xpcom/io/nsIAsyncOutputStream.idl@6474c204b198 (annotated)
xpcom/io/nsIAsyncOutputStream.idl
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 2 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 3 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 4 | |
| michael@0 | 5 | #include "nsIOutputStream.idl" |
| michael@0 | 6 | |
| michael@0 | 7 | interface nsIOutputStreamCallback; |
| michael@0 | 8 | interface nsIEventTarget; |
| michael@0 | 9 | |
| michael@0 | 10 | /** |
| michael@0 | 11 | * If an output stream is non-blocking, it may return NS_BASE_STREAM_WOULD_BLOCK |
| michael@0 | 12 | * when written to. The caller must then wait for the stream to become |
| michael@0 | 13 | * writable. If the stream implements nsIAsyncOutputStream, then the caller can |
| michael@0 | 14 | * use this interface to request an asynchronous notification when the stream |
| michael@0 | 15 | * becomes writable or closed (via the AsyncWait method). |
| michael@0 | 16 | * |
| michael@0 | 17 | * While this interface is almost exclusively used with non-blocking streams, it |
| michael@0 | 18 | * is not necessary that nsIOutputStream::isNonBlocking return true. Nor is it |
| michael@0 | 19 | * necessary that a non-blocking nsIOutputStream implementation also implement |
| michael@0 | 20 | * nsIAsyncOutputStream. |
| michael@0 | 21 | */ |
| michael@0 | 22 | [scriptable, uuid(beb632d3-d77a-4e90-9134-f9ece69e8200)] |
| michael@0 | 23 | interface nsIAsyncOutputStream : nsIOutputStream |
| michael@0 | 24 | { |
| michael@0 | 25 | /** |
| michael@0 | 26 | * This method closes the stream and sets its internal status. If the |
| michael@0 | 27 | * stream is already closed, then this method is ignored. Once the stream |
| michael@0 | 28 | * is closed, the stream's status cannot be changed. Any successful status |
| michael@0 | 29 | * code passed to this method is treated as NS_BASE_STREAM_CLOSED, which |
| michael@0 | 30 | * is equivalent to nsIInputStream::close. |
| michael@0 | 31 | * |
| michael@0 | 32 | * NOTE: this method exists in part to support pipes, which have both an |
| michael@0 | 33 | * input end and an output end. If the output end of a pipe is closed, then |
| michael@0 | 34 | * reads from the input end of the pipe will fail. The error code returned |
| michael@0 | 35 | * when an attempt is made to read from a "closed" pipe corresponds to the |
| michael@0 | 36 | * status code passed in when the output end of the pipe is closed, which |
| michael@0 | 37 | * greatly simplifies working with pipes in some cases. |
| michael@0 | 38 | * |
| michael@0 | 39 | * @param aStatus |
| michael@0 | 40 | * The error that will be reported if this stream is accessed after |
| michael@0 | 41 | * it has been closed. |
| michael@0 | 42 | */ |
| michael@0 | 43 | void closeWithStatus(in nsresult reason); |
| michael@0 | 44 | |
| michael@0 | 45 | /** |
| michael@0 | 46 | * Asynchronously wait for the stream to be writable or closed. The |
| michael@0 | 47 | * notification is one-shot, meaning that each asyncWait call will result |
| michael@0 | 48 | * in exactly one notification callback. After the OnOutputStreamReady event |
| michael@0 | 49 | * is dispatched, the stream releases its reference to the |
| michael@0 | 50 | * nsIOutputStreamCallback object. It is safe to call asyncWait again from the |
| michael@0 | 51 | * notification handler. |
| michael@0 | 52 | * |
| michael@0 | 53 | * This method may be called at any time (even if write has not been called). |
| michael@0 | 54 | * In other words, this method may be called when the stream already has |
| michael@0 | 55 | * room for more data. It may also be called when the stream is closed. If |
| michael@0 | 56 | * the stream is already writable or closed when AsyncWait is called, then the |
| michael@0 | 57 | * OnOutputStreamReady event will be dispatched immediately. Otherwise, the |
| michael@0 | 58 | * event will be dispatched when the stream becomes writable or closed. |
| michael@0 | 59 | * |
| michael@0 | 60 | * @param aCallback |
| michael@0 | 61 | * This object is notified when the stream becomes ready. This |
| michael@0 | 62 | * parameter may be null to clear an existing callback. |
| michael@0 | 63 | * @param aFlags |
| michael@0 | 64 | * This parameter specifies optional flags passed in to configure |
| michael@0 | 65 | * the behavior of this method. Pass zero to specify no flags. |
| michael@0 | 66 | * @param aRequestedCount |
| michael@0 | 67 | * Wait until at least this many bytes can be written. This is only |
| michael@0 | 68 | * a suggestion to the underlying stream; it may be ignored. The |
| michael@0 | 69 | * caller may pass zero to indicate no preference. |
| michael@0 | 70 | * @param aEventTarget |
| michael@0 | 71 | * Specify NULL to receive notification on ANY thread (possibly even |
| michael@0 | 72 | * recursively on the calling thread -- i.e., synchronously), or |
| michael@0 | 73 | * specify that the notification be delivered to a specific event |
| michael@0 | 74 | * target. |
| michael@0 | 75 | */ |
| michael@0 | 76 | void asyncWait(in nsIOutputStreamCallback aCallback, |
| michael@0 | 77 | in unsigned long aFlags, |
| michael@0 | 78 | in unsigned long aRequestedCount, |
| michael@0 | 79 | in nsIEventTarget aEventTarget); |
| michael@0 | 80 | |
| michael@0 | 81 | /** |
| michael@0 | 82 | * If passed to asyncWait, this flag overrides the default behavior, |
| michael@0 | 83 | * causing the OnOutputStreamReady notification to be suppressed until the |
| michael@0 | 84 | * stream becomes closed (either as a result of closeWithStatus/close being |
| michael@0 | 85 | * called on the stream or possibly due to some error in the underlying |
| michael@0 | 86 | * stream). |
| michael@0 | 87 | */ |
| michael@0 | 88 | const unsigned long WAIT_CLOSURE_ONLY = (1<<0); |
| michael@0 | 89 | }; |
| michael@0 | 90 | |
| michael@0 | 91 | /** |
| michael@0 | 92 | * This is a companion interface for nsIAsyncOutputStream::asyncWait. |
| michael@0 | 93 | */ |
| michael@0 | 94 | [scriptable, uuid(40dbcdff-9053-42c5-a57c-3ec910d0f148)] |
| michael@0 | 95 | interface nsIOutputStreamCallback : nsISupports |
| michael@0 | 96 | { |
| michael@0 | 97 | /** |
| michael@0 | 98 | * Called to indicate that the stream is either writable or closed. |
| michael@0 | 99 | * |
| michael@0 | 100 | * @param aStream |
| michael@0 | 101 | * The stream whose asyncWait method was called. |
| michael@0 | 102 | */ |
| michael@0 | 103 | void onOutputStreamReady(in nsIAsyncOutputStream aStream); |
| michael@0 | 104 | }; |
