1 files changed, 145 insertions, 0 deletions
diff --git a/netwerk/base/nsPreloadedStream.cpp b/netwerk/base/nsPreloadedStream.cpp
new file mode 100644
index 0000000000..e98298f59b
--- /dev/null
+++ b/netwerk/base/nsPreloadedStream.cpp
@@ -0,0 +1,145 @@
+/* -*- Mode: C++; tab-width: 4; 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 "nsPreloadedStream.h"
+#include "nsIRunnable.h"
+
+#include "nsThreadUtils.h"
+#include <algorithm>
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(nsPreloadedStream, nsIInputStream, nsIAsyncInputStream,
+                  nsIInputStreamCallback)
+
+nsPreloadedStream::nsPreloadedStream(nsIAsyncInputStream* aStream,
+                                     const char* data, uint32_t datalen)
+    : mStream(aStream),
+      mOffset(0),
+      mLen(datalen),
+      mCallback("nsPreloadedStream") {
+  mBuf = (char*)moz_xmalloc(datalen);
+  memcpy(mBuf, data, datalen);
+}
+
+nsPreloadedStream::~nsPreloadedStream() { free(mBuf); }
+
+NS_IMETHODIMP
+nsPreloadedStream::Close() {
+  mLen = 0;
+  return mStream->Close();
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::Available(uint64_t* _retval) {
+  uint64_t avail = 0;
+
+  nsresult rv = mStream->Available(&avail);
+  if (NS_FAILED(rv)) return rv;
+  *_retval = avail + mLen;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::Read(char* aBuf, uint32_t aCount, uint32_t* _retval) {
+  if (!mLen) return mStream->Read(aBuf, aCount, _retval);
+
+  uint32_t toRead = std::min(mLen, aCount);
+  memcpy(aBuf, mBuf + mOffset, toRead);
+  mOffset += toRead;
+  mLen -= toRead;
+  *_retval = toRead;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                                uint32_t aCount, uint32_t* result) {
+  if (!mLen) return mStream->ReadSegments(aWriter, aClosure, aCount, result);
+
+  *result = 0;
+  while (mLen > 0 && aCount > 0) {
+    uint32_t toRead = std::min(mLen, aCount);
+    uint32_t didRead = 0;
+    nsresult rv;
+
+    rv = aWriter(this, aClosure, mBuf + mOffset, *result, toRead, &didRead);
+
+    if (NS_FAILED(rv)) return NS_OK;
+
+    *result += didRead;
+    mOffset += didRead;
+    mLen -= didRead;
+    aCount -= didRead;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::IsNonBlocking(bool* _retval) {
+  return mStream->IsNonBlocking(_retval);
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::CloseWithStatus(nsresult aStatus) {
+  mLen = 0;
+  return mStream->CloseWithStatus(aStatus);
+}
+
+class RunOnThread : public Runnable {
+ public:
+  RunOnThread(nsIAsyncInputStream* aStream, nsIInputStreamCallback* aCallback)
+      : Runnable("net::RunOnThread"), mStream(aStream), mCallback(aCallback) {}
+
+  virtual ~RunOnThread() = default;
+
+  NS_IMETHOD Run() override {
+    mCallback->OnInputStreamReady(mStream);
+    return NS_OK;
+  }
+
+ private:
+  nsCOMPtr<nsIAsyncInputStream> mStream;
+  nsCOMPtr<nsIInputStreamCallback> mCallback;
+};
+
+NS_IMETHODIMP
+nsPreloadedStream::AsyncWait(nsIInputStreamCallback* aCallback, uint32_t aFlags,
+                             uint32_t aRequestedCount,
+                             nsIEventTarget* aEventTarget) {
+  if (!mLen) {
+    {
+      auto lock = mCallback.Lock();
+      *lock = aCallback;
+    }
+    return mStream->AsyncWait(aCallback ? this : nullptr, aFlags,
+                              aRequestedCount, aEventTarget);
+  }
+
+  if (!aCallback) return NS_OK;
+
+  if (!aEventTarget) return aCallback->OnInputStreamReady(this);
+
+  nsCOMPtr<nsIRunnable> event = new RunOnThread(this, aCallback);
+  return aEventTarget->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::OnInputStreamReady(nsIAsyncInputStream* aStream) {
+  nsCOMPtr<nsIInputStreamCallback> callback;
+  {
+    auto lock = mCallback.Lock();
+    callback = lock->forget();
+  }
+  if (callback) {
+    return callback->OnInputStreamReady(this);
+  }
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla