1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
7 #ifndef mozilla_storage_Connection_h
8 #define mozilla_storage_Connection_h
10 #include "nsAutoPtr.h"
12 #include "mozilla/Atomics.h"
13 #include "mozilla/Mutex.h"
14 #include "nsProxyRelease.h"
15 #include "nsThreadUtils.h"
16 #include "nsIInterfaceRequestor.h"
18 #include "nsDataHashtable.h"
19 #include "mozIStorageProgressHandler.h"
20 #include "SQLiteMutex.h"
21 #include "mozIStorageConnection.h"
22 #include "mozStorageService.h"
23 #include "mozIStorageAsyncConnection.h"
24 #include "mozIStorageCompletionCallback.h"
26 #include "nsIMutableArray.h"
27 #include "mozilla/Attributes.h"
39 class Connection final
: public mozIStorageConnection
,
40 public nsIInterfaceRequestor
{
42 NS_DECL_THREADSAFE_ISUPPORTS
43 NS_DECL_MOZISTORAGEASYNCCONNECTION
44 NS_DECL_MOZISTORAGECONNECTION
45 NS_DECL_NSIINTERFACEREQUESTOR
48 * Structure used to describe user functions on the database connection.
51 enum FunctionType
{ SIMPLE
, AGGREGATE
};
53 nsCOMPtr
<nsISupports
> function
;
60 * Pointer to the storage service. Held onto for the lifetime of the
63 * The flags to pass to sqlite3_open_v2.
65 * If |true|, the Connection only implements asynchronous interface:
66 * - |mozIStorageAsyncConnection|;
67 * If |false|, the result also implements synchronous interface:
68 * - |mozIStorageConnection|.
69 * @param aIgnoreLockingMode
70 * If |true|, ignore locks in force on the file. Only usable with
71 * read-only connections. Defaults to false.
72 * Use with extreme caution. If sqlite ignores locks, reads may fail
73 * indicating database corruption (the database won't actually be
74 * corrupt) or produce wrong results without any indication that has
77 Connection(Service
*aService
, int aFlags
, bool aAsyncOnly
,
78 bool aIgnoreLockingMode
= false);
81 * Creates the connection to an in-memory database.
83 nsresult
initialize();
86 * Creates the connection to the database.
88 * @param aDatabaseFile
89 * The nsIFile of the location of the database to open, or create if it
92 nsresult
initialize(nsIFile
*aDatabaseFile
);
95 * Creates the connection to the database.
98 * The nsIFileURL of the location of the database to open, or create if
101 nsresult
initialize(nsIFileURL
*aFileURL
);
104 * Same as initialize, but to be used on the async thread.
106 nsresult
initializeOnAsyncThread(nsIFile
*aStorageFile
);
109 * Fetches runtime status information for this connection.
111 * @param aStatusOption One of the SQLITE_DBSTATUS options defined at
112 * http://www.sqlite.org/c3ref/c_dbstatus_options.html
113 * @param [optional] aMaxValue if provided, will be set to the highest
114 * istantaneous value.
115 * @return the current value for the specified option.
117 int32_t getSqliteRuntimeStatus(int32_t aStatusOption
,
118 int32_t *aMaxValue
= nullptr);
120 * Registers/unregisters a commit hook callback.
122 * @param aCallbackFn a callback function to be invoked on transactions
123 * commit. Pass nullptr to unregister the current callback.
124 * @param [optional] aData if provided, will be passed to the callback.
125 * @see http://sqlite.org/c3ref/commit_hook.html
127 void setCommitHook(int (*aCallbackFn
)(void *), void *aData
= nullptr) {
128 MOZ_ASSERT(mDBConn
, "A connection must exist at this point");
129 ::sqlite3_commit_hook(mDBConn
, aCallbackFn
, aData
);
133 * Gets autocommit status.
135 bool getAutocommit() {
136 return mDBConn
&& static_cast<bool>(::sqlite3_get_autocommit(mDBConn
));
140 * Lazily creates and returns a background execution thread. In the future,
141 * the thread may be re-claimed if left idle, so you should call this
142 * method just before you dispatch and not save the reference.
144 * This must be called from the opener thread.
146 * @return an event target suitable for asynchronous statement execution.
147 * @note This method will return null once AsyncClose() has been called.
149 nsIEventTarget
*getAsyncExecutionTarget();
152 * Mutex used by asynchronous statements to protect state. The mutex is
153 * declared on the connection object because there is no contention between
154 * asynchronous statements (they are serialized on mAsyncExecutionThread).
155 * Currently protects:
156 * - Connection.mAsyncExecutionThreadShuttingDown
157 * - Connection.mConnectionClosed
158 * - AsyncExecuteStatements.mCancelRequested
160 Mutex sharedAsyncExecutionMutex
;
163 * Wraps the mutex that SQLite gives us from sqlite3_db_mutex. This is public
164 * because we already expose the sqlite3* native connection and proper
165 * operation of the deadlock detector requires everyone to use the same single
166 * SQLiteMutex instance for correctness.
168 SQLiteMutex sharedDBMutex
;
171 * References the thread this database was opened on. This MUST be thread it
174 const nsCOMPtr
<nsIThread
> threadOpenedOn
;
177 * Closes the SQLite database, and warns about any non-finalized statements.
179 nsresult
internalClose(sqlite3
*aDBConn
);
182 * Shuts down the passed-in async thread.
184 void shutdownAsyncThread();
187 * Obtains the filename of the connection. Useful for logging.
189 nsCString
getFilename();
192 * Creates an sqlite3 prepared statement object from an SQL string.
194 * @param aNativeConnection
195 * The underlying Sqlite connection to prepare the statement with.
197 * The SQL statement string to compile.
199 * New sqlite3_stmt object.
200 * @return the result from sqlite3_prepare_v2.
202 int prepareStatement(sqlite3
*aNativeConnection
, const nsCString
&aSQL
,
203 sqlite3_stmt
**_stmt
);
206 * Performs a sqlite3_step on aStatement, while properly handling
207 * SQLITE_LOCKED when not on the main thread by waiting until we are notified.
209 * @param aNativeConnection
210 * The underlying Sqlite connection to step the statement with.
212 * A pointer to a sqlite3_stmt object.
213 * @return the result from sqlite3_step.
215 int stepStatement(sqlite3
*aNativeConnection
, sqlite3_stmt
*aStatement
);
218 * Raw connection transaction management.
220 * @see BeginTransactionAs, CommitTransaction, RollbackTransaction.
222 nsresult
beginTransactionInternal(
223 sqlite3
*aNativeConnection
,
224 int32_t aTransactionType
= TRANSACTION_DEFERRED
);
225 nsresult
commitTransactionInternal(sqlite3
*aNativeConnection
);
226 nsresult
rollbackTransactionInternal(sqlite3
*aNativeConnection
);
228 bool connectionReady();
231 * Thread-aware version of connectionReady, results per caller's thread are:
232 * - owner thread: Same as connectionReady(). True means we have a valid,
233 * un-closed database connection and it's not going away until you invoke
234 * Close() or AsyncClose().
235 * - async thread: Returns true at all times because you can't schedule
236 * runnables against the async thread after AsyncClose() has been called.
237 * Therefore, the connection is still around if your code is running.
238 * - any other thread: Race-prone Lies! If you are main-thread code in
239 * mozStorageService iterating over the list of connections, you need to
240 * acquire the sharedAsyncExecutionMutex for the connection, invoke
241 * connectionReady() while holding it, and then continue to hold it while
242 * you do whatever you need to do. This is because of off-main-thread
243 * consumers like dom/cache and IndexedDB and other QuotaManager clients.
245 bool isConnectionReadyOnThisThread();
248 * True if this connection has inited shutdown.
253 * True if the underlying connection is closed.
254 * Any sqlite resources may be lost when this returns true, so nothing should
256 * This locks on sharedAsyncExecutionMutex.
261 * Same as isClosed(), but takes a proof-of-lock instead of locking
264 bool isClosed(MutexAutoLock
&lock
);
267 * True if the async execution thread is alive and able to be used (i.e., it
268 * is not in the process of shutting down.)
270 * This must be called from the opener thread.
272 bool isAsyncExecutionThreadAvailable();
274 nsresult
initializeClone(Connection
*aClone
, bool aReadOnly
);
278 nsresult
initializeInternal();
279 void initializeFailed();
282 * Sets the database into a closed state so no further actions can be
285 * @note mDBConn is set to nullptr in this method.
287 nsresult
setClosedState();
290 * Helper for calls to sqlite3_exec. Reports long delays to Telemetry.
292 * @param aNativeConnection
293 * The underlying Sqlite connection to execute the query with.
295 * SQL string to execute
296 * @return the result from sqlite3_exec.
298 int executeSql(sqlite3
*aNativeConnection
, const char *aSqlString
);
301 * Describes a certain primitive type in the database.
303 * Possible Values Are:
304 * INDEX - To check for the existence of an index
305 * TABLE - To check for the existence of a table
307 enum DatabaseElementType
{ INDEX
, TABLE
};
310 * Determines if the specified primitive exists.
312 * @param aElementType
313 * The type of element to check the existence of
314 * @param aElementName
315 * The name of the element to check for
316 * @returns true if element exists, false otherwise
318 nsresult
databaseElementExists(enum DatabaseElementType aElementType
,
319 const nsACString
&aElementName
, bool *_exists
);
321 bool findFunctionByInstance(nsISupports
*aInstance
);
323 static int sProgressHelper(void *aArg
);
324 // Generic progress handler
325 // Dispatch call to registered progress handler,
326 // if there is one. Do nothing in other cases.
327 int progressHandler();
330 nsCOMPtr
<nsIFileURL
> mFileURL
;
331 nsCOMPtr
<nsIFile
> mDatabaseFile
;
334 * The filename that will be reported to telemetry for this connection. By
335 * default this will be the leaf of the path to the database file.
337 nsCString mTelemetryFilename
;
340 * Lazily created thread for asynchronous statement execution. Consumers
341 * should use getAsyncExecutionTarget rather than directly accessing this
344 * This must be modified only on the opener thread.
346 nsCOMPtr
<nsIThread
> mAsyncExecutionThread
;
349 * Set to true by Close() or AsyncClose() prior to shutdown.
351 * If false, we guarantee both that the underlying sqlite3 database
352 * connection is still open and that getAsyncExecutionTarget() can
353 * return a thread. Once true, either the sqlite3 database
354 * connection is being shutdown or it has been
355 * shutdown. Additionally, once true, getAsyncExecutionTarget()
358 * This variable should be accessed while holding the
359 * sharedAsyncExecutionMutex.
361 bool mAsyncExecutionThreadShuttingDown
;
364 * Set to true just prior to calling sqlite3_close on the
367 * This variable should be accessed while holding the
368 * sharedAsyncExecutionMutex.
370 bool mConnectionClosed
;
373 * Stores the default behavior for all transactions run on this connection.
375 mozilla::Atomic
<int32_t> mDefaultTransactionType
;
378 * Tracks if we have a transaction in progress or not. Access protected by
381 bool mTransactionInProgress
;
384 * Used to trigger cleanup logic only the first time our refcount hits 1. We
385 * may trigger a failsafe Close() that invokes SpinningSynchronousClose()
386 * which invokes AsyncClose() which may bump our refcount back up to 2 (and
387 * which will then fall back down to 1 again). It's also possible that the
388 * Service may bump our refcount back above 1 if getConnections() runs before
389 * we invoke unregisterConnection().
391 mozilla::Atomic
<bool> mDestroying
;
394 * Stores the mapping of a given function by name to its instance. Access is
395 * protected by sharedDBMutex.
397 nsDataHashtable
<nsCStringHashKey
, FunctionInfo
> mFunctions
;
400 * Stores the registered progress handler for the database connection. Access
401 * is protected by sharedDBMutex.
403 nsCOMPtr
<mozIStorageProgressHandler
> mProgressHandler
;
406 * Stores the flags we passed to sqlite3_open_v2.
411 * Stores whether we should ask sqlite3_open_v2 to ignore locking.
413 const bool mIgnoreLockingMode
;
415 // This is here for two reasons: 1) It's used to make sure that the
416 // connections do not outlive the service. 2) Our custom collating functions
417 // call its localeCompareStrings() method.
418 RefPtr
<Service
> mStorageService
;
421 * If |false|, this instance supports synchronous operations
422 * and it can be cast to |mozIStorageConnection|.
424 const bool mAsyncOnly
;
428 * A Runnable designed to call a mozIStorageCompletionCallback on
429 * the appropriate thread.
431 class CallbackComplete final
: public Runnable
{
434 * @param aValue The result to pass to the callback. It must
435 * already be owned by the main thread.
436 * @param aCallback The callback. It must already be owned by the
439 CallbackComplete(nsresult aStatus
, nsISupports
*aValue
,
440 already_AddRefed
<mozIStorageCompletionCallback
> aCallback
)
441 : Runnable("storage::CallbackComplete"),
444 mCallback(aCallback
) {}
446 NS_IMETHOD
Run() override
{
447 MOZ_ASSERT(NS_IsMainThread());
448 nsresult rv
= mCallback
->Complete(mStatus
, mValue
);
450 // Ensure that we release on the main thread
458 nsCOMPtr
<nsISupports
> mValue
;
459 // This is a RefPtr<T> and not a nsCOMPtr<T> because
460 // nsCOMP<T> would cause an off-main thread QI, which
461 // is not a good idea (and crashes XPConnect).
462 RefPtr
<mozIStorageCompletionCallback
> mCallback
;
465 } // namespace storage
466 } // namespace mozilla
469 * Casting Connection to nsISupports is ambiguous.
470 * This method handles that.
472 inline nsISupports
*ToSupports(mozilla::storage::Connection
*p
) {
473 return NS_ISUPPORTS_CAST(mozIStorageAsyncConnection
*, p
);
476 #endif // mozilla_storage_Connection_h