1 files changed, 127 insertions, 0 deletions
diff --git a/netwerk/base/ArrayBufferInputStream.cpp b/netwerk/base/ArrayBufferInputStream.cpp
new file mode 100644
index 0000000000..fb86d44469
--- /dev/null
+++ b/netwerk/base/ArrayBufferInputStream.cpp
@@ -0,0 +1,127 @@
+/* -*- 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 <algorithm>
+#include "ArrayBufferInputStream.h"
+#include "nsStreamUtils.h"
+#include "js/ArrayBuffer.h"  // JS::{GetArrayBuffer{ByteLength,Data},IsArrayBufferObject}
+#include "js/RootingAPI.h"  // JS::{Handle,Rooted}
+#include "js/Value.h"       // JS::Value
+#include "mozilla/UniquePtrExtensions.h"
+#include "mozilla/dom/ScriptSettings.h"
+
+using mozilla::dom::RootingCx;
+
+NS_IMPL_ISUPPORTS(ArrayBufferInputStream, nsIArrayBufferInputStream,
+                  nsIInputStream);
+
+NS_IMETHODIMP
+ArrayBufferInputStream::SetData(JS::Handle<JS::Value> aBuffer,
+                                uint64_t aByteOffset, uint64_t aLength) {
+  NS_ASSERT_OWNINGTHREAD(ArrayBufferInputStream);
+
+  if (!aBuffer.isObject()) {
+    return NS_ERROR_FAILURE;
+  }
+  JS::Rooted<JSObject*> arrayBuffer(RootingCx(), &aBuffer.toObject());
+  if (!JS::IsArrayBufferObject(arrayBuffer)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  uint64_t buflen = JS::GetArrayBufferByteLength(arrayBuffer);
+  uint64_t offset = std::min(buflen, aByteOffset);
+  uint64_t bufferLength = std::min(buflen - offset, aLength);
+
+  // Prevent truncation.
+  if (bufferLength > UINT32_MAX) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  mArrayBuffer = mozilla::MakeUniqueFallible<char[]>(bufferLength);
+  if (!mArrayBuffer) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  mBufferLength = bufferLength;
+
+  JS::AutoCheckCannotGC nogc;
+  bool isShared;
+  char* src =
+      (char*)JS::GetArrayBufferData(arrayBuffer, &isShared, nogc) + offset;
+  memcpy(&mArrayBuffer[0], src, mBufferLength);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::Close() {
+  mClosed = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::Available(uint64_t* aCount) {
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+  if (mArrayBuffer) {
+    *aCount = mBufferLength ? mBufferLength - mPos : 0;
+  } else {
+    *aCount = 0;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::Read(char* aBuf, uint32_t aCount,
+                             uint32_t* aReadCount) {
+  return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, aReadCount);
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::ReadSegments(nsWriteSegmentFun writer, void* closure,
+                                     uint32_t aCount, uint32_t* result) {
+  NS_ASSERTION(result, "null ptr");
+  NS_ASSERTION(mBufferLength >= mPos, "bad stream state");
+
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  MOZ_ASSERT(mArrayBuffer || (mPos == mBufferLength),
+             "stream inited incorrectly");
+
+  *result = 0;
+  while (mPos < mBufferLength) {
+    uint32_t remaining = mBufferLength - mPos;
+    MOZ_ASSERT(mArrayBuffer);
+
+    uint32_t count = std::min(aCount, remaining);
+    if (count == 0) {
+      break;
+    }
+
+    uint32_t written;
+    nsresult rv = writer(this, closure, &mArrayBuffer[0] + mPos, *result, count,
+                         &written);
+    if (NS_FAILED(rv)) {
+      // InputStreams do not propagate errors to caller.
+      return NS_OK;
+    }
+
+    NS_ASSERTION(written <= count,
+                 "writer should not write more than we asked it to write");
+    mPos += written;
+    *result += written;
+    aCount -= written;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::IsNonBlocking(bool* aNonBlocking) {
+  *aNonBlocking = true;
+  return NS_OK;
+}