause + ** on a table column definition, and hence only when pCtx==0. This + ** check ensures that an EP_TokenOnly expression is never passed down + ** into valueFromFunction(). */ + assert( (pExpr->flags & EP_TokenOnly)==0 || pCtx==0 ); + + if( op==TK_CAST ){ + u8 aff; + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + aff = sqlite3AffinityType(pExpr->u.zToken,0); + rc = valueFromExpr(db, pExpr->pLeft, enc, aff, ppVal, pCtx); + testcase( rc!=SQLITE_OK ); + if( *ppVal ){ + sqlite3VdbeMemCast(*ppVal, aff, enc); + sqlite3ValueApplyAffinity(*ppVal, affinity, enc); + } + return rc; + } + + /* Handle negative integers in a single step. This is needed in the + ** case when the value is -9223372036854775808. + */ + if( op==TK_UMINUS + && (pExpr->pLeft->op==TK_INTEGER || pExpr->pLeft->op==TK_FLOAT) ){ + pExpr = pExpr->pLeft; + op = pExpr->op; + negInt = -1; + zNeg = "-"; + } + + if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){ + pVal = valueNew(db, pCtx); + if( pVal==0 ) goto no_mem; + if( ExprHasProperty(pExpr, EP_IntValue) ){ + sqlite3VdbeMemSetInt64(pVal, (i64)pExpr->u.iValue*negInt); + }else{ + zVal = sqlite3MPrintf(db, "%s%s", zNeg, pExpr->u.zToken); + if( zVal==0 ) goto no_mem; + sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, SQLITE_DYNAMIC); + } + if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_BLOB ){ + sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, SQLITE_UTF8); + }else{ + sqlite3ValueApplyAffinity(pVal, affinity, SQLITE_UTF8); + } + assert( (pVal->flags & MEM_IntReal)==0 ); + if( pVal->flags & (MEM_Int|MEM_IntReal|MEM_Real) ){ + testcase( pVal->flags & MEM_Int ); + testcase( pVal->flags & MEM_Real ); + pVal->flags &= ~MEM_Str; + } + if( enc!=SQLITE_UTF8 ){ + rc = sqlite3VdbeChangeEncoding(pVal, enc); + } + }else if( op==TK_UMINUS ) { + /* This branch happens for multiple negative signs. Ex: -(-5) */ + if( SQLITE_OK==valueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal,pCtx) + && pVal!=0 + ){ + sqlite3VdbeMemNumerify(pVal); + if( pVal->flags & MEM_Real ){ + pVal->u.r = -pVal->u.r; + }else if( pVal->u.i==SMALLEST_INT64 ){ +#ifndef SQLITE_OMIT_FLOATING_POINT + pVal->u.r = -(double)SMALLEST_INT64; +#else + pVal->u.r = LARGEST_INT64; +#endif + MemSetTypeFlag(pVal, MEM_Real); + }else{ + pVal->u.i = -pVal->u.i; + } + sqlite3ValueApplyAffinity(pVal, affinity, enc); + } + }else if( op==TK_NULL ){ + pVal = valueNew(db, pCtx); + if( pVal==0 ) goto no_mem; + sqlite3VdbeMemSetNull(pVal); + } +#ifndef SQLITE_OMIT_BLOB_LITERAL + else if( op==TK_BLOB ){ + int nVal; + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' ); + assert( pExpr->u.zToken[1]=='\'' ); + pVal = valueNew(db, pCtx); + if( !pVal ) goto no_mem; + zVal = &pExpr->u.zToken[2]; + nVal = sqlite3Strlen30(zVal)-1; + assert( zVal[nVal]=='\'' ); + sqlite3VdbeMemSetStr(pVal, sqlite3HexToBlob(db, zVal, nVal), nVal/2, + 0, SQLITE_DYNAMIC); + } +#endif +#ifdef SQLITE_ENABLE_STAT4 + else if( op==TK_FUNCTION && pCtx!=0 ){ + rc = valueFromFunction(db, pExpr, enc, affinity, &pVal, pCtx); + } +#endif + else if( op==TK_TRUEFALSE ){ + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + pVal = valueNew(db, pCtx); + if( pVal ){ + pVal->flags = MEM_Int; + pVal->u.i = pExpr->u.zToken[4]==0; + } + } + + *ppVal = pVal; + return rc; + +no_mem: +#ifdef SQLITE_ENABLE_STAT4 + if( pCtx==0 || NEVER(pCtx->pParse->nErr==0) ) +#endif + sqlite3OomFault(db); + sqlite3DbFree(db, zVal); + assert( *ppVal==0 ); +#ifdef SQLITE_ENABLE_STAT4 + if( pCtx==0 ) sqlite3ValueFree(pVal); +#else + assert( pCtx==0 ); sqlite3ValueFree(pVal); +#endif + return SQLITE_NOMEM_BKPT; +} + +/* +** Create a new sqlite3_value object, containing the value of pExpr. +** +** This only works for very simple expressions that consist of one constant +** token (i.e. "5", "5.1", "'a string'"). If the expression can +** be converted directly into a value, then the value is allocated and +** a pointer written to *ppVal. The caller is responsible for deallocating +** the value by passing it to sqlite3ValueFree() later on. If the expression +** cannot be converted to a value, then *ppVal is set to NULL. +*/ +int sqlite3ValueFromExpr( + sqlite3 *db, /* The database connection */ + const Expr *pExpr, /* The expression to evaluate */ + u8 enc, /* Encoding to use */ + u8 affinity, /* Affinity to use */ + sqlite3_value **ppVal /* Write the new value here */ +){ + return pExpr ? valueFromExpr(db, pExpr, enc, affinity, ppVal, 0) : 0; +} + +#ifdef SQLITE_ENABLE_STAT4 +/* +** Attempt to extract a value from pExpr and use it to construct *ppVal. +** +** If pAlloc is not NULL, then an UnpackedRecord object is created for +** pAlloc if one does not exist and the new value is added to the +** UnpackedRecord object. +** +** A value is extracted in the following cases: +** +** * (pExpr==0). In this case the value is assumed to be an SQL NULL, +** +** * The expression is a bound variable, and this is a reprepare, or +** +** * The expression is a literal value. +** +** On success, *ppVal is made to point to the extracted value. The caller +** is responsible for ensuring that the value is eventually freed. +*/ +static int stat4ValueFromExpr( + Parse *pParse, /* Parse context */ + Expr *pExpr, /* The expression to extract a value from */ + u8 affinity, /* Affinity to use */ + struct ValueNewStat4Ctx *pAlloc,/* How to allocate space. Or NULL */ + sqlite3_value **ppVal /* OUT: New value object (or NULL) */ +){ + int rc = SQLITE_OK; + sqlite3_value *pVal = 0; + sqlite3 *db = pParse->db; + + /* Skip over any TK_COLLATE nodes */ + pExpr = sqlite3ExprSkipCollate(pExpr); + + assert( pExpr==0 || pExpr->op!=TK_REGISTER || pExpr->op2!=TK_VARIABLE ); + if( !pExpr ){ + pVal = valueNew(db, pAlloc); + if( pVal ){ + sqlite3VdbeMemSetNull((Mem*)pVal); + } + }else if( pExpr->op==TK_VARIABLE && (db->flags & SQLITE_EnableQPSG)==0 ){ + Vdbe *v; + int iBindVar = pExpr->iColumn; + sqlite3VdbeSetVarmask(pParse->pVdbe, iBindVar); + if( (v = pParse->pReprepare)!=0 ){ + pVal = valueNew(db, pAlloc); + if( pVal ){ + rc = sqlite3VdbeMemCopy((Mem*)pVal, &v->aVar[iBindVar-1]); + sqlite3ValueApplyAffinity(pVal, affinity, ENC(db)); + pVal->db = pParse->db; + } + } + }else{ + rc = valueFromExpr(db, pExpr, ENC(db), affinity, &pVal, pAlloc); + } + + assert( pVal==0 || pVal->db==db ); + *ppVal = pVal; + return rc; +} + +/* +** This function is used to allocate and populate UnpackedRecord +** structures intended to be compared against sample index keys stored +** in the sqlite_stat4 table. +** +** A single call to this function populates zero or more fields of the +** record starting with field iVal (fields are numbered from left to +** right starting with 0). A single field is populated if: +** +** * (pExpr==0). In this case the value is assumed to be an SQL NULL, +** +** * The expression is a bound variable, and this is a reprepare, or +** +** * The sqlite3ValueFromExpr() function is able to extract a value +** from the expression (i.e. the expression is a literal value). +** +** Or, if pExpr is a TK_VECTOR, one field is populated for each of the +** vector components that match either of the two latter criteria listed +** above. +** +** Before any value is appended to the record, the affinity of the +** corresponding column within index pIdx is applied to it. Before +** this function returns, output parameter *pnExtract is set to the +** number of values appended to the record. +** +** When this function is called, *ppRec must either point to an object +** allocated by an earlier call to this function, or must be NULL. If it +** is NULL and a value can be successfully extracted, a new UnpackedRecord +** is allocated (and *ppRec set to point to it) before returning. +** +** Unless an error is encountered, SQLITE_OK is returned. It is not an +** error if a value cannot be extracted from pExpr. If an error does +** occur, an SQLite error code is returned. +*/ +int sqlite3Stat4ProbeSetValue( + Parse *pParse, /* Parse context */ + Index *pIdx, /* Index being probed */ + UnpackedRecord **ppRec, /* IN/OUT: Probe record */ + Expr *pExpr, /* The expression to extract a value from */ + int nElem, /* Maximum number of values to append */ + int iVal, /* Array element to populate */ + int *pnExtract /* OUT: Values appended to the record */ +){ + int rc = SQLITE_OK; + int nExtract = 0; + + if( pExpr==0 || pExpr->op!=TK_SELECT ){ + int i; + struct ValueNewStat4Ctx alloc; + + alloc.pParse = pParse; + alloc.pIdx = pIdx; + alloc.ppRec = ppRec; + + for(i=0; i<nElem; i++){ + sqlite3_value *pVal = 0; + Expr *pElem = (pExpr ? sqlite3VectorFieldSubexpr(pExpr, i) : 0); + u8 aff = sqlite3IndexColumnAffinity(pParse->db, pIdx, iVal+i); + alloc.iVal = iVal+i; + rc = stat4ValueFromExpr(pParse, pElem, aff, &alloc, &pVal); + if( !pVal ) break; + nExtract++; + } + } + + *pnExtract = nExtract; + return rc; +} + +/* +** Attempt to extract a value from expression pExpr using the methods +** as described for sqlite3Stat4ProbeSetValue() above. +** +** If successful, set *ppVal to point to a new value object and return +** SQLITE_OK. If no value can be extracted, but no other error occurs +** (e.g. OOM), return SQLITE_OK and set *ppVal to NULL. Or, if an error +** does occur, return an SQLite error code. The final value of *ppVal +** is undefined in this case. +*/ +int sqlite3Stat4ValueFromExpr( + Parse *pParse, /* Parse context */ + Expr *pExpr, /* The expression to extract a value from */ + u8 affinity, /* Affinity to use */ + sqlite3_value **ppVal /* OUT: New value object (or NULL) */ +){ + return stat4ValueFromExpr(pParse, pExpr, affinity, 0, ppVal); +} + +/* +** Extract the iCol-th column from the nRec-byte record in pRec. Write +** the column value into *ppVal. If *ppVal is initially NULL then a new +** sqlite3_value object is allocated. +** +** If *ppVal is initially NULL then the caller is responsible for +** ensuring that the value written into *ppVal is eventually freed. +*/ +int sqlite3Stat4Column( + sqlite3 *db, /* Database handle */ + const void *pRec, /* Pointer to buffer containing record */ + int nRec, /* Size of buffer pRec in bytes */ + int iCol, /* Column to extract */ + sqlite3_value **ppVal /* OUT: Extracted value */ +){ + u32 t = 0; /* a column type code */ + int nHdr; /* Size of the header in the record */ + int iHdr; /* Next unread header byte */ + int iField; /* Next unread data byte */ + int szField = 0; /* Size of the current data field */ + int i; /* Column index */ + u8 *a = (u8*)pRec; /* Typecast byte array */ + Mem *pMem = *ppVal; /* Write result into this Mem object */ + + assert( iCol>0 ); + iHdr = getVarint32(a, nHdr); + if( nHdr>nRec || iHdr>=nHdr ) return SQLITE_CORRUPT_BKPT; + iField = nHdr; + for(i=0; i<=iCol; i++){ + iHdr += getVarint32(&a[iHdr], t); + testcase( iHdr==nHdr ); + testcase( iHdr==nHdr+1 ); + if( iHdr>nHdr ) return SQLITE_CORRUPT_BKPT; + szField = sqlite3VdbeSerialTypeLen(t); + iField += szField; + } + testcase( iField==nRec ); + testcase( iField==nRec+1 ); + if( iField>nRec ) return SQLITE_CORRUPT_BKPT; + if( pMem==0 ){ + pMem = *ppVal = sqlite3ValueNew(db); + if( pMem==0 ) return SQLITE_NOMEM_BKPT; + } + sqlite3VdbeSerialGet(&a[iField-szField], t, pMem); + pMem->enc = ENC(db); + return SQLITE_OK; +} + +/* +** Unless it is NULL, the argument must be an UnpackedRecord object returned +** by an earlier call to sqlite3Stat4ProbeSetValue(). This call deletes +** the object. +*/ +void sqlite3Stat4ProbeFree(UnpackedRecord *pRec){ + if( pRec ){ + int i; + int nCol = pRec->pKeyInfo->nAllField; + Mem *aMem = pRec->aMem; + sqlite3 *db = aMem[0].db; + for(i=0; i<nCol; i++){ + sqlite3VdbeMemRelease(&aMem[i]); + } + sqlite3KeyInfoUnref(pRec->pKeyInfo); + sqlite3DbFreeNN(db, pRec); + } +} +#endif /* ifdef SQLITE_ENABLE_STAT4 */ + +/* +** Change the string value of an sqlite3_value object +*/ +void sqlite3ValueSetStr( + sqlite3_value *v, /* Value to be set */ + int n, /* Length of string z */ + const void *z, /* Text of the new string */ + u8 enc, /* Encoding to use */ + void (*xDel)(void*) /* Destructor for the string */ +){ + if( v ) sqlite3VdbeMemSetStr((Mem *)v, z, n, enc, xDel); +} + +/* +** Free an sqlite3_value object +*/ +void sqlite3ValueFree(sqlite3_value *v){ + if( !v ) return; + sqlite3VdbeMemRelease((Mem *)v); + sqlite3DbFreeNN(((Mem*)v)->db, v); +} + +/* +** The sqlite3ValueBytes() routine returns the number of bytes in the +** sqlite3_value object assuming that it uses the encoding "enc". +** The valueBytes() routine is a helper function. +*/ +static SQLITE_NOINLINE int valueBytes(sqlite3_value *pVal, u8 enc){ + return valueToText(pVal, enc)!=0 ? pVal->n : 0; +} +int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){ + Mem *p = (Mem*)pVal; + assert( (p->flags & MEM_Null)==0 || (p->flags & (MEM_Str|MEM_Blob))==0 ); + if( (p->flags & MEM_Str)!=0 && pVal->enc==enc ){ + return p->n; + } + if( (p->flags & MEM_Str)!=0 && enc!=SQLITE_UTF8 && pVal->enc!=SQLITE_UTF8 ){ + return p->n; + } + if( (p->flags & MEM_Blob)!=0 ){ + if( p->flags & MEM_Zero ){ + return p->n + p->u.nZero; + }else{ + return p->n; + } + } + if( p->flags & MEM_Null ) return 0; + return valueBytes(pVal, enc); +} |