/* ** 2009 November 25 ** ** 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 used to insert the values of host parameters ** (aka "wildcards") into the SQL text output by sqlite3_trace(). ** ** The Vdbe parse-tree explainer is also found here. */ #include "sqliteInt.h" #include "vdbeInt.h" #ifndef SQLITE_OMIT_TRACE /* ** zSql is a zero-terminated string of UTF-8 SQL text. Return the number of ** bytes in this text up to but excluding the first character in ** a host parameter. If the text contains no host parameters, return ** the total number of bytes in the text. */ static int findNextHostParameter(const char *zSql, int *pnToken){ int tokenType; int nTotal = 0; int n; *pnToken = 0; while( zSql[0] ){ n = sqlite3GetToken((u8*)zSql, &tokenType); assert( n>0 && tokenType!=TK_ILLEGAL ); if( tokenType==TK_VARIABLE ){ *pnToken = n; break; } nTotal += n; zSql += n; } return nTotal; } /* ** This function returns a pointer to a nul-terminated string in memory ** obtained from sqlite3DbMalloc(). If sqlite3.nVdbeExec is 1, then the ** string contains a copy of zRawSql but with host parameters expanded to ** their current bindings. Or, if sqlite3.nVdbeExec is greater than 1, ** then the returned string holds a copy of zRawSql with "-- " prepended ** to each line of text. ** ** If the SQLITE_TRACE_SIZE_LIMIT macro is defined to an integer, then ** then long strings and blobs are truncated to that many bytes. This ** can be used to prevent unreasonably large trace strings when dealing ** with large (multi-megabyte) strings and blobs. ** ** The calling function is responsible for making sure the memory returned ** is eventually freed. ** ** ALGORITHM: Scan the input string looking for host parameters in any of ** these forms: ?, ?N, $A, @A, :A. Take care to avoid text within ** string literals, quoted identifier names, and comments. For text forms, ** the host parameter index is found by scanning the prepared ** statement for the corresponding OP_Variable opcode. Once the host ** parameter index is known, locate the value in p->aVar[]. Then render ** the value as a literal in place of the host parameter name. */ char *sqlite3VdbeExpandSql( Vdbe *p, /* The prepared statement being evaluated */ const char *zRawSql /* Raw text of the SQL statement */ ){ sqlite3 *db; /* The database connection */ int idx = 0; /* Index of a host parameter */ int nextIndex = 1; /* Index of next ? host parameter */ int n; /* Length of a token prefix */ int nToken; /* Length of the parameter token */ int i; /* Loop counter */ Mem *pVar; /* Value of a host parameter */ StrAccum out; /* Accumulate the output here */ #ifndef SQLITE_OMIT_UTF16 Mem utf8; /* Used to convert UTF16 into UTF8 for display */ #endif char zBase[100]; /* Initial working space */ db = p->db; sqlite3StrAccumInit(&out, 0, zBase, sizeof(zBase), db->aLimit[SQLITE_LIMIT_LENGTH]); if( db->nVdbeExec>1 ){ while( *zRawSql ){ const char *zStart = zRawSql; while( *(zRawSql++)!='\n' && *zRawSql ); sqlite3StrAccumAppend(&out, "-- ", 3); assert( (zRawSql - zStart) > 0 ); sqlite3StrAccumAppend(&out, zStart, (int)(zRawSql-zStart)); } }else if( p->nVar==0 ){ sqlite3StrAccumAppend(&out, zRawSql, sqlite3Strlen30(zRawSql)); }else{ while( zRawSql[0] ){ n = findNextHostParameter(zRawSql, &nToken); assert( n>0 ); sqlite3StrAccumAppend(&out, zRawSql, n); zRawSql += n; assert( zRawSql[0] || nToken==0 ); if( nToken==0 ) break; if( zRawSql[0]=='?' ){ if( nToken>1 ){ assert( sqlite3Isdigit(zRawSql[1]) ); sqlite3GetInt32(&zRawSql[1], &idx); }else{ idx = nextIndex; } }else{ assert( zRawSql[0]==':' || zRawSql[0]=='$' || zRawSql[0]=='@' || zRawSql[0]=='#' ); testcase( zRawSql[0]==':' ); testcase( zRawSql[0]=='$' ); testcase( zRawSql[0]=='@' ); testcase( zRawSql[0]=='#' ); idx = sqlite3VdbeParameterIndex(p, zRawSql, nToken); assert( idx>0 ); } zRawSql += nToken; nextIndex = idx + 1; assert( idx>0 && idx<=p->nVar ); pVar = &p->aVar[idx-1]; if( pVar->flags & MEM_Null ){ sqlite3StrAccumAppend(&out, "NULL", 4); }else if( pVar->flags & MEM_Int ){ sqlite3XPrintf(&out, "%lld", pVar->u.i); }else if( pVar->flags & MEM_Real ){ sqlite3XPrintf(&out, "%!.15g", pVar->u.r); }else if( pVar->flags & MEM_Str ){ int nOut; /* Number of bytes of the string text to include in output */ #ifndef SQLITE_OMIT_UTF16 u8 enc = ENC(db); if( enc!=SQLITE_UTF8 ){ memset(&utf8, 0, sizeof(utf8)); utf8.db = db; sqlite3VdbeMemSetStr(&utf8, pVar->z, pVar->n, enc, SQLITE_STATIC); if( SQLITE_NOMEM==sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8) ){ out.accError = STRACCUM_NOMEM; out.nAlloc = 0; } pVar = &utf8; } #endif nOut = pVar->n; #ifdef SQLITE_TRACE_SIZE_LIMIT if( nOut>SQLITE_TRACE_SIZE_LIMIT ){ nOut = SQLITE_TRACE_SIZE_LIMIT; while( nOutn && (pVar->z[nOut]&0xc0)==0x80 ){ nOut++; } } #endif sqlite3XPrintf(&out, "'%.*q'", nOut, pVar->z); #ifdef SQLITE_TRACE_SIZE_LIMIT if( nOutn ){ sqlite3XPrintf(&out, "/*+%d bytes*/", pVar->n-nOut); } #endif #ifndef SQLITE_OMIT_UTF16 if( enc!=SQLITE_UTF8 ) sqlite3VdbeMemRelease(&utf8); #endif }else if( pVar->flags & MEM_Zero ){ sqlite3XPrintf(&out, "zeroblob(%d)", pVar->u.nZero); }else{ int nOut; /* Number of bytes of the blob to include in output */ assert( pVar->flags & MEM_Blob ); sqlite3StrAccumAppend(&out, "x'", 2); nOut = pVar->n; #ifdef SQLITE_TRACE_SIZE_LIMIT if( nOut>SQLITE_TRACE_SIZE_LIMIT ) nOut = SQLITE_TRACE_SIZE_LIMIT; #endif for(i=0; iz[i]&0xff); } sqlite3StrAccumAppend(&out, "'", 1); #ifdef SQLITE_TRACE_SIZE_LIMIT if( nOutn ){ sqlite3XPrintf(&out, "/*+%d bytes*/", pVar->n-nOut); } #endif } } } if( out.accError ) sqlite3StrAccumReset(&out); return sqlite3StrAccumFinish(&out); } #endif /* #ifndef SQLITE_OMIT_TRACE */