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- // Copyright (c) 2012 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #include "sql/database.h"
- #include <limits.h>
- #include <stddef.h>
- #include <stdint.h>
- #include <string.h>
- #include <algorithm>
- #include <memory>
- #include <tuple>
- #include "base/check.h"
- #include "base/dcheck_is_on.h"
- #include "base/feature_list.h"
- #include "base/files/file_path.h"
- #include "base/files/file_util.h"
- #include "base/format_macros.h"
- #include "base/location.h"
- #include "base/logging.h"
- #include "base/memory/raw_ptr.h"
- #include "base/no_destructor.h"
- #include "base/notreached.h"
- #include "base/numerics/safe_conversions.h"
- #include "base/ranges/algorithm.h"
- #include "base/sequence_checker.h"
- #include "base/strings/strcat.h"
- #include "base/strings/string_number_conversions.h"
- #include "base/strings/string_piece.h"
- #include "base/strings/string_split.h"
- #include "base/strings/string_util.h"
- #include "base/strings/stringprintf.h"
- #include "base/strings/utf_string_conversions.h"
- #include "base/synchronization/lock.h"
- #include "base/task/single_thread_task_runner.h"
- #include "base/threading/scoped_blocking_call.h"
- #include "base/trace_event/memory_dump_manager.h"
- #include "base/trace_event/trace_event.h"
- #include "base/tracing/protos/chrome_track_event.pbzero.h"
- #include "base/types/pass_key.h"
- #include "build/build_config.h"
- #include "sql/database_memory_dump_provider.h"
- #include "sql/initialization.h"
- #include "sql/meta_table.h"
- #include "sql/sql_features.h"
- #include "sql/sqlite_result_code.h"
- #include "sql/sqlite_result_code_values.h"
- #include "sql/statement.h"
- #include "sql/vfs_wrapper.h"
- #include "third_party/sqlite/sqlite3.h"
- namespace sql {
- namespace {
- bool enable_mmap_by_default_ = true;
- // The name of the main database associated with a sqlite3* connection.
- //
- // SQLite has the ability to ATTACH multiple databases to the same connection.
- // As a consequence, some SQLite APIs require the connection-specific database
- // name. This is the right name to be passed to such APIs.
- static constexpr char kSqliteMainDatabaseName[] = "main";
- // Magic path value telling sqlite3_open_v2() to open an in-memory database.
- static constexpr char kSqliteOpenInMemoryPath[] = ":memory:";
- // Spin for up to a second waiting for the lock to clear when setting
- // up the database.
- // TODO(shess): Better story on this. http://crbug.com/56559
- const int kBusyTimeoutSeconds = 1;
- class ScopedBusyTimeout {
- public:
- explicit ScopedBusyTimeout(sqlite3* db) : db_(db) {}
- ~ScopedBusyTimeout() { sqlite3_busy_timeout(db_, 0); }
- int SetTimeout(base::TimeDelta timeout) {
- DCHECK_LT(timeout.InMilliseconds(), INT_MAX);
- return sqlite3_busy_timeout(db_,
- static_cast<int>(timeout.InMilliseconds()));
- }
- private:
- raw_ptr<sqlite3> db_;
- };
- // Helper to "safely" enable writable_schema. No error checking
- // because it is reasonable to just forge ahead in case of an error.
- // If turning it on fails, then most likely nothing will work, whereas
- // if turning it off fails, it only matters if some code attempts to
- // continue working with the database and tries to modify the
- // sqlite_schema table (none of our code does this).
- class ScopedWritableSchema {
- public:
- explicit ScopedWritableSchema(sqlite3* db) : db_(db) {
- sqlite3_exec(db_, "PRAGMA writable_schema=1", nullptr, nullptr, nullptr);
- }
- ~ScopedWritableSchema() {
- sqlite3_exec(db_, "PRAGMA writable_schema=0", nullptr, nullptr, nullptr);
- }
- private:
- raw_ptr<sqlite3> db_;
- };
- // Raze() helper that uses SQLite's online backup API.
- //
- // Returns the SQLite error code produced by sqlite3_backup_step(). SQLITE_DONE
- // signals success. SQLITE_OK will never be returned.
- //
- // The implementation is tailored for the Raze() use case. In particular, the
- // SQLite API use and and error handling is optimized for 1-page databases.
- SqliteResultCode BackupDatabaseForRaze(sqlite3* source_db,
- sqlite3* destination_db) {
- DCHECK(source_db);
- DCHECK(destination_db);
- DCHECK_NE(source_db, destination_db);
- // https://www.sqlite.org/backup.html has a high-level overview of SQLite's
- // backup support. https://www.sqlite.org/c3ref/backup_finish.html describes
- // the API.
- static constexpr char kMainDatabaseName[] = "main";
- sqlite3_backup* backup = sqlite3_backup_init(
- destination_db, kMainDatabaseName, source_db, kMainDatabaseName);
- if (!backup) {
- // sqlite3_backup_init() fails if a transaction is ongoing. In particular,
- // SQL statements that return multiple rows keep a read transaction open
- // until all the Step() calls are executed.
- return ToSqliteResultCode(chrome_sqlite3_extended_errcode(destination_db));
- }
- constexpr int kUnlimitedPageCount = -1; // Back up entire database.
- auto sqlite_result_code =
- ToSqliteResultCode(sqlite3_backup_step(backup, kUnlimitedPageCount));
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_backup_step() returned SQLITE_OK (instead of SQLITE_DONE) "
- << "when asked to back up the entire database";
- #if DCHECK_IS_ON()
- if (sqlite_result_code == SqliteResultCode::kDone) {
- // If successful, exactly one page should have been backed up.
- DCHECK_EQ(sqlite3_backup_pagecount(backup), 1)
- << __func__ << " was intended to be used with 1-page databases";
- }
- #endif // DCHECK_IS_ON()
- // sqlite3_backup_finish() releases the sqlite3_backup object.
- //
- // It returns an error code only if the backup encountered a permanent error.
- // We use the the sqlite3_backup_step() result instead, because it also tells
- // us about temporary errors, like SQLITE_BUSY.
- //
- // We pass the sqlite3_backup_finish() result code through
- // ToSqliteResultCode() to catch codes that should never occur, like
- // SQLITE_MISUSE.
- std::ignore = ToSqliteResultCode(sqlite3_backup_finish(backup));
- return sqlite_result_code;
- }
- bool ValidAttachmentPoint(base::StringPiece attachment_point) {
- // SQLite could handle a much wider character set, with appropriate quoting.
- //
- // Chrome's constraint is easy to remember, and sufficient for the few
- // existing use cases. ATTACH is a discouraged feature, so no new use cases
- // are expected.
- return base::ranges::all_of(attachment_point,
- [](char ch) { return base::IsAsciiLower(ch); });
- }
- std::string AsUTF8ForSQL(const base::FilePath& path) {
- #if BUILDFLAG(IS_WIN)
- return base::WideToUTF8(path.value());
- #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
- return path.value();
- #endif
- }
- } // namespace
- // static
- Database::ScopedErrorExpecterCallback* Database::current_expecter_cb_ = nullptr;
- // static
- bool Database::IsExpectedSqliteError(int sqlite_error_code) {
- DCHECK_NE(sqlite_error_code, SQLITE_OK)
- << __func__ << " received non-error result code";
- DCHECK_NE(sqlite_error_code, SQLITE_DONE)
- << __func__ << " received non-error result code";
- DCHECK_NE(sqlite_error_code, SQLITE_ROW)
- << __func__ << " received non-error result code";
- if (!current_expecter_cb_)
- return false;
- return current_expecter_cb_->Run(sqlite_error_code);
- }
- // static
- void Database::SetScopedErrorExpecter(
- Database::ScopedErrorExpecterCallback* cb,
- base::PassKey<test::ScopedErrorExpecter>) {
- CHECK(!current_expecter_cb_);
- current_expecter_cb_ = cb;
- }
- // static
- void Database::ResetScopedErrorExpecter(
- base::PassKey<test::ScopedErrorExpecter>) {
- CHECK(current_expecter_cb_);
- current_expecter_cb_ = nullptr;
- }
- // static
- base::FilePath Database::JournalPath(const base::FilePath& db_path) {
- return base::FilePath(db_path.value() + FILE_PATH_LITERAL("-journal"));
- }
- // static
- base::FilePath Database::WriteAheadLogPath(const base::FilePath& db_path) {
- return base::FilePath(db_path.value() + FILE_PATH_LITERAL("-wal"));
- }
- // static
- base::FilePath Database::SharedMemoryFilePath(const base::FilePath& db_path) {
- return base::FilePath(db_path.value() + FILE_PATH_LITERAL("-shm"));
- }
- Database::StatementRef::StatementRef(Database* database,
- sqlite3_stmt* stmt,
- bool was_valid)
- : database_(database), stmt_(stmt), was_valid_(was_valid) {
- DCHECK_EQ(database == nullptr, stmt == nullptr);
- if (database)
- database_->StatementRefCreated(this);
- }
- Database::StatementRef::~StatementRef() {
- if (database_)
- database_->StatementRefDeleted(this);
- Close(false);
- }
- void Database::StatementRef::Close(bool forced) {
- if (stmt_) {
- // Call to InitScopedBlockingCall() cannot go at the beginning of the
- // function because Close() is called unconditionally from destructor to
- // clean database_. And if this is inactive statement this won't cause any
- // disk access and destructor most probably will be called on thread not
- // allowing disk access.
- // TODO(paivanof@gmail.com): This should move to the beginning
- // of the function. http://crbug.com/136655.
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- // `stmt_` references memory loaned from the sqlite3 library. Stop
- // referencing it from the raw_ptr<> before returning it. This avoids the
- // raw_ptr<> becoming dangling.
- sqlite3_stmt* statement = stmt_;
- stmt_ = nullptr;
- // sqlite3_finalize()'s result code is ignored because it reports the same
- // error as the most recent sqlite3_step(). The result code is passed
- // through ToSqliteResultCode() to catch issues like SQLITE_MISUSE.
- std::ignore = ToSqliteResultCode(sqlite3_finalize(statement));
- }
- database_ = nullptr; // The Database may be getting deleted.
- // Forced close is expected to happen from a statement error
- // handler. In that case maintain the sense of |was_valid_| which
- // previously held for this ref.
- was_valid_ = was_valid_ && forced;
- }
- static_assert(DatabaseOptions::kDefaultPageSize == SQLITE_DEFAULT_PAGE_SIZE,
- "DatabaseOptions::kDefaultPageSize must match the value "
- "configured into SQLite");
- DatabaseDiagnostics::DatabaseDiagnostics() = default;
- DatabaseDiagnostics::~DatabaseDiagnostics() = default;
- void DatabaseDiagnostics::WriteIntoTrace(
- perfetto::TracedProto<TraceProto> context) const {
- context->set_reported_sqlite_error_code(reported_sqlite_error_code);
- context->set_error_code(error_code);
- context->set_last_errno(last_errno);
- context->set_sql_statement(sql_statement);
- context->set_version(version);
- for (const auto& sql : schema_sql_rows) {
- context->add_schema_sql_rows(sql);
- }
- for (const auto& name : schema_other_row_names) {
- context->add_schema_other_row_names(name);
- }
- context->set_has_valid_header(has_valid_header);
- context->set_has_valid_schema(has_valid_schema);
- }
- // DatabaseOptions::explicit_locking needs to be set to false for historical
- // reasons.
- Database::Database() : Database({.exclusive_locking = false}) {}
- Database::Database(DatabaseOptions options)
- : options_(options), mmap_disabled_(!enable_mmap_by_default_) {
- DCHECK_GE(options.page_size, 512);
- DCHECK_LE(options.page_size, 65536);
- DCHECK(!(options.page_size & (options.page_size - 1)))
- << "page_size must be a power of two";
- DCHECK(!options_.mmap_alt_status_discouraged ||
- options_.enable_views_discouraged)
- << "mmap_alt_status requires views";
- // It's valid to construct a database on a sequence and then pass it to a
- // different sequence before usage.
- DETACH_FROM_SEQUENCE(sequence_checker_);
- }
- Database::~Database() {
- Close();
- }
- // static
- void Database::DisableMmapByDefault() {
- enable_mmap_by_default_ = false;
- }
- bool Database::Open(const base::FilePath& path) {
- std::string path_string = AsUTF8ForSQL(path);
- TRACE_EVENT1("sql", "Database::Open", "path", path_string);
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- DCHECK(!path.empty());
- DCHECK_NE(path_string, kSqliteOpenInMemoryPath)
- << "Path conflicts with SQLite magic identifier";
- return OpenInternal(path_string, OpenMode::kRetryOnPoision);
- }
- bool Database::OpenInMemory() {
- TRACE_EVENT0("sql", "Database::OpenInMemory");
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- in_memory_ = true;
- return OpenInternal(kSqliteOpenInMemoryPath, OpenMode::kInMemory);
- }
- bool Database::OpenTemporary(base::PassKey<Recovery>) {
- TRACE_EVENT0("sql", "Database::OpenTemporary");
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- return OpenInternal(std::string(), OpenMode::kTemporary);
- }
- void Database::CloseInternal(bool forced) {
- TRACE_EVENT0("sql", "Database::CloseInternal");
- // TODO(shess): Calling "PRAGMA journal_mode = DELETE" at this point
- // will delete the -journal file. For ChromiumOS or other more
- // embedded systems, this is probably not appropriate, whereas on
- // desktop it might make some sense.
- // sqlite3_close() needs all prepared statements to be finalized.
- // Release cached statements.
- statement_cache_.clear();
- // With cached statements released, in-use statements will remain.
- // Closing the database while statements are in use is an API
- // violation, except for forced close (which happens from within a
- // statement's error handler).
- DCHECK(forced || open_statements_.empty());
- // Deactivate any outstanding statements so sqlite3_close() works.
- for (StatementRef* statement_ref : open_statements_)
- statement_ref->Close(forced);
- open_statements_.clear();
- if (db_) {
- // Call to InitScopedBlockingCall() cannot go at the beginning of the
- // function because Close() must be called from destructor to clean
- // statement_cache_, it won't cause any disk access and it most probably
- // will happen on thread not allowing disk access.
- // TODO(paivanof@gmail.com): This should move to the beginning
- // of the function. http://crbug.com/136655.
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- // Resetting acquires a lock to ensure no dump is happening on the database
- // at the same time. Unregister takes ownership of provider and it is safe
- // since the db is reset. memory_dump_provider_ could be null if db_ was
- // poisoned.
- if (memory_dump_provider_) {
- memory_dump_provider_->ResetDatabase();
- base::trace_event::MemoryDumpManager::GetInstance()
- ->UnregisterAndDeleteDumpProviderSoon(
- std::move(memory_dump_provider_));
- }
- auto sqlite_result_code = ToSqliteResultCode(sqlite3_close(db_));
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kBusy)
- << "sqlite3_close() called while prepared statements are still alive";
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_close() failed in an unexpected way: " << GetErrorMessage();
- // The reset must happen after the DCHECKs above. GetErrorMessage() needs a
- // valid `db_` value.
- db_ = nullptr;
- }
- }
- void Database::Close() {
- TRACE_EVENT0("sql", "Database::Close");
- // If the database was already closed by RazeAndClose(), then no
- // need to close again. Clear the |poisoned_| bit so that incorrect
- // API calls are caught.
- if (poisoned_) {
- poisoned_ = false;
- return;
- }
- CloseInternal(false);
- }
- void Database::Preload() {
- TRACE_EVENT0("sql", "Database::Preload");
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- if (!db_) {
- DCHECK(poisoned_) << "Cannot preload null db";
- return;
- }
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- // Maximum number of bytes that will be prefetched from the database.
- //
- // This limit is very aggressive. The main trade-off involved is that having
- // SQLite block on reading from disk has a high impact on Chrome startup cost
- // for the databases that are on the critical path to startup. So, the limit
- // must exceed the expected sizes of databases on the critical path.
- //
- // On Windows 7, base::PreReadFile() falls back to a synchronous read, and
- // blocks until the entire file is read into memory. This is a minor factor at
- // this point, because Chrome has very limited support for Windows 7.
- constexpr int kPreReadSize = 128 * 1024 * 1024; // 128 MB
- base::PreReadFile(DbPath(), /*is_executable=*/false, kPreReadSize);
- }
- // SQLite keeps unused pages associated with a database in a cache. It asks
- // the cache for pages by an id, and if the page is present and the database is
- // unchanged, it considers the content of the page valid and doesn't read it
- // from disk. When memory-mapped I/O is enabled, on read SQLite uses page
- // structures created from the memory map data before consulting the cache. On
- // write SQLite creates a new in-memory page structure, copies the data from the
- // memory map, and later writes it, releasing the updated page back to the
- // cache.
- //
- // This means that in memory-mapped mode, the contents of the cached pages are
- // not re-used for reads, but they are re-used for writes if the re-written page
- // is still in the cache. The implementation of sqlite3_db_release_memory() as
- // of SQLite 3.8.7.4 frees all pages from pcaches associated with the
- // database, so it should free these pages.
- //
- // Unfortunately, the zero page is also freed. That page is never accessed
- // using memory-mapped I/O, and the cached copy can be re-used after verifying
- // the file change counter on disk. Also, fresh pages from cache receive some
- // pager-level initialization before they can be used. Since the information
- // involved will immediately be accessed in various ways, it is unclear if the
- // additional overhead is material, or just moving processor cache effects
- // around.
- //
- // TODO(shess): It would be better to release the pages immediately when they
- // are no longer needed. This would basically happen after SQLite commits a
- // transaction. I had implemented a pcache wrapper to do this, but it involved
- // layering violations, and it had to be setup before any other sqlite call,
- // which was brittle. Also, for large files it would actually make sense to
- // maintain the existing pcache behavior for blocks past the memory-mapped
- // segment. I think drh would accept a reasonable implementation of the overall
- // concept for upstreaming to SQLite core.
- //
- // TODO(shess): Another possibility would be to set the cache size small, which
- // would keep the zero page around, plus some pre-initialized pages, and SQLite
- // can manage things. The downside is that updates larger than the cache would
- // spill to the journal. That could be compensated by setting cache_spill to
- // false. The downside then is that it allows open-ended use of memory for
- // large transactions.
- void Database::ReleaseCacheMemoryIfNeeded(bool implicit_change_performed) {
- TRACE_EVENT0("sql", "Database::ReleaseCacheMemoryIfNeeded");
- // The database could have been closed during a transaction as part of error
- // recovery.
- if (!db_) {
- DCHECK(poisoned_) << "Illegal use of Database without a db";
- return;
- }
- // If memory-mapping is not enabled, the page cache helps performance.
- if (!mmap_enabled_)
- return;
- // On caller request, force the change comparison to fail. Done before the
- // transaction-nesting test so that the signal can carry to transaction
- // commit.
- if (implicit_change_performed)
- --total_changes_at_last_release_;
- // Cached pages may be re-used within the same transaction.
- DCHECK_GE(transaction_nesting_, 0);
- if (transaction_nesting_)
- return;
- // If no changes have been made, skip flushing. This allows the first page of
- // the database to remain in cache across multiple reads.
- const int64_t total_changes = sqlite3_total_changes64(db_);
- if (total_changes == total_changes_at_last_release_)
- return;
- total_changes_at_last_release_ = total_changes;
- // Passing the result code through ToSqliteResultCode() to catch issues such
- // as SQLITE_MISUSE.
- std::ignore = ToSqliteResultCode(sqlite3_db_release_memory(db_));
- }
- base::FilePath Database::DbPath() const {
- if (!is_open())
- return base::FilePath();
- const char* path = sqlite3_db_filename(db_, "main");
- if (!path)
- return base::FilePath();
- const base::StringPiece db_path(path);
- #if BUILDFLAG(IS_WIN)
- return base::FilePath(base::UTF8ToWide(db_path));
- #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
- return base::FilePath(db_path);
- #else
- NOTREACHED();
- return base::FilePath();
- #endif
- }
- std::string Database::CollectErrorInfo(int sqlite_error_code,
- Statement* stmt,
- DatabaseDiagnostics* diagnostics) const {
- TRACE_EVENT0("sql", "Database::CollectErrorInfo");
- DCHECK_NE(sqlite_error_code, SQLITE_OK)
- << __func__ << " received non-error result code";
- DCHECK_NE(sqlite_error_code, SQLITE_DONE)
- << __func__ << " received non-error result code";
- DCHECK_NE(sqlite_error_code, SQLITE_ROW)
- << __func__ << " received non-error result code";
- // Buffer for accumulating debugging info about the error. Place
- // more-relevant information earlier, in case things overflow the
- // fixed-size reporting buffer.
- std::string debug_info;
- // The error message from the failed operation.
- int error_code = GetErrorCode();
- base::StringAppendF(&debug_info, "db error: %d/%s\n", error_code,
- GetErrorMessage());
- if (diagnostics) {
- diagnostics->error_code = error_code;
- }
- // TODO(shess): |error| and |GetErrorCode()| should always be the same, but
- // reading code does not entirely convince me. Remove if they turn out to be
- // the same.
- if (sqlite_error_code != GetErrorCode())
- base::StringAppendF(&debug_info, "reported error: %d\n", sqlite_error_code);
- // System error information. Interpretation of Windows errors is different
- // from posix.
- #if BUILDFLAG(IS_WIN)
- int last_errno = GetLastErrno();
- base::StringAppendF(&debug_info, "LastError: %d\n", last_errno);
- if (diagnostics) {
- diagnostics->last_errno = last_errno;
- }
- #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
- int last_errno = GetLastErrno();
- base::StringAppendF(&debug_info, "errno: %d\n", last_errno);
- if (diagnostics) {
- diagnostics->last_errno = last_errno;
- }
- #else
- NOTREACHED(); // Add appropriate log info.
- #endif
- if (stmt) {
- std::string sql_string = stmt->GetSQLStatement();
- base::StringAppendF(&debug_info, "statement: %s\n", sql_string.c_str());
- if (diagnostics) {
- diagnostics->sql_statement = sql_string;
- }
- } else {
- base::StringAppendF(&debug_info, "statement: NULL\n");
- }
- // SQLITE_ERROR often indicates some sort of mismatch between the statement
- // and the schema, possibly due to a failed schema migration.
- if (sqlite_error_code == SQLITE_ERROR) {
- static constexpr char kVersionSql[] =
- "SELECT value FROM meta WHERE key='version'";
- sqlite3_stmt* sqlite_statement;
- // When the number of bytes passed to sqlite3_prepare_v3() includes the null
- // terminator, SQLite avoids a buffer copy.
- int rc = sqlite3_prepare_v3(db_, kVersionSql, sizeof(kVersionSql),
- SQLITE_PREPARE_NO_VTAB, &sqlite_statement,
- /* pzTail= */ nullptr);
- if (rc == SQLITE_OK) {
- rc = sqlite3_step(sqlite_statement);
- if (rc == SQLITE_ROW) {
- int version = sqlite3_column_int(sqlite_statement, 0);
- base::StringAppendF(&debug_info, "version: %d\n", version);
- if (diagnostics) {
- diagnostics->version = version;
- }
- } else if (rc == SQLITE_DONE) {
- debug_info += "version: none\n";
- } else {
- base::StringAppendF(&debug_info, "version: error %d\n", rc);
- }
- sqlite3_finalize(sqlite_statement);
- } else {
- base::StringAppendF(&debug_info, "version: prepare error %d\n", rc);
- }
- // Get all the SQL from sqlite_schema.
- debug_info += "schema:\n";
- static constexpr char kSchemaSql[] =
- "SELECT sql FROM sqlite_schema WHERE sql IS NOT NULL ORDER BY ROWID";
- rc = sqlite3_prepare_v3(db_, kSchemaSql, sizeof(kSchemaSql),
- SQLITE_PREPARE_NO_VTAB, &sqlite_statement,
- /* pzTail= */ nullptr);
- if (rc == SQLITE_OK) {
- while ((rc = sqlite3_step(sqlite_statement)) == SQLITE_ROW) {
- std::string text;
- base::StringAppendF(&text, "%s",
- sqlite3_column_text(sqlite_statement, 0));
- debug_info += text + "\n";
- if (diagnostics) {
- diagnostics->schema_sql_rows.push_back(text);
- }
- }
- if (rc != SQLITE_DONE)
- base::StringAppendF(&debug_info, "error %d\n", rc);
- sqlite3_finalize(sqlite_statement);
- } else {
- base::StringAppendF(&debug_info, "prepare error %d\n", rc);
- }
- // Automatically generated indices have a NULL 'sql' column. For those rows,
- // we log the name column instead.
- debug_info += "schema rows with only name:\n";
- static constexpr char kSchemaOtherRowNamesSql[] =
- "SELECT name FROM sqlite_schema WHERE sql IS NULL ORDER BY ROWID";
- rc = sqlite3_prepare_v3(db_, kSchemaOtherRowNamesSql,
- sizeof(kSchemaOtherRowNamesSql),
- SQLITE_PREPARE_NO_VTAB, &sqlite_statement,
- /* pzTail= */ nullptr);
- if (rc == SQLITE_OK) {
- while ((rc = sqlite3_step(sqlite_statement)) == SQLITE_ROW) {
- std::string text;
- base::StringAppendF(&text, "%s",
- sqlite3_column_text(sqlite_statement, 0));
- debug_info += text + "\n";
- if (diagnostics) {
- diagnostics->schema_other_row_names.push_back(text);
- }
- }
- if (rc != SQLITE_DONE)
- base::StringAppendF(&debug_info, "error %d\n", rc);
- sqlite3_finalize(sqlite_statement);
- } else {
- base::StringAppendF(&debug_info, "prepare error %d\n", rc);
- }
- }
- return debug_info;
- }
- // TODO(shess): Since this is only called in an error situation, it might be
- // prudent to rewrite in terms of SQLite API calls, and mark the function const.
- std::string Database::CollectCorruptionInfo() {
- TRACE_EVENT0("sql", "Database::CollectCorruptionInfo");
- // If the file cannot be accessed it is unlikely that an integrity check will
- // turn up actionable information.
- const base::FilePath db_path = DbPath();
- int64_t db_size = -1;
- if (!base::GetFileSize(db_path, &db_size) || db_size < 0)
- return std::string();
- // Buffer for accumulating debugging info about the error. Place
- // more-relevant information earlier, in case things overflow the
- // fixed-size reporting buffer.
- std::string debug_info;
- base::StringAppendF(&debug_info, "SQLITE_CORRUPT, db size %" PRId64 "\n",
- db_size);
- // Only check files up to 8M to keep things from blocking too long.
- const int64_t kMaxIntegrityCheckSize = 8192 * 1024;
- if (db_size > kMaxIntegrityCheckSize) {
- debug_info += "integrity_check skipped due to size\n";
- } else {
- std::vector<std::string> messages;
- // TODO(shess): FullIntegrityCheck() splits into a vector while this joins
- // into a string. Probably should be refactored.
- const base::TimeTicks before = base::TimeTicks::Now();
- FullIntegrityCheck(&messages);
- base::StringAppendF(
- &debug_info, "integrity_check %" PRId64 " ms, %" PRIuS " records:\n",
- (base::TimeTicks::Now() - before).InMilliseconds(), messages.size());
- // SQLite returns up to 100 messages by default, trim deeper to
- // keep close to the 2000-character size limit for dumping.
- const size_t kMaxMessages = 20;
- for (size_t i = 0; i < kMaxMessages && i < messages.size(); ++i) {
- base::StringAppendF(&debug_info, "%s\n", messages[i].c_str());
- }
- }
- return debug_info;
- }
- bool Database::GetMmapAltStatus(int64_t* status) {
- TRACE_EVENT0("sql", "Database::GetMmapAltStatus");
- // The [meta] version uses a missing table as a signal for a fresh database.
- // That will not work for the view, which would not exist in either a new or
- // an existing database. A new database _should_ be only one page long, so
- // just don't bother optimizing this case (start at offset 0).
- // TODO(shess): Could the [meta] case also get simpler, then?
- if (!DoesViewExist("MmapStatus")) {
- *status = 0;
- return true;
- }
- const char* kMmapStatusSql = "SELECT * FROM MmapStatus";
- Statement s(GetUniqueStatement(kMmapStatusSql));
- if (s.Step())
- *status = s.ColumnInt64(0);
- return s.Succeeded();
- }
- bool Database::SetMmapAltStatus(int64_t status) {
- if (!BeginTransaction())
- return false;
- // View may not exist on first run.
- if (!Execute("DROP VIEW IF EXISTS MmapStatus")) {
- RollbackTransaction();
- return false;
- }
- // Views live in the schema, so they cannot be parameterized. For an integer
- // value, this construct should be safe from SQL injection, if the value
- // becomes more complicated use "SELECT quote(?)" to generate a safe quoted
- // value.
- const std::string create_view_sql = base::StringPrintf(
- "CREATE VIEW MmapStatus (value) AS SELECT %" PRId64, status);
- if (!Execute(create_view_sql.c_str())) {
- RollbackTransaction();
- return false;
- }
- return CommitTransaction();
- }
- size_t Database::ComputeMmapSizeForOpen() {
- TRACE_EVENT0("sql", "Database::ComputeMmapSizeForOpen");
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- // How much to map if no errors are found. 50MB encompasses the 99th
- // percentile of Chrome databases in the wild, so this should be good.
- const size_t kMmapEverything = 256 * 1024 * 1024;
- // Progress information is tracked in the [meta] table for databases which use
- // sql::MetaTable, otherwise it is tracked in a special view.
- // TODO(pwnall): Migrate all databases to using a meta table.
- int64_t mmap_ofs = 0;
- if (options_.mmap_alt_status_discouraged) {
- if (!GetMmapAltStatus(&mmap_ofs))
- return 0;
- } else {
- // If [meta] doesn't exist, yet, it's a new database, assume the best.
- // sql::MetaTable::Init() will preload kMmapSuccess.
- if (!MetaTable::DoesTableExist(this))
- return kMmapEverything;
- if (!MetaTable::GetMmapStatus(this, &mmap_ofs))
- return 0;
- }
- // Database read failed in the past, don't memory map.
- if (mmap_ofs == MetaTable::kMmapFailure)
- return 0;
- if (mmap_ofs != MetaTable::kMmapSuccess) {
- // Continue reading from previous offset.
- DCHECK_GE(mmap_ofs, 0);
- // GetSqliteVfsFile() returns null for in-memory and temporary databases.
- // This is fine, we don't want to enable memory-mapping in those cases
- // anyway.
- //
- // First, memory-mapping is a no-op for in-memory databases.
- //
- // Second, temporary databases are only used for corruption recovery, which
- // occurs in response to I/O errors. An environment with heightened I/O
- // errors translates into a higher risk of mmap-induced Chrome crashes.
- sqlite3_int64 db_size = 0;
- sqlite3_file* file = GetSqliteVfsFile();
- if (!file || file->pMethods->xFileSize(file, &db_size) != SQLITE_OK)
- return 0;
- // Read more of the database looking for errors. The VFS interface is used
- // to assure that the reads are valid for SQLite. |g_reads_allowed| is used
- // to limit checking to 20MB per run of Chromium.
- //
- // Read the data left, or |g_reads_allowed|, whichever is smaller.
- // |g_reads_allowed| limits the total amount of I/O to spend verifying data
- // in a single Chromium run.
- sqlite3_int64 amount = db_size - mmap_ofs;
- if (amount < 0)
- amount = 0;
- if (amount > 0) {
- static base::NoDestructor<base::Lock> lock;
- base::AutoLock auto_lock(*lock);
- static sqlite3_int64 g_reads_allowed = 20 * 1024 * 1024;
- if (g_reads_allowed < amount)
- amount = g_reads_allowed;
- g_reads_allowed -= amount;
- }
- // |amount| can be <= 0 if |g_reads_allowed| ran out of quota, or if the
- // database was truncated after a previous pass.
- if (amount <= 0 && mmap_ofs < db_size) {
- DCHECK_EQ(0, amount);
- } else {
- static const int kPageSize = 4096;
- char buf[kPageSize];
- while (amount > 0) {
- int rc = file->pMethods->xRead(file, buf, sizeof(buf), mmap_ofs);
- if (rc == SQLITE_OK) {
- mmap_ofs += sizeof(buf);
- amount -= sizeof(buf);
- } else if (rc == SQLITE_IOERR_SHORT_READ) {
- // Reached EOF for a database with page size < |kPageSize|.
- mmap_ofs = db_size;
- break;
- } else {
- // TODO(shess): Consider calling OnSqliteError().
- mmap_ofs = MetaTable::kMmapFailure;
- break;
- }
- }
- // Log these events after update to distinguish meta update failure.
- if (mmap_ofs >= db_size) {
- mmap_ofs = MetaTable::kMmapSuccess;
- } else {
- DCHECK(mmap_ofs > 0 || mmap_ofs == MetaTable::kMmapFailure);
- }
- if (options_.mmap_alt_status_discouraged) {
- if (!SetMmapAltStatus(mmap_ofs))
- return 0;
- } else {
- if (!MetaTable::SetMmapStatus(this, mmap_ofs))
- return 0;
- }
- }
- }
- if (mmap_ofs == MetaTable::kMmapFailure)
- return 0;
- if (mmap_ofs == MetaTable::kMmapSuccess)
- return kMmapEverything;
- return mmap_ofs;
- }
- int Database::SqlitePrepareFlags() const {
- return options_.enable_virtual_tables_discouraged ? 0
- : SQLITE_PREPARE_NO_VTAB;
- }
- sqlite3_file* Database::GetSqliteVfsFile() {
- DCHECK(db_) << "Database not opened";
- // sqlite3_file_control() accepts a null pointer to mean the "main" database
- // attached to a connection. https://www.sqlite.org/c3ref/file_control.html
- constexpr const char* kMainDatabaseName = nullptr;
- sqlite3_file* result = nullptr;
- auto sqlite_result_code = ToSqliteResultCode(sqlite3_file_control(
- db_, kMainDatabaseName, SQLITE_FCNTL_FILE_POINTER, &result));
- // SQLITE_FCNTL_FILE_POINTER is handled directly by SQLite, not by the VFS. It
- // is only supposed to fail with SQLITE_ERROR if the database name is not
- // recognized. However, "main" should always be recognized.
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_file_control(SQLITE_FCNTL_FILE_POINTER) failed";
- // SQLite does not return null when called on an in-memory or temporary
- // database. Instead, it returns returns a VFS file object with a null
- // pMethods member.
- DCHECK(result)
- << "sqlite3_file_control() succeded but returned a null sqlite3_file*";
- if (!result->pMethods) {
- // If this assumption fails, sql::Database will still function correctly,
- // but will miss some configuration optimizations. The DCHECK is here to
- // alert us (via test failures and ASAN canary builds) of such cases.
- DCHECK_EQ(DbPath().AsUTF8Unsafe(), "")
- << "sqlite3_file_control() returned a sqlite3_file* with null pMethods "
- << "in a case when it shouldn't have.";
- return nullptr;
- }
- return result;
- }
- void Database::TrimMemory() {
- TRACE_EVENT0("sql", "Database::TrimMemory");
- if (!db_)
- return;
- // Passing the result code through ToSqliteResultCode() to catch issues such
- // as SQLITE_MISUSE.
- std::ignore = ToSqliteResultCode(sqlite3_db_release_memory(db_));
- // It is tempting to use sqlite3_release_memory() here as well. However, the
- // API is documented to be a no-op unless SQLite is built with
- // SQLITE_ENABLE_MEMORY_MANAGEMENT. We do not use this option, because it is
- // incompatible with per-database page cache pools. Behind the scenes,
- // SQLITE_ENABLE_MEMORY_MANAGEMENT causes SQLite to use a global page cache
- // pool, and sqlite3_release_memory() releases unused pages from this global
- // pool.
- #if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT)
- #error "This method assumes SQLITE_ENABLE_MEMORY_MANAGEMENT is not defined"
- #endif // defined(SQLITE_ENABLE_MEMORY_MANAGEMENT)
- }
- // Create an in-memory database with the existing database's page
- // size, then backup that database over the existing database.
- bool Database::Raze() {
- TRACE_EVENT0("sql", "Database::Raze");
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- if (!db_) {
- DCHECK(poisoned_) << "Cannot raze null db";
- return false;
- }
- DCHECK_GE(transaction_nesting_, 0);
- if (transaction_nesting_ > 0) {
- DLOG(DCHECK) << "Cannot raze within a transaction";
- return false;
- }
- sql::Database null_db(sql::DatabaseOptions{
- .exclusive_locking = true,
- .page_size = options_.page_size,
- .cache_size = 0,
- .enable_foreign_keys_discouraged =
- options_.enable_foreign_keys_discouraged,
- .enable_views_discouraged = options_.enable_views_discouraged,
- .enable_virtual_tables_discouraged =
- options_.enable_virtual_tables_discouraged,
- });
- if (!null_db.OpenInMemory()) {
- DLOG(DCHECK) << "Unable to open in-memory database.";
- return false;
- }
- #if BUILDFLAG(IS_ANDROID)
- // Android compiles with SQLITE_DEFAULT_AUTOVACUUM. Unfortunately,
- // in-memory databases do not respect this define.
- // TODO(shess): Figure out a way to set this without using platform
- // specific code. AFAICT from sqlite3.c, the only way to do it
- // would be to create an actual filesystem database, which is
- // unfortunate.
- if (!null_db.Execute("PRAGMA auto_vacuum = 1"))
- return false;
- #endif
- // The page size doesn't take effect until a database has pages, and
- // at this point the null database has none. Changing the schema
- // version will create the first page. This will not affect the
- // schema version in the resulting database, as SQLite's backup
- // implementation propagates the schema version from the original
- // database to the new version of the database, incremented by one
- // so that other readers see the schema change and act accordingly.
- if (!null_db.Execute("PRAGMA schema_version = 1"))
- return false;
- // SQLite tracks the expected number of database pages in the first
- // page, and if it does not match the total retrieved from a
- // filesystem call, treats the database as corrupt. This situation
- // breaks almost all SQLite calls. "PRAGMA writable_schema" can be
- // used to hint to SQLite to soldier on in that case, specifically
- // for purposes of recovery. [See SQLITE_CORRUPT_BKPT case in
- // sqlite3.c lockBtree().]
- // TODO(shess): With this, "PRAGMA auto_vacuum" and "PRAGMA
- // page_size" can be used to query such a database.
- ScopedWritableSchema writable_schema(db_);
- #if BUILDFLAG(IS_WIN)
- // On Windows, truncate silently fails when applied to memory-mapped files.
- // Disable memory-mapping so that the truncate succeeds. Note that other
- // Database connections may have memory-mapped the file, so this may not
- // entirely prevent the problem.
- // [Source: <https://sqlite.org/mmap.html> plus experiments.]
- std::ignore = Execute("PRAGMA mmap_size = 0");
- #endif
- SqliteResultCode sqlite_result_code = BackupDatabaseForRaze(null_db.db_, db_);
- // The destination database was locked.
- if (sqlite_result_code == SqliteResultCode::kBusy)
- return false;
- // SQLITE_NOTADB can happen if page 1 of db_ exists, but is not
- // formatted correctly. SQLITE_IOERR_SHORT_READ can happen if db_
- // isn't even big enough for one page. Either way, reach in and
- // truncate it before trying again.
- // TODO(shess): Maybe it would be worthwhile to just truncate from
- // the get-go?
- if (sqlite_result_code == SqliteResultCode::kNotADatabase ||
- sqlite_result_code == SqliteResultCode::kIoShortRead) {
- sqlite3_file* file = GetSqliteVfsFile();
- if (!file || file->pMethods->xTruncate(file, 0) != SQLITE_OK) {
- DLOG(DCHECK) << "Failed to truncate file.";
- return false;
- }
- sqlite_result_code = BackupDatabaseForRaze(null_db.db_, db_);
- if (sqlite_result_code != SqliteResultCode::kDone)
- return false;
- }
- // Page size of |db_| and |null_db| differ.
- if (sqlite_result_code == SqliteResultCode::kReadOnly) {
- // Enter TRUNCATE mode to change page size.
- // TODO(shuagga@microsoft.com): Need a guarantee here that there is no other
- // database connection open.
- std::ignore = Execute("PRAGMA journal_mode=TRUNCATE;");
- const std::string page_size_sql = base::StrCat(
- {"PRAGMA page_size=", base::NumberToString(options_.page_size)});
- if (!Execute(page_size_sql.c_str())) {
- return false;
- }
- // Page size isn't changed until the database is vacuumed.
- std::ignore = Execute("VACUUM");
- // Re-enter WAL mode.
- if (UseWALMode()) {
- std::ignore = Execute("PRAGMA journal_mode=WAL;");
- }
- sqlite_result_code = BackupDatabaseForRaze(null_db.db_, db_);
- if (sqlite_result_code != SqliteResultCode::kDone)
- return false;
- }
- if (sqlite_result_code != SqliteResultCode::kDone) {
- NOTIMPLEMENTED() << "Unhandled sqlite3_backup_step() error: "
- << sqlite_result_code;
- return false;
- }
- // Checkpoint to propagate transactions to the database file and empty the WAL
- // file.
- // The database can still contain old data if the Checkpoint fails so fail the
- // Raze.
- return CheckpointDatabase();
- }
- bool Database::RazeAndClose() {
- TRACE_EVENT0("sql", "Database::RazeAndClose");
- if (!db_) {
- DCHECK(poisoned_) << "Cannot raze null db";
- return false;
- }
- // Raze() cannot run in a transaction.
- RollbackAllTransactions();
- bool result = Raze();
- CloseInternal(true);
- // Mark the database so that future API calls fail appropriately,
- // but don't DCHECK (because after calling this function they are
- // expected to fail).
- poisoned_ = true;
- return result;
- }
- void Database::Poison() {
- TRACE_EVENT0("sql", "Database::Poison");
- if (!db_) {
- DCHECK(poisoned_) << "Cannot poison null db";
- return;
- }
- RollbackAllTransactions();
- CloseInternal(true);
- // Mark the database so that future API calls fail appropriately,
- // but don't DCHECK (because after calling this function they are
- // expected to fail).
- poisoned_ = true;
- }
- // TODO(shess): To the extent possible, figure out the optimal
- // ordering for these deletes which will prevent other Database connections
- // from seeing odd behavior. For instance, it may be necessary to
- // manually lock the main database file in a SQLite-compatible fashion
- // (to prevent other processes from opening it), then delete the
- // journal files, then delete the main database file. Another option
- // might be to lock the main database file and poison the header with
- // junk to prevent other processes from opening it successfully (like
- // Gears "SQLite poison 3" trick).
- //
- // static
- bool Database::Delete(const base::FilePath& path) {
- TRACE_EVENT1("sql", "Database::Delete", "path", path.MaybeAsASCII());
- base::ScopedBlockingCall scoped_blocking_call(FROM_HERE,
- base::BlockingType::MAY_BLOCK);
- base::FilePath journal_path = Database::JournalPath(path);
- base::FilePath wal_path = Database::WriteAheadLogPath(path);
- std::string journal_str = AsUTF8ForSQL(journal_path);
- std::string wal_str = AsUTF8ForSQL(wal_path);
- std::string path_str = AsUTF8ForSQL(path);
- EnsureSqliteInitialized();
- sqlite3_vfs* vfs = sqlite3_vfs_find(nullptr);
- CHECK(vfs);
- CHECK(vfs->xDelete);
- CHECK(vfs->xAccess);
- // We only work with the VFS implementations listed below. If you're trying to
- // use this code with any other VFS, you're not in a good place.
- CHECK(strncmp(vfs->zName, "unix", 4) == 0 ||
- strncmp(vfs->zName, "win32", 5) == 0 ||
- strcmp(vfs->zName, "storage_service") == 0);
- vfs->xDelete(vfs, journal_str.c_str(), 0);
- vfs->xDelete(vfs, wal_str.c_str(), 0);
- vfs->xDelete(vfs, path_str.c_str(), 0);
- int journal_exists = 0;
- vfs->xAccess(vfs, journal_str.c_str(), SQLITE_ACCESS_EXISTS, &journal_exists);
- int wal_exists = 0;
- vfs->xAccess(vfs, wal_str.c_str(), SQLITE_ACCESS_EXISTS, &wal_exists);
- int path_exists = 0;
- vfs->xAccess(vfs, path_str.c_str(), SQLITE_ACCESS_EXISTS, &path_exists);
- return !journal_exists && !wal_exists && !path_exists;
- }
- bool Database::BeginTransaction() {
- TRACE_EVENT0("sql", "Database::BeginTransaction");
- if (needs_rollback_) {
- DCHECK_GT(transaction_nesting_, 0);
- // When we're going to rollback, fail on this begin and don't actually
- // mark us as entering the nested transaction.
- return false;
- }
- bool success = true;
- DCHECK_GE(transaction_nesting_, 0);
- if (!transaction_nesting_) {
- needs_rollback_ = false;
- Statement begin(GetCachedStatement(SQL_FROM_HERE, "BEGIN TRANSACTION"));
- if (!begin.Run())
- return false;
- }
- ++transaction_nesting_;
- return success;
- }
- void Database::RollbackTransaction() {
- TRACE_EVENT0("sql", "Database::RollbackTransaction");
- DCHECK_GE(transaction_nesting_, 0);
- if (!transaction_nesting_) {
- DCHECK(poisoned_) << "Rolling back a nonexistent transaction";
- return;
- }
- DCHECK_GT(transaction_nesting_, 0);
- --transaction_nesting_;
- if (transaction_nesting_ > 0) {
- // Mark the outermost transaction as needing rollback.
- needs_rollback_ = true;
- return;
- }
- DoRollback();
- }
- bool Database::CommitTransaction() {
- TRACE_EVENT0("sql", "Database::CommitTransaction");
- DCHECK_GE(transaction_nesting_, 0);
- if (!transaction_nesting_) {
- DCHECK(poisoned_) << "Committing a nonexistent transaction";
- return false;
- }
- DCHECK_GT(transaction_nesting_, 0);
- --transaction_nesting_;
- if (transaction_nesting_ > 0) {
- // Mark any nested transactions as failing after we've already got one.
- return !needs_rollback_;
- }
- if (needs_rollback_) {
- DoRollback();
- return false;
- }
- Statement commit(GetCachedStatement(SQL_FROM_HERE, "COMMIT"));
- bool succeeded = commit.Run();
- // Release dirty cache pages after the transaction closes.
- ReleaseCacheMemoryIfNeeded(false);
- return succeeded;
- }
- void Database::RollbackAllTransactions() {
- TRACE_EVENT0("sql", "Database::RollbackAllTransactions");
- DCHECK_GE(transaction_nesting_, 0);
- if (transaction_nesting_ > 0) {
- transaction_nesting_ = 0;
- DoRollback();
- }
- }
- bool Database::AttachDatabase(const base::FilePath& other_db_path,
- base::StringPiece attachment_point,
- InternalApiToken) {
- TRACE_EVENT0("sql", "Database::AttachDatabase");
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- DCHECK(ValidAttachmentPoint(attachment_point));
- Statement statement(GetUniqueStatement("ATTACH ? AS ?"));
- #if OS_WIN
- statement.BindString16(0, base::AsStringPiece16(other_db_path.value()));
- #else
- statement.BindString(0, other_db_path.value());
- #endif
- statement.BindString(1, attachment_point);
- return statement.Run();
- }
- bool Database::DetachDatabase(base::StringPiece attachment_point,
- InternalApiToken) {
- TRACE_EVENT0("sql", "Database::DetachDatabase");
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- DCHECK(ValidAttachmentPoint(attachment_point));
- Statement statement(GetUniqueStatement("DETACH ?"));
- statement.BindString(0, attachment_point);
- return statement.Run();
- }
- // TODO(crbug.com/1230443): Change this to execute exactly one statement.
- SqliteResultCode Database::ExecuteAndReturnResultCode(const char* sql) {
- TRACE_EVENT0("sql", "Database::ExecuteAndReturnErrorCode");
- DCHECK(sql);
- if (!db_) {
- DCHECK(poisoned_) << "Illegal use of Database without a db";
- return SqliteResultCode::kError;
- }
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- SqliteResultCode sqlite_result_code = SqliteResultCode::kOk;
- while ((sqlite_result_code == SqliteResultCode::kOk) && *sql) {
- sqlite3_stmt* sqlite_statement;
- const char* leftover_sql;
- sqlite_result_code = ToSqliteResultCode(
- sqlite3_prepare_v3(db_, sql, /* nByte= */ -1, SqlitePrepareFlags(),
- &sqlite_statement, &leftover_sql));
- #if DCHECK_IS_ON()
- // Report SQL compilation errors. On developer machines, the errors are most
- // likely caused by invalid SQL in an under-development feature. In
- // production, SQL compilation errors are caused by database schema
- // corruption.
- //
- // DCHECK would not be appropriate here, because on-disk data is always
- // subject to corruption, so Chrome cannot assume that the database schema
- // will remain intact.
- if (sqlite_result_code == SqliteResultCode::kError) {
- DLOG(ERROR) << "SQL compilation error: " << GetErrorMessage()
- << ". Statement: " << sql;
- }
- #endif // DCHECK_IS_ON()
- // Stop if compiling the SQL statement fails.
- if (sqlite_result_code != SqliteResultCode::kOk) {
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kDone)
- << "sqlite3_prepare_v3() returned unexpected non-error result code";
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kRow)
- << "sqlite3_prepare_v3() returned unexpected non-error result code";
- break;
- }
- sql = leftover_sql;
- // This happens if |sql| originally only contained comments or whitespace.
- // TODO(shess): Audit to see if this can become a DCHECK(). Having
- // extraneous comments and whitespace in the SQL statements increases
- // runtime cost and can easily be shifted out to the C++ layer.
- if (!sqlite_statement)
- continue;
- while (true) {
- sqlite_result_code = ToSqliteResultCode(sqlite3_step(sqlite_statement));
- if (sqlite_result_code != SqliteResultCode::kRow)
- break;
- // TODO(shess): Audit to see if this can become a DCHECK. I think PRAGMA
- // is the only legitimate case for this. Previously recorded histograms
- // show significant use of this code path.
- }
- // sqlite3_finalize() returns SQLITE_OK if the most recent sqlite3_step()
- // returned SQLITE_DONE or SQLITE_ROW, otherwise the error code.
- sqlite_result_code = ToSqliteResultCode(sqlite3_finalize(sqlite_statement));
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kDone)
- << "sqlite3_finalize() returned unexpected non-error result code";
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kRow)
- << "sqlite3_finalize() returned unexpected non-error result code";
- // sqlite3_exec() does this, presumably to avoid spinning the parser for
- // trailing whitespace.
- // TODO(shess): Audit to see if this can become a DCHECK.
- while (base::IsAsciiWhitespace(*sql)) {
- sql++;
- }
- }
- // Most calls to Execute() modify the database. The main exceptions would be
- // calls such as CREATE TABLE IF NOT EXISTS which could modify the database
- // but sometimes don't.
- ReleaseCacheMemoryIfNeeded(true);
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kDone)
- << __func__ << " about to return unexpected non-error result code";
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kRow)
- << __func__ << " about to return unexpected non-error result code";
- return sqlite_result_code;
- }
- bool Database::Execute(const char* sql) {
- TRACE_EVENT1("sql", "Database::Execute", "query", TRACE_STR_COPY(sql));
- if (!db_) {
- DCHECK(poisoned_) << "Illegal use of Database without a db";
- return false;
- }
- SqliteResultCode sqlite_result_code = ExecuteAndReturnResultCode(sql);
- if (sqlite_result_code != SqliteResultCode::kOk)
- OnSqliteError(ToSqliteErrorCode(sqlite_result_code), nullptr, sql);
- return sqlite_result_code == SqliteResultCode::kOk;
- }
- bool Database::ExecuteWithTimeout(const char* sql, base::TimeDelta timeout) {
- TRACE_EVENT0("sql", "Database::ExecuteWithTimeout");
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- if (!db_) {
- DCHECK(poisoned_) << "Illegal use of Database without a db";
- return false;
- }
- ScopedBusyTimeout busy_timeout(db_);
- busy_timeout.SetTimeout(timeout);
- return Execute(sql);
- }
- bool Database::ExecuteScriptForTesting(const char* sql_script) {
- DCHECK(sql_script);
- if (!db_) {
- DCHECK(poisoned_) << "Illegal use of Database without a db";
- return false;
- }
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- while (*sql_script) {
- sqlite3_stmt* sqlite_statement;
- auto sqlite_result_code = ToSqliteResultCode(
- sqlite3_prepare_v3(db_, sql_script, /*nByte=*/-1, SqlitePrepareFlags(),
- &sqlite_statement, &sql_script));
- if (sqlite_result_code != SqliteResultCode::kOk)
- return false;
- if (!sqlite_statement) {
- // Trailing comment or whitespace after the last semicolon.
- return true;
- }
- // TODO(pwnall): Investigate restricting ExecuteScriptForTesting() to
- // statements that don't produce any result rows.
- do {
- sqlite_result_code = ToSqliteResultCode(sqlite3_step(sqlite_statement));
- } while (sqlite_result_code == SqliteResultCode::kRow);
- // sqlite3_finalize() returns SQLITE_OK if the most recent sqlite3_step()
- // returned SQLITE_DONE or SQLITE_ROW, otherwise the error code.
- sqlite_result_code = ToSqliteResultCode(sqlite3_finalize(sqlite_statement));
- if (sqlite_result_code != SqliteResultCode::kOk)
- return false;
- }
- return true;
- }
- scoped_refptr<Database::StatementRef> Database::GetCachedStatement(
- StatementID id,
- const char* sql) {
- auto it = statement_cache_.find(id);
- if (it != statement_cache_.end()) {
- // Statement is in the cache. It should still be valid. We're the only
- // entity invalidating cached statements, and we remove them from the cache
- // when we do that.
- DCHECK(it->second->is_valid());
- DCHECK_EQ(std::string(sqlite3_sql(it->second->stmt())), std::string(sql))
- << "GetCachedStatement used with same ID but different SQL";
- // Reset the statement so it can be reused.
- //
- // ToSqliteResultCode() is called to ensure that sqlite3_reset() doesn't
- // return a concerning code, such as SQLITE_MISUSE. The processed error code
- // is ignored because sqlite3_reset() returns an error code if the last
- // sqlite3_step() failed, and that error was already reported when we ran
- // sqlite3_step(), via Statement::Run() or Statement::Step().
- std::ignore = ToSqliteResultCode(sqlite3_reset(it->second->stmt()));
- return it->second;
- }
- scoped_refptr<StatementRef> statement = GetUniqueStatement(sql);
- if (statement->is_valid()) {
- statement_cache_[id] = statement; // Only cache valid statements.
- DCHECK_EQ(std::string(sqlite3_sql(statement->stmt())), std::string(sql))
- << "Input SQL does not match SQLite's normalized version";
- }
- return statement;
- }
- scoped_refptr<Database::StatementRef> Database::GetUniqueStatement(
- const char* sql) {
- return GetStatementImpl(sql, /*is_readonly=*/false);
- }
- scoped_refptr<Database::StatementRef> Database::GetReadonlyStatement(
- const char* sql) {
- return GetStatementImpl(sql, /*is_readonly=*/true);
- }
- scoped_refptr<Database::StatementRef> Database::GetStatementImpl(
- const char* sql,
- bool is_readonly) {
- DCHECK(sql);
- // Return inactive statement.
- if (!db_)
- return base::MakeRefCounted<StatementRef>(nullptr, nullptr, poisoned_);
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- #if DCHECK_IS_ON()
- const char* unused_sql = nullptr;
- const char** unused_sql_ptr = &unused_sql;
- #else
- constexpr const char** unused_sql_ptr = nullptr;
- #endif // DCHECK_IS_ON()
- // TODO(pwnall): Cached statements (but not unique statements) should be
- // prepared with prepFlags set to SQLITE_PREPARE_PERSISTENT.
- sqlite3_stmt* sqlite_statement;
- auto sqlite_result_code = ToSqliteResultCode(
- sqlite3_prepare_v3(db_, sql, /* nByte= */ -1, SqlitePrepareFlags(),
- &sqlite_statement, unused_sql_ptr));
- #if DCHECK_IS_ON()
- // Report SQL compilation errors. On developer machines, the errors are most
- // likely caused by invalid SQL in an under-development feature. In
- // production, SQL compilation errors are caused by database schema
- // corruption.
- //
- // DCHECK would not be appropriate here, because on-disk data is always
- // subject to corruption, so Chrome cannot assume that the database schema
- // will remain intact.
- if (sqlite_result_code == SqliteResultCode::kError) {
- DLOG(ERROR) << "SQL compilation error: " << GetErrorMessage()
- << ". Statement: " << sql;
- }
- #endif // DCHECK_IS_ON()
- if (sqlite_result_code != SqliteResultCode::kOk) {
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kDone)
- << "sqlite3_prepare_v3() returned unexpected non-error result code";
- DCHECK_NE(sqlite_result_code, SqliteResultCode::kRow)
- << "sqlite3_prepare_v3() returned unexpected non-error result code";
- OnSqliteError(ToSqliteErrorCode(sqlite_result_code), nullptr, sql);
- return base::MakeRefCounted<StatementRef>(nullptr, nullptr, false);
- }
- // If readonly statement is expected and the statement is not readonly, return
- // an invalid statement and close the created statement.
- if (is_readonly && sqlite3_stmt_readonly(sqlite_statement) == 0) {
- DLOG(ERROR) << "Readonly SQL statement failed readonly test " << sql;
- // Make a `StatementRef` that will close the created statement.
- base::MakeRefCounted<StatementRef>(this, sqlite_statement, true);
- return base::MakeRefCounted<StatementRef>(nullptr, nullptr, false);
- }
- #if DCHECK_IS_ON()
- DCHECK_EQ(unused_sql, sql + strlen(sql))
- << "Unused text: " << std::string(unused_sql) << "\n"
- << "in prepared SQL statement: " << std::string(sql);
- #endif // DCHECK_IS_ON()
- DCHECK(sqlite_statement) << "No SQL statement in string: " << sql;
- return base::MakeRefCounted<StatementRef>(this, sqlite_statement, true);
- }
- std::string Database::GetSchema() {
- // The ORDER BY should not be necessary, but relying on organic
- // order for something like this is questionable.
- static const char kSql[] =
- "SELECT type, name, tbl_name, sql "
- "FROM sqlite_schema ORDER BY 1, 2, 3, 4";
- Statement statement(GetUniqueStatement(kSql));
- std::string schema;
- while (statement.Step()) {
- schema += statement.ColumnString(0);
- schema += '|';
- schema += statement.ColumnString(1);
- schema += '|';
- schema += statement.ColumnString(2);
- schema += '|';
- schema += statement.ColumnString(3);
- schema += '\n';
- }
- return schema;
- }
- bool Database::IsSQLValid(const char* sql) {
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- if (!db_) {
- DCHECK(poisoned_) << "Illegal use of Database without a db";
- return false;
- }
- #if DCHECK_IS_ON()
- const char* unused_sql = nullptr;
- const char** unused_sql_ptr = &unused_sql;
- #else
- constexpr const char** unused_sql_ptr = nullptr;
- #endif // DCHECK_IS_ON()
- sqlite3_stmt* sqlite_statement = nullptr;
- auto sqlite_result_code = ToSqliteResultCode(
- sqlite3_prepare_v3(db_, sql, /* nByte= */ -1, SqlitePrepareFlags(),
- &sqlite_statement, unused_sql_ptr));
- if (sqlite_result_code != SqliteResultCode::kOk)
- return false;
- #if DCHECK_IS_ON()
- DCHECK_EQ(unused_sql, sql + strlen(sql))
- << "Unused text: " << std::string(unused_sql) << "\n"
- << "in SQL statement: " << std::string(sql);
- #endif // DCHECK_IS_ON()
- DCHECK(sqlite_statement) << "No SQL statement in string: " << sql;
- sqlite_result_code = ToSqliteResultCode(sqlite3_finalize(sqlite_statement));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_finalize() failed for valid statement";
- return true;
- }
- bool Database::DoesIndexExist(base::StringPiece index_name) {
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- return DoesSchemaItemExist(index_name, "index");
- }
- bool Database::DoesTableExist(base::StringPiece table_name) {
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- return DoesSchemaItemExist(table_name, "table");
- }
- bool Database::DoesViewExist(base::StringPiece view_name) {
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- return DoesSchemaItemExist(view_name, "view");
- }
- bool Database::DoesSchemaItemExist(base::StringPiece name,
- base::StringPiece type) {
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- static const char kSql[] =
- "SELECT 1 FROM sqlite_schema WHERE type=? AND name=?";
- Statement statement(GetUniqueStatement(kSql));
- if (!statement.is_valid()) {
- // The database is corrupt.
- return false;
- }
- statement.BindString(0, type);
- statement.BindString(1, name);
- return statement.Step(); // Table exists if any row was returned.
- }
- bool Database::DoesColumnExist(const char* table_name,
- const char* column_name) {
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- // sqlite3_table_column_metadata uses out-params to return column definition
- // details, such as the column type and whether it allows NULL values. These
- // aren't needed to compute the current method's result, so we pass in nullptr
- // for all the out-params.
- auto sqlite_result_code = ToSqliteResultCode(sqlite3_table_column_metadata(
- db_, "main", table_name, column_name, /* pzDataType= */ nullptr,
- /* pzCollSeq= */ nullptr, /* pNotNull= */ nullptr,
- /* pPrimaryKey= */ nullptr, /* pAutoinc= */ nullptr));
- return sqlite_result_code == SqliteResultCode::kOk;
- }
- int64_t Database::GetLastInsertRowId() const {
- if (!db_) {
- DCHECK(poisoned_) << "Illegal use of Database without a db";
- return 0;
- }
- int64_t last_rowid = sqlite3_last_insert_rowid(db_);
- DCHECK(last_rowid != 0) << "No successful INSERT in a table with ROWID";
- return last_rowid;
- }
- int64_t Database::GetLastChangeCount() {
- if (!db_) {
- DCHECK(poisoned_) << "Illegal use of Database without a db";
- return 0;
- }
- return sqlite3_changes64(db_);
- }
- int Database::GetMemoryUsage() {
- if (!db_) {
- DCHECK(poisoned_) << "Illegal use of Database without a db";
- return 0;
- }
- // The following calls all set the high watermark to zero.
- // See https://www.sqlite.org/c3ref/c_dbstatus_options.html
- int high_watermark = 0;
- int cache_memory = 0, schema_memory = 0, statement_memory = 0;
- auto sqlite_result_code = ToSqliteResultCode(sqlite3_db_status(
- db_, SQLITE_DBSTATUS_CACHE_USED, &cache_memory, &high_watermark,
- /*resetFlg=*/0));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_db_status(SQLITE_DBSTATUS_CACHE_USED) failed";
- #if DCHECK_IS_ON()
- int shared_cache_memory = 0;
- sqlite_result_code = ToSqliteResultCode(
- sqlite3_db_status(db_, SQLITE_DBSTATUS_CACHE_USED_SHARED,
- &shared_cache_memory, &high_watermark, /*resetFlg=*/0));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_db_status(SQLITE_DBSTATUS_CACHE_USED_SHARED) failed";
- DCHECK_EQ(shared_cache_memory, cache_memory)
- << "Memory counting assumes that each database uses a private page cache";
- #endif // DCHECK_IS_ON()
- sqlite_result_code = ToSqliteResultCode(sqlite3_db_status(
- db_, SQLITE_DBSTATUS_SCHEMA_USED, &schema_memory, &high_watermark,
- /*resetFlg=*/0));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_db_status(SQLITE_DBSTATUS_SCHEMA_USED) failed";
- sqlite_result_code = ToSqliteResultCode(sqlite3_db_status(
- db_, SQLITE_DBSTATUS_STMT_USED, &statement_memory, &high_watermark,
- /*resetFlg=*/0));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_db_status(SQLITE_DBSTATUS_STMT_USED) failed";
- return cache_memory + schema_memory + statement_memory;
- }
- int Database::GetErrorCode() const {
- if (!db_)
- return SQLITE_ERROR;
- return sqlite3_extended_errcode(db_);
- }
- int Database::GetLastErrno() const {
- if (!db_)
- return -1;
- int err = 0;
- if (SQLITE_OK != sqlite3_file_control(db_, nullptr, SQLITE_LAST_ERRNO, &err))
- return -2;
- return err;
- }
- const char* Database::GetErrorMessage() const {
- if (!db_)
- return "sql::Database is not opened.";
- return sqlite3_errmsg(db_);
- }
- bool Database::OpenInternal(const std::string& db_file_path,
- Database::OpenMode mode) {
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- TRACE_EVENT1("sql", "Database::OpenInternal", "path", db_file_path);
- DCHECK(mode != OpenMode::kTemporary || db_file_path.empty())
- << "Temporary databases should be open with an empty file path";
- if (mode == OpenMode::kInMemory) {
- DCHECK_EQ(db_file_path, kSqliteOpenInMemoryPath)
- << "In-memory databases should be open with the magic :memory: path";
- } else {
- DCHECK_NE(db_file_path, kSqliteOpenInMemoryPath)
- << "Database file path conflicts with SQLite magic identifier";
- }
- if (db_) {
- DLOG(DCHECK) << "sql::Database is already open.";
- return false;
- }
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- EnsureSqliteInitialized();
- // If |poisoned_| is set, it means an error handler called
- // RazeAndClose(). Until regular Close() is called, the caller
- // should be treating the database as open, but is_open() currently
- // only considers the sqlite3 handle's state.
- // TODO(shess): Revise is_open() to consider poisoned_, and review
- // to see if any non-testing code even depends on it.
- DCHECK(!poisoned_) << "sql::Database is already open.";
- poisoned_ = false;
- // Custom memory-mapping VFS which reads pages using regular I/O on first hit.
- sqlite3_vfs* vfs = VFSWrapper();
- const char* vfs_name = (vfs ? vfs->zName : nullptr);
- // The flags are documented at https://www.sqlite.org/c3ref/open.html.
- //
- // Chrome uses SQLITE_OPEN_PRIVATECACHE because SQLite is used by many
- // disparate features with their own databases, and having separate page
- // caches makes it easier to reason about each feature's performance in
- // isolation.
- //
- // SQLITE_OPEN_EXRESCODE enables the full range of SQLite error codes. See
- // https://www.sqlite.org/rescode.html for details.
- int open_flags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
- SQLITE_OPEN_EXRESCODE | SQLITE_OPEN_PRIVATECACHE;
- auto sqlite_result_code = ToSqliteResultCode(
- sqlite3_open_v2(db_file_path.c_str(), &db_, open_flags, vfs_name));
- if (sqlite_result_code != SqliteResultCode::kOk) {
- OnSqliteError(ToSqliteErrorCode(sqlite_result_code), nullptr,
- "-- sqlite3_open_v2()");
- bool was_poisoned = poisoned_;
- Close();
- if (was_poisoned && mode == OpenMode::kRetryOnPoision)
- return OpenInternal(db_file_path, OpenMode::kNone);
- return false;
- }
- ConfigureSqliteDatabaseObject();
- // If indicated, enable shared mode ("NORMAL") on the database, so it can be
- // opened by multiple processes. This needs to happen before WAL mode is
- // enabled.
- //
- // TODO(crbug.com/1120969): Remove support for non-exclusive mode.
- static_assert(
- SQLITE_DEFAULT_LOCKING_MODE == 1,
- "Chrome assumes SQLite is configured to default to EXCLUSIVE locking");
- if (!options_.exclusive_locking) {
- if (!Execute("PRAGMA locking_mode=NORMAL"))
- return false;
- }
- // The sqlite3_open*() methods only perform I/O on the database file if a hot
- // journal is found. Force SQLite to parse the header and database schema, so
- // we can signal irrecoverable corruption early.
- //
- // sqlite3_table_column_metadata() causes SQLite to parse the database schema.
- // Since the schema is stored inside a table B-tree, parsing the schema
- // implies parsing the database header.
- //
- // sqlite3_table_column_metadata() can be used with a null database name, but
- // that will cause it to search for the table in all databases that are
- // ATTACHed to the connection. While Chrome features (almost) never use
- // ATTACHed databases, we prefer to be explicit here.
- //
- // sqlite3_table_column_metadata() can be used with a null column name, and
- // will report on the existence of the table with the given name. This is
- // sufficient for the purpose of getting SQLite to parse the database schema.
- // See https://www.sqlite.org/c3ref/table_column_metadata.html for details.
- static constexpr char kSqliteSchemaTable[] = "sqlite_schema";
- sqlite_result_code = ToSqliteResultCode(sqlite3_table_column_metadata(
- db_, kSqliteMainDatabaseName, kSqliteSchemaTable, /*zColumnName=*/nullptr,
- /*pzDataType=*/nullptr, /*pzCollSeq=*/nullptr, /*pNotNull=*/nullptr,
- /*pPrimaryKey=*/nullptr, /*pAutoinc=*/nullptr));
- if (sqlite_result_code != SqliteResultCode::kOk) {
- OnSqliteError(ToSqliteErrorCode(sqlite_result_code), nullptr,
- "-- sqlite3_table_column_metadata()");
- // Retry or bail out if the error handler poisoned the handle.
- // TODO(shess): Move this handling to one place (see also sqlite3_open).
- // Possibly a wrapper function?
- if (poisoned_) {
- Close();
- if (mode == OpenMode::kRetryOnPoision)
- return OpenInternal(db_file_path, OpenMode::kNone);
- return false;
- }
- }
- const base::TimeDelta kBusyTimeout = base::Seconds(kBusyTimeoutSeconds);
- // Needs to happen before entering WAL mode. Will only work if this the first
- // time the database is being opened in WAL mode.
- const std::string page_size_sql =
- base::StringPrintf("PRAGMA page_size=%d", options_.page_size);
- std::ignore = ExecuteWithTimeout(page_size_sql.c_str(), kBusyTimeout);
- // http://www.sqlite.org/pragma.html#pragma_journal_mode
- // WAL - Use a write-ahead log instead of a journal file.
- // DELETE (default) - delete -journal file to commit.
- // TRUNCATE - truncate -journal file to commit.
- // PERSIST - zero out header of -journal file to commit.
- // TRUNCATE should be faster than DELETE because it won't need directory
- // changes for each transaction. PERSIST may break the spirit of using
- // secure_delete.
- //
- // Needs to be performed after setting exclusive locking mode. Otherwise can
- // fail if underlying VFS doesn't support shared memory.
- if (UseWALMode()) {
- // Set the synchronous flag to NORMAL. This means that writers don't flush
- // the WAL file after every write. The WAL file is only flushed on a
- // checkpoint. In this case, transcations might lose durability on a power
- // loss (but still durable after an application crash).
- // TODO(shuagga@microsoft.com): Evaluate if this loss of durability is a
- // concern.
- std::ignore = Execute("PRAGMA synchronous=NORMAL");
- // Opening the db in WAL mode can fail (eg if the underlying VFS doesn't
- // support shared memory and we are not in exclusive locking mode).
- //
- // TODO(shuagga@microsoft.com): We should probably catch a failure here.
- std::ignore = Execute("PRAGMA journal_mode=WAL");
- } else {
- std::ignore = Execute("PRAGMA journal_mode=TRUNCATE");
- }
- if (options_.flush_to_media)
- std::ignore = Execute("PRAGMA fullfsync=1");
- if (options_.cache_size != 0) {
- const std::string cache_size_sql = base::StrCat(
- {"PRAGMA cache_size=", base::NumberToString(options_.cache_size)});
- std::ignore = ExecuteWithTimeout(cache_size_sql.c_str(), kBusyTimeout);
- }
- static_assert(SQLITE_SECURE_DELETE == 1,
- "Chrome assumes secure_delete is on by default.");
- // When SQLite needs to grow a database file, it uses a configurable
- // increment. Larger values reduce filesystem fragmentation and mmap()
- // churn, as the database file is grown less often. Smaller values waste
- // less disk space.
- //
- // We currently set different values for small vs large files.
- //
- // TODO(crbug.com/1305778): Replace file size-based heuristic with a
- // DatabaseOptions member. Use the DatabaseOptions value for temporary
- // databases as well.
- sqlite3_file* file = GetSqliteVfsFile();
- // GetSqliteVfsFile() returns null for in-memory and temporary databases. This
- // is fine, because these databases start out empty, so the heuristic below
- // would never set a chunk size on them anyway.
- if (file) {
- sqlite3_int64 db_size = 0;
- sqlite_result_code =
- ToSqliteResultCode(file->pMethods->xFileSize(file, &db_size));
- if (sqlite_result_code == SqliteResultCode::kOk && db_size > 16 * 1024) {
- int chunk_size = 4 * 1024;
- if (db_size > 128 * 1024)
- chunk_size = 32 * 1024;
- sqlite3_file_control(db_, /*zDbName=*/nullptr, SQLITE_FCNTL_CHUNK_SIZE,
- &chunk_size);
- }
- }
- size_t mmap_size = mmap_disabled_ ? 0 : ComputeMmapSizeForOpen();
- // We explicitly issue a "PRGAMA mmap_size=0" to disable memory-mapping. We
- // could skip executing the PRAGMA in that case, and use a static_assert to
- // ensure that SQLITE_DEFAULT_MMAP_SIZE > 0. We didn't choose this alternative
- // because would cost us a bit more logic, and the optimization would apply to
- // edge cases, such as in-memory databases. More details at
- // https://www.sqlite.org/pragma.html#pragma_mmap_size.
- std::string pragma_mmap_size_sql =
- base::StrCat({"PRAGMA mmap_size=", base::NumberToString(mmap_size)});
- std::ignore = Execute(pragma_mmap_size_sql.c_str());
- // Determine if memory-mapping has actually been enabled. The Execute() above
- // can succeed without changing the amount mapped.
- mmap_enabled_ = false;
- {
- Statement pragma_mmap_size(GetUniqueStatement("PRAGMA mmap_size"));
- if (pragma_mmap_size.Step() && pragma_mmap_size.ColumnInt64(0) > 0)
- mmap_enabled_ = true;
- }
- DCHECK(!memory_dump_provider_);
- memory_dump_provider_ =
- std::make_unique<DatabaseMemoryDumpProvider>(db_, histogram_tag_);
- base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
- memory_dump_provider_.get(), "sql::Database", /*task_runner=*/nullptr);
- return true;
- }
- void Database::ConfigureSqliteDatabaseObject() {
- // The use of SQLite's non-standard string quoting is not allowed in Chrome.
- //
- // Allowing double-quoted string literals is now considered a misfeature by
- // SQLite authors. See https://www.sqlite.org/quirks.html#dblquote
- auto sqlite_result_code = ToSqliteResultCode(
- sqlite3_db_config(db_, SQLITE_DBCONFIG_DQS_DDL, 0, nullptr));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_db_config(SQLITE_DBCONFIG_DQS_DDL) should not fail";
- sqlite_result_code = ToSqliteResultCode(
- sqlite3_db_config(db_, SQLITE_DBCONFIG_DQS_DML, 0, nullptr));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_db_config(SQLITE_DBCONFIG_DQS_DML) should not fail";
- sqlite_result_code = ToSqliteResultCode(sqlite3_db_config(
- db_, SQLITE_DBCONFIG_ENABLE_FKEY,
- options_.enable_foreign_keys_discouraged ? 1 : 0, nullptr));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_db_config(SQLITE_DBCONFIG_ENABLE_FKEY) should not fail";
- // The use of triggers is discouraged for Chrome code. Thanks to this
- // configuration change, triggers are not executed. CREATE TRIGGER and DROP
- // TRIGGER still succeed.
- sqlite_result_code = ToSqliteResultCode(
- sqlite3_db_config(db_, SQLITE_DBCONFIG_ENABLE_TRIGGER, 0, nullptr));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_db_config() should not fail";
- sqlite_result_code = ToSqliteResultCode(
- sqlite3_db_config(db_, SQLITE_DBCONFIG_ENABLE_VIEW,
- options_.enable_views_discouraged ? 1 : 0, nullptr));
- DCHECK_EQ(sqlite_result_code, SqliteResultCode::kOk)
- << "sqlite3_db_config() should not fail";
- }
- void Database::DoRollback() {
- TRACE_EVENT0("sql", "Database::DoRollback");
- Statement rollback(GetCachedStatement(SQL_FROM_HERE, "ROLLBACK"));
- rollback.Run();
- // The cache may have been accumulating dirty pages for commit. Note that in
- // some cases sql::Transaction can fire rollback after a database is closed.
- if (is_open())
- ReleaseCacheMemoryIfNeeded(false);
- needs_rollback_ = false;
- }
- void Database::StatementRefCreated(StatementRef* ref) {
- DCHECK(!open_statements_.count(ref))
- << __func__ << " already called with this statement";
- open_statements_.insert(ref);
- }
- void Database::StatementRefDeleted(StatementRef* ref) {
- DCHECK(open_statements_.count(ref))
- << __func__ << " called with non-existing statement";
- open_statements_.erase(ref);
- }
- void Database::set_histogram_tag(const std::string& tag) {
- DCHECK(!is_open());
- histogram_tag_ = tag;
- }
- void Database::OnSqliteError(SqliteErrorCode sqlite_error_code,
- sql::Statement* statement,
- const char* sql_statement) {
- TRACE_EVENT0("sql", "Database::OnSqliteError");
- DCHECK_NE(statement != nullptr, sql_statement != nullptr)
- << __func__ << " should either get a Statement or a raw SQL string";
- // Log errors for developers.
- //
- // This block is wrapped around a DCHECK_IS_ON() check so we don't waste CPU
- // cycles computing the strings that make up the log message in production.
- #if DCHECK_IS_ON()
- std::string logged_statement;
- if (statement) {
- logged_statement = statement->GetSQLStatement();
- } else {
- logged_statement = sql_statement;
- }
- std::string database_id = histogram_tag_;
- if (database_id.empty())
- database_id = DbPath().BaseName().AsUTF8Unsafe();
- // This logging block cannot be a DCHECK, because valid usage of sql::Database
- // can still encounter SQLite errors in production. For example, valid SQL
- // statements can fail when a database is corrupted.
- //
- // This logging block should not use LOG(ERROR) because many features built on
- // top of sql::Database can recover from most errors.
- DVLOG(1) << "SQLite error! This may indicate a programming error!\n"
- << "Database: " << database_id
- << " sqlite_error_code: " << sqlite_error_code
- << " errno: " << GetLastErrno()
- << "\nSQLite error description: " << GetErrorMessage()
- << "\nSQL statement: " << logged_statement;
- #endif // DCHECK_IS_ON()
- // Inform the error expecter that we've encountered the error.
- std::ignore = IsExpectedSqliteError(static_cast<int>(sqlite_error_code));
- if (!error_callback_.is_null()) {
- // Create an additional reference to the state in `error_callback_`, so the
- // state doesn't go away if the callback changes `error_callback_` by
- // calling set_error_callback() or reset_error_callback(). This avoids a
- // subtle source of use-after-frees. See https://crbug.com/254584.
- ErrorCallback error_callback_copy = error_callback_;
- error_callback_copy.Run(static_cast<int>(sqlite_error_code), statement);
- return;
- }
- }
- std::string Database::GetDiagnosticInfo(int sqlite_error_code,
- Statement* statement,
- DatabaseDiagnostics* diagnostics) {
- DCHECK_NE(sqlite_error_code, SQLITE_OK)
- << __func__ << " received non-error result code";
- DCHECK_NE(sqlite_error_code, SQLITE_DONE)
- << __func__ << " received non-error result code";
- DCHECK_NE(sqlite_error_code, SQLITE_ROW)
- << __func__ << " received non-error result code";
- // Prevent reentrant calls to the error callback.
- ErrorCallback original_callback = std::move(error_callback_);
- error_callback_.Reset();
- if (diagnostics) {
- diagnostics->reported_sqlite_error_code = sqlite_error_code;
- }
- // Trim extended error codes.
- const int primary_error_code = sqlite_error_code & 0xff;
- // CollectCorruptionInfo() is implemented in terms of sql::Database,
- // TODO(shess): Rewrite IntegrityCheckHelper() in terms of raw SQLite.
- std::string result =
- (primary_error_code == SQLITE_CORRUPT)
- ? CollectCorruptionInfo()
- : CollectErrorInfo(sqlite_error_code, statement, diagnostics);
- // The following queries must be executed after CollectErrorInfo() above, so
- // if they result in their own errors, they don't interfere with
- // CollectErrorInfo().
- const bool has_valid_header = Execute("PRAGMA auto_vacuum");
- const bool has_valid_schema = Execute("SELECT COUNT(*) FROM sqlite_schema");
- // Restore the original error callback.
- error_callback_ = std::move(original_callback);
- base::StringAppendF(&result, "Has valid header: %s\n",
- (has_valid_header ? "Yes" : "No"));
- base::StringAppendF(&result, "Has valid schema: %s\n",
- (has_valid_schema ? "Yes" : "No"));
- if (diagnostics) {
- diagnostics->has_valid_header = has_valid_header;
- diagnostics->has_valid_schema = has_valid_schema;
- }
- return result;
- }
- bool Database::FullIntegrityCheck(std::vector<std::string>* messages) {
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- messages->clear();
- // The PRAGMA below has the side effect of setting SQLITE_RecoveryMode, which
- // allows SQLite to process through certain cases of corruption.
- if (!Execute("PRAGMA writable_schema=ON")) {
- // The "PRAGMA integrity_check" statement executed below may return less
- // useful information. However, incomplete information is still better than
- // nothing, so we press on.
- messages->push_back("PRAGMA writable_schema=ON failed");
- }
- // We need to bypass sql::Statement and use raw SQLite C API calls here.
- //
- // "PRAGMA integrity_check" reports SQLITE_CORRUPT when the database is
- // corrupt. Reporting SQLITE_CORRUPT is undesirable in this case, because it
- // causes our sql::Statement infrastructure to call the database error
- // handler, which triggers feature-level error handling. However,
- // FullIntegrityCheck() callers presumably already know that the database is
- // corrupted, and are trying to collect diagnostic information for reporting.
- sqlite3_stmt* statement = nullptr;
- // https://www.sqlite.org/c3ref/prepare.html states that SQLite will perform
- // slightly better if sqlite_prepare_v3() receives a zero-terminated statement
- // string, and a statement size that includes the zero byte. Fortunately,
- // C++'s string literal and sizeof() operator do exactly that.
- constexpr char kIntegrityCheckSql[] = "PRAGMA integrity_check";
- const auto prepare_result_code = ToSqliteResultCode(
- sqlite3_prepare_v3(db_, kIntegrityCheckSql, sizeof(kIntegrityCheckSql),
- SqlitePrepareFlags(), &statement, /*pzTail=*/nullptr));
- if (prepare_result_code != SqliteResultCode::kOk)
- return false;
- // "PRAGMA integrity_check" currently returns multiple lines as a single row.
- //
- // However, since https://www.sqlite.org/pragma.html#pragma_integrity_check
- // states that multiple records may be returned, the code below can handle
- // multiple records, each of which has multiple lines.
- std::vector<std::string> result_lines;
- while (ToSqliteResultCode(sqlite3_step(statement)) ==
- SqliteResultCode::kRow) {
- const uint8_t* row = chrome_sqlite3_column_text(statement, /*iCol=*/0);
- DCHECK(row) << "PRAGMA integrity_check should never return NULL rows";
- const int row_size = sqlite3_column_bytes(statement, /*iCol=*/0);
- base::StringPiece row_string(reinterpret_cast<const char*>(row), row_size);
- const std::vector<base::StringPiece> row_lines = base::SplitStringPiece(
- row_string, "\n", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
- for (base::StringPiece row_line : row_lines)
- result_lines.emplace_back(row_line);
- }
- const auto finalize_result_code =
- ToSqliteResultCode(sqlite3_finalize(statement));
- // sqlite3_finalize() may return SQLITE_CORRUPT when the integrity check
- // discovers any problems. We still consider this case a success, as long as
- // the statement produced at least one diagnostic message.
- const bool success = (result_lines.size() > 0) ||
- (finalize_result_code == SqliteResultCode::kOk);
- *messages = std::move(result_lines);
- // Best-effort attempt to undo the "PRAGMA writable_schema=ON" executed above.
- std::ignore = Execute("PRAGMA writable_schema=OFF");
- return success;
- }
- bool Database::ReportMemoryUsage(base::trace_event::ProcessMemoryDump* pmd,
- const std::string& dump_name) {
- return memory_dump_provider_ &&
- memory_dump_provider_->ReportMemoryUsage(pmd, dump_name);
- }
- bool Database::UseWALMode() const {
- #if BUILDFLAG(IS_FUCHSIA)
- // WAL mode is only enabled on Fuchsia for databases with exclusive
- // locking, because this case does not require shared memory support.
- // At the time this was implemented (May 2020), Fuchsia's shared
- // memory support was insufficient for SQLite's needs.
- return options_.wal_mode && options_.exclusive_locking;
- #else
- return options_.wal_mode;
- #endif // BUILDFLAG(IS_FUCHSIA)
- }
- bool Database::CheckpointDatabase() {
- DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
- absl::optional<base::ScopedBlockingCall> scoped_blocking_call;
- InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call);
- auto sqlite_result_code = ToSqliteResultCode(sqlite3_wal_checkpoint_v2(
- db_, kSqliteMainDatabaseName, SQLITE_CHECKPOINT_PASSIVE,
- /*pnLog=*/nullptr, /*pnCkpt=*/nullptr));
- return sqlite_result_code == SqliteResultCode::kOk;
- }
- } // namespace sql
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