forked from mirrors/gecko-dev
3b40268cc1
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
132 lines
3.6 KiB
C++
132 lines
3.6 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include <algorithm>
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#include "ArrayBufferInputStream.h"
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#include "nsStreamUtils.h"
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#include "js/ArrayBuffer.h" // JS::{GetArrayBuffer{ByteLength,Data},IsArrayBufferObject}
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#include "js/RootingAPI.h" // JS::{Handle,Rooted}
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#include "js/Value.h" // JS::Value
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#include "mozilla/UniquePtrExtensions.h"
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#include "mozilla/dom/ScriptSettings.h"
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using mozilla::dom::RootingCx;
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NS_IMPL_ISUPPORTS(ArrayBufferInputStream, nsIArrayBufferInputStream,
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nsIInputStream);
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NS_IMETHODIMP
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ArrayBufferInputStream::SetData(JS::Handle<JS::Value> aBuffer,
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uint64_t aByteOffset, uint64_t aLength) {
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NS_ASSERT_OWNINGTHREAD(ArrayBufferInputStream);
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if (!aBuffer.isObject()) {
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return NS_ERROR_FAILURE;
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}
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JS::Rooted<JSObject*> arrayBuffer(RootingCx(), &aBuffer.toObject());
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if (!JS::IsArrayBufferObject(arrayBuffer)) {
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return NS_ERROR_FAILURE;
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}
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uint64_t buflen = JS::GetArrayBufferByteLength(arrayBuffer);
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uint64_t offset = std::min(buflen, aByteOffset);
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uint64_t bufferLength = std::min(buflen - offset, aLength);
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// Prevent truncation.
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if (bufferLength > UINT32_MAX) {
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return NS_ERROR_INVALID_ARG;
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}
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mArrayBuffer = mozilla::MakeUniqueFallible<char[]>(bufferLength);
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if (!mArrayBuffer) {
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return NS_ERROR_OUT_OF_MEMORY;
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}
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mBufferLength = bufferLength;
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JS::AutoCheckCannotGC nogc;
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bool isShared;
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char* src =
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(char*)JS::GetArrayBufferData(arrayBuffer, &isShared, nogc) + offset;
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memcpy(&mArrayBuffer[0], src, mBufferLength);
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return NS_OK;
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}
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NS_IMETHODIMP
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ArrayBufferInputStream::Close() {
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mClosed = true;
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return NS_OK;
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}
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NS_IMETHODIMP
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ArrayBufferInputStream::Available(uint64_t* aCount) {
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if (mClosed) {
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return NS_BASE_STREAM_CLOSED;
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}
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if (mArrayBuffer) {
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*aCount = mBufferLength ? mBufferLength - mPos : 0;
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} else {
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*aCount = 0;
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}
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return NS_OK;
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}
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NS_IMETHODIMP
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ArrayBufferInputStream::StreamStatus() {
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return mClosed ? NS_BASE_STREAM_CLOSED : NS_OK;
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}
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NS_IMETHODIMP
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ArrayBufferInputStream::Read(char* aBuf, uint32_t aCount,
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uint32_t* aReadCount) {
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return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, aReadCount);
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}
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NS_IMETHODIMP
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ArrayBufferInputStream::ReadSegments(nsWriteSegmentFun writer, void* closure,
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uint32_t aCount, uint32_t* result) {
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NS_ASSERTION(result, "null ptr");
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NS_ASSERTION(mBufferLength >= mPos, "bad stream state");
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if (mClosed) {
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return NS_BASE_STREAM_CLOSED;
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}
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MOZ_ASSERT(mArrayBuffer || (mPos == mBufferLength),
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"stream inited incorrectly");
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*result = 0;
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while (mPos < mBufferLength) {
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uint32_t remaining = mBufferLength - mPos;
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MOZ_ASSERT(mArrayBuffer);
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uint32_t count = std::min(aCount, remaining);
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if (count == 0) {
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break;
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}
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uint32_t written;
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nsresult rv = writer(this, closure, &mArrayBuffer[0] + mPos, *result, count,
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&written);
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if (NS_FAILED(rv)) {
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// InputStreams do not propagate errors to caller.
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return NS_OK;
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}
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NS_ASSERTION(written <= count,
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"writer should not write more than we asked it to write");
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mPos += written;
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*result += written;
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aCount -= written;
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}
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return NS_OK;
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}
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NS_IMETHODIMP
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ArrayBufferInputStream::IsNonBlocking(bool* aNonBlocking) {
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*aNonBlocking = true;
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return NS_OK;
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}
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