| // 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. |
| |
| #ifndef SQL_DATABASE_H_ |
| #define SQL_DATABASE_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| #include <memory> |
| #include <set> |
| #include <string> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/callback.h" |
| #include "base/compiler_specific.h" |
| #include "base/component_export.h" |
| #include "base/containers/flat_map.h" |
| #include "base/gtest_prod_util.h" |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/optional.h" |
| #include "base/sequence_checker.h" |
| #include "base/threading/scoped_blocking_call.h" |
| #include "sql/internal_api_token.h" |
| #include "sql/statement_id.h" |
| |
| struct sqlite3; |
| struct sqlite3_stmt; |
| |
| namespace base { |
| class FilePath; |
| class HistogramBase; |
| namespace trace_event { |
| class ProcessMemoryDump; |
| } // namespace trace_event |
| } // namespace base |
| |
| namespace sql { |
| |
| class DatabaseMemoryDumpProvider; |
| class Statement; |
| |
| namespace test { |
| class ScopedErrorExpecter; |
| } // namespace test |
| |
| // Handle to an open SQLite database. |
| // |
| // Instances of this class are thread-unsafe and DCHECK that they are accessed |
| // on the same sequence. |
| class COMPONENT_EXPORT(SQL) Database { |
| private: |
| class StatementRef; // Forward declaration, see real one below. |
| |
| public: |
| // The database is opened by calling Open[InMemory](). Any uncommitted |
| // transactions will be rolled back when this object is deleted. |
| Database(); |
| ~Database(); |
| |
| // Allows mmapping to be disabled globally by default in the calling process. |
| // Must be called before any threads attempt to create a Database. |
| // |
| // TODO(crbug.com/1117049): Remove this global configuration. |
| static void DisableMmapByDefault(); |
| |
| // Pre-init configuration ---------------------------------------------------- |
| |
| // Sets the page size that will be used when creating a new database. This |
| // must be called before Init(), and will only have an effect on new |
| // databases. |
| // |
| // The page size must be a power of two between 512 and 65536 inclusive. |
| void set_page_size(int page_size) { |
| DCHECK_GE(page_size, 512); |
| DCHECK_LE(page_size, 65536); |
| DCHECK(!(page_size & (page_size - 1))) |
| << "page_size must be a power of two"; |
| |
| page_size_ = page_size; |
| } |
| |
| // The page size that will be used when creating a new database. |
| int page_size() const { return page_size_; } |
| |
| // Sets the number of pages that will be cached in memory by sqlite. The |
| // total cache size in bytes will be page_size * cache_size. This must be |
| // called before Open() to have an effect. |
| void set_cache_size(int cache_size) { |
| DCHECK_GE(cache_size, 0); |
| |
| cache_size_ = cache_size; |
| } |
| |
| // Returns whether a database will be opened in WAL mode. |
| bool UseWALMode() const; |
| |
| // Enables/disables WAL mode (https://www.sqlite.org/wal.html) when |
| // opening a new database. |
| // |
| // WAL mode is currently not fully supported on FuchsiaOS. It will only be |
| // turned on if the database is also using exclusive locking mode. |
| // (https://crbug.com/1082059) |
| // |
| // Note: Changing page size is not supported when in WAL mode. So running |
| // 'PRAGMA page_size = <new-size>' or using set_page_size will result in |
| // no-ops. |
| // |
| // This must be called before Open() to have an effect. |
| void want_wal_mode(bool enabled) { want_wal_mode_ = enabled; } |
| |
| // Call to put the database in exclusive locking mode. There is no "back to |
| // normal" flag because of some additional requirements sqlite puts on this |
| // transaction (requires another access to the DB) and because we don't |
| // actually need it. |
| // |
| // Exclusive mode means that the database is not unlocked at the end of each |
| // transaction, which means there may be less time spent initializing the |
| // next transaction because it doesn't have to re-aquire locks. |
| // |
| // This must be called before Open() to have an effect. |
| void set_exclusive_locking() { exclusive_locking_ = true; } |
| |
| // Call to use alternative status-tracking for mmap. Usually this is tracked |
| // in the meta table, but some databases have no meta table. |
| // TODO(shess): Maybe just have all databases use the alt option? |
| void set_mmap_alt_status() { mmap_alt_status_ = true; } |
| |
| // Opt out of memory-mapped file I/O. |
| void set_mmap_disabled() { mmap_disabled_ = true; } |
| |
| // Set an error-handling callback. On errors, the error number (and |
| // statement, if available) will be passed to the callback. |
| // |
| // If no callback is set, the default action is to crash in debug |
| // mode or return failure in release mode. |
| using ErrorCallback = base::RepeatingCallback<void(int, Statement*)>; |
| void set_error_callback(const ErrorCallback& callback) { |
| error_callback_ = callback; |
| } |
| bool has_error_callback() const { return !error_callback_.is_null(); } |
| void reset_error_callback() { error_callback_.Reset(); } |
| |
| // Set this to enable additional per-database histogramming. Must be called |
| // before Open(). |
| void set_histogram_tag(const std::string& tag); |
| |
| // Record a sparse UMA histogram sample under |
| // |name|+"."+|histogram_tag_|. If |histogram_tag_| is empty, no |
| // histogram is recorded. |
| void AddTaggedHistogram(const std::string& name, int sample) const; |
| |
| // Track various API calls and results. Values correspond to UMA |
| // histograms, do not modify, or add or delete other than directly |
| // before EVENT_MAX_VALUE. |
| enum Events { |
| // Number of statements run, either with sql::Statement or Execute*(). |
| EVENT_STATEMENT_RUN_DEPRECATED = 0, |
| |
| // Number of rows returned by statements run. |
| EVENT_STATEMENT_ROWS_DEPRECATED, |
| |
| // Number of statements successfully run (all steps returned SQLITE_DONE or |
| // SQLITE_ROW). |
| EVENT_STATEMENT_SUCCESS_DEPRECATED, |
| |
| // Number of statements run by Execute() or ExecuteAndReturnErrorCode(). |
| EVENT_EXECUTE_DEPRECATED, |
| |
| // Number of rows changed by autocommit statements. |
| EVENT_CHANGES_AUTOCOMMIT_DEPRECATED, |
| |
| // Number of rows changed by statements in transactions. |
| EVENT_CHANGES_DEPRECATED, |
| |
| // Count actual SQLite transaction statements (not including nesting). |
| EVENT_BEGIN_DEPRECATED, |
| EVENT_COMMIT_DEPRECATED, |
| EVENT_ROLLBACK_DEPRECATED, |
| |
| // Track success and failure in GetAppropriateMmapSize(). |
| // GetAppropriateMmapSize() should record at most one of these per run. The |
| // case of mapping everything is not recorded. |
| EVENT_MMAP_META_MISSING, // No meta table present. |
| EVENT_MMAP_META_FAILURE_READ, // Failed reading meta table. |
| EVENT_MMAP_META_FAILURE_UPDATE, // Failed updating meta table. |
| EVENT_MMAP_VFS_FAILURE, // Failed to access VFS. |
| EVENT_MMAP_FAILED, // Failure from past run. |
| EVENT_MMAP_FAILED_NEW, // Read error in this run. |
| EVENT_MMAP_SUCCESS_NEW_DEPRECATED, // Read to EOF in this run. |
| EVENT_MMAP_SUCCESS_PARTIAL_DEPRECATED, // Read but did not reach EOF. |
| EVENT_MMAP_SUCCESS_NO_PROGRESS_DEPRECATED, // Read quota exhausted. |
| |
| EVENT_MMAP_STATUS_FAILURE_READ, // Failure reading MmapStatus view. |
| EVENT_MMAP_STATUS_FAILURE_UPDATE, // Failure updating MmapStatus view. |
| |
| // Leave this at the end. |
| // TODO(shess): |EVENT_MAX| causes compile fail on Windows. |
| EVENT_MAX_VALUE, |
| }; |
| void RecordEvent(Events event, size_t count); |
| void RecordOneEvent(Events event) { RecordEvent(event, 1); } |
| |
| // Run "PRAGMA integrity_check" and post each line of |
| // results into |messages|. Returns the success of running the |
| // statement - per the SQLite documentation, if no errors are found the |
| // call should succeed, and a single value "ok" should be in messages. |
| bool FullIntegrityCheck(std::vector<std::string>* messages); |
| |
| // Runs "PRAGMA quick_check" and, unlike the FullIntegrityCheck method, |
| // interprets the results returning true if the the statement executes |
| // without error and results in a single "ok" value. |
| bool QuickIntegrityCheck() WARN_UNUSED_RESULT; |
| |
| // Meant to be called from a client error callback so that it's able to |
| // get diagnostic information about the database. |
| std::string GetDiagnosticInfo(int extended_error, Statement* statement); |
| |
| // Reports memory usage into provided memory dump with the given name. |
| bool ReportMemoryUsage(base::trace_event::ProcessMemoryDump* pmd, |
| const std::string& dump_name); |
| |
| // Initialization ------------------------------------------------------------ |
| |
| // Initializes the SQL database for the given file, returning true if the |
| // file could be opened. You can call this or OpenInMemory. |
| bool Open(const base::FilePath& path) WARN_UNUSED_RESULT; |
| |
| // Initializes the SQL database for a temporary in-memory database. There |
| // will be no associated file on disk, and the initial database will be |
| // empty. You can call this or Open. |
| bool OpenInMemory() WARN_UNUSED_RESULT; |
| |
| // Create a temporary on-disk database. The database will be |
| // deleted after close. This kind of database is similar to |
| // OpenInMemory() for small databases, but can page to disk if the |
| // database becomes large. |
| bool OpenTemporary() WARN_UNUSED_RESULT; |
| |
| // Returns true if the database has been successfully opened. |
| bool is_open() const { return static_cast<bool>(db_); } |
| |
| // Closes the database. This is automatically performed on destruction for |
| // you, but this allows you to close the database early. You must not call |
| // any other functions after closing it. It is permissable to call Close on |
| // an uninitialized or already-closed database. |
| void Close(); |
| |
| // Reads the first <cache-size>*<page-size> bytes of the file to prime the |
| // filesystem cache. This can be more efficient than faulting pages |
| // individually. Since this involves blocking I/O, it should only be used if |
| // the caller will immediately read a substantial amount of data from the |
| // database. |
| // |
| // TODO(shess): Design a set of histograms or an experiment to inform this |
| // decision. Preloading should almost always improve later performance |
| // numbers for this database simply because it pulls operations forward, but |
| // if the data isn't actually used soon then preloading just slows down |
| // everything else. |
| void Preload(); |
| |
| // Release all non-essential memory associated with this database connection. |
| void TrimMemory(); |
| |
| // Raze the database to the ground. This approximates creating a |
| // fresh database from scratch, within the constraints of SQLite's |
| // locking protocol (locks and open handles can make doing this with |
| // filesystem operations problematic). Returns true if the database |
| // was razed. |
| // |
| // false is returned if the database is locked by some other |
| // process. |
| // |
| // NOTE(shess): Raze() will DCHECK in the following situations: |
| // - database is not open. |
| // - the database has a transaction open. |
| // - a SQLite issue occurs which is structural in nature (like the |
| // statements used are broken). |
| // Since Raze() is expected to be called in unexpected situations, |
| // these all return false, since it is unlikely that the caller |
| // could fix them. |
| // |
| // The database's page size is taken from |page_size_|. The |
| // existing database's |auto_vacuum| setting is lost (the |
| // possibility of corruption makes it unreliable to pull it from the |
| // existing database). To re-enable on the empty database requires |
| // running "PRAGMA auto_vacuum = 1;" then "VACUUM". |
| // |
| // NOTE(shess): For Android, SQLITE_DEFAULT_AUTOVACUUM is set to 1, |
| // so Raze() sets auto_vacuum to 1. |
| // |
| // TODO(shess): Raze() needs a database so cannot clear SQLITE_NOTADB. |
| // TODO(shess): Bake auto_vacuum into Database's API so it can |
| // just pick up the default. |
| bool Raze(); |
| |
| // Breaks all outstanding transactions (as initiated by |
| // BeginTransaction()), closes the SQLite database, and poisons the |
| // object so that all future operations against the Database (or |
| // its Statements) fail safely, without side effects. |
| // |
| // This is intended as an alternative to Close() in error callbacks. |
| // Close() should still be called at some point. |
| void Poison(); |
| |
| // Raze() the database and Poison() the handle. Returns the return |
| // value from Raze(). |
| // TODO(shess): Rename to RazeAndPoison(). |
| bool RazeAndClose(); |
| |
| // Delete the underlying database files associated with |path|. This should be |
| // used on a database which is not opened by any Database instance. Open |
| // Database instances pointing to the database can cause odd results or |
| // corruption (for instance if a hot journal is deleted but the associated |
| // database is not). |
| // |
| // Returns true if the database file and associated journals no |
| // longer exist, false otherwise. If the database has never |
| // existed, this will return true. |
| static bool Delete(const base::FilePath& path); |
| |
| // Transactions -------------------------------------------------------------- |
| |
| // Transaction management. We maintain a virtual transaction stack to emulate |
| // nested transactions since sqlite can't do nested transactions. The |
| // limitation is you can't roll back a sub transaction: if any transaction |
| // fails, all transactions open will also be rolled back. Any nested |
| // transactions after one has rolled back will return fail for Begin(). If |
| // Begin() fails, you must not call Commit or Rollback(). |
| // |
| // Normally you should use sql::Transaction to manage a transaction, which |
| // will scope it to a C++ context. |
| bool BeginTransaction(); |
| void RollbackTransaction(); |
| bool CommitTransaction(); |
| |
| // Rollback all outstanding transactions. Use with care, there may |
| // be scoped transactions on the stack. |
| void RollbackAllTransactions(); |
| |
| // Returns the current transaction nesting, which will be 0 if there are |
| // no open transactions. |
| int transaction_nesting() const { return transaction_nesting_; } |
| |
| // Attached databases--------------------------------------------------------- |
| |
| // SQLite supports attaching multiple database files to a single connection. |
| // |
| // Attach the database in |other_db_path| to the current connection under |
| // |attachment_point|. |attachment_point| must only contain characters from |
| // [a-zA-Z0-9_]. |
| // |
| // On the SQLite version shipped with Chrome (3.21+, Oct 2017), databases can |
| // be attached while a transaction is opened. However, these databases cannot |
| // be detached until the transaction is committed or aborted. |
| // |
| // These APIs are only exposed for use in recovery. They are extremely subtle |
| // and are not useful for features built on top of //sql. |
| bool AttachDatabase(const base::FilePath& other_db_path, |
| const char* attachment_point, |
| InternalApiToken); |
| bool DetachDatabase(const char* attachment_point, InternalApiToken); |
| |
| // Statements ---------------------------------------------------------------- |
| |
| // Executes the given SQL string, returning true on success. This is |
| // normally used for simple, 1-off statements that don't take any bound |
| // parameters and don't return any data (e.g. CREATE TABLE). |
| // |
| // This will DCHECK if the |sql| contains errors. |
| // |
| // Do not use ignore_result() to ignore all errors. Use |
| // ExecuteAndReturnErrorCode() and ignore only specific errors. |
| bool Execute(const char* sql) WARN_UNUSED_RESULT; |
| |
| // Like Execute(), but returns the error code given by SQLite. |
| int ExecuteAndReturnErrorCode(const char* sql) WARN_UNUSED_RESULT; |
| |
| // Returns a statement for the given SQL using the statement cache. It can |
| // take a nontrivial amount of work to parse and compile a statement, so |
| // keeping commonly-used ones around for future use is important for |
| // performance. |
| // |
| // The SQL_FROM_HERE macro is the recommended way of generating a StatementID. |
| // Code that generates custom IDs must ensure that a StatementID is never used |
| // for different SQL statements. Failing to meet this requirement results in |
| // incorrect behavior, and should be caught by a DCHECK. |
| // |
| // The SQL statement passed in |sql| must match the SQL statement reported |
| // back by SQLite. Mismatches are caught by a DCHECK, so any code that has |
| // automated test coverage or that was manually tested on a DCHECK build will |
| // not exhibit this problem. Mismatches generally imply that the statement |
| // passed in has extra whitespace or comments surrounding it, which waste |
| // storage and CPU cycles. |
| // |
| // If the |sql| has an error, an invalid, inert StatementRef is returned (and |
| // the code will crash in debug). The caller must deal with this eventuality, |
| // either by checking validity of the |sql| before calling, by correctly |
| // handling the return of an inert statement, or both. |
| // |
| // Example: |
| // sql::Statement stmt(database_.GetCachedStatement( |
| // SQL_FROM_HERE, "SELECT * FROM foo")); |
| // if (!stmt) |
| // return false; // Error creating statement. |
| scoped_refptr<StatementRef> GetCachedStatement(StatementID id, |
| const char* sql); |
| |
| // Used to check a |sql| statement for syntactic validity. If the statement is |
| // valid SQL, returns true. |
| bool IsSQLValid(const char* sql); |
| |
| // Returns a non-cached statement for the given SQL. Use this for SQL that |
| // is only executed once or only rarely (there is overhead associated with |
| // keeping a statement cached). |
| // |
| // See GetCachedStatement above for examples and error information. |
| scoped_refptr<StatementRef> GetUniqueStatement(const char* sql); |
| |
| // Performs a passive checkpoint on the main attached database if it is in |
| // WAL mode. Returns true if the checkpoint was successful and false in case |
| // of an error. It is a no-op if the database is not in WAL mode. |
| // |
| // Note: Checkpointing is a very slow operation and will block any writes |
| // until it is finished. Please use with care. |
| bool CheckpointDatabase(); |
| |
| // Info querying ------------------------------------------------------------- |
| |
| // Returns true if the given structure exists. Instead of test-then-create, |
| // callers should almost always prefer the "IF NOT EXISTS" version of the |
| // CREATE statement. |
| bool DoesIndexExist(const char* index_name) const; |
| bool DoesTableExist(const char* table_name) const; |
| bool DoesViewExist(const char* table_name) const; |
| |
| // Returns true if a column with the given name exists in the given table. |
| // |
| // Calling this method on a VIEW returns an unspecified result. |
| // |
| // This should only be used by migration code for legacy features that do not |
| // use MetaTable, and need an alternative way of figuring out the database's |
| // current version. |
| bool DoesColumnExist(const char* table_name, const char* column_name) const; |
| |
| // Returns sqlite's internal ID for the last inserted row. Valid only |
| // immediately after an insert. |
| int64_t GetLastInsertRowId() const; |
| |
| // Returns sqlite's count of the number of rows modified by the last |
| // statement executed. Will be 0 if no statement has executed or the database |
| // is closed. |
| int GetLastChangeCount() const; |
| |
| // Errors -------------------------------------------------------------------- |
| |
| // Returns the error code associated with the last sqlite operation. |
| int GetErrorCode() const; |
| |
| // Returns the errno associated with GetErrorCode(). See |
| // SQLITE_LAST_ERRNO in SQLite documentation. |
| int GetLastErrno() const; |
| |
| // Returns a pointer to a statically allocated string associated with the |
| // last sqlite operation. |
| const char* GetErrorMessage() const; |
| |
| // Return a reproducible representation of the schema equivalent to |
| // running the following statement at a sqlite3 command-line: |
| // SELECT type, name, tbl_name, sql FROM sqlite_master ORDER BY 1, 2, 3, 4; |
| std::string GetSchema() const; |
| |
| // Returns |true| if there is an error expecter (see SetErrorExpecter), and |
| // that expecter returns |true| when passed |error|. Clients which provide an |
| // |error_callback| should use IsExpectedSqliteError() to check for unexpected |
| // errors; if one is detected, DLOG(DCHECK) is generally appropriate (see |
| // OnSqliteError implementation). |
| static bool IsExpectedSqliteError(int error); |
| |
| // Computes the path of a database's rollback journal. |
| // |
| // The journal file is created at the beginning of the database's first |
| // transaction. The file may be removed and re-created between transactions, |
| // depending on whether the database is opened in exclusive mode, and on |
| // configuration options. The journal file does not exist when the database |
| // operates in WAL mode. |
| // |
| // This is intended for internal use and tests. To preserve our ability to |
| // iterate on our SQLite configuration, features must avoid relying on |
| // the existence of specific files. |
| static base::FilePath JournalPath(const base::FilePath& db_path); |
| |
| // Computes the path of a database's write-ahead log (WAL). |
| // |
| // The WAL file exists while a database is opened in WAL mode. |
| // |
| // This is intended for internal use and tests. To preserve our ability to |
| // iterate on our SQLite configuration, features must avoid relying on |
| // the existence of specific files. |
| static base::FilePath WriteAheadLogPath(const base::FilePath& db_path); |
| |
| // Computes the path of a database's shared memory (SHM) file. |
| // |
| // The SHM file is used to coordinate between multiple processes using the |
| // same database in WAL mode. Thus, this file only exists for databases using |
| // WAL and not opened in exclusive mode. |
| // |
| // This is intended for internal use and tests. To preserve our ability to |
| // iterate on our SQLite configuration, features must avoid relying on |
| // the existence of specific files. |
| static base::FilePath SharedMemoryFilePath(const base::FilePath& db_path); |
| |
| // Default page size for newly created databases. |
| // |
| // Guaranteed to match SQLITE_DEFAULT_PAGE_SIZE. |
| static constexpr int kDefaultPageSize = 4096; |
| |
| // Internal state accessed by other classes in //sql. |
| sqlite3* db(InternalApiToken) const { return db_; } |
| bool poisoned(InternalApiToken) const { return poisoned_; } |
| |
| private: |
| // Allow test-support code to set/reset error expecter. |
| friend class test::ScopedErrorExpecter; |
| |
| // Statement accesses StatementRef which we don't want to expose to everybody |
| // (they should go through Statement). |
| friend class Statement; |
| |
| FRIEND_TEST_ALL_PREFIXES(SQLDatabaseTest, CachedStatement); |
| FRIEND_TEST_ALL_PREFIXES(SQLDatabaseTest, CollectDiagnosticInfo); |
| FRIEND_TEST_ALL_PREFIXES(SQLDatabaseTest, GetAppropriateMmapSize); |
| FRIEND_TEST_ALL_PREFIXES(SQLDatabaseTest, GetAppropriateMmapSizeAltStatus); |
| FRIEND_TEST_ALL_PREFIXES(SQLDatabaseTest, OnMemoryDump); |
| FRIEND_TEST_ALL_PREFIXES(SQLDatabaseTest, RegisterIntentToUpload); |
| FRIEND_TEST_ALL_PREFIXES(SQLiteFeaturesTest, WALNoClose); |
| |
| // Internal initialize function used by both Init and InitInMemory. The file |
| // name is always 8 bits since we want to use the 8-bit version of |
| // sqlite3_open. The string can also be sqlite's special ":memory:" string. |
| // |
| // |retry_flag| controls retrying the open if the error callback |
| // addressed errors using RazeAndClose(). |
| enum Retry { NO_RETRY = 0, RETRY_ON_POISON }; |
| bool OpenInternal(const std::string& file_name, Retry retry_flag); |
| |
| // Internal close function used by Close() and RazeAndClose(). |
| // |forced| indicates that orderly-shutdown checks should not apply. |
| void CloseInternal(bool forced); |
| |
| // Construct a ScopedBlockingCall to annotate IO calls, but only if |
| // database wasn't open in memory. ScopedBlockingCall uses |from_here| to |
| // declare its blocking execution scope (see https://www.crbug/934302). |
| void InitScopedBlockingCall( |
| const base::Location& from_here, |
| base::Optional<base::ScopedBlockingCall>* scoped_blocking_call) const { |
| if (!in_memory_) |
| scoped_blocking_call->emplace(from_here, base::BlockingType::MAY_BLOCK); |
| } |
| |
| // Internal helper for Does*Exist() functions. |
| bool DoesSchemaItemExist(const char* name, const char* type) const; |
| |
| // Accessors for global error-expecter, for injecting behavior during tests. |
| // See test/scoped_error_expecter.h. |
| using ErrorExpecterCallback = base::RepeatingCallback<bool(int)>; |
| static ErrorExpecterCallback* current_expecter_cb_; |
| static void SetErrorExpecter(ErrorExpecterCallback* expecter); |
| static void ResetErrorExpecter(); |
| |
| // A StatementRef is a refcounted wrapper around a sqlite statement pointer. |
| // Refcounting allows us to give these statements out to sql::Statement |
| // objects while also optionally maintaining a cache of compiled statements |
| // by just keeping a refptr to these objects. |
| // |
| // A statement ref can be valid, in which case it can be used, or invalid to |
| // indicate that the statement hasn't been created yet, has an error, or has |
| // been destroyed. |
| // |
| // The Database may revoke a StatementRef in some error cases, so callers |
| // should always check validity before using. |
| class COMPONENT_EXPORT(SQL) StatementRef |
| : public base::RefCounted<StatementRef> { |
| public: |
| REQUIRE_ADOPTION_FOR_REFCOUNTED_TYPE(); |
| |
| // |database| is the sql::Database instance associated with |
| // the statement, and is used for tracking outstanding statements |
| // and for error handling. Set to nullptr for invalid or untracked |
| // refs. |stmt| is the actual statement, and should only be null |
| // to create an invalid ref. |was_valid| indicates whether the |
| // statement should be considered valid for diagnostic purposes. |
| // |was_valid| can be true for a null |stmt| if the Database has |
| // been forcibly closed by an error handler. |
| StatementRef(Database* database, sqlite3_stmt* stmt, bool was_valid); |
| |
| // When true, the statement can be used. |
| bool is_valid() const { return !!stmt_; } |
| |
| // When true, the statement is either currently valid, or was |
| // previously valid but the database was forcibly closed. Used |
| // for diagnostic checks. |
| bool was_valid() const { return was_valid_; } |
| |
| // If we've not been linked to a database, this will be null. |
| // |
| // TODO(shess): database_ can be nullptr in case of |
| // GetUntrackedStatement(), which prevents Statement::OnError() from |
| // forwarding errors. |
| Database* database() const { return database_; } |
| |
| // Returns the sqlite statement if any. If the statement is not active, |
| // this will return nullptr. |
| sqlite3_stmt* stmt() const { return stmt_; } |
| |
| // Destroys the compiled statement and sets it to nullptr. The statement |
| // will no longer be active. |forced| is used to indicate if |
| // orderly-shutdown checks should apply (see Database::RazeAndClose()). |
| void Close(bool forced); |
| |
| // Construct a ScopedBlockingCall to annotate IO calls, but only if |
| // database wasn't open in memory. ScopedBlockingCall uses |from_here| to |
| // declare its blocking execution scope (see https://www.crbug/934302). |
| void InitScopedBlockingCall( |
| const base::Location& from_here, |
| base::Optional<base::ScopedBlockingCall>* scoped_blocking_call) const { |
| if (database_) |
| database_->InitScopedBlockingCall(from_here, scoped_blocking_call); |
| } |
| |
| private: |
| friend class base::RefCounted<StatementRef>; |
| |
| ~StatementRef(); |
| |
| Database* database_; |
| sqlite3_stmt* stmt_; |
| bool was_valid_; |
| |
| DISALLOW_COPY_AND_ASSIGN(StatementRef); |
| }; |
| friend class StatementRef; |
| |
| // Executes a rollback statement, ignoring all transaction state. Used |
| // internally in the transaction management code. |
| void DoRollback(); |
| |
| // Called by a StatementRef when it's being created or destroyed. See |
| // open_statements_ below. |
| void StatementRefCreated(StatementRef* ref); |
| void StatementRefDeleted(StatementRef* ref); |
| |
| // Called when a sqlite function returns an error, which is passed |
| // as |err|. The return value is the error code to be reflected |
| // back to client code. |stmt| is non-null if the error relates to |
| // an sql::Statement instance. |sql| is non-nullptr if the error |
| // relates to non-statement sql code (Execute, for instance). Both |
| // can be null, but both should never be set. |
| // NOTE(shess): Originally, the return value was intended to allow |
| // error handlers to transparently convert errors into success. |
| // Unfortunately, transactions are not generally restartable, so |
| // this did not work out. |
| int OnSqliteError(int err, Statement* stmt, const char* sql) const; |
| |
| // Like |Execute()|, but retries if the database is locked. |
| bool ExecuteWithTimeout(const char* sql, |
| base::TimeDelta ms_timeout) WARN_UNUSED_RESULT; |
| |
| // Implementation helper for GetUniqueStatement() and GetUntrackedStatement(). |
| // |tracking_db| is the db the resulting ref should register with for |
| // outstanding statement tracking, which should be |this| to track or null to |
| // not track. |
| scoped_refptr<StatementRef> GetStatementImpl(sql::Database* tracking_db, |
| const char* sql) const; |
| |
| // Helper for implementing const member functions. Like GetUniqueStatement(), |
| // except the StatementRef is not entered into |open_statements_|, so an |
| // outstanding StatementRef from this function can block closing the database. |
| // The StatementRef will not call OnSqliteError(), because that can call |
| // |error_callback_| which can close the database. |
| scoped_refptr<StatementRef> GetUntrackedStatement(const char* sql) const; |
| |
| bool IntegrityCheckHelper(const char* pragma_sql, |
| std::vector<std::string>* messages) |
| WARN_UNUSED_RESULT; |
| |
| // Release page-cache memory if memory-mapped I/O is enabled and the database |
| // was changed. Passing true for |implicit_change_performed| allows |
| // overriding the change detection for cases like DDL (CREATE, DROP, etc), |
| // which do not participate in the total-rows-changed tracking. |
| void ReleaseCacheMemoryIfNeeded(bool implicit_change_performed); |
| |
| // Returns the results of sqlite3_db_filename(), which should match the path |
| // passed to Open(). |
| base::FilePath DbPath() const; |
| |
| // Helper to collect diagnostic info for a corrupt database. |
| std::string CollectCorruptionInfo(); |
| |
| // Helper to collect diagnostic info for errors. |
| std::string CollectErrorInfo(int error, Statement* stmt) const; |
| |
| // Calculates a value appropriate to pass to "PRAGMA mmap_size = ". So errors |
| // can make it unsafe to map a file, so the file is read using regular I/O, |
| // with any errors causing 0 (don't map anything) to be returned. If the |
| // entire file is read without error, a large value is returned which will |
| // allow the entire file to be mapped in most cases. |
| // |
| // Results are recorded in the database's meta table for future reference, so |
| // the file should only be read through once. |
| size_t GetAppropriateMmapSize(); |
| |
| // Helpers for GetAppropriateMmapSize(). |
| bool GetMmapAltStatus(int64_t* status); |
| bool SetMmapAltStatus(int64_t status); |
| |
| // The actual sqlite database. Will be null before Init has been called or if |
| // Init resulted in an error. |
| sqlite3* db_; |
| |
| // Parameters we'll configure in sqlite before doing anything else. Zero means |
| // use the default value. |
| int page_size_; |
| int cache_size_; |
| |
| bool exclusive_locking_; |
| bool want_wal_mode_; |
| |
| // Holds references to all cached statements so they remain active. |
| // |
| // flat_map is appropriate here because the codebase has ~400 cached |
| // statements, and each statement is at most one insertion in the map |
| // throughout a process' lifetime. |
| base::flat_map<StatementID, scoped_refptr<StatementRef>> statement_cache_; |
| |
| // A list of all StatementRefs we've given out. Each ref must register with |
| // us when it's created or destroyed. This allows us to potentially close |
| // any open statements when we encounter an error. |
| std::set<StatementRef*> open_statements_; |
| |
| // Number of currently-nested transactions. |
| int transaction_nesting_; |
| |
| // True if any of the currently nested transactions have been rolled back. |
| // When we get to the outermost transaction, this will determine if we do |
| // a rollback instead of a commit. |
| bool needs_rollback_; |
| |
| // True if database is open with OpenInMemory(), False if database is open |
| // with Open(). |
| bool in_memory_; |
| |
| // |true| if the Database was closed using RazeAndClose(). Used |
| // to enable diagnostics to distinguish calls to never-opened |
| // databases (incorrect use of the API) from calls to once-valid |
| // databases. |
| bool poisoned_; |
| |
| // |true| to use alternate storage for tracking mmap status. |
| bool mmap_alt_status_; |
| |
| // |true| if SQLite memory-mapped I/O is not desired for this database. |
| bool mmap_disabled_; |
| |
| // |true| if SQLite memory-mapped I/O was enabled for this database. |
| // Used by ReleaseCacheMemoryIfNeeded(). |
| bool mmap_enabled_; |
| |
| // Used by ReleaseCacheMemoryIfNeeded() to track if new changes have happened |
| // since memory was last released. |
| int total_changes_at_last_release_; |
| |
| ErrorCallback error_callback_; |
| |
| // Tag for auxiliary histograms. |
| std::string histogram_tag_; |
| |
| // Linear histogram for RecordEvent(). |
| base::HistogramBase* stats_histogram_; |
| |
| // Stores the dump provider object when db is open. |
| std::unique_ptr<DatabaseMemoryDumpProvider> memory_dump_provider_; |
| |
| DISALLOW_COPY_AND_ASSIGN(Database); |
| }; |
| |
| } // namespace sql |
| |
| #endif // SQL_DATABASE_H_ |