# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
#endif
+#define SWARMVTAB_MAX_ATTACHED 9
+
typedef struct UnionCsr UnionCsr;
typedef struct UnionTab UnionTab;
typedef struct UnionSrc UnionSrc;
char *zTab; /* Source table name */
sqlite3_int64 iMin; /* Minimum rowid */
sqlite3_int64 iMax; /* Maximum rowid */
+
+ /* Fields used by swarmvtab only */
+ char *zFile; /* File to ATTACH */
+ int bAttached; /* True if currently attached */
+ UnionSrc *pNextAttached; /* Next in list of all attached sources */
};
/*
struct UnionTab {
sqlite3_vtab base; /* Base class - must be first */
sqlite3 *db; /* Database handle */
+ int bSwarm; /* 1 for "swarmvtab", 0 for "unionvtab" */
int iPK; /* INTEGER PRIMARY KEY column, or -1 */
int nSrc; /* Number of elements in the aSrc[] array */
+ sqlite3_stmt *pSourceStr; /* Used by unionSourceToStr() */
UnionSrc *aSrc; /* Array of source tables, sorted by rowid */
+
+ /* Used by swarmvtab only */
+ char *zSourceStr; /* Expected unionSourceToStr() value */
+ UnionSrc *pAttached; /* First in list of attached sources */
+ int nAttach; /* Current number of attached sources */
+ int nMaxAttach; /* Maximum number of attached sources */
};
/*
struct UnionCsr {
sqlite3_vtab_cursor base; /* Base class - must be first */
sqlite3_stmt *pStmt; /* SQL statement to run */
+
+ /* Used by swarmvtab only */
+ sqlite3_int64 iMaxRowid; /* Last rowid to visit */
+ int iTab; /* Index of table read by pStmt */
};
/*
sqlite3_stmt *pRet = 0;
if( *pRc==SQLITE_OK ){
int rc = sqlite3_prepare_v2(db, zSql, -1, &pRet, 0);
- if( rc!=SQLITE_OK ){
+ if( rc!=SQLITE_OK && pzErr ){
*pzErr = sqlite3_mprintf("sql error: %s", sqlite3_errmsg(db));
*pRc = rc;
}
if( *pRc==SQLITE_OK ) *pRc = rc;
}
+static int unionDetachDatabase(UnionTab *pTab, char **pzErr){
+ sqlite3_stmt *pStmt = 0;
+ int rc = SQLITE_OK;
+ UnionSrc **pp;
+ assert( pTab->pAttached );
+
+ pp = &pTab->pAttached;
+ while( (*pp)->pNextAttached ){
+ pp = &(*pp)->pNextAttached;
+ }
+
+ pStmt = unionPreparePrintf(&rc, pzErr, pTab->db, "DETACH %s", (*pp)->zDb);
+ if( rc==SQLITE_OK ) sqlite3_step(pStmt);
+ unionFinalize(&rc, pStmt);
+ assert( rc==SQLITE_OK );
+ if( rc==SQLITE_OK ){
+ assert( (*pp)->bAttached && (*pp)->pNextAttached==0 );
+ (*pp)->bAttached = 0;
+ *pp = 0;
+ pTab->nAttach--;
+ }
+
+ return rc;
+}
+
/*
** xDisconnect method.
*/
for(i=0; i<pTab->nSrc; i++){
sqlite3_free(pTab->aSrc[i].zDb);
sqlite3_free(pTab->aSrc[i].zTab);
+ sqlite3_free(pTab->aSrc[i].zFile);
}
+ while( pTab->pAttached ){
+ if( unionDetachDatabase(pTab, 0)!=SQLITE_OK ) break;
+ }
+ sqlite3_finalize(pTab->pSourceStr);
+ sqlite3_free(pTab->zSourceStr);
sqlite3_free(pTab->aSrc);
sqlite3_free(pTab);
}
return SQLITE_OK;
}
+/*
+** Check that the table identified by pSrc is a rowid table. If not,
+** return SQLITE_ERROR and set (*pzErr) to point to an English language
+** error message. If the table is a rowid table and no error occurs,
+** return SQLITE_OK and leave (*pzErr) unmodified.
+*/
+static int unionIsIntkeyTable(
+ sqlite3 *db, /* Database handle */
+ UnionSrc *pSrc, /* Source table to test */
+ char **pzErr /* OUT: Error message */
+){
+ int bPk = 0;
+ const char *zType = 0;
+ int rc;
+
+ sqlite3_table_column_metadata(
+ db, pSrc->zDb, pSrc->zTab, "_rowid_", &zType, 0, 0, &bPk, 0
+ );
+ rc = sqlite3_errcode(db);
+ if( rc==SQLITE_ERROR
+ || (rc==SQLITE_OK && (!bPk || sqlite3_stricmp("integer", zType)))
+ ){
+ rc = SQLITE_ERROR;
+ *pzErr = sqlite3_mprintf("no such rowid table: %s%s%s",
+ (pSrc->zDb ? pSrc->zDb : ""),
+ (pSrc->zDb ? "." : ""),
+ pSrc->zTab
+ );
+ }
+ return rc;
+}
+
/*
** This function is a no-op if *pRc is other than SQLITE_OK when it is
** called. In this case it returns NULL.
*/
static char *unionSourceToStr(
int *pRc, /* IN/OUT: Error code */
- sqlite3 *db, /* Database handle */
+ UnionTab *pTab, /* Virtual table object */
UnionSrc *pSrc, /* Source table to test */
- sqlite3_stmt *pStmt,
char **pzErr /* OUT: Error message */
){
char *zRet = 0;
if( *pRc==SQLITE_OK ){
- int bPk = 0;
- const char *zType = 0;
- int rc;
-
- sqlite3_table_column_metadata(
- db, pSrc->zDb, pSrc->zTab, "_rowid_", &zType, 0, 0, &bPk, 0
- );
- rc = sqlite3_errcode(db);
- if( rc==SQLITE_ERROR
- || (rc==SQLITE_OK && (!bPk || sqlite3_stricmp("integer", zType)))
- ){
- rc = SQLITE_ERROR;
- *pzErr = sqlite3_mprintf("no such rowid table: %s%s%s",
- (pSrc->zDb ? pSrc->zDb : ""),
- (pSrc->zDb ? "." : ""),
- pSrc->zTab
+ int rc = unionIsIntkeyTable(pTab->db, pSrc, pzErr);
+ if( rc==SQLITE_OK && pTab->pSourceStr==0 ){
+ pTab->pSourceStr = unionPrepare(&rc, pTab->db,
+ "SELECT group_concat(quote(name) || '.' || quote(type)) "
+ "FROM pragma_table_info(?, ?)", pzErr
);
}
-
if( rc==SQLITE_OK ){
- sqlite3_bind_text(pStmt, 1, pSrc->zTab, -1, SQLITE_STATIC);
- sqlite3_bind_text(pStmt, 2, pSrc->zDb, -1, SQLITE_STATIC);
- if( SQLITE_ROW==sqlite3_step(pStmt) ){
- zRet = unionStrdup(&rc, (const char*)sqlite3_column_text(pStmt, 0));
+ sqlite3_bind_text(pTab->pSourceStr, 1, pSrc->zTab, -1, SQLITE_STATIC);
+ sqlite3_bind_text(pTab->pSourceStr, 2, pSrc->zDb, -1, SQLITE_STATIC);
+ if( SQLITE_ROW==sqlite3_step(pTab->pSourceStr) ){
+ const char *z = (const char*)sqlite3_column_text(pTab->pSourceStr, 0);
+ zRet = unionStrdup(&rc, z);
}
- unionReset(&rc, pStmt, pzErr);
+ unionReset(&rc, pTab->pSourceStr, pzErr);
}
-
*pRc = rc;
}
** other error occurs, SQLITE_OK is returned.
*/
static int unionSourceCheck(UnionTab *pTab, char **pzErr){
- const char *zSql =
- "SELECT group_concat(quote(name) || '.' || quote(type)) "
- "FROM pragma_table_info(?, ?)";
int rc = SQLITE_OK;
+ assert( *pzErr==0 );
if( pTab->nSrc==0 ){
*pzErr = sqlite3_mprintf("no source tables configured");
rc = SQLITE_ERROR;
}else{
- sqlite3_stmt *pStmt = 0;
char *z0 = 0;
int i;
- pStmt = unionPrepare(&rc, pTab->db, zSql, pzErr);
- if( rc==SQLITE_OK ){
- z0 = unionSourceToStr(&rc, pTab->db, &pTab->aSrc[0], pStmt, pzErr);
- }
+ z0 = unionSourceToStr(&rc, pTab, &pTab->aSrc[0], pzErr);
for(i=1; i<pTab->nSrc; i++){
- char *z = unionSourceToStr(&rc, pTab->db, &pTab->aSrc[i], pStmt, pzErr);
+ char *z = unionSourceToStr(&rc, pTab, &pTab->aSrc[i], pzErr);
if( rc==SQLITE_OK && sqlite3_stricmp(z, z0) ){
*pzErr = sqlite3_mprintf("source table schema mismatch");
rc = SQLITE_ERROR;
sqlite3_free(z);
}
- unionFinalize(&rc, pStmt);
+ unionFinalize(&rc, pTab->pSourceStr);
+ pTab->pSourceStr = 0;
sqlite3_free(z0);
}
return rc;
}
+static int unionAttachDatabase(UnionTab *pTab, int iSrc, char **pzErr){
+ int rc = SQLITE_OK;
+ UnionSrc *pSrc = &pTab->aSrc[iSrc];
+
+ assert( pTab->bSwarm && iSrc<pTab->nSrc );
+ if( pSrc->bAttached==0 ){
+ sqlite3_stmt *pStmt;
+
+ if( pTab->nAttach>=pTab->nMaxAttach ){
+ rc = unionDetachDatabase(pTab, pzErr);
+ }
+
+ pStmt = unionPreparePrintf(
+ &rc, pzErr, pTab->db, "ATTACH %Q AS %s", pSrc->zFile, pSrc->zDb
+ );
+ if( rc==SQLITE_OK ){
+ sqlite3_step(pStmt);
+ rc = sqlite3_finalize(pStmt);
+ }
+ if( rc!=SQLITE_OK ){
+ *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
+ }else{
+ char *z = unionSourceToStr(&rc, pTab, pSrc, pzErr);
+ if( rc==SQLITE_OK ){
+ if( pTab->zSourceStr==0 ){
+ pTab->zSourceStr = z;
+ }else{
+ if( sqlite3_stricmp(z, pTab->zSourceStr) ){
+ *pzErr = sqlite3_mprintf("source table schema mismatch");
+ rc = SQLITE_ERROR;
+ }
+ sqlite3_free(z);
+ }
+ }
+ }
+
+ pSrc->pNextAttached = pTab->pAttached;
+ pSrc->bAttached = 1;
+ pTab->pAttached = pSrc;
+ pTab->nAttach++;
+ }
+
+ return rc;
+}
+
/*
** xConnect/xCreate method.
**
){
UnionTab *pTab = 0;
int rc = SQLITE_OK;
+ int bSwarm = (pAux==0 ? 0 : 1);
+ const char *zVtab = (bSwarm ? "swarmvtab" : "unionvtab");
+ const char *zName = argv[2];
- (void)pAux; /* Suppress harmless 'unused parameter' warning */
if( sqlite3_stricmp("temp", argv[1]) ){
/* unionvtab tables may only be created in the temp schema */
- *pzErr = sqlite3_mprintf("unionvtab tables must be created in TEMP schema");
+ *pzErr = sqlite3_mprintf("%s tables must be created in TEMP schema", zVtab);
rc = SQLITE_ERROR;
}else if( argc!=4 ){
- *pzErr = sqlite3_mprintf("wrong number of arguments for unionvtab");
+ *pzErr = sqlite3_mprintf("wrong number of arguments for %s", zVtab);
rc = SQLITE_ERROR;
}else{
int nAlloc = 0; /* Allocated size of pTab->aSrc[] */
rc = SQLITE_ERROR;
}
- pSrc = &pTab->aSrc[pTab->nSrc++];
- pSrc->zDb = unionStrdup(&rc, zDb);
- pSrc->zTab = unionStrdup(&rc, zTab);
- pSrc->iMin = iMin;
- pSrc->iMax = iMax;
+ if( rc==SQLITE_OK ){
+ pSrc = &pTab->aSrc[pTab->nSrc++];
+ pSrc->zTab = unionStrdup(&rc, zTab);
+ pSrc->iMin = iMin;
+ pSrc->iMax = iMax;
+ if( bSwarm ){
+ pSrc->zFile = unionStrdup(&rc, zDb);
+ pSrc->zDb = sqlite3_mprintf("swm_%s_%d", zName, pTab->nSrc);
+ if( pSrc->zDb==0 ) rc = SQLITE_NOMEM;
+ }else{
+ pSrc->zDb = unionStrdup(&rc, zDb);
+ pSrc->bAttached = 1;
+ }
+ }
}
unionFinalize(&rc, pStmt);
pStmt = 0;
- /* Verify that all source tables exist and have compatible schemas. */
+ /* It is an error if the SELECT statement returned zero rows. If only
+ ** because there is no way to determine the schema of the virtual
+ ** table in this case. */
+ if( rc==SQLITE_OK && pTab->nSrc==0 ){
+ *pzErr = sqlite3_mprintf("no source tables configured");
+ rc = SQLITE_ERROR;
+ }
+
+ /* For unionvtab, verify that all source tables exist and have
+ ** compatible schemas. For swarmvtab, attach the first database and
+ ** check that the first table is a rowid table only. */
if( rc==SQLITE_OK ){
pTab->db = db;
- rc = unionSourceCheck(pTab, pzErr);
+ pTab->bSwarm = bSwarm;
+ pTab->nMaxAttach = SWARMVTAB_MAX_ATTACHED;
+ if( bSwarm ){
+ rc = unionAttachDatabase(pTab, 0, pzErr);
+ }else{
+ rc = unionSourceCheck(pTab, pzErr);
+ }
}
/* Compose a CREATE TABLE statement and pass it to declare_vtab() */
/*
** xNext
*/
-static int unionNext(sqlite3_vtab_cursor *cur){
- UnionCsr *pCsr = (UnionCsr*)cur;
- int rc;
+static int doUnionNext(UnionCsr *pCsr){
+ int rc = SQLITE_OK;
assert( pCsr->pStmt );
if( sqlite3_step(pCsr->pStmt)!=SQLITE_ROW ){
+ UnionTab *pTab = (UnionTab*)pCsr->base.pVtab;
rc = sqlite3_finalize(pCsr->pStmt);
pCsr->pStmt = 0;
- }else{
- rc = SQLITE_OK;
+ if( rc==SQLITE_OK && pTab->bSwarm ){
+ pCsr->iTab++;
+ if( pCsr->iTab<pTab->nSrc ){
+ UnionSrc *pSrc = &pTab->aSrc[pCsr->iTab];
+ if( pCsr->iMaxRowid>=pSrc->iMin ){
+ /* It is necessary to scan the next table. */
+ rc = unionAttachDatabase(pTab, pCsr->iTab, &pTab->base.zErrMsg);
+ pCsr->pStmt = unionPreparePrintf(&rc, &pTab->base.zErrMsg, pTab->db,
+ "SELECT rowid, * FROM %Q.%Q %s %lld",
+ pSrc->zDb, pSrc->zTab,
+ (pSrc->iMax>pCsr->iMaxRowid ? "WHERE _rowid_ <=" : "-- "),
+ pCsr->iMaxRowid
+ );
+ if( rc==SQLITE_OK ) rc = SQLITE_ROW;
+ }
+ }
+ }
}
+
+ return rc;
+}
+
+static int unionNext(sqlite3_vtab_cursor *cur){
+ int rc;
+ do {
+ rc = doUnionNext((UnionCsr*)cur);
+ }while( rc==SQLITE_ROW );
return rc;
}
zSql = sqlite3_mprintf("%z %s rowid<=%lld", zSql, zWhere, iMax);
}
}
+
+ if( pTab->bSwarm ){
+ pCsr->iTab = i;
+ pCsr->iMaxRowid = iMax;
+ rc = unionAttachDatabase(pTab, i, &pTab->base.zErrMsg);
+ break;
+ }
}
0, /* xRelease */
0 /* xRollbackTo */
};
+ int rc;
- return sqlite3_create_module(db, "unionvtab", &unionModule, 0);
+ rc = sqlite3_create_module(db, "unionvtab", &unionModule, 0);
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_create_module(db, "swarmvtab", &unionModule, (void*)db);
+ }
+ return rc;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
projects / thirdparty / sqlite.git / commitdiff
