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Overview
Comment: | Avoid allocating large objects on the stack in the incremental BLOB I/O interface. (CVS 6703) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
ea7dfde700fb57ed0ecb5000a55abbf4 |
User & Date: | drh 2009-06-01 19:53:31.000 |
Context
2009-06-02
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15:21 | Add the vdbe-compress.tcl script which automatically refactors the sqlite3VdbeExec() routine to use less stack space. Use this script when constructing the amalgamation. (CVS 6704) (check-in: 7f43391831 user: drh tags: trunk) | |
2009-06-01
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19:53 | Avoid allocating large objects on the stack in the incremental BLOB I/O interface. (CVS 6703) (check-in: ea7dfde700 user: drh tags: trunk) | |
18:18 | Malloc for space to hold the Parse object in sqlite3_prepare() and friends. Or, if compiled with SQLITE_USE_ALLOCA, obtain space for the object from alloca(). (CVS 6702) (check-in: c7c0c58e47 user: drh tags: trunk) | |
Changes
Changes to src/vdbeblob.c.
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8 9 10 11 12 13 14 | ** 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 implement incremental BLOB I/O. ** | | | 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | ** 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 implement incremental BLOB I/O. ** ** $Id: vdbeblob.c,v 1.33 2009/06/01 19:53:31 drh Exp $ */ #include "sqliteInt.h" #include "vdbeInt.h" #ifndef SQLITE_OMIT_INCRBLOB |
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79 80 81 82 83 84 85 | {OP_ResultRow, 1, 0, 0}, /* 7 */ {OP_Close, 0, 0, 0}, /* 8 */ {OP_Halt, 0, 0, 0}, /* 9 */ }; Vdbe *v = 0; int rc = SQLITE_OK; | | > > < < > | > | | > | | > > | | | | > > | < > | | > | 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 | {OP_ResultRow, 1, 0, 0}, /* 7 */ {OP_Close, 0, 0, 0}, /* 8 */ {OP_Halt, 0, 0, 0}, /* 9 */ }; Vdbe *v = 0; int rc = SQLITE_OK; char *zErr = 0; Table *pTab; Parse *pParse; *ppBlob = 0; sqlite3_mutex_enter(db->mutex); pParse = sqlite3StackAllocRaw(db, sizeof(*pParse)); if( pParse==0 ){ rc = SQLITE_NOMEM; goto blob_open_out; } do { memset(pParse, 0, sizeof(Parse)); pParse->db = db; if( sqlite3SafetyOn(db) ){ sqlite3DbFree(db, zErr); sqlite3StackFree(db, pParse); sqlite3_mutex_leave(db->mutex); return SQLITE_MISUSE; } sqlite3BtreeEnterAll(db); pTab = sqlite3LocateTable(pParse, 0, zTable, zDb); if( pTab && IsVirtual(pTab) ){ pTab = 0; sqlite3ErrorMsg(pParse, "cannot open virtual table: %s", zTable); } #ifndef SQLITE_OMIT_VIEW if( pTab && pTab->pSelect ){ pTab = 0; sqlite3ErrorMsg(pParse, "cannot open view: %s", zTable); } #endif if( !pTab ){ if( pParse->zErrMsg ){ sqlite3DbFree(db, zErr); zErr = pParse->zErrMsg; pParse->zErrMsg = 0; } rc = SQLITE_ERROR; (void)sqlite3SafetyOff(db); sqlite3BtreeLeaveAll(db); goto blob_open_out; } /* Now search pTab for the exact column. */ for(iCol=0; iCol < pTab->nCol; iCol++) { if( sqlite3StrICmp(pTab->aCol[iCol].zName, zColumn)==0 ){ break; } } if( iCol==pTab->nCol ){ sqlite3DbFree(db, zErr); zErr = sqlite3MPrintf(db, "no such column: \"%s\"", zColumn); rc = SQLITE_ERROR; (void)sqlite3SafetyOff(db); sqlite3BtreeLeaveAll(db); goto blob_open_out; } /* If the value is being opened for writing, check that the ** column is not indexed. It is against the rules to open an ** indexed column for writing. */ if( flags ){ Index *pIdx; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ int j; for(j=0; j<pIdx->nColumn; j++){ if( pIdx->aiColumn[j]==iCol ){ sqlite3DbFree(db, zErr); zErr = sqlite3MPrintf(db, "cannot open indexed column for writing"); rc = SQLITE_ERROR; (void)sqlite3SafetyOff(db); sqlite3BtreeLeaveAll(db); goto blob_open_out; } } |
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203 204 205 206 207 208 209 | } sqlite3_bind_int64((sqlite3_stmt *)v, 1, iRow); rc = sqlite3_step((sqlite3_stmt *)v); if( rc!=SQLITE_ROW ){ nAttempt++; rc = sqlite3_finalize((sqlite3_stmt *)v); | > | > | | 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 | } sqlite3_bind_int64((sqlite3_stmt *)v, 1, iRow); rc = sqlite3_step((sqlite3_stmt *)v); if( rc!=SQLITE_ROW ){ nAttempt++; rc = sqlite3_finalize((sqlite3_stmt *)v); sqlite3DbFree(db, zErr); zErr = sqlite3MPrintf(db, sqlite3_errmsg(db)); v = 0; } } while( nAttempt<5 && rc==SQLITE_SCHEMA ); if( rc==SQLITE_ROW ){ /* The row-record has been opened successfully. Check that the ** column in question contains text or a blob. If it contains ** text, it is up to the caller to get the encoding right. */ Incrblob *pBlob; u32 type = v->apCsr[0]->aType[iCol]; if( type<12 ){ sqlite3DbFree(db, zErr); zErr = sqlite3MPrintf(db, "cannot open value of type %s", type==0?"null": type==7?"real": "integer" ); rc = SQLITE_ERROR; goto blob_open_out; } pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob)); if( db->mallocFailed ){ |
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240 241 242 243 244 245 246 | pBlob->pStmt = (sqlite3_stmt *)v; pBlob->iOffset = v->apCsr[0]->aOffset[iCol]; pBlob->nByte = sqlite3VdbeSerialTypeLen(type); pBlob->db = db; *ppBlob = (sqlite3_blob *)pBlob; rc = SQLITE_OK; }else if( rc==SQLITE_OK ){ | > | < | > > | 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 | pBlob->pStmt = (sqlite3_stmt *)v; pBlob->iOffset = v->apCsr[0]->aOffset[iCol]; pBlob->nByte = sqlite3VdbeSerialTypeLen(type); pBlob->db = db; *ppBlob = (sqlite3_blob *)pBlob; rc = SQLITE_OK; }else if( rc==SQLITE_OK ){ sqlite3DbFree(db, zErr); zErr = sqlite3MPrintf(db, "no such rowid: %lld", iRow); rc = SQLITE_ERROR; } blob_open_out: if( v && (rc!=SQLITE_OK || db->mallocFailed) ){ sqlite3VdbeFinalize(v); } sqlite3Error(db, rc, zErr); sqlite3DbFree(db, zErr); sqlite3StackFree(db, pParse); rc = sqlite3ApiExit(db, rc); sqlite3_mutex_leave(db->mutex); return rc; } /* ** Close a blob handle that was previously created using |
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