diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/ctime.c | 3 | ||||
| -rw-r--r-- | src/main.c | 6 | ||||
| -rw-r--r-- | src/vdbe.h | 3 | ||||
| -rw-r--r-- | src/vdbevtab.c | 223 |
4 files changed, 235 insertions, 0 deletions
diff --git a/src/ctime.c b/src/ctime.c index 7a2ace931..b104b35db 100644 --- a/src/ctime.c +++ b/src/ctime.c @@ -193,6 +193,9 @@ static const char * const sqlite3azCompileOpt[] = { #if SQLITE_ENABLE_BATCH_ATOMIC_WRITE "ENABLE_BATCH_ATOMIC_WRITE", #endif +#if SQLITE_ENABLE_BYTECODE_VTAB + "ENABLE_BYTECODE_VTAB", +#endif #if SQLITE_ENABLE_CEROD "ENABLE_CEROD=" CTIMEOPT_VAL(SQLITE_ENABLE_CEROD), #endif diff --git a/src/main.c b/src/main.c index 98e030fad..24cbe8bdb 100644 --- a/src/main.c +++ b/src/main.c @@ -3346,6 +3346,12 @@ static int openDatabase( } #endif +#ifdef SQLITE_ENABLE_BYTECODE_VTAB + if( !db->mallocFailed && rc==SQLITE_OK){ + rc = sqlite3VdbeBytecodeVtabInit(db); + } +#endif + #ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time ** option gives access to internal functions by default. diff --git a/src/vdbe.h b/src/vdbe.h index 482331eff..38b43eb71 100644 --- a/src/vdbe.h +++ b/src/vdbe.h @@ -290,6 +290,9 @@ void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *); int sqlite3VdbeHasSubProgram(Vdbe*); int sqlite3NotPureFunc(sqlite3_context*); +#ifdef SQLITE_ENABLE_BYTECODE_VTAB +int sqlite3VdbeBytecodeVtabInit(sqlite3*); +#endif /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on ** each VDBE opcode. diff --git a/src/vdbevtab.c b/src/vdbevtab.c new file mode 100644 index 000000000..b2994cb25 --- /dev/null +++ b/src/vdbevtab.c @@ -0,0 +1,223 @@ +/* +** 2020-03-23 +** +** 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 implements virtual-tables for examining the bytecode content +** of a prepared statement. +*/ +#ifdef SQLITE_ENABLE_BYTECODE_VTAB +#include "sqliteInt.h" +#include "vdbeInt.h" + +/* An instance of the bytecode() table-valued function. +*/ +typedef struct bytecodevtab_vtab bytecodevtab_vtab; +struct bytecodevtab_vtab { + sqlite3_vtab base; /* Base class - must be first */ + sqlite3_stmt *pStmt; /* The statement whose bytecode is to be displayed */ +}; + +/* A cursor for scanning through the bytecode +*/ +typedef struct bytecodevtab_cursor bytecodevtab_cursor; +struct bytecodevtab_cursor { + sqlite3_vtab_cursor base; /* Base class - must be first */ + sqlite3_int64 iRowid; /* The rowid */ +}; + +/* +** Create a new bytecode() table-valued function. +*/ +static int bytecodevtabConnect( + sqlite3 *db, + void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVtab, + char **pzErr +){ + bytecodevtab_vtab *pNew; + int rc; + + rc = sqlite3_declare_vtab(db, + "CREATE TABLE x(" + "addr INT," + "opcode TEXT," + "p1 INT," + "p2 INT," + "p3 INT," + "p4 TEXT," + "p5 INT," + "comment TEXT," + "subprog TEXT," + "stmt HIDDEN" + ");" + ); + if( rc==SQLITE_OK ){ + pNew = sqlite3_malloc( sizeof(*pNew) ); + *ppVtab = (sqlite3_vtab*)pNew; + if( pNew==0 ) return SQLITE_NOMEM; + memset(pNew, 0, sizeof(*pNew)); + } + return rc; +} + +/* +** This method is the destructor for bytecodevtab_vtab objects. +*/ +static int bytecodevtabDisconnect(sqlite3_vtab *pVtab){ + bytecodevtab_vtab *p = (bytecodevtab_vtab*)pVtab; + sqlite3_free(p); + return SQLITE_OK; +} + +/* +** Constructor for a new bytecodevtab_cursor object. +*/ +static int bytecodevtabOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){ + bytecodevtab_cursor *pCur; + pCur = sqlite3_malloc( sizeof(*pCur) ); + if( pCur==0 ) return SQLITE_NOMEM; + memset(pCur, 0, sizeof(*pCur)); + *ppCursor = &pCur->base; + return SQLITE_OK; +} + +/* +** Destructor for a bytecodevtab_cursor. +*/ +static int bytecodevtabClose(sqlite3_vtab_cursor *cur){ + bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur; + sqlite3_free(pCur); + return SQLITE_OK; +} + + +/* +** Advance a bytecodevtab_cursor to its next row of output. +*/ +static int bytecodevtabNext(sqlite3_vtab_cursor *cur){ + bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur; + pCur->iRowid++; + return SQLITE_OK; +} + +/* +** Return values of columns for the row at which the bytecodevtab_cursor +** is currently pointing. +*/ +static int bytecodevtabColumn( + sqlite3_vtab_cursor *cur, /* The cursor */ + sqlite3_context *ctx, /* First argument to sqlite3_result_...() */ + int i /* Which column to return */ +){ + bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur; +#if 0 + switch( i ){ + case TEMPLATEVTAB_A: + sqlite3_result_int(ctx, 1000 + pCur->iRowid); + break; + default: + assert( i==TEMPLATEVTAB_B ); + sqlite3_result_int(ctx, 2000 + pCur->iRowid); + break; + } +#endif + return SQLITE_OK; +} + +/* +** Return the rowid for the current row. In this implementation, the +** rowid is the same as the output value. +*/ +static int bytecodevtabRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ + bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur; + *pRowid = pCur->iRowid; + return SQLITE_OK; +} + +/* +** Return TRUE if the cursor has been moved off of the last +** row of output. +*/ +static int bytecodevtabEof(sqlite3_vtab_cursor *cur){ + bytecodevtab_cursor *pCur = (bytecodevtab_cursor*)cur; + return pCur->iRowid>=10; +} + +/* +** This method is called to "rewind" the bytecodevtab_cursor object back +** to the first row of output. This method is always called at least +** once prior to any call to bytecodevtabColumn() or bytecodevtabRowid() or +** bytecodevtabEof(). +*/ +static int bytecodevtabFilter( + sqlite3_vtab_cursor *pVtabCursor, + int idxNum, const char *idxStr, + int argc, sqlite3_value **argv +){ + bytecodevtab_cursor *pCur = (bytecodevtab_cursor *)pVtabCursor; + pCur->iRowid = 1; + return SQLITE_OK; +} + +/* +** SQLite will invoke this method one or more times while planning a query +** that uses the virtual table. This routine needs to create +** a query plan for each invocation and compute an estimated cost for that +** plan. +*/ +static int bytecodevtabBestIndex( + sqlite3_vtab *tab, + sqlite3_index_info *pIdxInfo +){ + pIdxInfo->estimatedCost = (double)10; + pIdxInfo->estimatedRows = 10; + return SQLITE_OK; +} + +/* +** This following structure defines all the methods for the +** virtual table. +*/ +static sqlite3_module bytecodevtabModule = { + /* iVersion */ 0, + /* xCreate */ 0, + /* xConnect */ bytecodevtabConnect, + /* xBestIndex */ bytecodevtabBestIndex, + /* xDisconnect */ bytecodevtabDisconnect, + /* xDestroy */ 0, + /* xOpen */ bytecodevtabOpen, + /* xClose */ bytecodevtabClose, + /* xFilter */ bytecodevtabFilter, + /* xNext */ bytecodevtabNext, + /* xEof */ bytecodevtabEof, + /* xColumn */ bytecodevtabColumn, + /* xRowid */ bytecodevtabRowid, + /* xUpdate */ 0, + /* xBegin */ 0, + /* xSync */ 0, + /* xCommit */ 0, + /* xRollback */ 0, + /* xFindMethod */ 0, + /* xRename */ 0, + /* xSavepoint */ 0, + /* xRelease */ 0, + /* xRollbackTo */ 0, + /* xShadowName */ 0 +}; + + +int sqlite3VdbeBytecodeVtabInit(sqlite3 *db){ + int rc; + rc = sqlite3_create_module(db, "bytecodevtab", &bytecodevtabModule, 0); + return rc; +} +#endif /* SQLITE_ENABLE_BYTECODE_VTAB */ |