gecko-dev/storage/mozIStorageConnection.idl
Lina Cambridge 38a1672309 Bug 1613835 - Use a SQLite API call to check for in-progress transactions. r=mak
Previously, `mozIStorageConnection#transactionInProgress` returned true
only if a transaction was started via `beginTransaction()`. This meant
that manually executing `BEGIN`, as `Sqlite.jsm` and the Rust bindings
do, wouldn't accurately report if a transaction was in progress.
Similarly, the flag wasn't accurate in cases where SQLite automatically
rolled back a transaction.

Fortunately, SQLite provides the `sqlite3_get_autocommit()` function,
which we can use to determine if a transaction is open or not. This
commit refactors the `transactionInProgress` getter, along with all
`Connection` methods that depend on it, to use the SQLite API instead
of managing that state on the connection. `mozStorageTransaction` and
`Sqlite.jsm` still use their own flags to decide whether to commit
their transactions, for reasons explained in the IDL comment.

This commit also moves `transactionInProgress` to
`mozIStorageAsyncConnection`, so that `Sqlite.jsm` can use it, and
exposes it to Rust.

Differential Revision: https://phabricator.services.mozilla.com/D63732

--HG--
extra : moz-landing-system : lando
2020-03-03 22:57:39 +00:00

260 lines
8.5 KiB
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/* -*- Mode: idl; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsISupports.idl"
#include "mozIStorageAsyncConnection.idl"
%{C++
namespace mozilla {
namespace dom {
namespace quota {
class QuotaObject;
}
}
}
%}
[ptr] native QuotaObject(mozilla::dom::quota::QuotaObject);
interface mozIStorageAggregateFunction;
interface mozIStorageCompletionCallback;
interface mozIStorageFunction;
interface mozIStorageProgressHandler;
interface mozIStorageBaseStatement;
interface mozIStorageStatement;
interface mozIStorageAsyncStatement;
interface mozIStorageStatementCallback;
interface mozIStoragePendingStatement;
interface nsIFile;
/**
* mozIStorageConnection represents a database connection attached to
* a specific file or to the in-memory data storage. It is the
* primary interface for interacting with a database, including
* creating prepared statements, executing SQL, and examining database
* errors.
*
* @note From the main thread, you should rather use mozIStorageAsyncConnection.
*
* @threadsafe
*/
[scriptable, uuid(4aa2ac47-8d24-4004-9b31-ec0bd85f0cc3)]
interface mozIStorageConnection : mozIStorageAsyncConnection {
/**
* Closes a database connection. Callers must finalize all statements created
* for this connection prior to calling this method. It is illegal to use
* call this method if any asynchronous statements have been executed on this
* connection.
*
* @throws NS_ERROR_UNEXPECTED
* If any statement has been executed asynchronously on this object.
* @throws NS_ERROR_UNEXPECTED
* If is called on a thread other than the one that opened it.
*/
void close();
/**
* Clones a database connection and makes the clone read only if needed.
* SQL Functions and attached on-disk databases are applied to the new clone.
*
* @param aReadOnly
* If true, the returned database should be put into read-only mode.
* Defaults to false.
* @return the cloned database connection.
*
* @throws NS_ERROR_UNEXPECTED
* If this connection is a memory database.
* @note If your connection is already read-only, you will get a read-only
* clone.
* @note Due to a bug in SQLite, if you use the shared cache (openDatabase),
* you end up with the same privileges as the first connection opened
* regardless of what is specified in aReadOnly.
* @note The following pragmas are copied over to a read-only clone:
* - cache_size
* - temp_store
* The following pragmas are copied over to a writeable clone:
* - cache_size
* - temp_store
* - foreign_keys
* - journal_size_limit
* - synchronous
* - wal_autocheckpoint
* All SQL functions are copied over to read-only and writeable clones.
* Additionally, all temporary tables, triggers, and views, as well as
* any indexes on temporary tables, are copied over to writeable clones.
* For temporary tables, only the schemas are copied, not their
* contents.
*
*/
mozIStorageConnection clone([optional] in boolean aReadOnly);
/**
* The default size for SQLite database pages used by mozStorage for new
* databases.
*/
readonly attribute long defaultPageSize;
/**
* Indicates if the connection is open and ready to use. This will be false
* if the connection failed to open, or it has been closed.
*/
readonly attribute boolean connectionReady;
/**
* lastInsertRowID returns the row ID from the last INSERT
* operation.
*/
readonly attribute long long lastInsertRowID;
/**
* affectedRows returns the number of database rows that were changed or
* inserted or deleted by last operation.
*/
readonly attribute long affectedRows;
/**
* The last error SQLite error code.
*/
readonly attribute long lastError;
/**
* The last SQLite error as a string (in english, straight from the
* sqlite library).
*/
readonly attribute AUTF8String lastErrorString;
/**
* The schema version of the database. This should not be used until the
* database is ready. The schema will be reported as zero if it is not set.
*/
attribute long schemaVersion;
//////////////////////////////////////////////////////////////////////////////
//// Statement creation
/**
* Create a mozIStorageStatement for the given SQL expression. The
* expression may use ? to indicate sequential numbered arguments,
* ?1, ?2 etc. to indicate specific numbered arguments or :name and
* $var to indicate named arguments.
*
* @param aSQLStatement
* The SQL statement to execute.
* @return a new mozIStorageStatement
*/
mozIStorageStatement createStatement(in AUTF8String aSQLStatement);
/**
* Execute a SQL expression, expecting no arguments.
*
* @param aSQLStatement The SQL statement to execute
*/
void executeSimpleSQL(in AUTF8String aSQLStatement);
/**
* Check if the given table exists.
*
* @param aTableName
* The table to check
* @return TRUE if table exists, FALSE otherwise.
*/
boolean tableExists(in AUTF8String aTableName);
/**
* Check if the given index exists.
*
* @param aIndexName The index to check
* @return TRUE if the index exists, FALSE otherwise.
*/
boolean indexExists(in AUTF8String aIndexName);
//////////////////////////////////////////////////////////////////////////////
//// Transactions
/**
* Begin a new transaction. If a transaction is active, throws an error.
*/
void beginTransaction();
/**
* Commits the current transaction. If no transaction is active,
* @throws NS_ERROR_UNEXPECTED.
* @throws NS_ERROR_NOT_INITIALIZED.
*/
void commitTransaction();
/**
* Rolls back the current transaction. If no transaction is active,
* @throws NS_ERROR_UNEXPECTED.
* @throws NS_ERROR_NOT_INITIALIZED.
*/
void rollbackTransaction();
//////////////////////////////////////////////////////////////////////////////
//// Tables
/**
* Create the table with the given name and schema.
*
* If the table already exists, NS_ERROR_FAILURE is thrown.
* (XXX at some point in the future it will check if the schema is
* the same as what is specified, but that doesn't happen currently.)
*
* @param aTableName
* The table name to be created, consisting of [A-Za-z0-9_], and
* beginning with a letter.
* @param aTableSchema
* The schema of the table; what would normally go between the parens
* in a CREATE TABLE statement: e.g., "foo INTEGER, bar STRING".
*
* @throws NS_ERROR_FAILURE
* If the table already exists or could not be created for any other
* reason.
*/
void createTable(in string aTableName,
in string aTableSchema);
/**
* Controls SQLITE_FCNTL_CHUNK_SIZE setting in sqlite. This helps avoid fragmentation
* by growing/shrinking the database file in SQLITE_FCNTL_CHUNK_SIZE increments. To
* conserve memory on systems short on storage space, this function will have no effect
* on mobile devices or if less than 500MiB of space is left available.
*
* @param aIncrement
* The database file will grow in multiples of chunkSize.
* @param aDatabaseName
* Sqlite database name. "" means pass NULL for zDbName to sqlite3_file_control.
* See http://sqlite.org/c3ref/file_control.html for more details.
* @throws NS_ERROR_FILE_TOO_BIG
* If the system is short on storage space.
*/
void setGrowthIncrement(in int32_t aIncrement, in AUTF8String aDatabaseName);
/**
* Enable a predefined virtual table implementation.
*
* @param aModuleName
* The module to enable. Only "filesystem" is currently supported.
*
* @throws NS_ERROR_FAILURE
* For unknown module names.
*/
[noscript] void enableModule(in ACString aModuleName);
/**
* Get quota objects.
*
* @param[out] aDatabaseQuotaObject
* The QuotaObject associated with the database file.
* @param[out] aJournalQuotaObject
* The QuotaObject associated with the journal file.
*
* @throws NS_ERROR_NOT_INITIALIZED.
*/
[noscript] void getQuotaObjects(out QuotaObject aDatabaseQuotaObject,
out QuotaObject aJournalQuotaObject);
};