1 files changed, 169 insertions, 0 deletions
diff --git a/netwerk/base/nsSyncStreamListener.cpp b/netwerk/base/nsSyncStreamListener.cpp
new file mode 100644
index 0000000000..7e5ec94231
--- /dev/null
+++ b/netwerk/base/nsSyncStreamListener.cpp
@@ -0,0 +1,169 @@
+/* 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 "mozilla/SpinEventLoopUntil.h"
+#include "nsIOService.h"
+#include "nsIPipe.h"
+#include "nsSyncStreamListener.h"
+#include "nsThreadUtils.h"
+#include <algorithm>
+
+using namespace mozilla::net;
+
+nsSyncStreamListener::nsSyncStreamListener() {
+  MOZ_ASSERT(NS_IsMainThread());
+  NS_NewPipe(getter_AddRefs(mPipeIn), getter_AddRefs(mPipeOut),
+             mozilla::net::nsIOService::gDefaultSegmentSize,
+             UINT32_MAX,  // no size limit
+             false, false);
+}
+
+nsresult nsSyncStreamListener::WaitForData() {
+  mKeepWaiting = true;
+
+  if (!mozilla::SpinEventLoopUntil("nsSyncStreamListener::Create"_ns,
+                                   [&]() { return !mKeepWaiting; })) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsSyncStreamListener::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsSyncStreamListener, nsIStreamListener, nsIRequestObserver,
+                  nsIInputStream, nsISyncStreamListener)
+
+//-----------------------------------------------------------------------------
+// nsSyncStreamListener::nsISyncStreamListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsSyncStreamListener::GetInputStream(nsIInputStream** result) {
+  *result = do_AddRef(this).take();
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsSyncStreamListener::nsIStreamListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsSyncStreamListener::OnStartRequest(nsIRequest* request) { return NS_OK; }
+
+NS_IMETHODIMP
+nsSyncStreamListener::OnDataAvailable(nsIRequest* request,
+                                      nsIInputStream* stream, uint64_t offset,
+                                      uint32_t count) {
+  uint32_t bytesWritten;
+
+  nsresult rv = mPipeOut->WriteFrom(stream, count, &bytesWritten);
+
+  // if we get an error, then return failure.  this will cause the
+  // channel to be canceled, and as a result our OnStopRequest method
+  // will be called immediately.  because of this we do not need to
+  // set mStatus or mKeepWaiting here.
+  if (NS_FAILED(rv)) return rv;
+
+  // we expect that all data will be written to the pipe because
+  // the pipe was created to have "infinite" room.
+  NS_ASSERTION(bytesWritten == count, "did not write all data");
+
+  mKeepWaiting = false;  // unblock Read
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::OnStopRequest(nsIRequest* request, nsresult status) {
+  mStatus = status;
+  mKeepWaiting = false;  // unblock Read
+  mDone = true;
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsSyncStreamListener::nsIInputStream
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsSyncStreamListener::Close() {
+  mStatus = NS_BASE_STREAM_CLOSED;
+  mDone = true;
+
+  // It'd be nice if we could explicitly cancel the request at this point,
+  // but we don't have a reference to it, so the best we can do is close the
+  // pipe so that the next OnDataAvailable event will fail.
+  if (mPipeIn) {
+    mPipeIn->Close();
+    mPipeIn = nullptr;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::Available(uint64_t* result) {
+  if (NS_FAILED(mStatus)) return mStatus;
+
+  mStatus = mPipeIn->Available(result);
+  if (NS_SUCCEEDED(mStatus) && (*result == 0) && !mDone) {
+    nsresult rv = WaitForData();
+    if (NS_FAILED(rv)) {
+      // Note that `WaitForData` could fail `mStatus`. Do not overwrite if it's
+      // the case.
+      mStatus = NS_SUCCEEDED(mStatus) ? rv : mStatus;
+    } else if (NS_SUCCEEDED(mStatus)) {
+      mStatus = mPipeIn->Available(result);
+    }
+  }
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::StreamStatus() {
+  if (NS_FAILED(mStatus)) {
+    return mStatus;
+  }
+
+  mStatus = mPipeIn->StreamStatus();
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::Read(char* buf, uint32_t bufLen, uint32_t* result) {
+  if (mStatus == NS_BASE_STREAM_CLOSED) {
+    *result = 0;
+    return NS_OK;
+  }
+
+  uint64_t avail64;
+  if (NS_FAILED(Available(&avail64))) return mStatus;
+
+  uint32_t avail = (uint32_t)std::min(avail64, (uint64_t)bufLen);
+  mStatus = mPipeIn->Read(buf, avail, result);
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::ReadSegments(nsWriteSegmentFun writer, void* closure,
+                                   uint32_t count, uint32_t* result) {
+  if (mStatus == NS_BASE_STREAM_CLOSED) {
+    *result = 0;
+    return NS_OK;
+  }
+
+  uint64_t avail64;
+  if (NS_FAILED(Available(&avail64))) return mStatus;
+
+  uint32_t avail = (uint32_t)std::min(avail64, (uint64_t)count);
+  mStatus = mPipeIn->ReadSegments(writer, closure, avail, result);
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::IsNonBlocking(bool* result) {
+  *result = false;
+  return NS_OK;
+}