1 /* 2 ** 2013 Jan 11 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 ** Code for testing the virtual table interfaces. This code 13 ** is not included in the SQLite library. It is used for automated 14 ** testing of the SQLite library. 15 ** 16 ** The FS virtual table is created as follows: 17 ** 18 ** CREATE VIRTUAL TABLE tbl USING fs(idx); 19 ** 20 ** where idx is the name of a table in the db with 2 columns. The virtual 21 ** table also has two columns - file path and file contents. 22 ** 23 ** The first column of table idx must be an IPK, and the second contains file 24 ** paths. For example: 25 ** 26 ** CREATE TABLE idx(id INTEGER PRIMARY KEY, path TEXT); 27 ** INSERT INTO idx VALUES(4, '/etc/passwd'); 28 ** 29 ** Adding the row to the idx table automatically creates a row in the 30 ** virtual table with rowid=4, path=/etc/passwd and a text field that 31 ** contains data read from file /etc/passwd on disk. 32 */ 33 #include "sqliteInt.h" 34 #include "tcl.h" 35 36 #include <stdlib.h> 37 #include <string.h> 38 #include <sys/types.h> 39 #include <sys/stat.h> 40 #include <unistd.h> 41 #include <fcntl.h> 42 43 #ifndef SQLITE_OMIT_VIRTUALTABLE 44 45 typedef struct fs_vtab fs_vtab; 46 typedef struct fs_cursor fs_cursor; 47 48 /* 49 ** A fs virtual-table object 50 */ 51 struct fs_vtab { 52 sqlite3_vtab base; 53 sqlite3 *db; 54 char *zDb; /* Name of db containing zTbl */ 55 char *zTbl; /* Name of docid->file map table */ 56 }; 57 58 /* A fs cursor object */ 59 struct fs_cursor { 60 sqlite3_vtab_cursor base; 61 sqlite3_stmt *pStmt; 62 char *zBuf; 63 int nBuf; 64 int nAlloc; 65 }; 66 67 /* 68 ** This function is the implementation of both the xConnect and xCreate 69 ** methods of the fs virtual table. 70 ** 71 ** The argv[] array contains the following: 72 ** 73 ** argv[0] -> module name ("fs") 74 ** argv[1] -> database name 75 ** argv[2] -> table name 76 ** argv[...] -> other module argument fields. 77 */ 78 static int fsConnect( 79 sqlite3 *db, 80 void *pAux, 81 int argc, const char *const*argv, 82 sqlite3_vtab **ppVtab, 83 char **pzErr 84 ){ 85 fs_vtab *pVtab; 86 int nByte; 87 const char *zTbl; 88 const char *zDb = argv[1]; 89 90 if( argc!=4 ){ 91 *pzErr = sqlite3_mprintf("wrong number of arguments"); 92 return SQLITE_ERROR; 93 } 94 zTbl = argv[3]; 95 96 nByte = sizeof(fs_vtab) + strlen(zTbl) + 1 + strlen(zDb) + 1; 97 pVtab = (fs_vtab *)sqlite3MallocZero( nByte ); 98 if( !pVtab ) return SQLITE_NOMEM; 99 100 pVtab->zTbl = (char *)&pVtab[1]; 101 pVtab->zDb = &pVtab->zTbl[strlen(zTbl)+1]; 102 pVtab->db = db; 103 memcpy(pVtab->zTbl, zTbl, strlen(zTbl)); 104 memcpy(pVtab->zDb, zDb, strlen(zDb)); 105 *ppVtab = &pVtab->base; 106 sqlite3_declare_vtab(db, "CREATE TABLE xyz(path TEXT, data TEXT)"); 107 108 return SQLITE_OK; 109 } 110 /* Note that for this virtual table, the xCreate and xConnect 111 ** methods are identical. */ 112 113 static int fsDisconnect(sqlite3_vtab *pVtab){ 114 sqlite3_free(pVtab); 115 return SQLITE_OK; 116 } 117 /* The xDisconnect and xDestroy methods are also the same */ 118 119 /* 120 ** Open a new fs cursor. 121 */ 122 static int fsOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ 123 fs_cursor *pCur; 124 pCur = sqlite3MallocZero(sizeof(fs_cursor)); 125 *ppCursor = &pCur->base; 126 return SQLITE_OK; 127 } 128 129 /* 130 ** Close a fs cursor. 131 */ 132 static int fsClose(sqlite3_vtab_cursor *cur){ 133 fs_cursor *pCur = (fs_cursor *)cur; 134 sqlite3_finalize(pCur->pStmt); 135 sqlite3_free(pCur->zBuf); 136 sqlite3_free(pCur); 137 return SQLITE_OK; 138 } 139 140 static int fsNext(sqlite3_vtab_cursor *cur){ 141 fs_cursor *pCur = (fs_cursor *)cur; 142 int rc; 143 144 rc = sqlite3_step(pCur->pStmt); 145 if( rc==SQLITE_ROW || rc==SQLITE_DONE ) rc = SQLITE_OK; 146 147 return rc; 148 } 149 150 static int fsFilter( 151 sqlite3_vtab_cursor *pVtabCursor, 152 int idxNum, const char *idxStr, 153 int argc, sqlite3_value **argv 154 ){ 155 int rc; 156 fs_cursor *pCur = (fs_cursor *)pVtabCursor; 157 fs_vtab *p = (fs_vtab *)(pVtabCursor->pVtab); 158 159 assert( (idxNum==0 && argc==0) || (idxNum==1 && argc==1) ); 160 if( idxNum==1 ){ 161 char *zStmt = sqlite3_mprintf( 162 "SELECT * FROM %Q.%Q WHERE rowid=?", p->zDb, p->zTbl); 163 if( !zStmt ) return SQLITE_NOMEM; 164 rc = sqlite3_prepare_v2(p->db, zStmt, -1, &pCur->pStmt, 0); 165 sqlite3_free(zStmt); 166 if( rc==SQLITE_OK ){ 167 sqlite3_bind_value(pCur->pStmt, 1, argv[0]); 168 } 169 }else{ 170 char *zStmt = sqlite3_mprintf("SELECT * FROM %Q.%Q", p->zDb, p->zTbl); 171 if( !zStmt ) return SQLITE_NOMEM; 172 rc = sqlite3_prepare_v2(p->db, zStmt, -1, &pCur->pStmt, 0); 173 sqlite3_free(zStmt); 174 } 175 176 if( rc==SQLITE_OK ){ 177 rc = fsNext(pVtabCursor); 178 } 179 return rc; 180 } 181 182 static int fsColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){ 183 fs_cursor *pCur = (fs_cursor*)cur; 184 185 assert( i==0 || i==1 ); 186 if( i==0 ){ 187 sqlite3_result_value(ctx, sqlite3_column_value(pCur->pStmt, 0)); 188 }else{ 189 const char *zFile = (const char *)sqlite3_column_text(pCur->pStmt, 1); 190 struct stat sbuf; 191 int fd; 192 193 fd = open(zFile, O_RDONLY); 194 if( fd<0 ) return SQLITE_IOERR; 195 fstat(fd, &sbuf); 196 197 if( sbuf.st_size>=pCur->nAlloc ){ 198 int nNew = sbuf.st_size*2; 199 char *zNew; 200 if( nNew<1024 ) nNew = 1024; 201 202 zNew = sqlite3Realloc(pCur->zBuf, nNew); 203 if( zNew==0 ){ 204 close(fd); 205 return SQLITE_NOMEM; 206 } 207 pCur->zBuf = zNew; 208 pCur->nAlloc = nNew; 209 } 210 211 read(fd, pCur->zBuf, sbuf.st_size); 212 close(fd); 213 pCur->nBuf = sbuf.st_size; 214 pCur->zBuf[pCur->nBuf] = '\0'; 215 216 sqlite3_result_text(ctx, pCur->zBuf, -1, SQLITE_TRANSIENT); 217 } 218 return SQLITE_OK; 219 } 220 221 static int fsRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ 222 fs_cursor *pCur = (fs_cursor*)cur; 223 *pRowid = sqlite3_column_int64(pCur->pStmt, 0); 224 return SQLITE_OK; 225 } 226 227 static int fsEof(sqlite3_vtab_cursor *cur){ 228 fs_cursor *pCur = (fs_cursor*)cur; 229 return (sqlite3_data_count(pCur->pStmt)==0); 230 } 231 232 static int fsBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ 233 int ii; 234 235 for(ii=0; ii<pIdxInfo->nConstraint; ii++){ 236 struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii]; 237 if( pCons->iColumn<0 && pCons->usable 238 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){ 239 struct sqlite3_index_constraint_usage *pUsage; 240 pUsage = &pIdxInfo->aConstraintUsage[ii]; 241 pUsage->omit = 0; 242 pUsage->argvIndex = 1; 243 pIdxInfo->idxNum = 1; 244 pIdxInfo->estimatedCost = 1.0; 245 break; 246 } 247 } 248 249 return SQLITE_OK; 250 } 251 252 /* 253 ** A virtual table module that provides read-only access to a 254 ** Tcl global variable namespace. 255 */ 256 static sqlite3_module fsModule = { 257 0, /* iVersion */ 258 fsConnect, 259 fsConnect, 260 fsBestIndex, 261 fsDisconnect, 262 fsDisconnect, 263 fsOpen, /* xOpen - open a cursor */ 264 fsClose, /* xClose - close a cursor */ 265 fsFilter, /* xFilter - configure scan constraints */ 266 fsNext, /* xNext - advance a cursor */ 267 fsEof, /* xEof - check for end of scan */ 268 fsColumn, /* xColumn - read data */ 269 fsRowid, /* xRowid - read data */ 270 0, /* xUpdate */ 271 0, /* xBegin */ 272 0, /* xSync */ 273 0, /* xCommit */ 274 0, /* xRollback */ 275 0, /* xFindMethod */ 276 0, /* xRename */ 277 }; 278 279 /* 280 ** Decode a pointer to an sqlite3 object. 281 */ 282 extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb); 283 284 /* 285 ** Register the echo virtual table module. 286 */ 287 static int register_fs_module( 288 ClientData clientData, /* Pointer to sqlite3_enable_XXX function */ 289 Tcl_Interp *interp, /* The TCL interpreter that invoked this command */ 290 int objc, /* Number of arguments */ 291 Tcl_Obj *CONST objv[] /* Command arguments */ 292 ){ 293 sqlite3 *db; 294 if( objc!=2 ){ 295 Tcl_WrongNumArgs(interp, 1, objv, "DB"); 296 return TCL_ERROR; 297 } 298 if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR; 299 #ifndef SQLITE_OMIT_VIRTUALTABLE 300 sqlite3_create_module(db, "fs", &fsModule, (void *)interp); 301 #endif 302 return TCL_OK; 303 } 304 305 #endif 306 307 308 /* 309 ** Register commands with the TCL interpreter. 310 */ 311 int Sqlitetestfs_Init(Tcl_Interp *interp){ 312 #ifndef SQLITE_OMIT_VIRTUALTABLE 313 static struct { 314 char *zName; 315 Tcl_ObjCmdProc *xProc; 316 void *clientData; 317 } aObjCmd[] = { 318 { "register_fs_module", register_fs_module, 0 }, 319 }; 320 int i; 321 for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){ 322 Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 323 aObjCmd[i].xProc, aObjCmd[i].clientData, 0); 324 } 325 #endif 326 return TCL_OK; 327 } 328