michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include <algorithm>
michael@0: #include "ArrayBufferInputStream.h"
michael@0: #include "nsStreamUtils.h"
michael@0: #include "jsapi.h"
michael@0: #include "jsfriendapi.h"
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(ArrayBufferInputStream, nsIArrayBufferInputStream, nsIInputStream);
michael@0: 
michael@0: ArrayBufferInputStream::ArrayBufferInputStream()
michael@0: : mBuffer(nullptr)
michael@0: , mBufferLength(0)
michael@0: , mOffset(0)
michael@0: , mPos(0)
michael@0: , mClosed(false)
michael@0: {
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: ArrayBufferInputStream::SetData(JS::Handle<JS::Value> aBuffer,
michael@0:                                 uint32_t aByteOffset,
michael@0:                                 uint32_t aLength,
michael@0:                                 JSContext* aCx)
michael@0: {
michael@0:   if (!aBuffer.isObject()) {
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0:   JS::RootedObject arrayBuffer(aCx, &aBuffer.toObject());
michael@0:   if (!JS_IsArrayBufferObject(arrayBuffer)) {
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0: 
michael@0:   mArrayBuffer.construct(aCx, aBuffer);
michael@0: 
michael@0:   uint32_t buflen = JS_GetArrayBufferByteLength(arrayBuffer);
michael@0:   mOffset = std::min(buflen, aByteOffset);
michael@0:   mBufferLength = std::min(buflen - mOffset, aLength);
michael@0:   mBuffer = JS_GetStableArrayBufferData(aCx, arrayBuffer);
michael@0:   if (!mBuffer) {
michael@0:       return NS_ERROR_FAILURE;
michael@0:   }
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: ArrayBufferInputStream::Close()
michael@0: {
michael@0:   mClosed = true;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: ArrayBufferInputStream::Available(uint64_t* aCount)
michael@0: {
michael@0:   if (mClosed) {
michael@0:     return NS_BASE_STREAM_CLOSED;
michael@0:   }
michael@0:   *aCount = mBufferLength - mPos;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: ArrayBufferInputStream::Read(char* aBuf, uint32_t aCount, uint32_t *aReadCount)
michael@0: {
michael@0:   return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, aReadCount);
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: ArrayBufferInputStream::ReadSegments(nsWriteSegmentFun writer, void *closure,
michael@0:                                      uint32_t aCount, uint32_t *result)
michael@0: {
michael@0:   NS_ASSERTION(result, "null ptr");
michael@0:   NS_ASSERTION(mBufferLength >= mPos, "bad stream state");
michael@0: 
michael@0:   if (mClosed) {
michael@0:     return NS_BASE_STREAM_CLOSED;
michael@0:   }
michael@0: 
michael@0:   uint32_t remaining = mBufferLength - mPos;
michael@0:   if (!mArrayBuffer.empty()) {
michael@0:     JSObject* buf = &mArrayBuffer.ref().get().toObject();
michael@0:     uint32_t byteLength = JS_GetArrayBufferByteLength(buf);
michael@0:     if (byteLength == 0 && remaining != 0) {
michael@0:       mClosed = true;
michael@0:       return NS_BASE_STREAM_CLOSED;
michael@0:     }
michael@0:   } else {
michael@0:     MOZ_ASSERT(remaining == 0, "stream inited incorrectly");
michael@0:   }
michael@0: 
michael@0:   if (!remaining) {
michael@0:     *result = 0;
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   if (aCount > remaining) {
michael@0:     aCount = remaining;
michael@0:   }
michael@0:   nsresult rv = writer(this, closure, (char*)(mBuffer + mOffset) + mPos,
michael@0:                        0, aCount, result);
michael@0:   if (NS_SUCCEEDED(rv)) {
michael@0:     NS_ASSERTION(*result <= aCount,
michael@0:                  "writer should not write more than we asked it to write");
michael@0:     mPos += *result;
michael@0:   }
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: ArrayBufferInputStream::IsNonBlocking(bool *aNonBlocking)
michael@0: {
michael@0:   *aNonBlocking = true;
michael@0:   return NS_OK;
michael@0: }