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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /xpcom/io/nsIAsyncInputStream.idl | |
parent | Initial commit. (diff) | |
download | firefox-upstream/124.0.1.tar.xz firefox-upstream/124.0.1.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | xpcom/io/nsIAsyncInputStream.idl | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/xpcom/io/nsIAsyncInputStream.idl b/xpcom/io/nsIAsyncInputStream.idl new file mode 100644 index 0000000000..8dbe442663 --- /dev/null +++ b/xpcom/io/nsIAsyncInputStream.idl @@ -0,0 +1,105 @@ +/* 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 "nsIInputStream.idl" + +interface nsIInputStreamCallback; +interface nsIEventTarget; + +/** + * If an input stream is non-blocking, it may return NS_BASE_STREAM_WOULD_BLOCK + * when read. The caller must then wait for the stream to have some data to + * read. If the stream implements nsIAsyncInputStream, then the caller can use + * this interface to request an asynchronous notification when the stream + * becomes readable or closed (via the AsyncWait method). + * + * While this interface is almost exclusively used with non-blocking streams, it + * is not necessary that nsIInputStream::isNonBlocking return true. Nor is it + * necessary that a non-blocking nsIInputStream implementation also implement + * nsIAsyncInputStream. + */ +[scriptable, builtinclass, uuid(a5f255ab-4801-4161-8816-277ac92f6ad1)] +interface nsIAsyncInputStream : nsIInputStream +{ + /** + * This method closes the stream and sets its internal status. If the + * stream is already closed, then this method is ignored. Once the stream + * is closed, the stream's status cannot be changed. Any successful status + * code passed to this method is treated as NS_BASE_STREAM_CLOSED, which + * has an effect equivalent to nsIInputStream::close. + * + * NOTE: this method exists in part to support pipes, which have both an + * input end and an output end. If the input end of a pipe is closed, then + * writes to the output end of the pipe will fail. The error code returned + * when an attempt is made to write to a "broken" pipe corresponds to the + * status code passed in when the input end of the pipe was closed, which + * greatly simplifies working with pipes in some cases. + * + * @param aStatus + * The error that will be reported if this stream is accessed after + * it has been closed. + */ + void closeWithStatus(in nsresult aStatus); + + /** + * Asynchronously wait for the stream to be readable or closed. The + * notification is one-shot, meaning that each asyncWait call will result + * in exactly one notification callback. After the OnInputStreamReady event + * is dispatched, the stream releases its reference to the + * nsIInputStreamCallback object. It is safe to call asyncWait again from the + * notification handler. + * + * This method may be called at any time (even if read has not been called). + * In other words, this method may be called when the stream already has + * data to read. It may also be called when the stream is closed and will NOT + * result in an error return, e.g., NS_BASE_STREAM_CLOSED. If the stream is + * already readable or closed when AsyncWait is called, then the + * OnInputStreamReady event will be dispatched immediately. Otherwise, the + * event will be dispatched when the stream becomes readable or closed. + * + * @param aCallback + * This object is notified when the stream becomes ready. This + * parameter may be null to clear an existing callback. + * @param aFlags + * This parameter specifies optional flags passed in to configure + * the behavior of this method. Pass zero to specify no flags. + * @param aRequestedCount + * Wait until at least this many bytes can be read. This is only + * a suggestion to the underlying stream; it may be ignored. The + * caller may pass zero to indicate no preference. + * @param aEventTarget + * Specify NULL to receive notification on ANY thread (possibly even + * recursively on the calling thread -- i.e., synchronously), or + * specify that the notification be delivered to a specific event + * target. + */ + void asyncWait(in nsIInputStreamCallback aCallback, + in unsigned long aFlags, + in unsigned long aRequestedCount, + in nsIEventTarget aEventTarget); + + /** + * If passed to asyncWait, this flag overrides the default behavior, + * causing the OnInputStreamReady notification to be suppressed until the + * stream becomes closed (either as a result of closeWithStatus/close being + * called on the stream or possibly due to some error in the underlying + * stream). + */ + const unsigned long WAIT_CLOSURE_ONLY = (1<<0); +}; + +/** + * This is a companion interface for nsIAsyncInputStream::asyncWait. + */ +[function, scriptable, uuid(d1f28e94-3a6e-4050-a5f5-2e81b1fc2a43)] +interface nsIInputStreamCallback : nsISupports +{ + /** + * Called to indicate that the stream is either readable or closed. + * + * @param aStream + * The stream whose asyncWait method was called. + */ + void onInputStreamReady(in nsIAsyncInputStream aStream); +}; |