1 // Copyright 2012 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "sql/database.h"
16 #include "base/check.h"
17 #include "base/dcheck_is_on.h"
18 #include "base/feature_list.h"
19 #include "base/files/file_path.h"
20 #include "base/files/file_util.h"
21 #include "base/format_macros.h"
22 #include "base/location.h"
23 #include "base/logging.h"
24 #include "base/memory/raw_ptr.h"
25 #include "base/no_destructor.h"
26 #include "base/notreached.h"
27 #include "base/numerics/safe_conversions.h"
28 #include "base/ranges/algorithm.h"
29 #include "base/sequence_checker.h"
30 #include "base/strings/strcat.h"
31 #include "base/strings/string_number_conversions.h"
32 #include "base/strings/string_piece.h"
33 #include "base/strings/string_split.h"
34 #include "base/strings/string_util.h"
35 #include "base/strings/stringprintf.h"
36 #include "base/strings/utf_string_conversions.h"
37 #include "base/synchronization/lock.h"
38 #include "base/task/single_thread_task_runner.h"
39 #include "base/threading/scoped_blocking_call.h"
40 #include "base/trace_event/memory_dump_manager.h"
41 #include "base/trace_event/trace_event.h"
42 #include "base/tracing/protos/chrome_track_event.pbzero.h"
43 #include "base/types/pass_key.h"
44 #include "build/build_config.h"
45 #include "sql/database_memory_dump_provider.h"
46 #include "sql/initialization.h"
47 #include "sql/meta_table.h"
48 #include "sql/sql_features.h"
49 #include "sql/sqlite_result_code.h"
50 #include "sql/sqlite_result_code_values.h"
51 #include "sql/statement.h"
52 #include "sql/vfs_wrapper.h"
53 #include "third_party/sqlite/sqlite3.h"
59 bool enable_mmap_by_default_ = true;
61 // The name of the main database associated with a sqlite3* connection.
63 // SQLite has the ability to ATTACH multiple databases to the same connection.
64 // As a consequence, some SQLite APIs require the connection-specific database
65 // name. This is the right name to be passed to such APIs.
66 static constexpr char kSqliteMainDatabaseName[] = "main";
68 // Magic path value telling sqlite3_open_v2() to open an in-memory database.
69 static constexpr char kSqliteOpenInMemoryPath[] = ":memory:";
71 // Spin for up to a second waiting for the lock to clear when setting
73 // TODO(shess): Better story on this. http://crbug.com/56559
74 const int kBusyTimeoutSeconds = 1;
76 class ScopedBusyTimeout {
78 explicit ScopedBusyTimeout(sqlite3* db) : db_(db) {}
79 ~ScopedBusyTimeout() { sqlite3_busy_timeout(db_, 0); }
81 int SetTimeout(base::TimeDelta timeout) {
82 DCHECK_LT(timeout.InMilliseconds(), INT_MAX);
83 return sqlite3_busy_timeout(db_,
84 static_cast<int>(timeout.InMilliseconds()));
91 // Helper to "safely" enable writable_schema. No error checking
92 // because it is reasonable to just forge ahead in case of an error.
93 // If turning it on fails, then most likely nothing will work, whereas
94 // if turning it off fails, it only matters if some code attempts to
95 // continue working with the database and tries to modify the
96 // sqlite_schema table (none of our code does this).
97 class ScopedWritableSchema {
99 explicit ScopedWritableSchema(sqlite3* db) : db_(db) {
100 sqlite3_exec(db_, "PRAGMA writable_schema=1", nullptr, nullptr, nullptr);
102 ~ScopedWritableSchema() {
103 sqlite3_exec(db_, "PRAGMA writable_schema=0", nullptr, nullptr, nullptr);
107 raw_ptr<sqlite3> db_;
110 // Raze() helper that uses SQLite's online backup API.
112 // Returns the SQLite error code produced by sqlite3_backup_step(). SQLITE_DONE
113 // signals success. SQLITE_OK will never be returned.
115 // The implementation is tailored for the Raze() use case. In particular, the
116 // SQLite API use and and error handling is optimized for 1-page databases.
117 SqliteResultCode BackupDatabaseForRaze(sqlite3* source_db,
118 sqlite3* destination_db) {
120 DCHECK(destination_db);
121 DCHECK_NE(source_db, destination_db);
123 // https://www.sqlite.org/backup.html has a high-level overview of SQLite's
124 // backup support. https://www.sqlite.org/c3ref/backup_finish.html describes
126 static constexpr char kMainDatabaseName[] = "main";
127 sqlite3_backup* backup = sqlite3_backup_init(
128 destination_db, kMainDatabaseName, source_db, kMainDatabaseName);
130 // sqlite3_backup_init() fails if a transaction is ongoing. In particular,
131 // SQL statements that return multiple rows keep a read transaction open
132 // until all the Step() calls are executed.
133 return ToSqliteResultCode(chrome_sqlite3_extended_errcode(destination_db));
136 constexpr int kUnlimitedPageCount = -1; // Back up entire database.
137 auto sqlite_result_code =
138 ToSqliteResultCode(sqlite3_backup_step(backup, kUnlimitedPageCount));
139 DCHECK_NE(sqlite_result_code, SqliteResultCode::kOk)
140 << "sqlite3_backup_step() returned SQLITE_OK (instead of SQLITE_DONE) "
141 << "when asked to back up the entire database";
144 if (sqlite_result_code == SqliteResultCode::kDone) {
145 // If successful, exactly one page should have been backed up.
146 DCHECK_EQ(sqlite3_backup_pagecount(backup), 1)
147 << __func__ << " was intended to be used with 1-page databases";
149 #endif // DCHECK_IS_ON()
151 // sqlite3_backup_finish() releases the sqlite3_backup object.
153 // It returns an error code only if the backup encountered a permanent error.
154 // We use the the sqlite3_backup_step() result instead, because it also tells
155 // us about temporary errors, like SQLITE_BUSY.
157 // We pass the sqlite3_backup_finish() result code through
158 // ToSqliteResultCode() to catch codes that should never occur, like
160 std::ignore = ToSqliteResultCode(sqlite3_backup_finish(backup));
162 return sqlite_result_code;
165 bool ValidAttachmentPoint(base::StringPiece attachment_point) {
166 // SQLite could handle a much wider character set, with appropriate quoting.
168 // Chrome's constraint is easy to remember, and sufficient for the few
169 // existing use cases. ATTACH is a discouraged feature, so no new use cases
171 return base::ranges::all_of(attachment_point,
172 [](char ch) { return base::IsAsciiLower(ch); });
175 std::string AsUTF8ForSQL(const base::FilePath& path) {
176 #if BUILDFLAG(IS_WIN)
177 return base::WideToUTF8(path.value());
178 #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
186 Database::ScopedErrorExpecterCallback* Database::current_expecter_cb_ = nullptr;
189 bool Database::IsExpectedSqliteError(int sqlite_error_code) {
190 DCHECK_NE(sqlite_error_code, SQLITE_OK)
191 << __func__ << " received non-error result code";
192 DCHECK_NE(sqlite_error_code, SQLITE_DONE)
193 << __func__ << " received non-error result code";
194 DCHECK_NE(sqlite_error_code, SQLITE_ROW)
195 << __func__ << " received non-error result code";
197 if (!current_expecter_cb_)
199 return current_expecter_cb_->Run(sqlite_error_code);
203 void Database::SetScopedErrorExpecter(
204 Database::ScopedErrorExpecterCallback* cb,
205 base::PassKey<test::ScopedErrorExpecter>) {
206 CHECK(!current_expecter_cb_);
207 current_expecter_cb_ = cb;
211 void Database::ResetScopedErrorExpecter(
212 base::PassKey<test::ScopedErrorExpecter>) {
213 CHECK(current_expecter_cb_);
214 current_expecter_cb_ = nullptr;
218 base::FilePath Database::JournalPath(const base::FilePath& db_path) {
219 return base::FilePath(db_path.value() + FILE_PATH_LITERAL("-journal"));
223 base::FilePath Database::WriteAheadLogPath(const base::FilePath& db_path) {
224 return base::FilePath(db_path.value() + FILE_PATH_LITERAL("-wal"));
228 base::FilePath Database::SharedMemoryFilePath(const base::FilePath& db_path) {
229 return base::FilePath(db_path.value() + FILE_PATH_LITERAL("-shm"));
232 Database::StatementRef::StatementRef(Database* database,
235 : database_(database), stmt_(stmt), was_valid_(was_valid) {
236 DCHECK_EQ(database == nullptr, stmt == nullptr);
238 database_->StatementRefCreated(this);
241 Database::StatementRef::~StatementRef() {
243 database_->StatementRefDeleted(this);
247 void Database::StatementRef::Close(bool forced) {
249 // Call to InitScopedBlockingCall() cannot go at the beginning of the
250 // function because Close() is called unconditionally from destructor to
251 // clean database_. And if this is inactive statement this won't cause any
252 // disk access and destructor most probably will be called on thread not
253 // allowing disk access.
254 // TODO(paivanof@gmail.com): This should move to the beginning
255 // of the function. http://crbug.com/136655.
256 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
257 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
259 // `stmt_` references memory loaned from the sqlite3 library. Stop
260 // referencing it from the raw_ptr<> before returning it. This avoids the
261 // raw_ptr<> becoming dangling.
262 sqlite3_stmt* statement = stmt_;
265 // sqlite3_finalize()'s result code is ignored because it reports the same
266 // error as the most recent sqlite3_step(). The result code is passed
267 // through ToSqliteResultCode() to catch issues like SQLITE_MISUSE.
268 std::ignore = ToSqliteResultCode(sqlite3_finalize(statement));
270 database_ = nullptr; // The Database may be getting deleted.
272 // Forced close is expected to happen from a statement error
273 // handler. In that case maintain the sense of |was_valid_| which
274 // previously held for this ref.
275 was_valid_ = was_valid_ && forced;
278 static_assert(DatabaseOptions::kDefaultPageSize == SQLITE_DEFAULT_PAGE_SIZE,
279 "DatabaseOptions::kDefaultPageSize must match the value "
280 "configured into SQLite");
282 DatabaseDiagnostics::DatabaseDiagnostics() = default;
283 DatabaseDiagnostics::~DatabaseDiagnostics() = default;
285 void DatabaseDiagnostics::WriteIntoTrace(
286 perfetto::TracedProto<TraceProto> context) const {
287 context->set_reported_sqlite_error_code(reported_sqlite_error_code);
288 context->set_error_code(error_code);
289 context->set_last_errno(last_errno);
290 context->set_sql_statement(sql_statement);
291 context->set_version(version);
292 for (const auto& sql : schema_sql_rows) {
293 context->add_schema_sql_rows(sql);
295 for (const auto& name : schema_other_row_names) {
296 context->add_schema_other_row_names(name);
298 context->set_has_valid_header(has_valid_header);
299 context->set_has_valid_schema(has_valid_schema);
300 context->set_error_message(error_message);
303 // DatabaseOptions::explicit_locking needs to be set to false for historical
305 Database::Database() : Database({.exclusive_locking = false}) {}
307 Database::Database(DatabaseOptions options)
308 : options_(options), mmap_disabled_(!enable_mmap_by_default_) {
309 DCHECK_GE(options.page_size, 512);
310 DCHECK_LE(options.page_size, 65536);
311 DCHECK(!(options.page_size & (options.page_size - 1)))
312 << "page_size must be a power of two";
313 DCHECK(!options_.mmap_alt_status_discouraged ||
314 options_.enable_views_discouraged)
315 << "mmap_alt_status requires views";
317 // It's valid to construct a database on a sequence and then pass it to a
318 // different sequence before usage.
319 DETACH_FROM_SEQUENCE(sequence_checker_);
322 Database::~Database() {
327 void Database::DisableMmapByDefault() {
328 enable_mmap_by_default_ = false;
331 bool Database::Open(const base::FilePath& path) {
332 std::string path_string = AsUTF8ForSQL(path);
333 TRACE_EVENT1("sql", "Database::Open", "path", path_string);
335 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
336 DCHECK(!path.empty());
337 DCHECK_NE(path_string, kSqliteOpenInMemoryPath)
338 << "Path conflicts with SQLite magic identifier";
340 return OpenInternal(path_string, OpenMode::kRetryOnPoision);
343 bool Database::OpenInMemory() {
344 TRACE_EVENT0("sql", "Database::OpenInMemory");
346 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
349 return OpenInternal(kSqliteOpenInMemoryPath, OpenMode::kInMemory);
352 bool Database::OpenTemporary(base::PassKey<Recovery>) {
353 TRACE_EVENT0("sql", "Database::OpenTemporary");
355 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
356 return OpenInternal(std::string(), OpenMode::kTemporary);
359 void Database::CloseInternal(bool forced) {
360 TRACE_EVENT0("sql", "Database::CloseInternal");
361 // TODO(shess): Calling "PRAGMA journal_mode = DELETE" at this point
362 // will delete the -journal file. For ChromiumOS or other more
363 // embedded systems, this is probably not appropriate, whereas on
364 // desktop it might make some sense.
366 // sqlite3_close() needs all prepared statements to be finalized.
368 // Release cached statements.
369 statement_cache_.clear();
371 // With cached statements released, in-use statements will remain.
372 // Closing the database while statements are in use is an API
373 // violation, except for forced close (which happens from within a
374 // statement's error handler).
375 DCHECK(forced || open_statements_.empty());
377 // Deactivate any outstanding statements so sqlite3_close() works.
378 for (StatementRef* statement_ref : open_statements_)
379 statement_ref->Close(forced);
380 open_statements_.clear();
383 // Call to InitScopedBlockingCall() cannot go at the beginning of the
384 // function because Close() must be called from destructor to clean
385 // statement_cache_, it won't cause any disk access and it most probably
386 // will happen on thread not allowing disk access.
387 // TODO(paivanof@gmail.com): This should move to the beginning
388 // of the function. http://crbug.com/136655.
389 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
390 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
392 // Resetting acquires a lock to ensure no dump is happening on the database
393 // at the same time. Unregister takes ownership of provider and it is safe
394 // since the db is reset. memory_dump_provider_ could be null if db_ was
396 if (memory_dump_provider_) {
397 memory_dump_provider_->ResetDatabase();
398 base::trace_event::MemoryDumpManager::GetInstance()
399 ->UnregisterAndDeleteDumpProviderSoon(
400 std::move(memory_dump_provider_));
403 auto sqlite_result_code = ToSqliteResultCode(sqlite3_close(db_));
405 DCHECK_NE(sqlite_result_code, SqliteResultCode::kBusy)
406 << "sqlite3_close() called while prepared statements are still alive";
407 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
408 << "sqlite3_close() failed in an unexpected way: " << GetErrorMessage();
410 // The reset must happen after the DCHECKs above. GetErrorMessage() needs a
411 // valid `db_` value.
416 void Database::Close() {
417 TRACE_EVENT0("sql", "Database::Close");
418 // If the database was already closed by RazeAndClose(), then no
419 // need to close again. Clear the |poisoned_| bit so that incorrect
420 // API calls are caught.
426 CloseInternal(false);
429 void Database::Preload() {
430 TRACE_EVENT0("sql", "Database::Preload");
432 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
434 DCHECK(poisoned_) << "Cannot preload null db";
438 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
439 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
441 // Maximum number of bytes that will be prefetched from the database.
443 // This limit is very aggressive. The main trade-off involved is that having
444 // SQLite block on reading from disk has a high impact on Chrome startup cost
445 // for the databases that are on the critical path to startup. So, the limit
446 // must exceed the expected sizes of databases on the critical path.
448 // On Windows 7, base::PreReadFile() falls back to a synchronous read, and
449 // blocks until the entire file is read into memory. This is a minor factor at
450 // this point, because Chrome has very limited support for Windows 7.
451 constexpr int kPreReadSize = 128 * 1024 * 1024; // 128 MB
452 base::PreReadFile(DbPath(), /*is_executable=*/false, kPreReadSize);
455 // SQLite keeps unused pages associated with a database in a cache. It asks
456 // the cache for pages by an id, and if the page is present and the database is
457 // unchanged, it considers the content of the page valid and doesn't read it
458 // from disk. When memory-mapped I/O is enabled, on read SQLite uses page
459 // structures created from the memory map data before consulting the cache. On
460 // write SQLite creates a new in-memory page structure, copies the data from the
461 // memory map, and later writes it, releasing the updated page back to the
464 // This means that in memory-mapped mode, the contents of the cached pages are
465 // not re-used for reads, but they are re-used for writes if the re-written page
466 // is still in the cache. The implementation of sqlite3_db_release_memory() as
467 // of SQLite 3.8.7.4 frees all pages from pcaches associated with the
468 // database, so it should free these pages.
470 // Unfortunately, the zero page is also freed. That page is never accessed
471 // using memory-mapped I/O, and the cached copy can be re-used after verifying
472 // the file change counter on disk. Also, fresh pages from cache receive some
473 // pager-level initialization before they can be used. Since the information
474 // involved will immediately be accessed in various ways, it is unclear if the
475 // additional overhead is material, or just moving processor cache effects
478 // TODO(shess): It would be better to release the pages immediately when they
479 // are no longer needed. This would basically happen after SQLite commits a
480 // transaction. I had implemented a pcache wrapper to do this, but it involved
481 // layering violations, and it had to be setup before any other sqlite call,
482 // which was brittle. Also, for large files it would actually make sense to
483 // maintain the existing pcache behavior for blocks past the memory-mapped
484 // segment. I think drh would accept a reasonable implementation of the overall
485 // concept for upstreaming to SQLite core.
487 // TODO(shess): Another possibility would be to set the cache size small, which
488 // would keep the zero page around, plus some pre-initialized pages, and SQLite
489 // can manage things. The downside is that updates larger than the cache would
490 // spill to the journal. That could be compensated by setting cache_spill to
491 // false. The downside then is that it allows open-ended use of memory for
492 // large transactions.
493 void Database::ReleaseCacheMemoryIfNeeded(bool implicit_change_performed) {
494 TRACE_EVENT0("sql", "Database::ReleaseCacheMemoryIfNeeded");
495 // The database could have been closed during a transaction as part of error
498 DCHECK(poisoned_) << "Illegal use of Database without a db";
502 // If memory-mapping is not enabled, the page cache helps performance.
506 // On caller request, force the change comparison to fail. Done before the
507 // transaction-nesting test so that the signal can carry to transaction
509 if (implicit_change_performed)
510 --total_changes_at_last_release_;
512 // Cached pages may be re-used within the same transaction.
513 DCHECK_GE(transaction_nesting_, 0);
514 if (transaction_nesting_)
517 // If no changes have been made, skip flushing. This allows the first page of
518 // the database to remain in cache across multiple reads.
519 const int64_t total_changes = sqlite3_total_changes64(db_);
520 if (total_changes == total_changes_at_last_release_)
523 total_changes_at_last_release_ = total_changes;
525 // Passing the result code through ToSqliteResultCode() to catch issues such
527 std::ignore = ToSqliteResultCode(sqlite3_db_release_memory(db_));
530 base::FilePath Database::DbPath() const {
532 return base::FilePath();
534 const char* path = sqlite3_db_filename(db_, "main");
536 return base::FilePath();
537 const base::StringPiece db_path(path);
538 #if BUILDFLAG(IS_WIN)
539 return base::FilePath(base::UTF8ToWide(db_path));
540 #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
541 return base::FilePath(db_path);
544 return base::FilePath();
548 std::string Database::CollectErrorInfo(int sqlite_error_code,
550 DatabaseDiagnostics* diagnostics) const {
551 TRACE_EVENT0("sql", "Database::CollectErrorInfo");
553 DCHECK_NE(sqlite_error_code, SQLITE_OK)
554 << __func__ << " received non-error result code";
555 DCHECK_NE(sqlite_error_code, SQLITE_DONE)
556 << __func__ << " received non-error result code";
557 DCHECK_NE(sqlite_error_code, SQLITE_ROW)
558 << __func__ << " received non-error result code";
560 // Buffer for accumulating debugging info about the error. Place
561 // more-relevant information earlier, in case things overflow the
562 // fixed-size reporting buffer.
563 std::string debug_info;
565 // The error message from the failed operation.
566 int error_code = GetErrorCode();
567 base::StringAppendF(&debug_info, "db error: %d/%s\n", error_code,
570 diagnostics->error_code = error_code;
571 diagnostics->error_message = GetErrorMessage();
574 // TODO(shess): |error| and |GetErrorCode()| should always be the same, but
575 // reading code does not entirely convince me. Remove if they turn out to be
577 if (sqlite_error_code != GetErrorCode())
578 base::StringAppendF(&debug_info, "reported error: %d\n", sqlite_error_code);
580 // System error information. Interpretation of Windows errors is different
582 #if BUILDFLAG(IS_WIN)
583 int last_errno = GetLastErrno();
584 base::StringAppendF(&debug_info, "LastError: %d\n", last_errno);
586 diagnostics->last_errno = last_errno;
588 #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
589 int last_errno = GetLastErrno();
590 base::StringAppendF(&debug_info, "errno: %d\n", last_errno);
592 diagnostics->last_errno = last_errno;
595 NOTREACHED(); // Add appropriate log info.
599 std::string sql_string = stmt->GetSQLStatement();
600 base::StringAppendF(&debug_info, "statement: %s\n", sql_string.c_str());
602 diagnostics->sql_statement = sql_string;
605 base::StringAppendF(&debug_info, "statement: NULL\n");
608 // SQLITE_ERROR often indicates some sort of mismatch between the statement
609 // and the schema, possibly due to a failed schema migration.
610 if (sqlite_error_code == SQLITE_ERROR) {
611 static constexpr char kVersionSql[] =
612 "SELECT value FROM meta WHERE key='version'";
613 sqlite3_stmt* sqlite_statement;
614 // When the number of bytes passed to sqlite3_prepare_v3() includes the null
615 // terminator, SQLite avoids a buffer copy.
616 int rc = sqlite3_prepare_v3(db_, kVersionSql, sizeof(kVersionSql),
617 SQLITE_PREPARE_NO_VTAB, &sqlite_statement,
618 /* pzTail= */ nullptr);
619 if (rc == SQLITE_OK) {
620 rc = sqlite3_step(sqlite_statement);
621 if (rc == SQLITE_ROW) {
622 int version = sqlite3_column_int(sqlite_statement, 0);
623 base::StringAppendF(&debug_info, "version: %d\n", version);
625 diagnostics->version = version;
627 } else if (rc == SQLITE_DONE) {
628 debug_info += "version: none\n";
630 base::StringAppendF(&debug_info, "version: error %d\n", rc);
632 sqlite3_finalize(sqlite_statement);
634 base::StringAppendF(&debug_info, "version: prepare error %d\n", rc);
637 // Get all the SQL from sqlite_schema.
638 debug_info += "schema:\n";
639 static constexpr char kSchemaSql[] =
640 "SELECT sql FROM sqlite_schema WHERE sql IS NOT NULL ORDER BY ROWID";
641 rc = sqlite3_prepare_v3(db_, kSchemaSql, sizeof(kSchemaSql),
642 SQLITE_PREPARE_NO_VTAB, &sqlite_statement,
643 /* pzTail= */ nullptr);
644 if (rc == SQLITE_OK) {
645 while ((rc = sqlite3_step(sqlite_statement)) == SQLITE_ROW) {
647 base::StringAppendF(&text, "%s",
648 sqlite3_column_text(sqlite_statement, 0));
649 debug_info += text + "\n";
651 diagnostics->schema_sql_rows.push_back(text);
655 if (rc != SQLITE_DONE)
656 base::StringAppendF(&debug_info, "error %d\n", rc);
657 sqlite3_finalize(sqlite_statement);
659 base::StringAppendF(&debug_info, "prepare error %d\n", rc);
662 // Automatically generated indices have a NULL 'sql' column. For those rows,
663 // we log the name column instead.
664 debug_info += "schema rows with only name:\n";
665 static constexpr char kSchemaOtherRowNamesSql[] =
666 "SELECT name FROM sqlite_schema WHERE sql IS NULL ORDER BY ROWID";
667 rc = sqlite3_prepare_v3(db_, kSchemaOtherRowNamesSql,
668 sizeof(kSchemaOtherRowNamesSql),
669 SQLITE_PREPARE_NO_VTAB, &sqlite_statement,
670 /* pzTail= */ nullptr);
671 if (rc == SQLITE_OK) {
672 while ((rc = sqlite3_step(sqlite_statement)) == SQLITE_ROW) {
674 base::StringAppendF(&text, "%s",
675 sqlite3_column_text(sqlite_statement, 0));
676 debug_info += text + "\n";
678 diagnostics->schema_other_row_names.push_back(text);
682 if (rc != SQLITE_DONE)
683 base::StringAppendF(&debug_info, "error %d\n", rc);
684 sqlite3_finalize(sqlite_statement);
686 base::StringAppendF(&debug_info, "prepare error %d\n", rc);
693 // TODO(shess): Since this is only called in an error situation, it might be
694 // prudent to rewrite in terms of SQLite API calls, and mark the function const.
695 std::string Database::CollectCorruptionInfo() {
696 TRACE_EVENT0("sql", "Database::CollectCorruptionInfo");
697 // If the file cannot be accessed it is unlikely that an integrity check will
698 // turn up actionable information.
699 const base::FilePath db_path = DbPath();
700 int64_t db_size = -1;
701 if (!base::GetFileSize(db_path, &db_size) || db_size < 0)
702 return std::string();
704 // Buffer for accumulating debugging info about the error. Place
705 // more-relevant information earlier, in case things overflow the
706 // fixed-size reporting buffer.
707 std::string debug_info;
708 base::StringAppendF(&debug_info, "SQLITE_CORRUPT, db size %" PRId64 "\n",
711 // Only check files up to 8M to keep things from blocking too long.
712 const int64_t kMaxIntegrityCheckSize = 8192 * 1024;
713 if (db_size > kMaxIntegrityCheckSize) {
714 debug_info += "integrity_check skipped due to size\n";
716 std::vector<std::string> messages;
718 // TODO(shess): FullIntegrityCheck() splits into a vector while this joins
719 // into a string. Probably should be refactored.
720 const base::TimeTicks before = base::TimeTicks::Now();
721 FullIntegrityCheck(&messages);
723 &debug_info, "integrity_check %" PRId64 " ms, %" PRIuS " records:\n",
724 (base::TimeTicks::Now() - before).InMilliseconds(), messages.size());
726 // SQLite returns up to 100 messages by default, trim deeper to
727 // keep close to the 2000-character size limit for dumping.
728 const size_t kMaxMessages = 20;
729 for (size_t i = 0; i < kMaxMessages && i < messages.size(); ++i) {
730 base::StringAppendF(&debug_info, "%s\n", messages[i].c_str());
737 bool Database::GetMmapAltStatus(int64_t* status) {
738 TRACE_EVENT0("sql", "Database::GetMmapAltStatus");
740 // The [meta] version uses a missing table as a signal for a fresh database.
741 // That will not work for the view, which would not exist in either a new or
742 // an existing database. A new database _should_ be only one page long, so
743 // just don't bother optimizing this case (start at offset 0).
744 // TODO(shess): Could the [meta] case also get simpler, then?
745 if (!DoesViewExist("MmapStatus")) {
750 const char* kMmapStatusSql = "SELECT * FROM MmapStatus";
751 Statement s(GetUniqueStatement(kMmapStatusSql));
753 *status = s.ColumnInt64(0);
754 return s.Succeeded();
757 bool Database::SetMmapAltStatus(int64_t status) {
758 if (!BeginTransaction())
761 // View may not exist on first run.
762 if (!Execute("DROP VIEW IF EXISTS MmapStatus")) {
763 RollbackTransaction();
767 // Views live in the schema, so they cannot be parameterized. For an integer
768 // value, this construct should be safe from SQL injection, if the value
769 // becomes more complicated use "SELECT quote(?)" to generate a safe quoted
771 const std::string create_view_sql = base::StringPrintf(
772 "CREATE VIEW MmapStatus (value) AS SELECT %" PRId64, status);
773 if (!Execute(create_view_sql.c_str())) {
774 RollbackTransaction();
778 return CommitTransaction();
781 size_t Database::ComputeMmapSizeForOpen() {
782 TRACE_EVENT0("sql", "Database::ComputeMmapSizeForOpen");
784 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
785 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
787 // How much to map if no errors are found. 50MB encompasses the 99th
788 // percentile of Chrome databases in the wild, so this should be good.
789 const size_t kMmapEverything = 256 * 1024 * 1024;
791 // Progress information is tracked in the [meta] table for databases which use
792 // sql::MetaTable, otherwise it is tracked in a special view.
793 // TODO(pwnall): Migrate all databases to using a meta table.
794 int64_t mmap_ofs = 0;
795 if (options_.mmap_alt_status_discouraged) {
796 if (!GetMmapAltStatus(&mmap_ofs))
799 // If [meta] doesn't exist, yet, it's a new database, assume the best.
800 // sql::MetaTable::Init() will preload kMmapSuccess.
801 if (!MetaTable::DoesTableExist(this))
802 return kMmapEverything;
804 if (!MetaTable::GetMmapStatus(this, &mmap_ofs))
808 // Database read failed in the past, don't memory map.
809 if (mmap_ofs == MetaTable::kMmapFailure)
812 if (mmap_ofs != MetaTable::kMmapSuccess) {
813 // Continue reading from previous offset.
814 DCHECK_GE(mmap_ofs, 0);
816 // GetSqliteVfsFile() returns null for in-memory and temporary databases.
817 // This is fine, we don't want to enable memory-mapping in those cases
820 // First, memory-mapping is a no-op for in-memory databases.
822 // Second, temporary databases are only used for corruption recovery, which
823 // occurs in response to I/O errors. An environment with heightened I/O
824 // errors translates into a higher risk of mmap-induced Chrome crashes.
825 sqlite3_int64 db_size = 0;
826 sqlite3_file* file = GetSqliteVfsFile();
827 if (!file || file->pMethods->xFileSize(file, &db_size) != SQLITE_OK)
830 // Read more of the database looking for errors. The VFS interface is used
831 // to assure that the reads are valid for SQLite. |g_reads_allowed| is used
832 // to limit checking to 20MB per run of Chromium.
834 // Read the data left, or |g_reads_allowed|, whichever is smaller.
835 // |g_reads_allowed| limits the total amount of I/O to spend verifying data
836 // in a single Chromium run.
837 sqlite3_int64 amount = db_size - mmap_ofs;
841 static base::NoDestructor<base::Lock> lock;
842 base::AutoLock auto_lock(*lock);
843 static sqlite3_int64 g_reads_allowed = 20 * 1024 * 1024;
844 if (g_reads_allowed < amount)
845 amount = g_reads_allowed;
846 g_reads_allowed -= amount;
849 // |amount| can be <= 0 if |g_reads_allowed| ran out of quota, or if the
850 // database was truncated after a previous pass.
851 if (amount <= 0 && mmap_ofs < db_size) {
852 DCHECK_EQ(0, amount);
854 static const int kPageSize = 4096;
857 int rc = file->pMethods->xRead(file, buf, sizeof(buf), mmap_ofs);
858 if (rc == SQLITE_OK) {
859 mmap_ofs += sizeof(buf);
860 amount -= sizeof(buf);
861 } else if (rc == SQLITE_IOERR_SHORT_READ) {
862 // Reached EOF for a database with page size < |kPageSize|.
866 // TODO(shess): Consider calling OnSqliteError().
867 mmap_ofs = MetaTable::kMmapFailure;
872 // Log these events after update to distinguish meta update failure.
873 if (mmap_ofs >= db_size) {
874 mmap_ofs = MetaTable::kMmapSuccess;
876 DCHECK(mmap_ofs > 0 || mmap_ofs == MetaTable::kMmapFailure);
879 if (options_.mmap_alt_status_discouraged) {
880 if (!SetMmapAltStatus(mmap_ofs))
883 if (!MetaTable::SetMmapStatus(this, mmap_ofs))
889 if (mmap_ofs == MetaTable::kMmapFailure)
891 if (mmap_ofs == MetaTable::kMmapSuccess)
892 return kMmapEverything;
896 int Database::SqlitePrepareFlags() const {
897 return options_.enable_virtual_tables_discouraged ? 0
898 : SQLITE_PREPARE_NO_VTAB;
901 sqlite3_file* Database::GetSqliteVfsFile() {
902 DCHECK(db_) << "Database not opened";
904 // sqlite3_file_control() accepts a null pointer to mean the "main" database
905 // attached to a connection. https://www.sqlite.org/c3ref/file_control.html
906 constexpr const char* kMainDatabaseName = nullptr;
908 sqlite3_file* result = nullptr;
909 auto sqlite_result_code = ToSqliteResultCode(sqlite3_file_control(
910 db_, kMainDatabaseName, SQLITE_FCNTL_FILE_POINTER, &result));
912 // SQLITE_FCNTL_FILE_POINTER is handled directly by SQLite, not by the VFS. It
913 // is only supposed to fail with SQLITE_ERROR if the database name is not
914 // recognized. However, "main" should always be recognized.
915 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
916 << "sqlite3_file_control(SQLITE_FCNTL_FILE_POINTER) failed";
918 // SQLite does not return null when called on an in-memory or temporary
919 // database. Instead, it returns returns a VFS file object with a null
922 << "sqlite3_file_control() succeded but returned a null sqlite3_file*";
923 if (!result->pMethods) {
924 // If this assumption fails, sql::Database will still function correctly,
925 // but will miss some configuration optimizations. The DCHECK is here to
926 // alert us (via test failures and ASAN canary builds) of such cases.
927 DCHECK_EQ(DbPath().AsUTF8Unsafe(), "")
928 << "sqlite3_file_control() returned a sqlite3_file* with null pMethods "
929 << "in a case when it shouldn't have.";
937 void Database::TrimMemory() {
938 TRACE_EVENT0("sql", "Database::TrimMemory");
943 // Passing the result code through ToSqliteResultCode() to catch issues such
945 std::ignore = ToSqliteResultCode(sqlite3_db_release_memory(db_));
947 // It is tempting to use sqlite3_release_memory() here as well. However, the
948 // API is documented to be a no-op unless SQLite is built with
949 // SQLITE_ENABLE_MEMORY_MANAGEMENT. We do not use this option, because it is
950 // incompatible with per-database page cache pools. Behind the scenes,
951 // SQLITE_ENABLE_MEMORY_MANAGEMENT causes SQLite to use a global page cache
952 // pool, and sqlite3_release_memory() releases unused pages from this global
954 #if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT)
955 #error "This method assumes SQLITE_ENABLE_MEMORY_MANAGEMENT is not defined"
956 #endif // defined(SQLITE_ENABLE_MEMORY_MANAGEMENT)
959 // Create an in-memory database with the existing database's page
960 // size, then backup that database over the existing database.
961 bool Database::Raze() {
962 TRACE_EVENT0("sql", "Database::Raze");
964 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
965 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
968 DCHECK(poisoned_) << "Cannot raze null db";
972 DCHECK_GE(transaction_nesting_, 0);
973 if (transaction_nesting_ > 0) {
974 DLOG(DCHECK) << "Cannot raze within a transaction";
978 sql::Database null_db(sql::DatabaseOptions{
979 .exclusive_locking = true,
980 .page_size = options_.page_size,
982 .enable_foreign_keys_discouraged =
983 options_.enable_foreign_keys_discouraged,
984 .enable_views_discouraged = options_.enable_views_discouraged,
985 .enable_virtual_tables_discouraged =
986 options_.enable_virtual_tables_discouraged,
988 if (!null_db.OpenInMemory()) {
989 DLOG(DCHECK) << "Unable to open in-memory database.";
993 #if BUILDFLAG(IS_ANDROID)
994 // Android compiles with SQLITE_DEFAULT_AUTOVACUUM. Unfortunately,
995 // in-memory databases do not respect this define.
996 // TODO(shess): Figure out a way to set this without using platform
997 // specific code. AFAICT from sqlite3.c, the only way to do it
998 // would be to create an actual filesystem database, which is
1000 if (!null_db.Execute("PRAGMA auto_vacuum = 1"))
1004 // The page size doesn't take effect until a database has pages, and
1005 // at this point the null database has none. Changing the schema
1006 // version will create the first page. This will not affect the
1007 // schema version in the resulting database, as SQLite's backup
1008 // implementation propagates the schema version from the original
1009 // database to the new version of the database, incremented by one
1010 // so that other readers see the schema change and act accordingly.
1011 if (!null_db.Execute("PRAGMA schema_version = 1"))
1014 // SQLite tracks the expected number of database pages in the first
1015 // page, and if it does not match the total retrieved from a
1016 // filesystem call, treats the database as corrupt. This situation
1017 // breaks almost all SQLite calls. "PRAGMA writable_schema" can be
1018 // used to hint to SQLite to soldier on in that case, specifically
1019 // for purposes of recovery. [See SQLITE_CORRUPT_BKPT case in
1020 // sqlite3.c lockBtree().]
1021 // TODO(shess): With this, "PRAGMA auto_vacuum" and "PRAGMA
1022 // page_size" can be used to query such a database.
1023 ScopedWritableSchema writable_schema(db_);
1025 #if BUILDFLAG(IS_WIN)
1026 // On Windows, truncate silently fails when applied to memory-mapped files.
1027 // Disable memory-mapping so that the truncate succeeds. Note that other
1028 // Database connections may have memory-mapped the file, so this may not
1029 // entirely prevent the problem.
1030 // [Source: <https://sqlite.org/mmap.html> plus experiments.]
1031 std::ignore = Execute("PRAGMA mmap_size = 0");
1034 SqliteResultCode sqlite_result_code = BackupDatabaseForRaze(null_db.db_, db_);
1036 // The destination database was locked.
1037 if (sqlite_result_code == SqliteResultCode::kBusy)
1040 // SQLITE_NOTADB can happen if page 1 of db_ exists, but is not
1041 // formatted correctly. SQLITE_IOERR_SHORT_READ can happen if db_
1042 // isn't even big enough for one page. Either way, reach in and
1043 // truncate it before trying again.
1044 // TODO(shess): Maybe it would be worthwhile to just truncate from
1046 if (sqlite_result_code == SqliteResultCode::kNotADatabase ||
1047 sqlite_result_code == SqliteResultCode::kIoShortRead) {
1048 sqlite3_file* file = GetSqliteVfsFile();
1049 if (!file || file->pMethods->xTruncate(file, 0) != SQLITE_OK) {
1050 DLOG(DCHECK) << "Failed to truncate file.";
1054 sqlite_result_code = BackupDatabaseForRaze(null_db.db_, db_);
1055 if (sqlite_result_code != SqliteResultCode::kDone)
1059 // Page size of |db_| and |null_db| differ.
1060 if (sqlite_result_code == SqliteResultCode::kReadOnly) {
1061 // Enter TRUNCATE mode to change page size.
1062 // TODO(shuagga@microsoft.com): Need a guarantee here that there is no other
1063 // database connection open.
1064 std::ignore = Execute("PRAGMA journal_mode=TRUNCATE;");
1065 const std::string page_size_sql = base::StrCat(
1066 {"PRAGMA page_size=", base::NumberToString(options_.page_size)});
1067 if (!Execute(page_size_sql.c_str())) {
1070 // Page size isn't changed until the database is vacuumed.
1071 std::ignore = Execute("VACUUM");
1072 // Re-enter WAL mode.
1074 std::ignore = Execute("PRAGMA journal_mode=WAL;");
1077 sqlite_result_code = BackupDatabaseForRaze(null_db.db_, db_);
1078 if (sqlite_result_code != SqliteResultCode::kDone)
1082 if (sqlite_result_code != SqliteResultCode::kDone) {
1083 NOTIMPLEMENTED() << "Unhandled sqlite3_backup_step() error: "
1084 << sqlite_result_code;
1088 // Checkpoint to propagate transactions to the database file and empty the WAL
1090 // The database can still contain old data if the Checkpoint fails so fail the
1092 return CheckpointDatabase();
1095 bool Database::RazeAndClose() {
1096 TRACE_EVENT0("sql", "Database::RazeAndClose");
1099 DCHECK(poisoned_) << "Cannot raze null db";
1103 // Raze() cannot run in a transaction.
1104 RollbackAllTransactions();
1106 bool result = Raze();
1108 CloseInternal(true);
1110 // Mark the database so that future API calls fail appropriately,
1111 // but don't DCHECK (because after calling this function they are
1112 // expected to fail).
1118 void Database::Poison() {
1119 TRACE_EVENT0("sql", "Database::Poison");
1122 DCHECK(poisoned_) << "Cannot poison null db";
1126 RollbackAllTransactions();
1127 CloseInternal(true);
1129 // Mark the database so that future API calls fail appropriately,
1130 // but don't DCHECK (because after calling this function they are
1131 // expected to fail).
1135 // TODO(shess): To the extent possible, figure out the optimal
1136 // ordering for these deletes which will prevent other Database connections
1137 // from seeing odd behavior. For instance, it may be necessary to
1138 // manually lock the main database file in a SQLite-compatible fashion
1139 // (to prevent other processes from opening it), then delete the
1140 // journal files, then delete the main database file. Another option
1141 // might be to lock the main database file and poison the header with
1142 // junk to prevent other processes from opening it successfully (like
1143 // Gears "SQLite poison 3" trick).
1146 bool Database::Delete(const base::FilePath& path) {
1147 TRACE_EVENT1("sql", "Database::Delete", "path", path.MaybeAsASCII());
1149 base::ScopedBlockingCall scoped_blocking_call(FROM_HERE,
1150 base::BlockingType::MAY_BLOCK);
1152 base::FilePath journal_path = Database::JournalPath(path);
1153 base::FilePath wal_path = Database::WriteAheadLogPath(path);
1155 std::string journal_str = AsUTF8ForSQL(journal_path);
1156 std::string wal_str = AsUTF8ForSQL(wal_path);
1157 std::string path_str = AsUTF8ForSQL(path);
1159 EnsureSqliteInitialized();
1161 sqlite3_vfs* vfs = sqlite3_vfs_find(nullptr);
1163 CHECK(vfs->xDelete);
1164 CHECK(vfs->xAccess);
1166 // We only work with the VFS implementations listed below. If you're trying to
1167 // use this code with any other VFS, you're not in a good place.
1168 CHECK(strncmp(vfs->zName, "unix", 4) == 0 ||
1169 strncmp(vfs->zName, "win32", 5) == 0 ||
1170 strcmp(vfs->zName, "storage_service") == 0);
1172 vfs->xDelete(vfs, journal_str.c_str(), 0);
1173 vfs->xDelete(vfs, wal_str.c_str(), 0);
1174 vfs->xDelete(vfs, path_str.c_str(), 0);
1176 int journal_exists = 0;
1177 vfs->xAccess(vfs, journal_str.c_str(), SQLITE_ACCESS_EXISTS, &journal_exists);
1180 vfs->xAccess(vfs, wal_str.c_str(), SQLITE_ACCESS_EXISTS, &wal_exists);
1182 int path_exists = 0;
1183 vfs->xAccess(vfs, path_str.c_str(), SQLITE_ACCESS_EXISTS, &path_exists);
1185 return !journal_exists && !wal_exists && !path_exists;
1188 bool Database::BeginTransaction() {
1189 TRACE_EVENT0("sql", "Database::BeginTransaction");
1191 if (needs_rollback_) {
1192 DCHECK_GT(transaction_nesting_, 0);
1194 // When we're going to rollback, fail on this begin and don't actually
1195 // mark us as entering the nested transaction.
1199 bool success = true;
1200 DCHECK_GE(transaction_nesting_, 0);
1201 if (!transaction_nesting_) {
1202 needs_rollback_ = false;
1204 Statement begin(GetCachedStatement(SQL_FROM_HERE, "BEGIN TRANSACTION"));
1208 ++transaction_nesting_;
1212 void Database::RollbackTransaction() {
1213 TRACE_EVENT0("sql", "Database::RollbackTransaction");
1215 DCHECK_GE(transaction_nesting_, 0);
1216 if (!transaction_nesting_) {
1217 DCHECK(poisoned_) << "Rolling back a nonexistent transaction";
1221 DCHECK_GT(transaction_nesting_, 0);
1222 --transaction_nesting_;
1224 if (transaction_nesting_ > 0) {
1225 // Mark the outermost transaction as needing rollback.
1226 needs_rollback_ = true;
1233 bool Database::CommitTransaction() {
1234 TRACE_EVENT0("sql", "Database::CommitTransaction");
1236 DCHECK_GE(transaction_nesting_, 0);
1237 if (!transaction_nesting_) {
1238 DCHECK(poisoned_) << "Committing a nonexistent transaction";
1242 DCHECK_GT(transaction_nesting_, 0);
1243 --transaction_nesting_;
1245 if (transaction_nesting_ > 0) {
1246 // Mark any nested transactions as failing after we've already got one.
1247 return !needs_rollback_;
1250 if (needs_rollback_) {
1255 Statement commit(GetCachedStatement(SQL_FROM_HERE, "COMMIT"));
1257 bool succeeded = commit.Run();
1259 // Release dirty cache pages after the transaction closes.
1260 ReleaseCacheMemoryIfNeeded(false);
1265 void Database::RollbackAllTransactions() {
1266 TRACE_EVENT0("sql", "Database::RollbackAllTransactions");
1268 DCHECK_GE(transaction_nesting_, 0);
1269 if (transaction_nesting_ > 0) {
1270 transaction_nesting_ = 0;
1275 bool Database::AttachDatabase(const base::FilePath& other_db_path,
1276 base::StringPiece attachment_point,
1278 TRACE_EVENT0("sql", "Database::AttachDatabase");
1280 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1281 DCHECK(ValidAttachmentPoint(attachment_point));
1283 Statement statement(GetUniqueStatement("ATTACH ? AS ?"));
1285 statement.BindString16(0, base::AsStringPiece16(other_db_path.value()));
1287 statement.BindString(0, other_db_path.value());
1289 statement.BindString(1, attachment_point);
1290 return statement.Run();
1293 bool Database::DetachDatabase(base::StringPiece attachment_point,
1295 TRACE_EVENT0("sql", "Database::DetachDatabase");
1297 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1298 DCHECK(ValidAttachmentPoint(attachment_point));
1300 Statement statement(GetUniqueStatement("DETACH ?"));
1301 statement.BindString(0, attachment_point);
1302 return statement.Run();
1305 // TODO(crbug.com/1230443): Change this to execute exactly one statement.
1306 SqliteResultCode Database::ExecuteAndReturnResultCode(const char* sql) {
1307 TRACE_EVENT0("sql", "Database::ExecuteAndReturnErrorCode");
1312 DCHECK(poisoned_) << "Illegal use of Database without a db";
1313 return SqliteResultCode::kError;
1316 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
1317 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
1319 SqliteResultCode sqlite_result_code = SqliteResultCode::kOk;
1320 while ((sqlite_result_code == SqliteResultCode::kOk) && *sql) {
1321 sqlite3_stmt* sqlite_statement;
1322 const char* leftover_sql;
1323 sqlite_result_code = ToSqliteResultCode(
1324 sqlite3_prepare_v3(db_, sql, /* nByte= */ -1, SqlitePrepareFlags(),
1325 &sqlite_statement, &leftover_sql));
1328 // Report SQL compilation errors. On developer machines, the errors are most
1329 // likely caused by invalid SQL in an under-development feature. In
1330 // production, SQL compilation errors are caused by database schema
1333 // DCHECK would not be appropriate here, because on-disk data is always
1334 // subject to corruption, so Chrome cannot assume that the database schema
1335 // will remain intact.
1336 if (sqlite_result_code == SqliteResultCode::kError) {
1337 DLOG(ERROR) << "SQL compilation error: " << GetErrorMessage()
1338 << ". Statement: " << sql;
1340 #endif // DCHECK_IS_ON()
1342 // Stop if compiling the SQL statement fails.
1343 if (sqlite_result_code != SqliteResultCode::kOk) {
1344 DCHECK_NE(sqlite_result_code, SqliteResultCode::kDone)
1345 << "sqlite3_prepare_v3() returned unexpected non-error result code";
1346 DCHECK_NE(sqlite_result_code, SqliteResultCode::kRow)
1347 << "sqlite3_prepare_v3() returned unexpected non-error result code";
1353 // This happens if |sql| originally only contained comments or whitespace.
1354 // TODO(shess): Audit to see if this can become a DCHECK(). Having
1355 // extraneous comments and whitespace in the SQL statements increases
1356 // runtime cost and can easily be shifted out to the C++ layer.
1357 if (!sqlite_statement)
1361 sqlite_result_code = ToSqliteResultCode(sqlite3_step(sqlite_statement));
1362 if (sqlite_result_code != SqliteResultCode::kRow)
1365 // TODO(shess): Audit to see if this can become a DCHECK. I think PRAGMA
1366 // is the only legitimate case for this. Previously recorded histograms
1367 // show significant use of this code path.
1370 // sqlite3_finalize() returns SQLITE_OK if the most recent sqlite3_step()
1371 // returned SQLITE_DONE or SQLITE_ROW, otherwise the error code.
1372 sqlite_result_code = ToSqliteResultCode(sqlite3_finalize(sqlite_statement));
1373 DCHECK_NE(sqlite_result_code, SqliteResultCode::kDone)
1374 << "sqlite3_finalize() returned unexpected non-error result code";
1375 DCHECK_NE(sqlite_result_code, SqliteResultCode::kRow)
1376 << "sqlite3_finalize() returned unexpected non-error result code";
1378 // sqlite3_exec() does this, presumably to avoid spinning the parser for
1379 // trailing whitespace.
1380 // TODO(shess): Audit to see if this can become a DCHECK.
1381 while (base::IsAsciiWhitespace(*sql)) {
1386 // Most calls to Execute() modify the database. The main exceptions would be
1387 // calls such as CREATE TABLE IF NOT EXISTS which could modify the database
1388 // but sometimes don't.
1389 ReleaseCacheMemoryIfNeeded(true);
1391 DCHECK_NE(sqlite_result_code, SqliteResultCode::kDone)
1392 << __func__ << " about to return unexpected non-error result code";
1393 DCHECK_NE(sqlite_result_code, SqliteResultCode::kRow)
1394 << __func__ << " about to return unexpected non-error result code";
1395 return sqlite_result_code;
1398 bool Database::Execute(const char* sql) {
1399 TRACE_EVENT1("sql", "Database::Execute", "query", TRACE_STR_COPY(sql));
1402 DCHECK(poisoned_) << "Illegal use of Database without a db";
1406 SqliteResultCode sqlite_result_code = ExecuteAndReturnResultCode(sql);
1407 if (sqlite_result_code != SqliteResultCode::kOk)
1408 OnSqliteError(ToSqliteErrorCode(sqlite_result_code), nullptr, sql);
1410 return sqlite_result_code == SqliteResultCode::kOk;
1413 bool Database::ExecuteWithTimeout(const char* sql, base::TimeDelta timeout) {
1414 TRACE_EVENT0("sql", "Database::ExecuteWithTimeout");
1416 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1418 DCHECK(poisoned_) << "Illegal use of Database without a db";
1422 ScopedBusyTimeout busy_timeout(db_);
1423 busy_timeout.SetTimeout(timeout);
1424 return Execute(sql);
1427 bool Database::ExecuteScriptForTesting(const char* sql_script) {
1430 DCHECK(poisoned_) << "Illegal use of Database without a db";
1434 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
1435 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
1437 while (*sql_script) {
1438 sqlite3_stmt* sqlite_statement;
1439 auto sqlite_result_code = ToSqliteResultCode(
1440 sqlite3_prepare_v3(db_, sql_script, /*nByte=*/-1, SqlitePrepareFlags(),
1441 &sqlite_statement, &sql_script));
1442 if (sqlite_result_code != SqliteResultCode::kOk)
1445 if (!sqlite_statement) {
1446 // Trailing comment or whitespace after the last semicolon.
1450 // TODO(pwnall): Investigate restricting ExecuteScriptForTesting() to
1451 // statements that don't produce any result rows.
1453 sqlite_result_code = ToSqliteResultCode(sqlite3_step(sqlite_statement));
1454 } while (sqlite_result_code == SqliteResultCode::kRow);
1456 // sqlite3_finalize() returns SQLITE_OK if the most recent sqlite3_step()
1457 // returned SQLITE_DONE or SQLITE_ROW, otherwise the error code.
1458 sqlite_result_code = ToSqliteResultCode(sqlite3_finalize(sqlite_statement));
1459 if (sqlite_result_code != SqliteResultCode::kOk)
1466 scoped_refptr<Database::StatementRef> Database::GetCachedStatement(
1469 auto it = statement_cache_.find(id);
1470 if (it != statement_cache_.end()) {
1471 // Statement is in the cache. It should still be valid. We're the only
1472 // entity invalidating cached statements, and we remove them from the cache
1474 DCHECK(it->second->is_valid());
1475 DCHECK_EQ(std::string(sqlite3_sql(it->second->stmt())), std::string(sql))
1476 << "GetCachedStatement used with same ID but different SQL";
1478 // Reset the statement so it can be reused.
1480 // ToSqliteResultCode() is called to ensure that sqlite3_reset() doesn't
1481 // return a concerning code, such as SQLITE_MISUSE. The processed error code
1482 // is ignored because sqlite3_reset() returns an error code if the last
1483 // sqlite3_step() failed, and that error was already reported when we ran
1484 // sqlite3_step(), via Statement::Run() or Statement::Step().
1485 std::ignore = ToSqliteResultCode(sqlite3_reset(it->second->stmt()));
1489 scoped_refptr<StatementRef> statement = GetUniqueStatement(sql);
1490 if (statement->is_valid()) {
1491 statement_cache_[id] = statement; // Only cache valid statements.
1492 DCHECK_EQ(std::string(sqlite3_sql(statement->stmt())), std::string(sql))
1493 << "Input SQL does not match SQLite's normalized version";
1498 scoped_refptr<Database::StatementRef> Database::GetUniqueStatement(
1500 return GetStatementImpl(sql, /*is_readonly=*/false);
1503 scoped_refptr<Database::StatementRef> Database::GetReadonlyStatement(
1505 return GetStatementImpl(sql, /*is_readonly=*/true);
1508 scoped_refptr<Database::StatementRef> Database::GetStatementImpl(
1513 // Return inactive statement.
1515 return base::MakeRefCounted<StatementRef>(nullptr, nullptr, poisoned_);
1517 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
1518 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
1521 const char* unused_sql = nullptr;
1522 const char** unused_sql_ptr = &unused_sql;
1524 constexpr const char** unused_sql_ptr = nullptr;
1525 #endif // DCHECK_IS_ON()
1526 // TODO(pwnall): Cached statements (but not unique statements) should be
1527 // prepared with prepFlags set to SQLITE_PREPARE_PERSISTENT.
1528 sqlite3_stmt* sqlite_statement;
1529 auto sqlite_result_code = ToSqliteResultCode(
1530 sqlite3_prepare_v3(db_, sql, /* nByte= */ -1, SqlitePrepareFlags(),
1531 &sqlite_statement, unused_sql_ptr));
1534 // Report SQL compilation errors. On developer machines, the errors are most
1535 // likely caused by invalid SQL in an under-development feature. In
1536 // production, SQL compilation errors are caused by database schema
1539 // DCHECK would not be appropriate here, because on-disk data is always
1540 // subject to corruption, so Chrome cannot assume that the database schema
1541 // will remain intact.
1542 if (sqlite_result_code == SqliteResultCode::kError) {
1543 DLOG(ERROR) << "SQL compilation error: " << GetErrorMessage()
1544 << ". Statement: " << sql;
1546 #endif // DCHECK_IS_ON()
1548 if (sqlite_result_code != SqliteResultCode::kOk) {
1549 DCHECK_NE(sqlite_result_code, SqliteResultCode::kDone)
1550 << "sqlite3_prepare_v3() returned unexpected non-error result code";
1551 DCHECK_NE(sqlite_result_code, SqliteResultCode::kRow)
1552 << "sqlite3_prepare_v3() returned unexpected non-error result code";
1553 OnSqliteError(ToSqliteErrorCode(sqlite_result_code), nullptr, sql);
1554 return base::MakeRefCounted<StatementRef>(nullptr, nullptr, false);
1557 // If readonly statement is expected and the statement is not readonly, return
1558 // an invalid statement and close the created statement.
1559 if (is_readonly && sqlite3_stmt_readonly(sqlite_statement) == 0) {
1560 DLOG(ERROR) << "Readonly SQL statement failed readonly test " << sql;
1561 // Make a `StatementRef` that will close the created statement.
1562 base::MakeRefCounted<StatementRef>(this, sqlite_statement, true);
1564 return base::MakeRefCounted<StatementRef>(nullptr, nullptr, false);
1568 DCHECK_EQ(unused_sql, sql + strlen(sql))
1569 << "Unused text: " << std::string(unused_sql) << "\n"
1570 << "in prepared SQL statement: " << std::string(sql);
1571 #endif // DCHECK_IS_ON()
1573 DCHECK(sqlite_statement) << "No SQL statement in string: " << sql;
1575 return base::MakeRefCounted<StatementRef>(this, sqlite_statement, true);
1578 std::string Database::GetSchema() {
1579 // The ORDER BY should not be necessary, but relying on organic
1580 // order for something like this is questionable.
1581 static const char kSql[] =
1582 "SELECT type, name, tbl_name, sql "
1583 "FROM sqlite_schema ORDER BY 1, 2, 3, 4";
1584 Statement statement(GetUniqueStatement(kSql));
1587 while (statement.Step()) {
1588 schema += statement.ColumnString(0);
1590 schema += statement.ColumnString(1);
1592 schema += statement.ColumnString(2);
1594 schema += statement.ColumnString(3);
1601 bool Database::IsSQLValid(const char* sql) {
1602 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1604 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
1605 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
1607 DCHECK(poisoned_) << "Illegal use of Database without a db";
1612 const char* unused_sql = nullptr;
1613 const char** unused_sql_ptr = &unused_sql;
1615 constexpr const char** unused_sql_ptr = nullptr;
1616 #endif // DCHECK_IS_ON()
1618 sqlite3_stmt* sqlite_statement = nullptr;
1619 auto sqlite_result_code = ToSqliteResultCode(
1620 sqlite3_prepare_v3(db_, sql, /* nByte= */ -1, SqlitePrepareFlags(),
1621 &sqlite_statement, unused_sql_ptr));
1622 if (sqlite_result_code != SqliteResultCode::kOk)
1626 DCHECK_EQ(unused_sql, sql + strlen(sql))
1627 << "Unused text: " << std::string(unused_sql) << "\n"
1628 << "in SQL statement: " << std::string(sql);
1629 #endif // DCHECK_IS_ON()
1631 DCHECK(sqlite_statement) << "No SQL statement in string: " << sql;
1633 sqlite_result_code = ToSqliteResultCode(sqlite3_finalize(sqlite_statement));
1634 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
1635 << "sqlite3_finalize() failed for valid statement";
1639 bool Database::DoesIndexExist(base::StringPiece index_name) {
1640 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1641 return DoesSchemaItemExist(index_name, "index");
1644 bool Database::DoesTableExist(base::StringPiece table_name) {
1645 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1646 return DoesSchemaItemExist(table_name, "table");
1649 bool Database::DoesViewExist(base::StringPiece view_name) {
1650 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1651 return DoesSchemaItemExist(view_name, "view");
1654 bool Database::DoesSchemaItemExist(base::StringPiece name,
1655 base::StringPiece type) {
1656 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1658 static const char kSql[] =
1659 "SELECT 1 FROM sqlite_schema WHERE type=? AND name=?";
1660 Statement statement(GetUniqueStatement(kSql));
1662 if (!statement.is_valid()) {
1663 // The database is corrupt.
1667 statement.BindString(0, type);
1668 statement.BindString(1, name);
1670 return statement.Step(); // Table exists if any row was returned.
1673 bool Database::DoesColumnExist(const char* table_name,
1674 const char* column_name) {
1675 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1677 // sqlite3_table_column_metadata uses out-params to return column definition
1678 // details, such as the column type and whether it allows NULL values. These
1679 // aren't needed to compute the current method's result, so we pass in nullptr
1680 // for all the out-params.
1681 auto sqlite_result_code = ToSqliteResultCode(sqlite3_table_column_metadata(
1682 db_, "main", table_name, column_name, /* pzDataType= */ nullptr,
1683 /* pzCollSeq= */ nullptr, /* pNotNull= */ nullptr,
1684 /* pPrimaryKey= */ nullptr, /* pAutoinc= */ nullptr));
1685 return sqlite_result_code == SqliteResultCode::kOk;
1688 int64_t Database::GetLastInsertRowId() const {
1690 DCHECK(poisoned_) << "Illegal use of Database without a db";
1693 int64_t last_rowid = sqlite3_last_insert_rowid(db_);
1694 DCHECK(last_rowid != 0) << "No successful INSERT in a table with ROWID";
1698 int64_t Database::GetLastChangeCount() {
1700 DCHECK(poisoned_) << "Illegal use of Database without a db";
1703 return sqlite3_changes64(db_);
1706 int Database::GetMemoryUsage() {
1708 DCHECK(poisoned_) << "Illegal use of Database without a db";
1712 // The following calls all set the high watermark to zero.
1713 // See https://www.sqlite.org/c3ref/c_dbstatus_options.html
1714 int high_watermark = 0;
1716 int cache_memory = 0, schema_memory = 0, statement_memory = 0;
1718 auto sqlite_result_code = ToSqliteResultCode(sqlite3_db_status(
1719 db_, SQLITE_DBSTATUS_CACHE_USED, &cache_memory, &high_watermark,
1721 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
1722 << "sqlite3_db_status(SQLITE_DBSTATUS_CACHE_USED) failed";
1725 int shared_cache_memory = 0;
1726 sqlite_result_code = ToSqliteResultCode(
1727 sqlite3_db_status(db_, SQLITE_DBSTATUS_CACHE_USED_SHARED,
1728 &shared_cache_memory, &high_watermark, /*resetFlg=*/0));
1729 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
1730 << "sqlite3_db_status(SQLITE_DBSTATUS_CACHE_USED_SHARED) failed";
1731 DCHECK_EQ(shared_cache_memory, cache_memory)
1732 << "Memory counting assumes that each database uses a private page cache";
1733 #endif // DCHECK_IS_ON()
1735 sqlite_result_code = ToSqliteResultCode(sqlite3_db_status(
1736 db_, SQLITE_DBSTATUS_SCHEMA_USED, &schema_memory, &high_watermark,
1738 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
1739 << "sqlite3_db_status(SQLITE_DBSTATUS_SCHEMA_USED) failed";
1741 sqlite_result_code = ToSqliteResultCode(sqlite3_db_status(
1742 db_, SQLITE_DBSTATUS_STMT_USED, &statement_memory, &high_watermark,
1744 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
1745 << "sqlite3_db_status(SQLITE_DBSTATUS_STMT_USED) failed";
1747 return cache_memory + schema_memory + statement_memory;
1750 int Database::GetErrorCode() const {
1752 return SQLITE_ERROR;
1753 return sqlite3_extended_errcode(db_);
1756 int Database::GetLastErrno() const {
1761 if (SQLITE_OK != sqlite3_file_control(db_, nullptr, SQLITE_LAST_ERRNO, &err))
1767 const char* Database::GetErrorMessage() const {
1769 return "sql::Database is not opened.";
1770 return sqlite3_errmsg(db_);
1773 bool Database::OpenInternal(const std::string& db_file_path,
1774 Database::OpenMode mode) {
1775 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
1776 TRACE_EVENT1("sql", "Database::OpenInternal", "path", db_file_path);
1778 DCHECK(mode != OpenMode::kTemporary || db_file_path.empty())
1779 << "Temporary databases should be open with an empty file path";
1781 if (mode == OpenMode::kInMemory) {
1782 DCHECK_EQ(db_file_path, kSqliteOpenInMemoryPath)
1783 << "In-memory databases should be open with the magic :memory: path";
1785 DCHECK_NE(db_file_path, kSqliteOpenInMemoryPath)
1786 << "Database file path conflicts with SQLite magic identifier";
1790 DLOG(DCHECK) << "sql::Database is already open.";
1794 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
1795 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
1797 EnsureSqliteInitialized();
1799 // If |poisoned_| is set, it means an error handler called
1800 // RazeAndClose(). Until regular Close() is called, the caller
1801 // should be treating the database as open, but is_open() currently
1802 // only considers the sqlite3 handle's state.
1803 // TODO(shess): Revise is_open() to consider poisoned_, and review
1804 // to see if any non-testing code even depends on it.
1805 DCHECK(!poisoned_) << "sql::Database is already open.";
1808 // Custom memory-mapping VFS which reads pages using regular I/O on first hit.
1809 sqlite3_vfs* vfs = VFSWrapper();
1810 const char* vfs_name = (vfs ? vfs->zName : nullptr);
1812 // The flags are documented at https://www.sqlite.org/c3ref/open.html.
1814 // Chrome uses SQLITE_OPEN_PRIVATECACHE because SQLite is used by many
1815 // disparate features with their own databases, and having separate page
1816 // caches makes it easier to reason about each feature's performance in
1819 // SQLITE_OPEN_EXRESCODE enables the full range of SQLite error codes. See
1820 // https://www.sqlite.org/rescode.html for details.
1821 int open_flags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
1822 SQLITE_OPEN_EXRESCODE | SQLITE_OPEN_PRIVATECACHE;
1823 auto sqlite_result_code = ToSqliteResultCode(
1824 sqlite3_open_v2(db_file_path.c_str(), &db_, open_flags, vfs_name));
1825 if (sqlite_result_code != SqliteResultCode::kOk) {
1826 OnSqliteError(ToSqliteErrorCode(sqlite_result_code), nullptr,
1827 "-- sqlite3_open_v2()");
1828 bool was_poisoned = poisoned_;
1831 if (was_poisoned && mode == OpenMode::kRetryOnPoision)
1832 return OpenInternal(db_file_path, OpenMode::kNone);
1836 ConfigureSqliteDatabaseObject();
1838 // If indicated, enable shared mode ("NORMAL") on the database, so it can be
1839 // opened by multiple processes. This needs to happen before WAL mode is
1842 // TODO(crbug.com/1120969): Remove support for non-exclusive mode.
1844 SQLITE_DEFAULT_LOCKING_MODE == 1,
1845 "Chrome assumes SQLite is configured to default to EXCLUSIVE locking");
1846 if (!options_.exclusive_locking) {
1847 if (!Execute("PRAGMA locking_mode=NORMAL"))
1851 // The sqlite3_open*() methods only perform I/O on the database file if a hot
1852 // journal is found. Force SQLite to parse the header and database schema, so
1853 // we can signal irrecoverable corruption early.
1855 // sqlite3_table_column_metadata() causes SQLite to parse the database schema.
1856 // Since the schema is stored inside a table B-tree, parsing the schema
1857 // implies parsing the database header.
1859 // sqlite3_table_column_metadata() can be used with a null database name, but
1860 // that will cause it to search for the table in all databases that are
1861 // ATTACHed to the connection. While Chrome features (almost) never use
1862 // ATTACHed databases, we prefer to be explicit here.
1864 // sqlite3_table_column_metadata() can be used with a null column name, and
1865 // will report on the existence of the table with the given name. This is
1866 // sufficient for the purpose of getting SQLite to parse the database schema.
1867 // See https://www.sqlite.org/c3ref/table_column_metadata.html for details.
1868 static constexpr char kSqliteSchemaTable[] = "sqlite_schema";
1869 sqlite_result_code = ToSqliteResultCode(sqlite3_table_column_metadata(
1870 db_, kSqliteMainDatabaseName, kSqliteSchemaTable, /*zColumnName=*/nullptr,
1871 /*pzDataType=*/nullptr, /*pzCollSeq=*/nullptr, /*pNotNull=*/nullptr,
1872 /*pPrimaryKey=*/nullptr, /*pAutoinc=*/nullptr));
1873 if (sqlite_result_code != SqliteResultCode::kOk) {
1874 OnSqliteError(ToSqliteErrorCode(sqlite_result_code), nullptr,
1875 "-- sqlite3_table_column_metadata()");
1877 // Retry or bail out if the error handler poisoned the handle.
1878 // TODO(shess): Move this handling to one place (see also sqlite3_open).
1879 // Possibly a wrapper function?
1882 if (mode == OpenMode::kRetryOnPoision)
1883 return OpenInternal(db_file_path, OpenMode::kNone);
1888 const base::TimeDelta kBusyTimeout = base::Seconds(kBusyTimeoutSeconds);
1890 // Needs to happen before entering WAL mode. Will only work if this the first
1891 // time the database is being opened in WAL mode.
1892 const std::string page_size_sql =
1893 base::StringPrintf("PRAGMA page_size=%d", options_.page_size);
1894 std::ignore = ExecuteWithTimeout(page_size_sql.c_str(), kBusyTimeout);
1896 // http://www.sqlite.org/pragma.html#pragma_journal_mode
1897 // WAL - Use a write-ahead log instead of a journal file.
1898 // DELETE (default) - delete -journal file to commit.
1899 // TRUNCATE - truncate -journal file to commit.
1900 // PERSIST - zero out header of -journal file to commit.
1901 // TRUNCATE should be faster than DELETE because it won't need directory
1902 // changes for each transaction. PERSIST may break the spirit of using
1905 // Needs to be performed after setting exclusive locking mode. Otherwise can
1906 // fail if underlying VFS doesn't support shared memory.
1908 // Set the synchronous flag to NORMAL. This means that writers don't flush
1909 // the WAL file after every write. The WAL file is only flushed on a
1910 // checkpoint. In this case, transcations might lose durability on a power
1911 // loss (but still durable after an application crash).
1912 // TODO(shuagga@microsoft.com): Evaluate if this loss of durability is a
1914 std::ignore = Execute("PRAGMA synchronous=NORMAL");
1916 // Opening the db in WAL mode can fail (eg if the underlying VFS doesn't
1917 // support shared memory and we are not in exclusive locking mode).
1919 // TODO(shuagga@microsoft.com): We should probably catch a failure here.
1920 std::ignore = Execute("PRAGMA journal_mode=WAL");
1922 std::ignore = Execute("PRAGMA journal_mode=TRUNCATE");
1925 if (options_.flush_to_media)
1926 std::ignore = Execute("PRAGMA fullfsync=1");
1928 if (options_.cache_size != 0) {
1929 const std::string cache_size_sql = base::StrCat(
1930 {"PRAGMA cache_size=", base::NumberToString(options_.cache_size)});
1931 std::ignore = ExecuteWithTimeout(cache_size_sql.c_str(), kBusyTimeout);
1934 static_assert(SQLITE_SECURE_DELETE == 1,
1935 "Chrome assumes secure_delete is on by default.");
1937 // When SQLite needs to grow a database file, it uses a configurable
1938 // increment. Larger values reduce filesystem fragmentation and mmap()
1939 // churn, as the database file is grown less often. Smaller values waste
1942 // We currently set different values for small vs large files.
1944 // TODO(crbug.com/1305778): Replace file size-based heuristic with a
1945 // DatabaseOptions member. Use the DatabaseOptions value for temporary
1946 // databases as well.
1947 sqlite3_file* file = GetSqliteVfsFile();
1949 // GetSqliteVfsFile() returns null for in-memory and temporary databases. This
1950 // is fine, because these databases start out empty, so the heuristic below
1951 // would never set a chunk size on them anyway.
1953 sqlite3_int64 db_size = 0;
1954 sqlite_result_code =
1955 ToSqliteResultCode(file->pMethods->xFileSize(file, &db_size));
1956 if (sqlite_result_code == SqliteResultCode::kOk && db_size > 16 * 1024) {
1957 int chunk_size = 4 * 1024;
1958 if (db_size > 128 * 1024)
1959 chunk_size = 32 * 1024;
1961 sqlite3_file_control(db_, /*zDbName=*/nullptr, SQLITE_FCNTL_CHUNK_SIZE,
1966 size_t mmap_size = mmap_disabled_ ? 0 : ComputeMmapSizeForOpen();
1968 // We explicitly issue a "PRGAMA mmap_size=0" to disable memory-mapping. We
1969 // could skip executing the PRAGMA in that case, and use a static_assert to
1970 // ensure that SQLITE_DEFAULT_MMAP_SIZE > 0. We didn't choose this alternative
1971 // because would cost us a bit more logic, and the optimization would apply to
1972 // edge cases, such as in-memory databases. More details at
1973 // https://www.sqlite.org/pragma.html#pragma_mmap_size.
1974 std::string pragma_mmap_size_sql =
1975 base::StrCat({"PRAGMA mmap_size=", base::NumberToString(mmap_size)});
1976 std::ignore = Execute(pragma_mmap_size_sql.c_str());
1978 // Determine if memory-mapping has actually been enabled. The Execute() above
1979 // can succeed without changing the amount mapped.
1980 mmap_enabled_ = false;
1982 Statement pragma_mmap_size(GetUniqueStatement("PRAGMA mmap_size"));
1983 if (pragma_mmap_size.Step() && pragma_mmap_size.ColumnInt64(0) > 0)
1984 mmap_enabled_ = true;
1987 DCHECK(!memory_dump_provider_);
1988 memory_dump_provider_ =
1989 std::make_unique<DatabaseMemoryDumpProvider>(db_, histogram_tag_);
1990 base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
1991 memory_dump_provider_.get(), "sql::Database", /*task_runner=*/nullptr);
1996 void Database::ConfigureSqliteDatabaseObject() {
1997 // The use of SQLite's non-standard string quoting is not allowed in Chrome.
1999 // Allowing double-quoted string literals is now considered a misfeature by
2000 // SQLite authors. See https://www.sqlite.org/quirks.html#dblquote
2001 auto sqlite_result_code = ToSqliteResultCode(
2002 sqlite3_db_config(db_, SQLITE_DBCONFIG_DQS_DDL, 0, nullptr));
2003 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
2004 << "sqlite3_db_config(SQLITE_DBCONFIG_DQS_DDL) should not fail";
2005 sqlite_result_code = ToSqliteResultCode(
2006 sqlite3_db_config(db_, SQLITE_DBCONFIG_DQS_DML, 0, nullptr));
2007 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
2008 << "sqlite3_db_config(SQLITE_DBCONFIG_DQS_DML) should not fail";
2010 sqlite_result_code = ToSqliteResultCode(sqlite3_db_config(
2011 db_, SQLITE_DBCONFIG_ENABLE_FKEY,
2012 options_.enable_foreign_keys_discouraged ? 1 : 0, nullptr));
2013 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
2014 << "sqlite3_db_config(SQLITE_DBCONFIG_ENABLE_FKEY) should not fail";
2016 // The use of triggers is discouraged for Chrome code. Thanks to this
2017 // configuration change, triggers are not executed. CREATE TRIGGER and DROP
2018 // TRIGGER still succeed.
2019 sqlite_result_code = ToSqliteResultCode(
2020 sqlite3_db_config(db_, SQLITE_DBCONFIG_ENABLE_TRIGGER, 0, nullptr));
2021 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
2022 << "sqlite3_db_config() should not fail";
2024 sqlite_result_code = ToSqliteResultCode(
2025 sqlite3_db_config(db_, SQLITE_DBCONFIG_ENABLE_VIEW,
2026 options_.enable_views_discouraged ? 1 : 0, nullptr));
2027 DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
2028 << "sqlite3_db_config() should not fail";
2031 void Database::DoRollback() {
2032 TRACE_EVENT0("sql", "Database::DoRollback");
2034 Statement rollback(GetCachedStatement(SQL_FROM_HERE, "ROLLBACK"));
2038 // The cache may have been accumulating dirty pages for commit. Note that in
2039 // some cases sql::Transaction can fire rollback after a database is closed.
2041 ReleaseCacheMemoryIfNeeded(false);
2043 needs_rollback_ = false;
2046 void Database::StatementRefCreated(StatementRef* ref) {
2047 DCHECK(!open_statements_.count(ref))
2048 << __func__ << " already called with this statement";
2049 open_statements_.insert(ref);
2052 void Database::StatementRefDeleted(StatementRef* ref) {
2053 DCHECK(open_statements_.count(ref))
2054 << __func__ << " called with non-existing statement";
2055 open_statements_.erase(ref);
2058 void Database::set_histogram_tag(const std::string& tag) {
2061 histogram_tag_ = tag;
2064 void Database::OnSqliteError(SqliteErrorCode sqlite_error_code,
2065 sql::Statement* statement,
2066 const char* sql_statement) {
2067 TRACE_EVENT0("sql", "Database::OnSqliteError");
2069 DCHECK_NE(statement != nullptr, sql_statement != nullptr)
2070 << __func__ << " should either get a Statement or a raw SQL string";
2072 // Log errors for developers.
2074 // This block is wrapped around a DCHECK_IS_ON() check so we don't waste CPU
2075 // cycles computing the strings that make up the log message in production.
2077 std::string logged_statement;
2079 logged_statement = statement->GetSQLStatement();
2081 logged_statement = sql_statement;
2084 std::string database_id = histogram_tag_;
2085 if (database_id.empty())
2086 database_id = DbPath().BaseName().AsUTF8Unsafe();
2088 // This logging block cannot be a DCHECK, because valid usage of sql::Database
2089 // can still encounter SQLite errors in production. For example, valid SQL
2090 // statements can fail when a database is corrupted.
2092 // This logging block should not use LOG(ERROR) because many features built on
2093 // top of sql::Database can recover from most errors.
2094 DVLOG(1) << "SQLite error! This may indicate a programming error!\n"
2095 << "Database: " << database_id
2096 << " sqlite_error_code: " << sqlite_error_code
2097 << " errno: " << GetLastErrno()
2098 << "\nSQLite error description: " << GetErrorMessage()
2099 << "\nSQL statement: " << logged_statement;
2100 #endif // DCHECK_IS_ON()
2102 // Inform the error expecter that we've encountered the error.
2103 std::ignore = IsExpectedSqliteError(static_cast<int>(sqlite_error_code));
2105 if (!error_callback_.is_null()) {
2106 // Create an additional reference to the state in `error_callback_`, so the
2107 // state doesn't go away if the callback changes `error_callback_` by
2108 // calling set_error_callback() or reset_error_callback(). This avoids a
2109 // subtle source of use-after-frees. See https://crbug.com/254584.
2110 ErrorCallback error_callback_copy = error_callback_;
2111 error_callback_copy.Run(static_cast<int>(sqlite_error_code), statement);
2116 std::string Database::GetDiagnosticInfo(int sqlite_error_code,
2117 Statement* statement,
2118 DatabaseDiagnostics* diagnostics) {
2119 DCHECK_NE(sqlite_error_code, SQLITE_OK)
2120 << __func__ << " received non-error result code";
2121 DCHECK_NE(sqlite_error_code, SQLITE_DONE)
2122 << __func__ << " received non-error result code";
2123 DCHECK_NE(sqlite_error_code, SQLITE_ROW)
2124 << __func__ << " received non-error result code";
2126 // Prevent reentrant calls to the error callback.
2127 ErrorCallback original_callback = std::move(error_callback_);
2128 error_callback_.Reset();
2131 diagnostics->reported_sqlite_error_code = sqlite_error_code;
2134 // Trim extended error codes.
2135 const int primary_error_code = sqlite_error_code & 0xff;
2137 // CollectCorruptionInfo() is implemented in terms of sql::Database,
2138 // TODO(shess): Rewrite IntegrityCheckHelper() in terms of raw SQLite.
2139 std::string result =
2140 (primary_error_code == SQLITE_CORRUPT)
2141 ? CollectCorruptionInfo()
2142 : CollectErrorInfo(sqlite_error_code, statement, diagnostics);
2144 // The following queries must be executed after CollectErrorInfo() above, so
2145 // if they result in their own errors, they don't interfere with
2146 // CollectErrorInfo().
2147 const bool has_valid_header = Execute("PRAGMA auto_vacuum");
2148 const bool has_valid_schema = Execute("SELECT COUNT(*) FROM sqlite_schema");
2150 // Restore the original error callback.
2151 error_callback_ = std::move(original_callback);
2153 base::StringAppendF(&result, "Has valid header: %s\n",
2154 (has_valid_header ? "Yes" : "No"));
2155 base::StringAppendF(&result, "Has valid schema: %s\n",
2156 (has_valid_schema ? "Yes" : "No"));
2158 diagnostics->has_valid_header = has_valid_header;
2159 diagnostics->has_valid_schema = has_valid_schema;
2165 bool Database::FullIntegrityCheck(std::vector<std::string>* messages) {
2166 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
2169 // The PRAGMA below has the side effect of setting SQLITE_RecoveryMode, which
2170 // allows SQLite to process through certain cases of corruption.
2171 if (!Execute("PRAGMA writable_schema=ON")) {
2172 // The "PRAGMA integrity_check" statement executed below may return less
2173 // useful information. However, incomplete information is still better than
2174 // nothing, so we press on.
2175 messages->push_back("PRAGMA writable_schema=ON failed");
2178 // We need to bypass sql::Statement and use raw SQLite C API calls here.
2180 // "PRAGMA integrity_check" reports SQLITE_CORRUPT when the database is
2181 // corrupt. Reporting SQLITE_CORRUPT is undesirable in this case, because it
2182 // causes our sql::Statement infrastructure to call the database error
2183 // handler, which triggers feature-level error handling. However,
2184 // FullIntegrityCheck() callers presumably already know that the database is
2185 // corrupted, and are trying to collect diagnostic information for reporting.
2186 sqlite3_stmt* statement = nullptr;
2188 // https://www.sqlite.org/c3ref/prepare.html states that SQLite will perform
2189 // slightly better if sqlite_prepare_v3() receives a zero-terminated statement
2190 // string, and a statement size that includes the zero byte. Fortunately,
2191 // C++'s string literal and sizeof() operator do exactly that.
2192 constexpr char kIntegrityCheckSql[] = "PRAGMA integrity_check";
2193 const auto prepare_result_code = ToSqliteResultCode(
2194 sqlite3_prepare_v3(db_, kIntegrityCheckSql, sizeof(kIntegrityCheckSql),
2195 SqlitePrepareFlags(), &statement, /*pzTail=*/nullptr));
2196 if (prepare_result_code != SqliteResultCode::kOk)
2199 // "PRAGMA integrity_check" currently returns multiple lines as a single row.
2201 // However, since https://www.sqlite.org/pragma.html#pragma_integrity_check
2202 // states that multiple records may be returned, the code below can handle
2203 // multiple records, each of which has multiple lines.
2204 std::vector<std::string> result_lines;
2206 while (ToSqliteResultCode(sqlite3_step(statement)) ==
2207 SqliteResultCode::kRow) {
2208 const uint8_t* row = chrome_sqlite3_column_text(statement, /*iCol=*/0);
2209 DCHECK(row) << "PRAGMA integrity_check should never return NULL rows";
2211 const int row_size = sqlite3_column_bytes(statement, /*iCol=*/0);
2212 base::StringPiece row_string(reinterpret_cast<const char*>(row), row_size);
2214 const std::vector<base::StringPiece> row_lines = base::SplitStringPiece(
2215 row_string, "\n", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
2216 for (base::StringPiece row_line : row_lines)
2217 result_lines.emplace_back(row_line);
2220 const auto finalize_result_code =
2221 ToSqliteResultCode(sqlite3_finalize(statement));
2222 // sqlite3_finalize() may return SQLITE_CORRUPT when the integrity check
2223 // discovers any problems. We still consider this case a success, as long as
2224 // the statement produced at least one diagnostic message.
2225 const bool success = (result_lines.size() > 0) ||
2226 (finalize_result_code == SqliteResultCode::kOk);
2227 *messages = std::move(result_lines);
2229 // Best-effort attempt to undo the "PRAGMA writable_schema=ON" executed above.
2230 std::ignore = Execute("PRAGMA writable_schema=OFF");
2235 bool Database::ReportMemoryUsage(base::trace_event::ProcessMemoryDump* pmd,
2236 const std::string& dump_name) {
2237 return memory_dump_provider_ &&
2238 memory_dump_provider_->ReportMemoryUsage(pmd, dump_name);
2241 bool Database::UseWALMode() const {
2242 #if BUILDFLAG(IS_FUCHSIA)
2243 // WAL mode is only enabled on Fuchsia for databases with exclusive
2244 // locking, because this case does not require shared memory support.
2245 // At the time this was implemented (May 2020), Fuchsia's shared
2246 // memory support was insufficient for SQLite's needs.
2247 return options_.wal_mode && options_.exclusive_locking;
2249 return options_.wal_mode;
2250 #endif // BUILDFLAG(IS_FUCHSIA)
2253 bool Database::CheckpointDatabase() {
2254 DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
2255 absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
2256 InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
2258 auto sqlite_result_code = ToSqliteResultCode(sqlite3_wal_checkpoint_v2(
2259 db_, kSqliteMainDatabaseName, SQLITE_CHECKPOINT_PASSIVE,
2260 /*pnLog=*/nullptr, /*pnCkpt=*/nullptr));
2262 return sqlite_result_code == SqliteResultCode::kOk;