vdbetrace.c revision 5821806d5e7f356e8fa4b058a389a808ea183019
1/* 2** 2009 November 25 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** 13** This file contains code used to insert the values of host parameters 14** (aka "wildcards") into the SQL text output by sqlite3_trace(). 15*/ 16#include "sqliteInt.h" 17#include "vdbeInt.h" 18 19#ifndef SQLITE_OMIT_TRACE 20 21/* 22** zSql is a zero-terminated string of UTF-8 SQL text. Return the number of 23** bytes in this text up to but excluding the first character in 24** a host parameter. If the text contains no host parameters, return 25** the total number of bytes in the text. 26*/ 27static int findNextHostParameter(const char *zSql, int *pnToken){ 28 int tokenType; 29 int nTotal = 0; 30 int n; 31 32 *pnToken = 0; 33 while( zSql[0] ){ 34 n = sqlite3GetToken((u8*)zSql, &tokenType); 35 assert( n>0 && tokenType!=TK_ILLEGAL ); 36 if( tokenType==TK_VARIABLE ){ 37 *pnToken = n; 38 break; 39 } 40 nTotal += n; 41 zSql += n; 42 } 43 return nTotal; 44} 45 46/* 47** This function returns a pointer to a nul-terminated string in memory 48** obtained from sqlite3DbMalloc(). If sqlite3.vdbeExecCnt is 1, then the 49** string contains a copy of zRawSql but with host parameters expanded to 50** their current bindings. Or, if sqlite3.vdbeExecCnt is greater than 1, 51** then the returned string holds a copy of zRawSql with "-- " prepended 52** to each line of text. 53** 54** The calling function is responsible for making sure the memory returned 55** is eventually freed. 56** 57** ALGORITHM: Scan the input string looking for host parameters in any of 58** these forms: ?, ?N, $A, @A, :A. Take care to avoid text within 59** string literals, quoted identifier names, and comments. For text forms, 60** the host parameter index is found by scanning the perpared 61** statement for the corresponding OP_Variable opcode. Once the host 62** parameter index is known, locate the value in p->aVar[]. Then render 63** the value as a literal in place of the host parameter name. 64*/ 65char *sqlite3VdbeExpandSql( 66 Vdbe *p, /* The prepared statement being evaluated */ 67 const char *zRawSql /* Raw text of the SQL statement */ 68){ 69 sqlite3 *db; /* The database connection */ 70 int idx = 0; /* Index of a host parameter */ 71 int nextIndex = 1; /* Index of next ? host parameter */ 72 int n; /* Length of a token prefix */ 73 int nToken; /* Length of the parameter token */ 74 int i; /* Loop counter */ 75 Mem *pVar; /* Value of a host parameter */ 76 StrAccum out; /* Accumulate the output here */ 77 char zBase[100]; /* Initial working space */ 78 79 db = p->db; 80 sqlite3StrAccumInit(&out, zBase, sizeof(zBase), 81 db->aLimit[SQLITE_LIMIT_LENGTH]); 82 out.db = db; 83 if( db->vdbeExecCnt>1 ){ 84 while( *zRawSql ){ 85 const char *zStart = zRawSql; 86 while( *(zRawSql++)!='\n' && *zRawSql ); 87 sqlite3StrAccumAppend(&out, "-- ", 3); 88 sqlite3StrAccumAppend(&out, zStart, (int)(zRawSql-zStart)); 89 } 90 }else{ 91 while( zRawSql[0] ){ 92 n = findNextHostParameter(zRawSql, &nToken); 93 assert( n>0 ); 94 sqlite3StrAccumAppend(&out, zRawSql, n); 95 zRawSql += n; 96 assert( zRawSql[0] || nToken==0 ); 97 if( nToken==0 ) break; 98 if( zRawSql[0]=='?' ){ 99 if( nToken>1 ){ 100 assert( sqlite3Isdigit(zRawSql[1]) ); 101 sqlite3GetInt32(&zRawSql[1], &idx); 102 }else{ 103 idx = nextIndex; 104 } 105 }else{ 106 assert( zRawSql[0]==':' || zRawSql[0]=='$' || zRawSql[0]=='@' ); 107 testcase( zRawSql[0]==':' ); 108 testcase( zRawSql[0]=='$' ); 109 testcase( zRawSql[0]=='@' ); 110 idx = sqlite3VdbeParameterIndex(p, zRawSql, nToken); 111 assert( idx>0 ); 112 } 113 zRawSql += nToken; 114 nextIndex = idx + 1; 115 assert( idx>0 && idx<=p->nVar ); 116 pVar = &p->aVar[idx-1]; 117 if( pVar->flags & MEM_Null ){ 118 sqlite3StrAccumAppend(&out, "NULL", 4); 119 }else if( pVar->flags & MEM_Int ){ 120 sqlite3XPrintf(&out, "%lld", pVar->u.i); 121 }else if( pVar->flags & MEM_Real ){ 122 sqlite3XPrintf(&out, "%!.15g", pVar->r); 123 }else if( pVar->flags & MEM_Str ){ 124#ifndef SQLITE_OMIT_UTF16 125 u8 enc = ENC(db); 126 if( enc!=SQLITE_UTF8 ){ 127 Mem utf8; 128 memset(&utf8, 0, sizeof(utf8)); 129 utf8.db = db; 130 sqlite3VdbeMemSetStr(&utf8, pVar->z, pVar->n, enc, SQLITE_STATIC); 131 sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8); 132 sqlite3XPrintf(&out, "'%.*q'", utf8.n, utf8.z); 133 sqlite3VdbeMemRelease(&utf8); 134 }else 135#endif 136 { 137 sqlite3XPrintf(&out, "'%.*q'", pVar->n, pVar->z); 138 } 139 }else if( pVar->flags & MEM_Zero ){ 140 sqlite3XPrintf(&out, "zeroblob(%d)", pVar->u.nZero); 141 }else{ 142 assert( pVar->flags & MEM_Blob ); 143 sqlite3StrAccumAppend(&out, "x'", 2); 144 for(i=0; i<pVar->n; i++){ 145 sqlite3XPrintf(&out, "%02x", pVar->z[i]&0xff); 146 } 147 sqlite3StrAccumAppend(&out, "'", 1); 148 } 149 } 150 } 151 return sqlite3StrAccumFinish(&out); 152} 153 154#endif /* #ifndef SQLITE_OMIT_TRACE */ 155