[tarantool-patches] Re: [PATCH 1/2] sql: Refactor initialization routines

["v.shpilevoy@tarantool.org" <v.shpilevoy@tarantool.org>]

Ack.

> 20 марта 2018 г., в 11:35, Kirill Yukhin <kyukhin@tarantool.org> написал(а):
> 
> Make SQL load schema during initialization. It was
> initialized on first query before the patch. Replace
> check that schema is loaded w/ assert arouns the code base.
> 
> As far as DDL is prohibited inside the transaction, schema
> cannot be changed inside a transaction and hence, no need to
> reload it during rollback. No internal changes
> (SQLITE_InernChanges) are possible.
> 
> Part of #3235
> ---
> src/box/sql.c           |  16 +----
> src/box/sql/analyze.c   |   7 +--
> src/box/sql/build.c     |  33 ++---------
> src/box/sql/main.c      | 154 +++++++++++++-----------------------------------
> src/box/sql/pragma.c    |   3 +-
> src/box/sql/prepare.c   |  53 -----------------
> src/box/sql/sqlite3.h   |   7 +--
> src/box/sql/sqliteInt.h |   2 -
> src/box/sql/trigger.c   |   5 +-
> 9 files changed, 55 insertions(+), 225 deletions(-)
> 
> diff --git a/src/box/sql.c b/src/box/sql.c
> index 817926226..224747157 100644
> --- a/src/box/sql.c
> +++ b/src/box/sql.c
> @@ -71,24 +71,12 @@ static const uint32_t default_sql_flags = SQLITE_ShortColNames
> void
> sql_init()
> {
> -	int rc;
> 	default_flags |= default_sql_flags;
> 
> -	rc = sqlite3_open("", &db);
> -	if (rc != SQLITE_OK) {
> -		panic("failed to initialize SQL subsystem");
> -	} else {
> -		/* XXX */
> -	}
> -
> 	current_session()->sql_flags |= default_sql_flags;
> 
> -	rc = sqlite3Init(db);
> -	if (rc != SQLITE_OK) {
> -		panic("database initialization failed");
> -	} else {
> -		/* XXX */
> -	}
> +	if (sql_init_db(&db) != SQLITE_OK)
> +		panic("failed to initialize SQL subsystem");
> 
> 	assert(db != NULL);
> }
> diff --git a/src/box/sql/analyze.c b/src/box/sql/analyze.c
> index 130e87665..a77b7c758 100644
> --- a/src/box/sql/analyze.c
> +++ b/src/box/sql/analyze.c
> @@ -1176,12 +1176,7 @@ sqlite3Analyze(Parse * pParse, Token * pName)
> 	Table *pTab;
> 	Vdbe *v;
> 
> -	/* Read the database schema. If an error occurs, leave an error message
> -	 * and code in pParse and return NULL.
> -	 */
> -	if (SQLITE_OK != sqlite3ReadSchema(pParse)) {
> -		return;
> -	}
> +	assert(db->pSchema != NULL);
> 
> 	if (pName == 0) {
> 		/* Form 1:  Analyze everything */
> diff --git a/src/box/sql/build.c b/src/box/sql/build.c
> index 5d2876d68..a719136cd 100644
> --- a/src/box/sql/build.c
> +++ b/src/box/sql/build.c
> @@ -217,12 +217,7 @@ sqlite3LocateTable(Parse * pParse,	/* context in which to report errors */
> {
> 	Table *p;
> 
> -	/* Read the database schema. If an error occurs, leave an error message
> -	 * and code in pParse and return NULL.
> -	 */
> -	if (SQLITE_OK != sqlite3ReadSchema(pParse)) {
> -		return 0;
> -	}
> +	assert(pParse->db->pSchema != NULL);
> 
> 	p = sqlite3FindTable(pParse->db, zName);
> 	if (p == 0) {
> @@ -647,13 +642,7 @@ sqlite3StartTable(Parse *pParse, Token *pName, int noErr)
> 	if (zName == 0)
> 		return;
> 
> -	/*
> -	 * Make sure the new table name does not collide with an
> -	 * existing index or table name in the same database.
> -	 * Issue an error message if it does.
> -	 */
> -	if (SQLITE_OK != sqlite3ReadSchema(pParse))
> -		goto begin_table_error;
> +	assert(db->pSchema != NULL);
> 	pTable = sqlite3FindTable(db, zName);
> 	if (pTable) {
> 		if (!noErr) {
> @@ -2401,8 +2390,7 @@ sqlite3DropTable(Parse * pParse, SrcList * pName, int isView, int noErr)
> 		sqlite3VdbeCountChanges(v);
> 	assert(pParse->nErr == 0);
> 	assert(pName->nSrc == 1);
> -	if (sqlite3ReadSchema(pParse))
> -		goto exit_drop_table;
> +	assert(db->pSchema != NULL);
> 	if (noErr)
> 		db->suppressErr++;
> 	assert(isView == 0 || isView == LOCATE_VIEW);
> @@ -2878,9 +2866,7 @@ sqlite3CreateIndex(Parse * pParse,	/* All information about this parse */
> 			goto exit_create_index;
> 		sqlite3VdbeCountChanges(v);
> 	}
> -	if (SQLITE_OK != sqlite3ReadSchema(pParse)) {
> -		goto exit_create_index;
> -	}
> +	assert(db->pSchema != NULL);
> 
> 	/*
> 	 * Find the table that is to be indexed.  Return early if not found.
> @@ -3389,9 +3375,7 @@ sqlite3DropIndex(Parse * pParse, SrcList * pName, Token * pName2, int ifExists)
> 	if (!pParse->nested)
> 		sqlite3VdbeCountChanges(v);
> 	assert(pName->nSrc == 1);
> -	if (SQLITE_OK != sqlite3ReadSchema(pParse)) {
> -		goto exit_drop_index;
> -	}
> +	assert(db->pSchema != NULL);
> 
> 	assert(pName2->n > 0);
> 	zTableName = sqlite3NameFromToken(db, pName2);
> @@ -4151,12 +4135,7 @@ sqlite3Reindex(Parse * pParse, Token * pName1, Token * pName2)
> 	Index *pIndex;		/* An index associated with pTab */
> 	sqlite3 *db = pParse->db;	/* The database connection */
> 
> -	/* Read the database schema. If an error occurs, leave an error message
> -	 * and code in pParse and return NULL.
> -	 */
> -	if (SQLITE_OK != sqlite3ReadSchema(pParse)) {
> -		return;
> -	}
> +	assert(db->pSchema != NULL);
> 
> 	if (pName1 == 0) {
> 		reindexDatabases(pParse, 0);
> diff --git a/src/box/sql/main.c b/src/box/sql/main.c
> index 540570dc8..4ae6df6dd 100644
> --- a/src/box/sql/main.c
> +++ b/src/box/sql/main.c
> @@ -981,6 +981,15 @@ sqlite3RollbackAll(Vdbe * pVdbe, int tripCode)
> 	    && db->init.busy == 0) {
> 		sqlite3ExpirePreparedStatements(db);
> 		sqlite3ResetAllSchemasOfConnection(db);
> +
> +		db->init.busy = 1;
> +		db->pSchema = sqlite3SchemaCreate(db);
> +		int rc = sqlite3InitDatabase(db);
> +		if (rc != SQLITE_OK)
> +			sqlite3SchemaClear(db);
> +		db->init.busy = 0;
> +		if (rc == SQLITE_OK)
> +			sqlite3CommitInternalChanges();
> 	}
> 
> 	/* Any deferred constraint violations have now been resolved. */
> @@ -2246,85 +2255,35 @@ sqlite3ParseUri(const char *zDefaultVfs,	/* VFS to use if no "vfs=xxx" query opt
> 	return rc;
> }
> 
> -/*
> - * This routine does the work of opening a database on behalf of
> - * sqlite3_open() and database filename "zFilename"
> - * is UTF-8 encoded.
> +/**
> + * This routine does the work of initialization of main
> + * SQL connection instance.
> + *
> + * @param[out] out_db returned database handle.
> + * @return error status code.
>  */
> -static int
> -openDatabase(const char *zFilename,	/* Database filename UTF-8 encoded */
> -	     sqlite3 ** ppDb,		/* OUT: Returned database handle */
> -	     unsigned int flags,	/* Operational flags */
> -	     const char *zVfs)		/* Name of the VFS to use */
> +int
> +sql_init_db(sqlite3 **out_db)
> {
> -	sqlite3 *db;		/* Store allocated handle here */
> +	sqlite3 *db;
> 	int rc;			/* Return code */
> 	int isThreadsafe;	/* True for threadsafe connections */
> -	char *zOpen = 0;	/* Filename argument to pass to BtreeOpen() */
> -	char *zErrMsg = 0;	/* Error message from sqlite3ParseUri() */
> 
> #ifdef SQLITE_ENABLE_API_ARMOR
> 	if (ppDb == 0)
> 		return SQLITE_MISUSE_BKPT;
> #endif
> -	*ppDb = 0;
> #ifndef SQLITE_OMIT_AUTOINIT
> 	rc = sqlite3_initialize();
> 	if (rc)
> 		return rc;
> #endif
> 
> -	/* Only allow sensible combinations of bits in the flags argument.
> -	 * Throw an error if any non-sense combination is used.  If we
> -	 * do not block illegal combinations here, it could trigger
> -	 * assert() statements in deeper layers.  Sensible combinations
> -	 * are:
> -	 *
> -	 *  1:  SQLITE_OPEN_READONLY
> -	 *  2:  SQLITE_OPEN_READWRITE
> -	 *  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
> -	 */
> -	assert(SQLITE_OPEN_READONLY == 0x01);
> -	assert(SQLITE_OPEN_READWRITE == 0x02);
> -	assert(SQLITE_OPEN_CREATE == 0x04);
> -	testcase((1 << (flags & 7)) == 0x02);	/* READONLY */
> -	testcase((1 << (flags & 7)) == 0x04);	/* READWRITE */
> -	testcase((1 << (flags & 7)) == 0x40);	/* READWRITE | CREATE */
> -	if (((1 << (flags & 7)) & 0x46) == 0) {
> -		return SQLITE_MISUSE_BKPT;	/* IMP: R-65497-44594 */
> -	}
> -
> 	if (sqlite3GlobalConfig.bCoreMutex == 0) {
> 		isThreadsafe = 0;
> -	} else if (flags & SQLITE_OPEN_NOMUTEX) {
> -		isThreadsafe = 0;
> -	} else if (flags & SQLITE_OPEN_FULLMUTEX) {
> -		isThreadsafe = 1;
> 	} else {
> 		isThreadsafe = sqlite3GlobalConfig.bFullMutex;
> 	}
> -	if (flags & SQLITE_OPEN_PRIVATECACHE) {
> -		flags &= ~SQLITE_OPEN_SHAREDCACHE;
> -	} else if (sqlite3GlobalConfig.sharedCacheEnabled) {
> -		flags |= SQLITE_OPEN_SHAREDCACHE;
> -	}
> -	/* Remove harmful bits from the flags parameter
> -	 *
> -	 * The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
> -	 * dealt with in the previous code block. Besides these, the only
> -	 * valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
> -	 * SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
> -	 * SQLITE_OPEN_PRIVATECACHE, and some reserved bits. Silently mask
> -	 * off all other flags.
> -	 */
> -	flags &= ~(SQLITE_OPEN_DELETEONCLOSE |
> -		   SQLITE_OPEN_EXCLUSIVE |
> -		   SQLITE_OPEN_MAIN_DB |
> -		   SQLITE_OPEN_TEMP_DB |
> -		   SQLITE_OPEN_TRANSIENT_DB |
> -		   SQLITE_OPEN_NOMUTEX |
> -		   SQLITE_OPEN_FULLMUTEX);
> -	flags |= SQLITE_OPEN_MEMORY;
> 	/* Allocate the sqlite data structure */
> 	db = sqlite3MallocZero(sizeof(sqlite3));
> 	if (db == 0)
> @@ -2341,24 +2300,14 @@ openDatabase(const char *zFilename,	/* Database filename UTF-8 encoded */
> 	db->errMask = 0xff;
> 	db->magic = SQLITE_MAGIC_BUSY;
> 
> +	db->pVfs = sqlite3_vfs_find(0);
> +
> 	assert(sizeof(db->aLimit) == sizeof(aHardLimit));
> 	memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
> 	db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
> 	db->szMmap = sqlite3GlobalConfig.szMmap;
> 	db->nMaxSorterMmap = 0x7FFFFFFF;
> 
> -	db->openFlags = flags;
> -	/* Parse the filename/URI argument. */
> -	rc = sqlite3ParseUri(zVfs, zFilename,
> -			     &flags, &db->pVfs, &zOpen, &zErrMsg);
> -	if (rc != SQLITE_OK) {
> -		if (rc == SQLITE_NOMEM)
> -			sqlite3OomFault(db);
> -		sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
> -		sqlite3_free(zErrMsg);
> -		goto opendb_out;
> -	}
> -
> 	db->pSchema = NULL;
> 	db->magic = SQLITE_MAGIC_OPEN;
> 	if (db->mallocFailed) {
> @@ -2428,7 +2377,22 @@ openDatabase(const char *zFilename,	/* Database filename UTF-8 encoded */
> 	setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
> 		       sqlite3GlobalConfig.nLookaside);
> 
> - opendb_out:
> +	if (rc == SQLITE_OK) {
> +		struct session *user_session = current_session();
> +		int commit_internal = !(user_session->sql_flags
> +					& SQLITE_InternChanges);
> +
> +		assert(db->init.busy == 0);
> +		db->init.busy = 1;
> +		db->pSchema = sqlite3SchemaCreate(db);
> +		rc = sqlite3InitDatabase(db);
> +		if (rc != SQLITE_OK)
> +			sqlite3SchemaClear(db);
> +		db->init.busy = 0;
> +		if (rc == SQLITE_OK && commit_internal)
> +			sqlite3CommitInternalChanges();
> +	}
> +opendb_out:
> 	if (db) {
> 		assert(db->mutex != 0 || isThreadsafe == 0
> 		       || sqlite3GlobalConfig.bFullMutex == 0);
> @@ -2439,10 +2403,10 @@ openDatabase(const char *zFilename,	/* Database filename UTF-8 encoded */
> 	if (rc == SQLITE_NOMEM) {
> 		sqlite3_close(db);
> 		db = 0;
> -	} else if (rc != SQLITE_OK) {
> +	} else if (rc != SQLITE_OK)
> 		db->magic = SQLITE_MAGIC_SICK;
> -	}
> -	*ppDb = db;
> +
> +	*out_db = db;
> #ifdef SQLITE_ENABLE_SQLLOG
> 	if (sqlite3GlobalConfig.xSqllog) {
> 		/* Opening a db handle. Fourth parameter is passed 0. */
> @@ -2450,46 +2414,8 @@ openDatabase(const char *zFilename,	/* Database filename UTF-8 encoded */
> 		sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
> 	}
> #endif
> -#if defined(SQLITE_HAS_CODEC)
> -	if (rc == SQLITE_OK) {
> -		const char *zHexKey = sqlite3_uri_parameter(zOpen, "hexkey");
> -		if (zHexKey && zHexKey[0]) {
> -			u8 iByte;
> -			int i;
> -			char zKey[40];
> -			for (i = 0, iByte = 0;
> -			     i < sizeof(zKey) * 2
> -			     && sqlite3Isxdigit(zHexKey[i]); i++) {
> -				iByte =
> -				    (iByte << 4) + sqlite3HexToInt(zHexKey[i]);
> -				if ((i & 1) != 0)
> -					zKey[i / 2] = iByte;
> -			}
> -			sqlite3_key_v2(db, 0, zKey, i / 2);
> -		}
> -	}
> -#endif
> -	sqlite3_free(zOpen);
> -	return rc & 0xff;
> -}
> 
> -/*
> - * Open a new database handle.
> - */
> -int
> -sqlite3_open(const char *zFilename, sqlite3 ** ppDb)
> -{
> -	return openDatabase(zFilename, ppDb,
> -			    SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
> -}
> -
> -int
> -sqlite3_open_v2(const char *filename,	/* Database filename (UTF-8) */
> -		sqlite3 ** ppDb,	/* OUT: SQLite db handle */
> -		int flags,		/* Flags */
> -		const char *zVfs)	/* Name of VFS module to use */
> -{
> -	return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
> +	return rc;
> }
> 
> /*
> diff --git a/src/box/sql/pragma.c b/src/box/sql/pragma.c
> index aa135c4ce..4db553bcf 100644
> --- a/src/box/sql/pragma.c
> +++ b/src/box/sql/pragma.c
> @@ -292,8 +292,7 @@ sqlite3Pragma(Parse * pParse, Token * pId,	/* First part of [schema.]id field */
> 
> 	/* Make sure the database schema is loaded if the pragma requires that */
> 	if ((pPragma->mPragFlg & PragFlg_NeedSchema) != 0) {
> -		if (sqlite3ReadSchema(pParse))
> -			goto pragma_out;
> +		assert(db->pSchema != NULL);
> 	}
> 	/* Register the result column names for pragmas that return results */
> 	if ((pPragma->mPragFlg & PragFlg_NoColumns) == 0
> diff --git a/src/box/sql/prepare.c b/src/box/sql/prepare.c
> index 85d578eb6..9b8028277 100644
> --- a/src/box/sql/prepare.c
> +++ b/src/box/sql/prepare.c
> @@ -207,59 +207,6 @@ sqlite3InitDatabase(sqlite3 * db)
> }
> 
> /*
> - * Initialize all database files - the main database file
> - * Return a success code.
> - * After a database is initialized, the pSchema field in database
> - * structure will be not NULL.
> - */
> -int
> -sqlite3Init(sqlite3 * db)
> -{
> -	int rc;
> -	struct session *user_session = current_session();
> -	int commit_internal = !(user_session->sql_flags & SQLITE_InternChanges);
> -
> -	assert(sqlite3_mutex_held(db->mutex));
> -	assert(db->init.busy == 0);
> -	rc = SQLITE_OK;
> -	db->init.busy = 1;
> -	if (!db->pSchema) {
> -		db->pSchema = sqlite3SchemaCreate(db);
> -		rc = sqlite3InitDatabase(db);
> -		if (rc) {
> -			sqlite3SchemaClear(db);
> -		}
> -	}
> -
> -	db->init.busy = 0;
> -	if (rc == SQLITE_OK && commit_internal) {
> -		sqlite3CommitInternalChanges();
> -	}
> -
> -	return rc;
> -}
> -
> -/*
> - * This routine is a no-op if the database schema is already initialized.
> - * Otherwise, the schema is loaded. An error code is returned.
> - */
> -int
> -sqlite3ReadSchema(Parse * pParse)
> -{
> -	int rc = SQLITE_OK;
> -	sqlite3 *db = pParse->db;
> -	assert(sqlite3_mutex_held(db->mutex));
> -	if (!db->init.busy) {
> -		rc = sqlite3Init(db);
> -	}
> -	if (rc != SQLITE_OK) {
> -		pParse->rc = rc;
> -		pParse->nErr++;
> -	}
> -	return rc;
> -}
> -
> -/*
>  * Convert a schema pointer into the 0 index that indicates
>  * that schema refers to a single database.
>  * This method is inherited from SQLite, which has several dbs.
> diff --git a/src/box/sql/sqlite3.h b/src/box/sql/sqlite3.h
> index 73e916991..d60d74d0e 100644
> --- a/src/box/sql/sqlite3.h
> +++ b/src/box/sql/sqlite3.h
> @@ -2869,10 +2869,9 @@ sqlite3_progress_handler(sqlite3 *, int,
>  *
>  * See also: [sqlite3_temp_directory]
> */
> -SQLITE_API int
> -sqlite3_open(const char *filename,	/* Database filename (UTF-8) */
> -	     sqlite3 ** ppDb	/* OUT: SQLite db handle */
> -	);
> +
> +int
> +sql_init_db(sqlite3 **db);
> 
> SQLITE_API int
> sqlite3_open16(const void *filename,	/* Database filename (UTF-16) */
> diff --git a/src/box/sql/sqliteInt.h b/src/box/sql/sqliteInt.h
> index de2b47bfc..cda862d68 100644
> --- a/src/box/sql/sqliteInt.h
> +++ b/src/box/sql/sqliteInt.h
> @@ -960,7 +960,6 @@ struct sqlite3 {
> 	sqlite3_mutex *mutex;	/* Connection mutex */
> 	struct Schema *pSchema; /* Schema of the database */
> 	i64 szMmap;		/* Default mmap_size setting */
> -	unsigned int openFlags;	/* Flags passed to sqlite3_vfs.xOpen() */
> 	int errCode;		/* Most recent error code (SQLITE_*) */
> 	int errMask;		/* & result codes with this before returning */
> 	int iSysErrno;		/* Errno value from last system error */
> @@ -3259,7 +3258,6 @@ const char *sqlite3ErrName(int);
> #endif
> 
> const char *sqlite3ErrStr(int);
> -int sqlite3ReadSchema(Parse * pParse);
> struct coll *sqlite3FindCollSeq(const char *);
> struct coll *sqlite3LocateCollSeq(Parse * pParse, sqlite3 * db, const char *zName);
> struct coll *sqlite3ExprCollSeq(Parse * pParse, Expr * pExpr);
> diff --git a/src/box/sql/trigger.c b/src/box/sql/trigger.c
> index a2827c882..08963cb79 100644
> --- a/src/box/sql/trigger.c
> +++ b/src/box/sql/trigger.c
> @@ -507,9 +507,8 @@ sqlite3DropTrigger(Parse * pParse, SrcList * pName, int noErr)
> 
> 	if (db->mallocFailed)
> 		goto drop_trigger_cleanup;
> -	if (SQLITE_OK != sqlite3ReadSchema(pParse)) {
> -		goto drop_trigger_cleanup;
> -	}
> +	assert(db->pSchema != NULL);
> +
> 	/* Do not account nested operations: the count of such
> 	 * operations depends on Tarantool data dictionary internals,
> 	 * such as data layout in system spaces. Activate the counter
> -- 
> 2.11.0
> 
>