| // 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 "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/metrics/histogram_functions.h" |
| #include "base/metrics/histogram_macros.h" |
| #include "base/metrics/sparse_histogram.h" |
| #include "base/no_destructor.h" |
| #include "base/numerics/safe_conversions.h" |
| #include "base/single_thread_task_runner.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/threading/scoped_blocking_call.h" |
| #include "base/trace_event/memory_dump_manager.h" |
| #include "base/trace_event/trace_event.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/statement.h" |
| #include "sql/vfs_wrapper.h" |
| #include "third_party/sqlite/sqlite3.h" |
| |
| namespace { |
| |
| // 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: |
| 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_master 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: |
| sqlite3* db_; |
| }; |
| |
| // Helper to wrap the sqlite3_backup_*() step of Raze(). Return |
| // SQLite error code from running the backup step. |
| int BackupDatabase(sqlite3* src, sqlite3* dst, const char* db_name) { |
| DCHECK_NE(src, dst); |
| sqlite3_backup* backup = sqlite3_backup_init(dst, db_name, src, db_name); |
| if (!backup) { |
| // Since this call only sets things up, this indicates a gross |
| // error in SQLite. |
| DLOG(DCHECK) << "Unable to start sqlite3_backup(): " << sqlite3_errmsg(dst); |
| return sqlite3_errcode(dst); |
| } |
| |
| // -1 backs up the entire database. |
| int rc = sqlite3_backup_step(backup, -1); |
| int pages = sqlite3_backup_pagecount(backup); |
| sqlite3_backup_finish(backup); |
| |
| // If successful, exactly one page should have been backed up. If |
| // this breaks, check this function to make sure assumptions aren't |
| // being broken. |
| if (rc == SQLITE_DONE) |
| DCHECK_EQ(pages, 1); |
| |
| return rc; |
| } |
| |
| // Be very strict on attachment point. SQLite can handle a much wider |
| // character set with appropriate quoting, but Chromium code should |
| // just use clean names to start with. |
| bool ValidAttachmentPoint(const char* attachment_point) { |
| for (size_t i = 0; attachment_point[i]; ++i) { |
| if (!(base::IsAsciiDigit(attachment_point[i]) || |
| base::IsAsciiAlpha(attachment_point[i]) || |
| attachment_point[i] == '_')) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| // Helper to get the sqlite3_file* associated with the "main" database. |
| int GetSqlite3File(sqlite3* db, sqlite3_file** file) { |
| *file = nullptr; |
| int rc = sqlite3_file_control(db, nullptr, SQLITE_FCNTL_FILE_POINTER, file); |
| if (rc != SQLITE_OK) |
| return rc; |
| |
| // TODO(shess): null in file->pMethods has been observed on android_dbg |
| // content_unittests, even though it should not be possible. |
| // http://crbug.com/329982 |
| if (!*file || !(*file)->pMethods) |
| return SQLITE_ERROR; |
| |
| return rc; |
| } |
| |
| // Convenience to get the sqlite3_file* and the size for the "main" database. |
| int GetSqlite3FileAndSize(sqlite3* db, |
| sqlite3_file** file, |
| sqlite3_int64* db_size) { |
| int rc = GetSqlite3File(db, file); |
| if (rc != SQLITE_OK) |
| return rc; |
| |
| return (*file)->pMethods->xFileSize(*file, db_size); |
| } |
| |
| std::string AsUTF8ForSQL(const base::FilePath& path) { |
| #if defined(OS_WIN) |
| return base::UTF16ToUTF8(path.value()); |
| #elif defined(OS_POSIX) || defined(OS_FUCHSIA) |
| return path.value(); |
| #endif |
| } |
| |
| } // namespace |
| |
| namespace sql { |
| |
| // static |
| Database::ErrorExpecterCallback* Database::current_expecter_cb_ = nullptr; |
| |
| // static |
| bool Database::IsExpectedSqliteError(int error) { |
| if (!current_expecter_cb_) |
| return false; |
| return current_expecter_cb_->Run(error); |
| } |
| |
| // static |
| void Database::SetErrorExpecter(Database::ErrorExpecterCallback* cb) { |
| CHECK(!current_expecter_cb_); |
| current_expecter_cb_ = cb; |
| } |
| |
| // static |
| void Database::ResetErrorExpecter() { |
| 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) { |
| 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. |
| base::Optional<base::ScopedBlockingCall> scoped_blocking_call; |
| InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call); |
| sqlite3_finalize(stmt_); |
| stmt_ = nullptr; |
| } |
| 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( |
| Database::kDefaultPageSize == SQLITE_DEFAULT_PAGE_SIZE, |
| "Database::kDefaultPageSize must match the value configured into SQLite"); |
| |
| constexpr int Database::kDefaultPageSize; |
| |
| Database::Database() |
| : db_(nullptr), |
| page_size_(kDefaultPageSize), |
| cache_size_(0), |
| exclusive_locking_(false), |
| transaction_nesting_(0), |
| needs_rollback_(false), |
| in_memory_(false), |
| poisoned_(false), |
| mmap_alt_status_(false), |
| mmap_disabled_(false), |
| mmap_enabled_(false), |
| total_changes_at_last_release_(0), |
| stats_histogram_(nullptr) {} |
| |
| Database::~Database() { |
| Close(); |
| } |
| |
| void Database::RecordEvent(Events event, size_t count) { |
| for (size_t i = 0; i < count; ++i) { |
| UMA_HISTOGRAM_ENUMERATION("Sqlite.Stats2", event, EVENT_MAX_VALUE); |
| } |
| |
| if (stats_histogram_) { |
| for (size_t i = 0; i < count; ++i) { |
| stats_histogram_->Add(event); |
| } |
| } |
| } |
| |
| bool Database::Open(const base::FilePath& path) { |
| TRACE_EVENT1("sql", "Database::Open", "path", path.MaybeAsASCII()); |
| return OpenInternal(AsUTF8ForSQL(path), RETRY_ON_POISON); |
| } |
| |
| bool Database::OpenInMemory() { |
| TRACE_EVENT0("sql", "Database::OpenInMemory"); |
| in_memory_ = true; |
| return OpenInternal(":memory:", NO_RETRY); |
| } |
| |
| bool Database::OpenTemporary() { |
| TRACE_EVENT0("sql", "Database::OpenTemporary"); |
| return OpenInternal("", NO_RETRY); |
| } |
| |
| 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. |
| base::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_)); |
| } |
| |
| int rc = sqlite3_close(db_); |
| if (rc != SQLITE_OK) { |
| base::UmaHistogramSparse("Sqlite.CloseFailure", rc); |
| DLOG(DCHECK) << "sqlite3_close failed: " << GetErrorMessage(); |
| } |
| } |
| 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"); |
| if (base::FeatureList::IsEnabled(features::kSqlSkipPreload)) |
| return; |
| |
| if (!db_) { |
| DCHECK(poisoned_) << "Cannot preload null db"; |
| return; |
| } |
| |
| base::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. Here are the trade-offs involved. |
| // 1) Accessing bytes that weren't preread is very expensive on |
| // performance-critical databases, so the limit must exceed the expected |
| // sizes of feature databases. |
| // 2) On some platforms (Windows 7 and, currently, macOS), base::PreReadFile() |
| // falls back to a synchronous read, and blocks until the entire file is |
| // read into memory. So, there's a tangible cost to reading data that would |
| // get evicted before base::PreReadFile() completes. This cost needs to be |
| // balanced with the benefit reading the entire database at once, and |
| // avoiding seeks on spinning disks. |
| 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. |
| 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 int total_changes = sqlite3_total_changes(db_); |
| if (total_changes == total_changes_at_last_release_) |
| return; |
| |
| total_changes_at_last_release_ = total_changes; |
| sqlite3_db_release_memory(db_); |
| } |
| |
| base::FilePath Database::DbPath() const { |
| if (!is_open()) |
| return base::FilePath(); |
| |
| const char* path = sqlite3_db_filename(db_, "main"); |
| const base::StringPiece db_path(path); |
| #if defined(OS_WIN) |
| return base::FilePath(base::UTF8ToUTF16(db_path)); |
| #elif defined(OS_POSIX) || defined(OS_FUCHSIA) |
| return base::FilePath(db_path); |
| #else |
| NOTREACHED(); |
| return base::FilePath(); |
| #endif |
| } |
| |
| std::string Database::CollectErrorInfo(int error, Statement* stmt) const { |
| TRACE_EVENT0("sql", "Database::CollectErrorInfo"); |
| // 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. |
| base::StringAppendF(&debug_info, "db error: %d/%s\n", GetErrorCode(), |
| GetErrorMessage()); |
| |
| // 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 (error != GetErrorCode()) |
| base::StringAppendF(&debug_info, "reported error: %d\n", error); |
| |
| // System error information. Interpretation of Windows errors is different |
| // from posix. |
| #if defined(OS_WIN) |
| base::StringAppendF(&debug_info, "LastError: %d\n", GetLastErrno()); |
| #elif defined(OS_POSIX) || defined(OS_FUCHSIA) |
| base::StringAppendF(&debug_info, "errno: %d\n", GetLastErrno()); |
| #else |
| NOTREACHED(); // Add appropriate log info. |
| #endif |
| |
| if (stmt) { |
| base::StringAppendF(&debug_info, "statement: %s\n", |
| stmt->GetSQLStatement()); |
| } 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 (error == SQLITE_ERROR) { |
| static const 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) { |
| base::StringAppendF(&debug_info, "version: %d\n", |
| sqlite3_column_int(sqlite_statement, 0)); |
| } 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); |
| } |
| |
| debug_info += "schema:\n"; |
| |
| // sqlite_master has columns: |
| // type - "index" or "table". |
| // name - name of created element. |
| // tbl_name - name of element, or target table in case of index. |
| // rootpage - root page of the element in database file. |
| // sql - SQL to create the element. |
| // In general, the |sql| column is sufficient to derive the other columns. |
| // |rootpage| is not interesting for debugging, without the contents of the |
| // database. The COALESCE is because certain automatic elements will have a |
| // |name| but no |sql|, |
| static const char kSchemaSql[] = |
| "SELECT COALESCE(sql,name) FROM sqlite_master"; |
| 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) { |
| base::StringAppendF(&debug_info, "%s\n", |
| sqlite3_column_text(sqlite_statement, 0)); |
| } |
| 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::GetAppropriateMmapSize() { |
| TRACE_EVENT0("sql", "Database::GetAppropriateMmapSize"); |
| |
| base::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(shess): Move all cases to the view implementation. |
| int64_t mmap_ofs = 0; |
| if (mmap_alt_status_) { |
| if (!GetMmapAltStatus(&mmap_ofs)) { |
| RecordOneEvent(EVENT_MMAP_STATUS_FAILURE_READ); |
| 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)) { |
| RecordOneEvent(EVENT_MMAP_META_MISSING); |
| return kMmapEverything; |
| } |
| |
| if (!MetaTable::GetMmapStatus(this, &mmap_ofs)) { |
| RecordOneEvent(EVENT_MMAP_META_FAILURE_READ); |
| return 0; |
| } |
| } |
| |
| // Database read failed in the past, don't memory map. |
| if (mmap_ofs == MetaTable::kMmapFailure) { |
| RecordOneEvent(EVENT_MMAP_FAILED); |
| return 0; |
| } |
| |
| if (mmap_ofs != MetaTable::kMmapSuccess) { |
| // Continue reading from previous offset. |
| DCHECK_GE(mmap_ofs, 0); |
| |
| // TODO(shess): Could this reading code be shared with Preload()? It would |
| // require locking twice (this code wouldn't be able to access |db_size| so |
| // the helper would have to return amount read). |
| |
| // 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. |
| sqlite3_file* file = nullptr; |
| sqlite3_int64 db_size = 0; |
| if (SQLITE_OK != GetSqlite3FileAndSize(db_, &file, &db_size)) { |
| RecordOneEvent(EVENT_MMAP_VFS_FAILURE); |
| return 0; |
| } |
| |
| // 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 (mmap_alt_status_) { |
| if (!SetMmapAltStatus(mmap_ofs)) { |
| RecordOneEvent(EVENT_MMAP_STATUS_FAILURE_UPDATE); |
| return 0; |
| } |
| } else { |
| if (!MetaTable::SetMmapStatus(this, mmap_ofs)) { |
| RecordOneEvent(EVENT_MMAP_META_FAILURE_UPDATE); |
| return 0; |
| } |
| } |
| |
| if (mmap_ofs == MetaTable::kMmapFailure) |
| RecordOneEvent(EVENT_MMAP_FAILED_NEW); |
| } |
| } |
| |
| if (mmap_ofs == MetaTable::kMmapFailure) |
| return 0; |
| if (mmap_ofs == MetaTable::kMmapSuccess) |
| return kMmapEverything; |
| return mmap_ofs; |
| } |
| |
| void Database::TrimMemory() { |
| TRACE_EVENT0("sql", "Database::TrimMemory"); |
| |
| if (!db_) |
| return; |
| |
| 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. |
| } |
| |
| // 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"); |
| |
| base::Optional<base::ScopedBlockingCall> scoped_blocking_call; |
| InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call); |
| |
| if (!db_) { |
| DCHECK(poisoned_) << "Cannot raze null db"; |
| return false; |
| } |
| |
| if (transaction_nesting_ > 0) { |
| DLOG(DCHECK) << "Cannot raze within a transaction"; |
| return false; |
| } |
| |
| sql::Database null_db; |
| if (!null_db.OpenInMemory()) { |
| DLOG(DCHECK) << "Unable to open in-memory database."; |
| return false; |
| } |
| |
| const std::string sql = base::StringPrintf("PRAGMA page_size=%d", page_size_); |
| if (!null_db.Execute(sql.c_str())) |
| return false; |
| |
| #if defined(OS_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 defined(OS_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.] |
| ignore_result(Execute("PRAGMA mmap_size = 0")); |
| #endif |
| |
| const char* kMain = "main"; |
| int rc = BackupDatabase(null_db.db_, db_, kMain); |
| base::UmaHistogramSparse("Sqlite.RazeDatabase", rc); |
| |
| // The destination database was locked. |
| if (rc == SQLITE_BUSY) { |
| 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 (rc == SQLITE_NOTADB || rc == SQLITE_IOERR_SHORT_READ) { |
| sqlite3_file* file = nullptr; |
| rc = GetSqlite3File(db_, &file); |
| if (rc != SQLITE_OK) { |
| DLOG(DCHECK) << "Failure getting file handle."; |
| return false; |
| } |
| |
| rc = file->pMethods->xTruncate(file, 0); |
| if (rc != SQLITE_OK) { |
| base::UmaHistogramSparse("Sqlite.RazeDatabaseTruncate", rc); |
| DLOG(DCHECK) << "Failed to truncate file."; |
| return false; |
| } |
| |
| rc = BackupDatabase(null_db.db_, db_, kMain); |
| base::UmaHistogramSparse("Sqlite.RazeDatabase2", rc); |
| |
| DCHECK_EQ(rc, SQLITE_DONE) << "Failed retrying Raze()."; |
| } |
| |
| // TODO(shess): Figure out which other cases can happen. |
| DCHECK_EQ(rc, SQLITE_DONE) << "Unable to copy entire null database."; |
| |
| // The entire database should have been backed up. |
| return rc == SQLITE_DONE; |
| } |
| |
| 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 unix, win32 and mojo filesystems. 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, "mojo") == 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; |
| 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"); |
| |
| if (!transaction_nesting_) { |
| DCHECK(poisoned_) << "Rolling back a nonexistent transaction"; |
| return; |
| } |
| |
| 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"); |
| |
| if (!transaction_nesting_) { |
| DCHECK(poisoned_) << "Committing a nonexistent transaction"; |
| return false; |
| } |
| 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"); |
| |
| if (transaction_nesting_ > 0) { |
| transaction_nesting_ = 0; |
| DoRollback(); |
| } |
| } |
| |
| bool Database::AttachDatabase(const base::FilePath& other_db_path, |
| const char* attachment_point, |
| InternalApiToken) { |
| TRACE_EVENT0("sql", "Database::AttachDatabase"); |
| |
| DCHECK(ValidAttachmentPoint(attachment_point)); |
| |
| Statement s(GetUniqueStatement("ATTACH DATABASE ? AS ?")); |
| #if OS_WIN |
| s.BindString16(0, other_db_path.value()); |
| #elif defined(OS_POSIX) || defined(OS_FUCHSIA) |
| s.BindString(0, other_db_path.value()); |
| #else |
| #error Unsupported platform |
| #endif |
| s.BindString(1, attachment_point); |
| return s.Run(); |
| } |
| |
| bool Database::DetachDatabase(const char* attachment_point, InternalApiToken) { |
| TRACE_EVENT0("sql", "Database::DetachDatabase"); |
| |
| DCHECK(ValidAttachmentPoint(attachment_point)); |
| |
| Statement s(GetUniqueStatement("DETACH DATABASE ?")); |
| s.BindString(0, attachment_point); |
| return s.Run(); |
| } |
| |
| // TODO(shess): Consider changing this to execute exactly one statement. If a |
| // caller wishes to execute multiple statements, that should be explicit, and |
| // perhaps tucked into an explicit transaction with rollback in case of error. |
| int Database::ExecuteAndReturnErrorCode(const char* sql) { |
| TRACE_EVENT0("sql", "Database::ExecuteAndReturnErrorCode"); |
| |
| DCHECK(sql); |
| |
| if (!db_) { |
| DCHECK(poisoned_) << "Illegal use of Database without a db"; |
| return SQLITE_ERROR; |
| } |
| |
| base::Optional<base::ScopedBlockingCall> scoped_blocking_call; |
| InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call); |
| |
| int rc = SQLITE_OK; |
| while ((rc == SQLITE_OK) && *sql) { |
| sqlite3_stmt* sqlite_statement; |
| const char* leftover_sql; |
| rc = sqlite3_prepare_v3(db_, sql, /* nByte= */ -1, /* prepFlags= */ 0, |
| &sqlite_statement, &leftover_sql); |
| // Stop if an error is encountered. |
| if (rc != SQLITE_OK) |
| 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 ((rc = sqlite3_step(sqlite_statement)) == SQLITE_ROW) { |
| // 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. |
| rc = sqlite3_finalize(sqlite_statement); |
| |
| // 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); |
| |
| return rc; |
| } |
| |
| 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; |
| } |
| |
| int error = ExecuteAndReturnErrorCode(sql); |
| if (error != SQLITE_OK) |
| error = OnSqliteError(error, nullptr, sql); |
| |
| // This needs to be a FATAL log because the error case of arriving here is |
| // that there's a malformed SQL statement. This can arise in development if |
| // a change alters the schema but not all queries adjust. This can happen |
| // in production if the schema is corrupted. |
| DCHECK_NE(error, SQLITE_ERROR) |
| << "SQL Error in " << sql << ", " << GetErrorMessage(); |
| return error == SQLITE_OK; |
| } |
| |
| bool Database::ExecuteWithTimeout(const char* sql, base::TimeDelta timeout) { |
| TRACE_EVENT0("sql", "Database::ExecuteWithTimeout"); |
| |
| if (!db_) { |
| DCHECK(poisoned_) << "Illegal use of Database without a db"; |
| return false; |
| } |
| |
| ScopedBusyTimeout busy_timeout(db_); |
| busy_timeout.SetTimeout(timeout); |
| return Execute(sql); |
| } |
| |
| 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. |
| 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(this, sql); |
| } |
| |
| scoped_refptr<Database::StatementRef> Database::GetStatementImpl( |
| sql::Database* tracking_db, |
| const char* sql) const { |
| DCHECK(sql); |
| DCHECK(!tracking_db || tracking_db == this); |
| |
| // Return inactive statement. |
| if (!db_) |
| return base::MakeRefCounted<StatementRef>(nullptr, nullptr, poisoned_); |
| |
| base::Optional<base::ScopedBlockingCall> scoped_blocking_call; |
| InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call); |
| |
| // TODO(pwnall): Cached statements (but not unique statements) should be |
| // prepared with prepFlags set to SQLITE_PREPARE_PERSISTENT. |
| sqlite3_stmt* sqlite_statement; |
| int rc = sqlite3_prepare_v3(db_, sql, /* nByte= */ -1, /* prepFlags= */ 0, |
| &sqlite_statement, /* pzTail= */ nullptr); |
| if (rc != SQLITE_OK) { |
| // This is evidence of a syntax error in the incoming SQL. |
| DCHECK_NE(rc, SQLITE_ERROR) << "SQL compile error " << GetErrorMessage(); |
| |
| // It could also be database corruption. |
| OnSqliteError(rc, nullptr, sql); |
| return base::MakeRefCounted<StatementRef>(nullptr, nullptr, false); |
| } |
| return base::MakeRefCounted<StatementRef>(tracking_db, sqlite_statement, |
| true); |
| } |
| |
| scoped_refptr<Database::StatementRef> Database::GetUntrackedStatement( |
| const char* sql) const { |
| return GetStatementImpl(nullptr, sql); |
| } |
| |
| std::string Database::GetSchema() const { |
| // 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_master ORDER BY 1, 2, 3, 4"; |
| Statement statement(GetUntrackedStatement(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) { |
| base::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; |
| } |
| |
| sqlite3_stmt* sqlite_statement = nullptr; |
| if (sqlite3_prepare_v3(db_, sql, /* nByte= */ -1, /* prepFlags= */ 0, |
| &sqlite_statement, |
| /* pzTail= */ nullptr) != SQLITE_OK) { |
| return false; |
| } |
| |
| sqlite3_finalize(sqlite_statement); |
| return true; |
| } |
| |
| bool Database::DoesIndexExist(const char* index_name) const { |
| return DoesSchemaItemExist(index_name, "index"); |
| } |
| |
| bool Database::DoesTableExist(const char* table_name) const { |
| return DoesSchemaItemExist(table_name, "table"); |
| } |
| |
| bool Database::DoesViewExist(const char* view_name) const { |
| return DoesSchemaItemExist(view_name, "view"); |
| } |
| |
| bool Database::DoesSchemaItemExist(const char* name, const char* type) const { |
| static const char kSql[] = |
| "SELECT 1 FROM sqlite_master WHERE type=? AND name=?"; |
| Statement statement(GetUntrackedStatement(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) const { |
| // 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. |
| int error = sqlite3_table_column_metadata( |
| db_, "main", table_name, column_name, /* pzDataType= */ nullptr, |
| /* pzCollSeq= */ nullptr, /* pNotNull= */ nullptr, |
| /* pPrimaryKey= */ nullptr, /* pAutoinc= */ nullptr); |
| return error == SQLITE_OK; |
| } |
| |
| int64_t Database::GetLastInsertRowId() const { |
| if (!db_) { |
| DCHECK(poisoned_) << "Illegal use of Database without a db"; |
| return 0; |
| } |
| return sqlite3_last_insert_rowid(db_); |
| } |
| |
| int Database::GetLastChangeCount() const { |
| if (!db_) { |
| DCHECK(poisoned_) << "Illegal use of Database without a db"; |
| return 0; |
| } |
| return sqlite3_changes(db_); |
| } |
| |
| int Database::GetErrorCode() const { |
| if (!db_) |
| return SQLITE_ERROR; |
| return sqlite3_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& file_name, |
| Database::Retry retry_flag) { |
| TRACE_EVENT1("sql", "Database::OpenInternal", "path", file_name); |
| |
| if (db_) { |
| DLOG(DCHECK) << "sql::Database is already open."; |
| return false; |
| } |
| |
| base::Optional<base::ScopedBlockingCall> scoped_blocking_call; |
| InitScopedBlockingCall(FROM_HERE, &scoped_blocking_call); |
| |
| EnsureSqliteInitialized(); |
| |
| // Setup the stats histograms immediately rather than allocating lazily. |
| // Databases which won't exercise all of these probably shouldn't exist. |
| if (!histogram_tag_.empty()) { |
| stats_histogram_ = base::LinearHistogram::FactoryGet( |
| "Sqlite.Stats2." + histogram_tag_, 1, EVENT_MAX_VALUE, |
| EVENT_MAX_VALUE + 1, base::HistogramBase::kUmaTargetedHistogramFlag); |
| } |
| |
| // 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. |
| int err = sqlite3_open_v2( |
| file_name.c_str(), &db_, |
| SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_PRIVATECACHE, |
| vfs_name); |
| if (err != SQLITE_OK) { |
| // Extended error codes cannot be enabled until a handle is |
| // available, fetch manually. |
| err = sqlite3_extended_errcode(db_); |
| |
| // Histogram failures specific to initial open for debugging |
| // purposes. |
| base::UmaHistogramSparse("Sqlite.OpenFailure", err); |
| |
| OnSqliteError(err, nullptr, "-- sqlite3_open()"); |
| bool was_poisoned = poisoned_; |
| Close(); |
| |
| if (was_poisoned && retry_flag == RETRY_ON_POISON) |
| return OpenInternal(file_name, NO_RETRY); |
| return false; |
| } |
| |
| // Enable extended result codes to provide more color on I/O errors. |
| // Not having extended result codes is not a fatal problem, as |
| // Chromium code does not attempt to handle I/O errors anyhow. The |
| // current implementation always returns SQLITE_OK, the DCHECK is to |
| // quickly notify someone if SQLite changes. |
| err = sqlite3_extended_result_codes(db_, 1); |
| DCHECK_EQ(err, SQLITE_OK) << "Could not enable extended result codes"; |
| |
| // sqlite3_open() does not actually read the database file (unless a hot |
| // journal is found). Successfully executing this pragma on an existing |
| // database requires a valid header on page 1. ExecuteAndReturnErrorCode() to |
| // get the error code before error callback (potentially) overwrites. |
| // TODO(shess): For now, just probing to see what the lay of the |
| // land is. If it's mostly SQLITE_NOTADB, then the database should |
| // be razed. |
| err = ExecuteAndReturnErrorCode("PRAGMA auto_vacuum"); |
| if (err != SQLITE_OK) { |
| base::UmaHistogramSparse("Sqlite.OpenProbeFailure", err); |
| OnSqliteError(err, nullptr, "PRAGMA auto_vacuum"); |
| |
| // 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 (retry_flag == RETRY_ON_POISON) |
| return OpenInternal(file_name, NO_RETRY); |
| return false; |
| } |
| } |
| |
| // If indicated, lock up the database before doing anything else, so |
| // that the following code doesn't have to deal with locking. |
| // TODO(shess): This code is brittle. Find the cases where code |
| // doesn't request |exclusive_locking_| and audit that it does the |
| // right thing with SQLITE_BUSY, and that it doesn't make |
| // assumptions about who might change things in the database. |
| // http://crbug.com/56559 |
| if (exclusive_locking_) { |
| // TODO(shess): This should probably be a failure. Code which |
| // requests exclusive locking but doesn't get it is almost certain |
| // to be ill-tested. |
| ignore_result(Execute("PRAGMA locking_mode=EXCLUSIVE")); |
| } |
| |
| // http://www.sqlite.org/pragma.html#pragma_journal_mode |
| // 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. |
| ignore_result(Execute("PRAGMA journal_mode=TRUNCATE")); |
| |
| const base::TimeDelta kBusyTimeout = |
| base::TimeDelta::FromSeconds(kBusyTimeoutSeconds); |
| |
| const std::string page_size_sql = |
| base::StringPrintf("PRAGMA page_size=%d", page_size_); |
| ignore_result(ExecuteWithTimeout(page_size_sql.c_str(), kBusyTimeout)); |
| |
| if (cache_size_ != 0) { |
| const std::string cache_size_sql = |
| base::StringPrintf("PRAGMA cache_size=%d", cache_size_); |
| ignore_result(ExecuteWithTimeout(cache_size_sql.c_str(), kBusyTimeout)); |
| } |
| |
| static_assert(SQLITE_SECURE_DELETE == 1, |
| "Chrome assumes secure_delete is on by default."); |
| |
| // Set a reasonable chunk size for larger files. This reduces churn from |
| // remapping memory on size changes. It also reduces filesystem |
| // fragmentation. |
| // TODO(shess): It may make sense to have this be hinted by the client. |
| // Database sizes seem to be bimodal, some clients have consistently small |
| // databases (<20k) while other clients have a broad distribution of sizes |
| // (hundreds of kilobytes to many megabytes). |
| sqlite3_file* file = nullptr; |
| sqlite3_int64 db_size = 0; |
| int rc = GetSqlite3FileAndSize(db_, &file, &db_size); |
| if (rc == SQLITE_OK && db_size > 16 * 1024) { |
| int chunk_size = 4 * 1024; |
| if (db_size > 128 * 1024) |
| chunk_size = 32 * 1024; |
| sqlite3_file_control(db_, nullptr, SQLITE_FCNTL_CHUNK_SIZE, &chunk_size); |
| } |
| |
| // Enable memory-mapped access. The explicit-disable case is because SQLite |
| // can be built to default-enable mmap. GetAppropriateMmapSize() calculates a |
| // safe range to memory-map based on past regular I/O. This value will be |
| // capped by SQLITE_MAX_MMAP_SIZE, which could be different between 32-bit and |
| // 64-bit platforms. |
| size_t mmap_size = mmap_disabled_ ? 0 : GetAppropriateMmapSize(); |
| std::string mmap_sql = |
| base::StringPrintf("PRAGMA mmap_size=%" PRIuS, mmap_size); |
| ignore_result(Execute(mmap_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 s(GetUniqueStatement("PRAGMA mmap_size")); |
| if (s.Step() && s.ColumnInt64(0) > 0) |
| mmap_enabled_ = true; |
| } |
| |
| DCHECK(!memory_dump_provider_); |
| memory_dump_provider_.reset( |
| new DatabaseMemoryDumpProvider(db_, histogram_tag_)); |
| base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider( |
| memory_dump_provider_.get(), "sql::Database", nullptr); |
| |
| return true; |
| } |
| |
| 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::AddTaggedHistogram(const std::string& name, int sample) const { |
| if (histogram_tag_.empty()) |
| return; |
| |
| // TODO(shess): The histogram macros create a bit of static storage |
| // for caching the histogram object. This code shouldn't execute |
| // often enough for such caching to be crucial. If it becomes an |
| // issue, the object could be cached alongside histogram_prefix_. |
| std::string full_histogram_name = name + "." + histogram_tag_; |
| base::HistogramBase* histogram = base::SparseHistogram::FactoryGet( |
| full_histogram_name, base::HistogramBase::kUmaTargetedHistogramFlag); |
| if (histogram) |
| histogram->Add(sample); |
| } |
| |
| int Database::OnSqliteError(int err, |
| sql::Statement* stmt, |
| const char* sql) const { |
| TRACE_EVENT0("sql", "Database::OnSqliteError"); |
| |
| base::UmaHistogramSparse("Sqlite.Error", err); |
| AddTaggedHistogram("Sqlite.Error", err); |
| |
| // Always log the error. |
| if (!sql && stmt) |
| sql = stmt->GetSQLStatement(); |
| if (!sql) |
| sql = "-- unknown"; |
| |
| std::string id = histogram_tag_; |
| if (id.empty()) |
| id = DbPath().BaseName().AsUTF8Unsafe(); |
| LOG(ERROR) << id << " sqlite error " << err << ", errno " << GetLastErrno() |
| << ": " << GetErrorMessage() << ", sql: " << sql; |
| |
| if (!error_callback_.is_null()) { |
| // Fire from a copy of the callback in case of reentry into |
| // re/set_error_callback(). |
| // TODO(shess): <http://crbug.com/254584> |
| ErrorCallback(error_callback_).Run(err, stmt); |
| return err; |
| } |
| |
| // The default handling is to assert on debug and to ignore on release. |
| if (!IsExpectedSqliteError(err)) |
| DLOG(DCHECK) << GetErrorMessage(); |
| return err; |
| } |
| |
| bool Database::FullIntegrityCheck(std::vector<std::string>* messages) { |
| return IntegrityCheckHelper("PRAGMA integrity_check", messages); |
| } |
| |
| bool Database::QuickIntegrityCheck() { |
| std::vector<std::string> messages; |
| if (!IntegrityCheckHelper("PRAGMA quick_check", &messages)) |
| return false; |
| return messages.size() == 1 && messages[0] == "ok"; |
| } |
| |
| std::string Database::GetDiagnosticInfo(int extended_error, |
| Statement* statement) { |
| // Prevent reentrant calls to the error callback. |
| ErrorCallback original_callback = std::move(error_callback_); |
| reset_error_callback(); |
| |
| // Trim extended error codes. |
| const int error = (extended_error & 0xFF); |
| // CollectCorruptionInfo() is implemented in terms of sql::Database, |
| // TODO(shess): Rewrite IntegrityCheckHelper() in terms of raw SQLite. |
| std::string result = (error == SQLITE_CORRUPT) |
| ? CollectCorruptionInfo() |
| : CollectErrorInfo(extended_error, statement); |
| |
| // 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 = |
| (ExecuteAndReturnErrorCode("PRAGMA auto_vacuum") == SQLITE_OK); |
| const bool select_sqlite_master_result = |
| (ExecuteAndReturnErrorCode("SELECT COUNT(*) FROM sqlite_master") == |
| SQLITE_OK); |
| |
| // 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", |
| (select_sqlite_master_result ? "Yes" : "No")); |
| |
| return result; |
| } |
| |
| // TODO(shess): Allow specifying maximum results (default 100 lines). |
| bool Database::IntegrityCheckHelper(const char* pragma_sql, |
| std::vector<std::string>* messages) { |
| messages->clear(); |
| |
| // This has the side effect of setting SQLITE_RecoveryMode, which |
| // allows SQLite to process through certain cases of corruption. |
| // Failing to set this pragma probably means that the database is |
| // beyond recovery. |
| static const char kWritableSchemaSql[] = "PRAGMA writable_schema=ON"; |
| if (!Execute(kWritableSchemaSql)) |
| return false; |
| |
| bool ret = false; |
| { |
| sql::Statement stmt(GetUniqueStatement(pragma_sql)); |
| |
| // The pragma appears to return all results (up to 100 by default) |
| // as a single string. This doesn't appear to be an API contract, |
| // it could return separate lines, so loop _and_ split. |
| while (stmt.Step()) { |
| std::string result(stmt.ColumnString(0)); |
| *messages = base::SplitString(result, "\n", base::TRIM_WHITESPACE, |
| base::SPLIT_WANT_ALL); |
| } |
| ret = stmt.Succeeded(); |
| } |
| |
| // Best effort to put things back as they were before. |
| static const char kNoWritableSchemaSql[] = "PRAGMA writable_schema=OFF"; |
| ignore_result(Execute(kNoWritableSchemaSql)); |
| |
| return ret; |
| } |
| |
| bool Database::ReportMemoryUsage(base::trace_event::ProcessMemoryDump* pmd, |
| const std::string& dump_name) { |
| return memory_dump_provider_ && |
| memory_dump_provider_->ReportMemoryUsage(pmd, dump_name); |
| } |
| |
| } // namespace sql |