gecko-dev/netwerk/base/nsBaseContentStream.cpp
Nika Layzell 3b40268cc1 Bug 1818305 - Part 2: Add a streamStatus method to nsIInputStream, r=xpcom-reviewers,necko-reviewers,geckoview-reviewers,valentin,jesup,m_kato,mccr8
This is semantically similar to the existing available() method, however will
not block, and doesn't need to do the work to actually determine the number of
available bytes.

As part of this patch, I also fixed one available() implementation which was
incorrectly throwing NS_BASE_STREAM_WOULD_BLOCK.

Differential Revision: https://phabricator.services.mozilla.com/D170697
2023-03-15 19:52:34 +00:00

128 lines
3.7 KiB
C++

/* -*- Mode: C++; 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 "nsBaseContentStream.h"
#include "nsStreamUtils.h"
//-----------------------------------------------------------------------------
void nsBaseContentStream::DispatchCallback(bool async) {
if (!mCallback) return;
// It's important to clear mCallback and mCallbackTarget up-front because the
// OnInputStreamReady implementation may call our AsyncWait method.
nsCOMPtr<nsIInputStreamCallback> callback;
if (async) {
callback = NS_NewInputStreamReadyEvent(
"nsBaseContentStream::DispatchCallback", mCallback, mCallbackTarget);
mCallback = nullptr;
} else {
callback.swap(mCallback);
}
mCallbackTarget = nullptr;
callback->OnInputStreamReady(this);
}
//-----------------------------------------------------------------------------
// nsBaseContentStream::nsISupports
NS_IMPL_ADDREF(nsBaseContentStream)
NS_IMPL_RELEASE(nsBaseContentStream)
// We only support nsIAsyncInputStream when we are in non-blocking mode.
NS_INTERFACE_MAP_BEGIN(nsBaseContentStream)
NS_INTERFACE_MAP_ENTRY(nsIInputStream)
NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream, mNonBlocking)
NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIInputStream)
NS_INTERFACE_MAP_END
//-----------------------------------------------------------------------------
// nsBaseContentStream::nsIInputStream
NS_IMETHODIMP
nsBaseContentStream::Close() {
return IsClosed() ? NS_OK : CloseWithStatus(NS_BASE_STREAM_CLOSED);
}
NS_IMETHODIMP
nsBaseContentStream::Available(uint64_t* result) {
*result = 0;
return mStatus;
}
NS_IMETHODIMP
nsBaseContentStream::StreamStatus() { return mStatus; }
NS_IMETHODIMP
nsBaseContentStream::Read(char* buf, uint32_t count, uint32_t* result) {
return ReadSegments(NS_CopySegmentToBuffer, buf, count, result);
}
NS_IMETHODIMP
nsBaseContentStream::ReadSegments(nsWriteSegmentFun fun, void* closure,
uint32_t count, uint32_t* result) {
*result = 0;
if (mStatus == NS_BASE_STREAM_CLOSED) return NS_OK;
// No data yet
if (!IsClosed() && IsNonBlocking()) return NS_BASE_STREAM_WOULD_BLOCK;
return mStatus;
}
NS_IMETHODIMP
nsBaseContentStream::IsNonBlocking(bool* result) {
*result = mNonBlocking;
return NS_OK;
}
//-----------------------------------------------------------------------------
// nsBaseContentStream::nsIAsyncInputStream
NS_IMETHODIMP
nsBaseContentStream::CloseWithStatus(nsresult status) {
if (IsClosed()) return NS_OK;
NS_ENSURE_ARG(NS_FAILED(status));
mStatus = status;
DispatchCallback();
return NS_OK;
}
NS_IMETHODIMP
nsBaseContentStream::AsyncWait(nsIInputStreamCallback* callback, uint32_t flags,
uint32_t requestedCount,
nsIEventTarget* target) {
// Our _only_ consumer is nsInputStreamPump, so we simplify things here by
// making assumptions about how we will be called.
NS_ASSERTION(target, "unexpected parameter");
NS_ASSERTION(flags == 0, "unexpected parameter");
NS_ASSERTION(requestedCount == 0, "unexpected parameter");
#ifdef DEBUG
bool correctThread;
target->IsOnCurrentThread(&correctThread);
NS_ASSERTION(correctThread, "event target must be on the current thread");
#endif
mCallback = callback;
mCallbackTarget = target;
if (!mCallback) return NS_OK;
// If we're already closed, then dispatch this callback immediately.
if (IsClosed()) {
DispatchCallback();
return NS_OK;
}
OnCallbackPending();
return NS_OK;
}