[tarantool-patches] Re: [PATCH 1/2] sql: after table rename properly update indexes

[Kirill Yukhin <kyukhin@tarantool.org>]

Hello Nikita,
Thanks for review. My ansewers inlined,
updated patch in the bottom. Branch force-pushed.

On 21 авг 13:26, n.pettik wrote:
> 
> > diff --git a/src/box/sql.c b/src/box/sql.c
> > index ae12cae..9485899 100644
> > --- a/src/box/sql.c
> > +++ b/src/box/sql.c
> > @@ -840,6 +840,46 @@ rename_fail:
> > 	return SQL_TARANTOOL_ERROR;
> > }
> > 
> > +int
> > +sql_update_index_table_name(struct index_def *def, const char *new_tbl_name,
> > +			    char **sql_stmt)
> 
> I guess name should be like (according to naming convention):
> sql_index_update_table_name()..

Renamed.

> > +{
> > +	assert(new_tbl_name != NULL);
> > +	uint32_t iid = def->iid;
> 
> Do you really need this shortcut for single (or two) usage(s)?

Removed.

> > +
> > +	bool is_quoted = false;
> > +	*sql_stmt = rename_table(db, def->opts.sql, new_tbl_name, &is_quoted);
> 
> You need here check: rename_table() may fail and return NULL.

Added.

> > +
> > +	uint32_t key_len = mp_sizeof_uint(def->space_id) + mp_sizeof_uint(iid) +
> > +			   mp_sizeof_array(2);
> > +	uint32_t new_opts_sz = tarantoolSqlite3MakeIdxOpts(def->opts.is_unique,
> > +							   *sql_stmt, NULL);
> > +	uint32_t op_sz = mp_sizeof_array(1) + mp_sizeof_array(3) +
> > +			 mp_sizeof_str(1) + mp_sizeof_uint(4) + new_opts_sz;
> > +
> > +	char *key_begin = (char*) region_alloc(&fiber()->gc, key_len + op_sz);
> > +	if (key_begin == NULL) {
> > +		diag_set(OutOfMemory, key_len, "region_alloc", "key_begin”);
> 
> In diag_set you pass key_len, but allocate key_len + op_sz.

Added op_sz.

> > +		return SQL_TARANTOOL_ERROR;
> > +	}
> > +	char *key = mp_encode_array(key_begin, 2);
> > +	key = mp_encode_uint(key, def->space_id);
> > +	key = mp_encode_uint(key, iid);
> > +
> > +	char *op_begin = key;
> > +	char *op = mp_encode_array(op_begin, 1);
> > +	op = mp_encode_array(op, 3);
> > +	op = mp_encode_str(op, "=", 1);
> > +	op = mp_encode_uint(op, 4);
> 
> Mb it would be better to use BOX_INDEX_FIELD_OPTS?
> At least it would be easier to understand what happen here.

Used.

> > +	op += tarantoolSqlite3MakeIdxOpts(def->opts.is_unique, *sql_stmt, op);
> > +
> > +	if (box_update(BOX_INDEX_ID, 0, key_begin, key, op_begin, op,
> > +		       0, NULL) != 0)
> > +		return SQL_TARANTOOL_ERROR;
> > +
> > +	return SQLITE_OK;
> 
> AFAIR we decided to avoid using SQLITE_OK macros.
> Lets use instead simple return 0/-1.

Okay, let it be 0.

> > +}
> > +
> > int
> > tarantoolSqlite3IdxKeyCompare(struct BtCursor *cursor,
> > 			      struct UnpackedRecord *unpacked)
> > @@ -1484,23 +1524,12 @@ int tarantoolSqlite3MakeIdxParts(SqliteIndex *pIndex, void *buf)
> > 	return p - base;
> > }
> > 
> > -/*
> > - * Format "opts" dictionary for _index entry.
> > - * Returns result size.
> > - * If buf==NULL estimate result size.
> > - *
> > - * Ex: {
> > - *   "unique": "true",
> > - *   "sql": "CREATE INDEX student_by_name ON students(name)"
> > - * }
> > - */
> > -int tarantoolSqlite3MakeIdxOpts(SqliteIndex *index, const char *zSql, void *buf)
> > +int
> > +tarantoolSqlite3MakeIdxOpts(bool is_unique, const char *zSql, void *buf)
> > {
> 
> You can pass here struct index_def (or struct index_opts)
> instead of two args:
> is_unique ---> def->opst.is_unique and zSql ---> def->opts.sql.
> I see that you pass new zSql, but you still can reassign def->opts.sql.
> It is up to you, thou.

Refactored.

> > 	const struct Enc *enc = get_enc(buf);
> > 	char *base = buf, *p;
> > 
> > -	(void)index;
> > -
> > 	p = enc->encode_map(base, 2);
> > 	/* Mark as unique pk and unique indexes */
> > 	p = enc->encode_str(p, "unique", 6);
> > @@ -1511,7 +1540,7 @@ int tarantoolSqlite3MakeIdxOpts(SqliteIndex *index, const char *zSql, void *buf)
> > 	 * INSERT OR REPLACE/IGNORE uniqueness checks will be also done by
> > 	 * Tarantool.
> > 	 */
> > -	p = enc->encode_bool(p, IsUniqueIndex(index));
> > +	p = enc->encode_bool(p, is_unique);
> > 	p = enc->encode_str(p, "sql", 3);
> > 	p = enc->encode_str(p, zSql, zSql ? strlen(zSql) : 0);
> > 	return (int)(p - base);
> > diff --git a/src/box/sql/build.c b/src/box/sql/build.c
> > index dddeb12..05b729d 100644
> > --- a/src/box/sql/build.c
> > +++ b/src/box/sql/build.c
> > @@ -1246,13 +1246,14 @@ createIndex(Parse * pParse, Index * pIndex, int iSpaceId, int iIndexId,
> > 
> > 	/* Format "opts" and "parts" for _index entry. */
> > 	zOpts = sqlite3DbMallocRaw(pParse->db,
> > -				   tarantoolSqlite3MakeIdxOpts(pIndex, zSql,
> > -							       NULL) +
> > +				   tarantoolSqlite3MakeIdxOpts(IsUniqueIndex(pIndex),
> > +							       zSql, NULL) +
> > 				   tarantoolSqlite3MakeIdxParts(pIndex,
> > 								NULL) + 2);
> > 	if (!zOpts)
> > 		return;
> > -	zOptsSz = tarantoolSqlite3MakeIdxOpts(pIndex, zSql, zOpts);
> > +	zOptsSz = tarantoolSqlite3MakeIdxOpts(IsUniqueIndex(pIndex), zSql,
> > +					      zOpts);
> > 	zParts = zOpts + zOptsSz + 1;
> > 	zPartsSz = tarantoolSqlite3MakeIdxParts(pIndex, zParts);
> > #if SQLITE_DEBUG
> > diff --git a/src/box/sql/tarantoolInt.h b/src/box/sql/tarantoolInt.h
> > index 94517f6..536b0e3 100644
> > --- a/src/box/sql/tarantoolInt.h
> > +++ b/src/box/sql/tarantoolInt.h
> > @@ -89,6 +89,20 @@ int tarantoolSqlite3ClearTable(struct space *space);
> > int
> > sql_rename_table(uint32_t space_id, const char *new_name, char **sql_stmt);
> > 
> > +/**
> > + * Update CREATE INDEX field (def->opt.sql) replacing table name
> > + * w/ new one in _index space.
> > + *
> > + * @param idef Index definition.
> > + * @param new_tbl_name new name of table
> 
> Nitpicking: put dot at the end of sentence and start sentence with capital letter.
> 
> > + * @param[out] sql_stmt New CREATE INDEX statement.
> > + *
> > + * @retval SQLITE_OK on success, SQLITE_TARANTOOL_ERROR otherwise.
> > + */
> > +int
> > +sql_update_index_table_name(struct index_def *idef, const char *new_tbl_name,
> > +			    char **sql_stmt);
> > +
> > /* Alter trigger statement after rename table. */
> > int tarantoolSqlite3RenameTrigger(const char *zTriggerName,
> > 				  const char *zOldName, const char *zNewName);
> > @@ -171,12 +185,17 @@ fkey_encode_links(const struct fkey_def *def, int type, char *buf);
> >  */
> > int tarantoolSqlite3MakeIdxParts(Index * index, void *buf);
> > 
> > -/*
> > +/**
> >  * Format "opts" dictionary for _index entry.
> >  * Returns result size.
> >  * If buf==NULL estimate result size.
> > + *
> > + * @param is_unique Flag if index is unique.
> > + * @param zSql SQL create stmt.
> > + * @param[out] buf destination buffer.
> 
> You didn’t specify @retval for this function.

Added.

> > /**
> >  * Extract next id from _sequence space.
> > diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c
> > index dc5146f..4516ee9 100644
> > --- a/src/box/sql/vdbe.c
> > +++ b/src/box/sql/vdbe.c
> > @@ -4625,13 +4625,35 @@ case OP_RenameTable: {
> > 	db->init.busy = 1;
> > 	init.rc = SQLITE_OK;
> > 	sql_init_callback(&init, zNewTableName, space_id, 0, zSqlStmt);
> > -	db->init.busy = 0;
> > 	rc = init.rc;
> > -	if (rc) {
> > +	if (rc != SQLITE_OK) {
> > 		sqlite3CommitInternalChanges();
> > +		db->init.busy = 0;
> > 		goto abort_due_to_error;
> > 	}
> > 
> > +	/* Space was altered, refetch the pointer. */
> > +	space = space_by_id(space_id);
> > +	for (uint32_t i = 0; i < space->index_count; ++i) {
> > +		struct index_def *def = space->index[i]->def;
> > +		if (def->opts.sql == NULL)
> > +			continue;
> > +		char *sql_stmt;
> > +		rc = sql_update_index_table_name(def, zNewTableName, &sql_stmt);
> > +		if (rc != SQLITE_OK)
> > +			goto abort_due_to_error;
> 
> Again the same problem with RENAME: in case of fail part of indexes would
> remain with old ‘create index …’ statement and after server’s restart it is likely
> to result in segfault/assertion.

Yes, w/o transactional DDL we can end up w/ inconsistent state. So, any alter in
SQL is a dangerous zone.

> > +		space = space_by_id(space_id);
> 
> Does opts.sql update can lead to renewal of space ptr?
> If so, it looks quite weird: string with ‘CREATE INDEX …’ statement
> seems to be sort of static attribute which may be useful only during
> instance restart...

It is state of the things right now. Index update, even in SQL opt,
re-creates space. We can try to somwhat optimizw alter, but I don't
think in that patch.

> > +		sql_init_callback(&init, zNewTableName, space_id,
> > +				  space->index[i]->def->iid, sql_stmt);
> > +		rc = init.rc;
> > +		if (rc != SQLITE_OK) {
> > +			sqlite3CommitInternalChanges();
> > +			db->init.busy = 0;
> > +			goto abort_due_to_error;
> > +		}
> > +	}
> > +	db->init.busy = 0;
> > +
> > 	/*
> > 	 * Rebuild 'CREATE TRIGGER' expressions of all triggers
> > 	 * created on this table. Sure, this action is not atomic
> > 
> > diff --git a/test/sql/gh-3613-idx-alter-update.test.lua b/test/sql/gh-3613-idx-alter-update.test.lua
> > new file mode 100644
> > index 0000000..287096b
> > --- /dev/null
> > +++ b/test/sql/gh-3613-idx-alter-update.test.lua
> > @@ -0,0 +1,21 @@
> > +test_run = require('test_run').new()
> > +engine = test_run:get_cfg('engine')
> > +box.sql.execute('pragma sql_default_engine=\''..engine..'\'')
> > +
> > +box.sql.execute('CREATE TABLE t (s1 INT PRIMARY KEY)')
> > +box.sql.execute('CREATE INDEX i ON t (s1)')
> > +box.sql.execute('ALTER TABLE t RENAME TO j3')
> > +
> > +-- Due to gh-3613, next stmt caused segfault
> > +box.sql.execute('DROP INDEX i ON j3')
> > +
> > +box.sql.execute('CREATE INDEX i ON j3 (s1)’)
> 
> Well, actually I would also add test when instance is restarted
> right after dropping to make sure that no artefacts are left after rename.
> Recreation may be misleading in this case.
Added.

--
Regards, Kirill Yukhin

commit 31aae70d08fe3e799641a382c8c25ad92c6ee995
Author: Kirill Yukhin <kyukhin@tarantool.org>
Date:   Fri Aug 10 15:22:19 2018 +0300

    sql: after table rename properly update indexes
    
    After table was altered due to rename, indexes were not updated.
    Re-create all table's indexes (in legacy SQL DD), also perform
    update of corresponding entry in _index for each index to fix
    table name in create statement.
    
    Closes #3613
---
 src/box/sql.c                              | 62 ++++++++++++++++++++++--------
 src/box/sql/build.c                        |  7 ++--
 src/box/sql/tarantoolInt.h                 | 25 ++++++++++--
 src/box/sql/vdbe.c                         | 26 ++++++++++++-
 test/sql/gh-3613-idx-alter-update.result   | 48 +++++++++++++++++++++++
 test/sql/gh-3613-idx-alter-update.test.lua | 26 +++++++++++++
 6 files changed, 170 insertions(+), 24 deletions(-)

diff --git a/src/box/sql.c b/src/box/sql.c
index ae12cae..789681e 100644
--- a/src/box/sql.c
+++ b/src/box/sql.c
@@ -840,6 +840,49 @@ rename_fail:
 	return SQL_TARANTOOL_ERROR;
 }
 
+int
+sql_index_update_table_name(struct index_def *def, const char *new_tbl_name,
+			    char **sql_stmt)
+{
+	assert(new_tbl_name != NULL);
+
+	bool is_quoted = false;
+	*sql_stmt = rename_table(db, def->opts.sql, new_tbl_name, &is_quoted);
+	if (*sql_stmt == NULL)
+		return -1;
+
+	uint32_t key_len = mp_sizeof_uint(def->space_id) +
+			   mp_sizeof_uint(def->iid) + mp_sizeof_array(2);
+	struct index_opts opts = def->opts;
+	opts.sql = *sql_stmt;
+	uint32_t new_opts_sz = sql_encode_index_opts(&opts, NULL);
+	uint32_t op_sz = mp_sizeof_array(1) + mp_sizeof_array(3) +
+			 mp_sizeof_str(1) + mp_sizeof_uint(4) + new_opts_sz;
+
+	char *key_begin = (char*) region_alloc(&fiber()->gc, key_len + op_sz);
+	if (key_begin == NULL) {
+		diag_set(OutOfMemory, key_len + op_sz, "region_alloc",
+			 "key_begin");
+		return -1;
+	}
+	char *key = mp_encode_array(key_begin, 2);
+	key = mp_encode_uint(key, def->space_id);
+	key = mp_encode_uint(key, def->iid);
+
+	char *op_begin = key;
+	char *op = mp_encode_array(op_begin, 1);
+	op = mp_encode_array(op, 3);
+	op = mp_encode_str(op, "=", 1);
+	op = mp_encode_uint(op, BOX_INDEX_FIELD_OPTS);
+	op += sql_encode_index_opts(&opts, op);
+
+	if (box_update(BOX_INDEX_ID, 0, key_begin, key, op_begin, op,
+		       0, NULL) != 0)
+		return -1;
+
+	return 0;
+}
+
 int
 tarantoolSqlite3IdxKeyCompare(struct BtCursor *cursor,
 			      struct UnpackedRecord *unpacked)
@@ -1484,23 +1527,12 @@ int tarantoolSqlite3MakeIdxParts(SqliteIndex *pIndex, void *buf)
 	return p - base;
 }
 
-/*
- * Format "opts" dictionary for _index entry.
- * Returns result size.
- * If buf==NULL estimate result size.
- *
- * Ex: {
- *   "unique": "true",
- *   "sql": "CREATE INDEX student_by_name ON students(name)"
- * }
- */
-int tarantoolSqlite3MakeIdxOpts(SqliteIndex *index, const char *zSql, void *buf)
+int
+sql_encode_index_opts(struct index_opts *opts, void *buf)
 {
 	const struct Enc *enc = get_enc(buf);
 	char *base = buf, *p;
 
-	(void)index;
-
 	p = enc->encode_map(base, 2);
 	/* Mark as unique pk and unique indexes */
 	p = enc->encode_str(p, "unique", 6);
@@ -1511,9 +1543,9 @@ int tarantoolSqlite3MakeIdxOpts(SqliteIndex *index, const char *zSql, void *buf)
 	 * INSERT OR REPLACE/IGNORE uniqueness checks will be also done by
 	 * Tarantool.
 	 */
-	p = enc->encode_bool(p, IsUniqueIndex(index));
+	p = enc->encode_bool(p, opts->is_unique);
 	p = enc->encode_str(p, "sql", 3);
-	p = enc->encode_str(p, zSql, zSql ? strlen(zSql) : 0);
+	p = enc->encode_str(p, opts->sql, opts->sql ? strlen(opts->sql) : 0);
 	return (int)(p - base);
 }
 
diff --git a/src/box/sql/build.c b/src/box/sql/build.c
index dddeb12..da7668b 100644
--- a/src/box/sql/build.c
+++ b/src/box/sql/build.c
@@ -1245,14 +1245,15 @@ createIndex(Parse * pParse, Index * pIndex, int iSpaceId, int iIndexId,
 	int zOptsSz, zPartsSz;
 
 	/* Format "opts" and "parts" for _index entry. */
+	struct index_opts opts = pIndex->def->opts;
+	opts.sql = (char *)zSql;
 	zOpts = sqlite3DbMallocRaw(pParse->db,
-				   tarantoolSqlite3MakeIdxOpts(pIndex, zSql,
-							       NULL) +
+				   sql_encode_index_opts(&opts, NULL) +
 				   tarantoolSqlite3MakeIdxParts(pIndex,
 								NULL) + 2);
 	if (!zOpts)
 		return;
-	zOptsSz = tarantoolSqlite3MakeIdxOpts(pIndex, zSql, zOpts);
+	zOptsSz = sql_encode_index_opts(&opts, zOpts);
 	zParts = zOpts + zOptsSz + 1;
 	zPartsSz = tarantoolSqlite3MakeIdxParts(pIndex, zParts);
 #if SQLITE_DEBUG
diff --git a/src/box/sql/tarantoolInt.h b/src/box/sql/tarantoolInt.h
index 94517f6..a3ad52a 100644
--- a/src/box/sql/tarantoolInt.h
+++ b/src/box/sql/tarantoolInt.h
@@ -89,6 +89,20 @@ int tarantoolSqlite3ClearTable(struct space *space);
 int
 sql_rename_table(uint32_t space_id, const char *new_name, char **sql_stmt);
 
+/**
+ * Update CREATE INDEX field (def->opt.sql) replacing table name
+ * w/ new one in _index space.
+ *
+ * @param idef Index definition.
+ * @param new_tbl_name new name of table
+ * @param[out] sql_stmt New CREATE INDEX statement.
+ *
+ * @retval 0 on success, -1 otherwise.
+ */
+int
+sql_index_update_table_name(struct index_def *idef, const char *new_tbl_name,
+			    char **sql_stmt);
+
 /* Alter trigger statement after rename table. */
 int tarantoolSqlite3RenameTrigger(const char *zTriggerName,
 				  const char *zOldName, const char *zNewName);
@@ -171,12 +185,15 @@ fkey_encode_links(const struct fkey_def *def, int type, char *buf);
  */
 int tarantoolSqlite3MakeIdxParts(Index * index, void *buf);
 
-/*
+/**
  * Format "opts" dictionary for _index entry.
- * Returns result size.
- * If buf==NULL estimate result size.
+ *
+ * @param opts Options to encode.
+ * @param[out] buf destination buffer.
+ * @retval Result size or size estimation if buf == NULL.
  */
-int tarantoolSqlite3MakeIdxOpts(Index * index, const char *zSql, void *buf);
+int
+sql_encode_index_opts(struct index_opts *opts, void *buf);
 
 /**
  * Extract next id from _sequence space.
diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c
index dc5146f..821c7a9 100644
--- a/src/box/sql/vdbe.c
+++ b/src/box/sql/vdbe.c
@@ -4625,13 +4625,35 @@ case OP_RenameTable: {
 	db->init.busy = 1;
 	init.rc = SQLITE_OK;
 	sql_init_callback(&init, zNewTableName, space_id, 0, zSqlStmt);
-	db->init.busy = 0;
 	rc = init.rc;
-	if (rc) {
+	if (rc != SQLITE_OK) {
 		sqlite3CommitInternalChanges();
+		db->init.busy = 0;
 		goto abort_due_to_error;
 	}
 
+	/* Space was altered, refetch the pointer. */
+	space = space_by_id(space_id);
+	for (uint32_t i = 0; i < space->index_count; ++i) {
+		struct index_def *def = space->index[i]->def;
+		if (def->opts.sql == NULL)
+			continue;
+		char *sql_stmt;
+		rc = sql_index_update_table_name(def, zNewTableName, &sql_stmt);
+		if (rc != SQLITE_OK)
+			goto abort_due_to_error;
+		space = space_by_id(space_id);
+		sql_init_callback(&init, zNewTableName, space_id,
+				  space->index[i]->def->iid, sql_stmt);
+		rc = init.rc;
+		if (rc != SQLITE_OK) {
+			sqlite3CommitInternalChanges();
+			db->init.busy = 0;
+			goto abort_due_to_error;
+		}
+	}
+	db->init.busy = 0;
+
 	/*
 	 * Rebuild 'CREATE TRIGGER' expressions of all triggers
 	 * created on this table. Sure, this action is not atomic
diff --git a/test/sql/gh-3613-idx-alter-update.result b/test/sql/gh-3613-idx-alter-update.result
new file mode 100644
index 0000000..ac62b5f
--- /dev/null
+++ b/test/sql/gh-3613-idx-alter-update.result
@@ -0,0 +1,48 @@
+test_run = require('test_run').new()
+---
+...
+engine = test_run:get_cfg('engine')
+---
+...
+box.sql.execute('pragma sql_default_engine=\''..engine..'\'')
+---
+...
+box.sql.execute('CREATE TABLE t (s1 INT PRIMARY KEY)')
+---
+...
+box.sql.execute('CREATE INDEX i ON t (s1)')
+---
+...
+box.sql.execute('ALTER TABLE t RENAME TO j3')
+---
+...
+-- Due to gh-3613, next stmt caused segfault
+box.sql.execute('DROP INDEX i ON j3')
+---
+...
+-- Make sure that no artifacts remain after restart.
+box.snapshot()
+---
+- ok
+...
+test_run:cmd('restart server default')
+box.sql.execute('DROP INDEX i ON j3')
+---
+- error: 'no such index: J3.I'
+...
+box.sql.execute('CREATE INDEX i ON j3 (s1)')
+---
+...
+-- Check that _index was altered properly
+box.snapshot()
+---
+- ok
+...
+test_run:cmd('restart server default')
+box.sql.execute('DROP INDEX i ON j3')
+---
+...
+-- Cleanup
+box.sql.execute('DROP TABLE j3')
+---
+...
diff --git a/test/sql/gh-3613-idx-alter-update.test.lua b/test/sql/gh-3613-idx-alter-update.test.lua
new file mode 100644
index 0000000..49b81d7
--- /dev/null
+++ b/test/sql/gh-3613-idx-alter-update.test.lua
@@ -0,0 +1,26 @@
+test_run = require('test_run').new()
+engine = test_run:get_cfg('engine')
+box.sql.execute('pragma sql_default_engine=\''..engine..'\'')
+
+box.sql.execute('CREATE TABLE t (s1 INT PRIMARY KEY)')
+box.sql.execute('CREATE INDEX i ON t (s1)')
+box.sql.execute('ALTER TABLE t RENAME TO j3')
+
+-- Due to gh-3613, next stmt caused segfault
+box.sql.execute('DROP INDEX i ON j3')
+
+-- Make sure that no artifacts remain after restart.
+box.snapshot()
+test_run:cmd('restart server default')
+box.sql.execute('DROP INDEX i ON j3')
+
+box.sql.execute('CREATE INDEX i ON j3 (s1)')
+
+-- Check that _index was altered properly
+box.snapshot()
+test_run:cmd('restart server default')
+
+box.sql.execute('DROP INDEX i ON j3')
+
+-- Cleanup
+box.sql.execute('DROP TABLE j3')