gecko/storage/public/mozIStorageConnection.idl

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/* -*- Mode: idl; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2012-05-21 04:12:37 -07:00
/* 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"
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.
*
* @threadsafe
*/
[scriptable, uuid(b2a4b534-f92e-4387-9bd9-d10408173925)]
interface mozIStorageConnection : nsISupports {
/**
* The default size for SQLite database pages used by mozStorage for new
* databases.
* This value must stay in sync with the SQLITE_DEFAULT_PAGE_SIZE define in
* /db/sqlite3/src/Makefile.in
*/
const long DEFAULT_PAGE_SIZE = 32768;
/**
* 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();
/**
* Asynchronously closes a database connection, allowing all pending
* asynchronous statements to complete first.
*
* @param aCallback [optional]
* A callback that will be notified when the close is completed.
*
* @throws NS_ERROR_UNEXPECTED
* If is called on a thread other than the one that opened it.
*/
void asyncClose([optional] in mozIStorageCompletionCallback aCallback);
/**
* Clones a database and makes the clone read only if needed.
*
* @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
*
* @throws NS_ERROR_UNEXPECTED
* If this connection is a memory database.
*
* @param aReadOnly
* If true, the returned database should be put into read-only mode.
* Defaults to false.
* @return the cloned database connection.
*/
mozIStorageConnection clone([optional] in boolean aReadOnly);
/**
* 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;
/**
* The current database nsIFile. Null if the database
* connection refers to an in-memory database.
*/
readonly attribute nsIFile databaseFile;
/**
* 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);
/**
* Create an asynchronous statement (mozIStorageAsyncStatement) for the given
* SQL expression. An asynchronous statement can only be used to dispatch
* asynchronous requests to the asynchronous execution thread and cannot be
* used to take any synchronous actions on the database.
*
* 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 mozIStorageAsyncStatement
*/
mozIStorageAsyncStatement createAsyncStatement(in AUTF8String aSQLStatement);
/**
* Execute a SQL expression, expecting no arguments.
*
* @param aSQLStatement The SQL statement to execute
*/
void executeSimpleSQL(in AUTF8String aSQLStatement);
/**
* Execute an array of queries created with this connection asynchronously
* using any currently bound parameters. The statements are ran wrapped in a
* transaction. These statements can be reused immediately, and reset does
* not need to be called.
*
* Note: If you have any custom defined functions, they must be re-entrant
* since they can be called on multiple threads.
*
* @param aStatements
* The array of statements to execute asynchronously, in the order they
* are given in the array.
* @param aNumStatements
* The number of statements in aStatements.
* @param aCallback [optional]
* The callback object that will be notified of progress, errors, and
* completion.
* @return an object that can be used to cancel the statements execution.
*/
mozIStoragePendingStatement executeAsync(
[array, size_is(aNumStatements)] in mozIStorageBaseStatement aStatements,
in unsigned long aNumStatements,
[optional] in mozIStorageStatementCallback aCallback
);
/**
* 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
/**
* Returns true if a transaction is active on this connection.
*/
readonly attribute boolean transactionInProgress;
/**
* Begin a new transaction. sqlite default transactions are deferred.
* If a transaction is active, throws an error.
*/
void beginTransaction();
/**
* Begins a new transaction with the given type.
*/
const int32_t TRANSACTION_DEFERRED = 0;
const int32_t TRANSACTION_IMMEDIATE = 1;
const int32_t TRANSACTION_EXCLUSIVE = 2;
void beginTransactionAs(in int32_t transactionType);
/**
* 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);
//////////////////////////////////////////////////////////////////////////////
//// Functions
/**
* Create a new SQL function. If you use your connection on multiple threads,
* your function needs to be threadsafe, or it should only be called on one
* thread.
*
* @param aFunctionName
* The name of function to create, as seen in SQL.
* @param aNumArguments
* The number of arguments the function takes. Pass -1 for
* variable-argument functions.
* @param aFunction
* The instance of mozIStorageFunction, which implements the function
* in question.
*/
void createFunction(in AUTF8String aFunctionName,
in long aNumArguments,
in mozIStorageFunction aFunction);
/**
* Create a new SQL aggregate function. If you use your connection on
* multiple threads, your function needs to be threadsafe, or it should only
* be called on one thread.
*
* @param aFunctionName
* The name of aggregate function to create, as seen in SQL.
* @param aNumArguments
* The number of arguments the function takes. Pass -1 for
* variable-argument functions.
* @param aFunction
* The instance of mozIStorageAggreagteFunction, which implements the
* function in question.
*/
void createAggregateFunction(in AUTF8String aFunctionName,
in long aNumArguments,
in mozIStorageAggregateFunction aFunction);
/**
* Delete custom SQL function (simple or aggregate one).
*
* @param aFunctionName
* The name of function to remove.
*/
void removeFunction(in AUTF8String aFunctionName);
/**
* Sets a progress handler. Only one handler can be registered at a time.
* If you need more than one, you need to chain them yourself. This progress
* handler should be threadsafe if you use this connection object on more than
* one thread.
*
* @param aGranularity
* The number of SQL virtual machine steps between progress handler
* callbacks.
* @param aHandler
* The instance of mozIStorageProgressHandler.
* @return previous registered handler.
*/
mozIStorageProgressHandler setProgressHandler(in int32_t aGranularity,
in mozIStorageProgressHandler aHandler);
/**
* Remove a progress handler.
*
* @return previous registered handler.
*/
mozIStorageProgressHandler removeProgressHandler();
/**
* 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);
};