gecko-dev/dom/file/FileReaderSync.cpp
Andrew McCreight 837f0af066 Bug 1493737 - Fix many trivial calls to do_QueryInterface r=smaug
If class A is derived from class B, then an instance of class A can be
converted to B via a static cast, so a slower QI is not needed.

Differential Revision: https://phabricator.services.mozilla.com/D6861

--HG--
extra : moz-landing-system : lando
2018-10-01 21:38:01 +00:00

510 lines
14 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "FileReaderSync.h"
#include "jsfriendapi.h"
#include "mozilla/Unused.h"
#include "mozilla/Base64.h"
#include "mozilla/dom/File.h"
#include "mozilla/Encoding.h"
#include "mozilla/dom/FileReaderSyncBinding.h"
#include "nsCExternalHandlerService.h"
#include "nsComponentManagerUtils.h"
#include "nsCOMPtr.h"
#include "nsError.h"
#include "nsIConverterInputStream.h"
#include "nsIInputStream.h"
#include "nsIMultiplexInputStream.h"
#include "nsStreamUtils.h"
#include "nsStringStream.h"
#include "nsISupportsImpl.h"
#include "nsNetUtil.h"
#include "nsServiceManagerUtils.h"
#include "nsIAsyncInputStream.h"
#include "mozilla/dom/WorkerPrivate.h"
#include "mozilla/dom/WorkerRunnable.h"
using namespace mozilla;
using namespace mozilla::dom;
using mozilla::dom::Optional;
using mozilla::dom::GlobalObject;
// static
already_AddRefed<FileReaderSync>
FileReaderSync::Constructor(const GlobalObject& aGlobal, ErrorResult& aRv)
{
RefPtr<FileReaderSync> frs = new FileReaderSync();
return frs.forget();
}
bool
FileReaderSync::WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto,
JS::MutableHandle<JSObject*> aReflector)
{
return FileReaderSync_Binding::Wrap(aCx, this, aGivenProto, aReflector);
}
void
FileReaderSync::ReadAsArrayBuffer(JSContext* aCx,
JS::Handle<JSObject*> aScopeObj,
Blob& aBlob,
JS::MutableHandle<JSObject*> aRetval,
ErrorResult& aRv)
{
uint64_t blobSize = aBlob.GetSize(aRv);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
UniquePtr<char[], JS::FreePolicy> bufferData(
js_pod_arena_malloc<char>(js::ArrayBufferContentsArena, blobSize));
if (!bufferData) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
nsCOMPtr<nsIInputStream> stream;
aBlob.CreateInputStream(getter_AddRefs(stream), aRv);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
uint32_t numRead;
aRv = SyncRead(stream, bufferData.get(), blobSize, &numRead);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
// The file is changed in the meantime?
if (numRead != blobSize) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
JSObject* arrayBuffer = JS_NewArrayBufferWithContents(aCx, blobSize, bufferData.get());
if (!arrayBuffer) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
// arrayBuffer takes the ownership when it is not null. Otherwise we
// need to release it explicitly.
mozilla::Unused << bufferData.release();
aRetval.set(arrayBuffer);
}
void
FileReaderSync::ReadAsBinaryString(Blob& aBlob,
nsAString& aResult,
ErrorResult& aRv)
{
nsCOMPtr<nsIInputStream> stream;
aBlob.CreateInputStream(getter_AddRefs(stream), aRv);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
uint32_t numRead;
do {
char readBuf[4096];
aRv = SyncRead(stream, readBuf, sizeof(readBuf), &numRead);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
uint32_t oldLength = aResult.Length();
AppendASCIItoUTF16(Substring(readBuf, readBuf + numRead), aResult);
if (aResult.Length() - oldLength != numRead) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
} while (numRead > 0);
}
void
FileReaderSync::ReadAsText(Blob& aBlob,
const Optional<nsAString>& aEncoding,
nsAString& aResult,
ErrorResult& aRv)
{
nsCOMPtr<nsIInputStream> stream;
aBlob.CreateInputStream(getter_AddRefs(stream), aRv);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
nsCString sniffBuf;
if (!sniffBuf.SetLength(3, fallible)) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
uint32_t numRead = 0;
aRv = SyncRead(stream, sniffBuf.BeginWriting(), sniffBuf.Length(), &numRead);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
// No data, we don't need to continue.
if (numRead == 0) {
aResult.Truncate();
return;
}
// Try the API argument.
const Encoding* encoding = aEncoding.WasPassed() ?
Encoding::ForLabel(aEncoding.Value()) : nullptr;
if (!encoding) {
// API argument failed. Try the type property of the blob.
nsAutoString type16;
aBlob.GetType(type16);
NS_ConvertUTF16toUTF8 type(type16);
nsAutoCString specifiedCharset;
bool haveCharset;
int32_t charsetStart, charsetEnd;
NS_ExtractCharsetFromContentType(type,
specifiedCharset,
&haveCharset,
&charsetStart,
&charsetEnd);
encoding = Encoding::ForLabel(specifiedCharset);
if (!encoding) {
// Type property failed. Use UTF-8.
encoding = UTF_8_ENCODING;
}
}
if (numRead < sniffBuf.Length()) {
sniffBuf.Truncate(numRead);
}
// Let's recreate the full stream using a:
// multiplexStream(syncStream + original stream)
// In theory, we could try to see if the inputStream is a nsISeekableStream,
// but this doesn't work correctly for nsPipe3 - See bug 1349570.
nsCOMPtr<nsIMultiplexInputStream> multiplexStream =
do_CreateInstance("@mozilla.org/io/multiplex-input-stream;1");
if (NS_WARN_IF(!multiplexStream)) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
nsCOMPtr<nsIInputStream> sniffStringStream;
aRv = NS_NewCStringInputStream(getter_AddRefs(sniffStringStream), sniffBuf);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
aRv = multiplexStream->AppendStream(sniffStringStream);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
uint64_t blobSize = aBlob.GetSize(aRv);
if (NS_WARN_IF(aRv.Failed())){
return;
}
nsCOMPtr<nsIInputStream> syncStream;
aRv = ConvertAsyncToSyncStream(blobSize - sniffBuf.Length(), stream.forget(),
getter_AddRefs(syncStream));
if (NS_WARN_IF(aRv.Failed())) {
return;
}
// ConvertAsyncToSyncStream returns a null syncStream if the stream has been
// already closed or there is nothing to read.
if (syncStream) {
aRv = multiplexStream->AppendStream(syncStream);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
}
nsAutoCString charset;
encoding->Name(charset);
nsCOMPtr<nsIInputStream> multiplex(do_QueryInterface(multiplexStream));
aRv = ConvertStream(multiplex, charset.get(), aResult);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
}
void
FileReaderSync::ReadAsDataURL(Blob& aBlob, nsAString& aResult,
ErrorResult& aRv)
{
nsAutoString scratchResult;
scratchResult.AssignLiteral("data:");
nsString contentType;
aBlob.GetType(contentType);
if (contentType.IsEmpty()) {
scratchResult.AppendLiteral("application/octet-stream");
} else {
scratchResult.Append(contentType);
}
scratchResult.AppendLiteral(";base64,");
nsCOMPtr<nsIInputStream> stream;
aBlob.CreateInputStream(getter_AddRefs(stream), aRv);
if (NS_WARN_IF(aRv.Failed())){
return;
}
uint64_t blobSize = aBlob.GetSize(aRv);
if (NS_WARN_IF(aRv.Failed())){
return;
}
nsCOMPtr<nsIInputStream> syncStream;
aRv = ConvertAsyncToSyncStream(blobSize, stream.forget(),
getter_AddRefs(syncStream));
if (NS_WARN_IF(aRv.Failed())) {
return;
}
MOZ_ASSERT(syncStream);
uint64_t size;
aRv = syncStream->Available(&size);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
// The file is changed in the meantime?
if (blobSize != size) {
return;
}
nsAutoString encodedData;
aRv = Base64EncodeInputStream(syncStream, encodedData, size);
if (NS_WARN_IF(aRv.Failed())){
return;
}
scratchResult.Append(encodedData);
aResult = scratchResult;
}
nsresult
FileReaderSync::ConvertStream(nsIInputStream *aStream,
const char *aCharset,
nsAString &aResult)
{
nsCOMPtr<nsIConverterInputStream> converterStream =
do_CreateInstance("@mozilla.org/intl/converter-input-stream;1");
NS_ENSURE_TRUE(converterStream, NS_ERROR_FAILURE);
nsresult rv = converterStream->Init(aStream, aCharset, 8192,
nsIConverterInputStream::DEFAULT_REPLACEMENT_CHARACTER);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIUnicharInputStream> unicharStream = converterStream;
NS_ENSURE_TRUE(unicharStream, NS_ERROR_FAILURE);
uint32_t numChars;
nsString result;
while (NS_SUCCEEDED(unicharStream->ReadString(8192, result, &numChars)) &&
numChars > 0) {
uint32_t oldLength = aResult.Length();
aResult.Append(result);
if (aResult.Length() - oldLength != result.Length()) {
return NS_ERROR_OUT_OF_MEMORY;
}
}
return rv;
}
namespace {
// This runnable is used to terminate the sync event loop.
class ReadReadyRunnable final : public WorkerSyncRunnable
{
public:
ReadReadyRunnable(WorkerPrivate* aWorkerPrivate,
nsIEventTarget* aSyncLoopTarget)
: WorkerSyncRunnable(aWorkerPrivate, aSyncLoopTarget)
{}
bool
WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override
{
aWorkerPrivate->AssertIsOnWorkerThread();
MOZ_ASSERT(mSyncLoopTarget);
nsCOMPtr<nsIEventTarget> syncLoopTarget;
mSyncLoopTarget.swap(syncLoopTarget);
aWorkerPrivate->StopSyncLoop(syncLoopTarget, true);
return true;
}
private:
~ReadReadyRunnable()
{}
};
// This class implements nsIInputStreamCallback and it will be called when the
// stream is ready to be read.
class ReadCallback final : public nsIInputStreamCallback
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
ReadCallback(WorkerPrivate* aWorkerPrivate, nsIEventTarget* aEventTarget)
: mWorkerPrivate(aWorkerPrivate)
, mEventTarget(aEventTarget)
{}
NS_IMETHOD
OnInputStreamReady(nsIAsyncInputStream* aStream) override
{
// I/O Thread. Now we need to block the sync event loop.
RefPtr<ReadReadyRunnable> runnable =
new ReadReadyRunnable(mWorkerPrivate, mEventTarget);
return mEventTarget->Dispatch(runnable.forget(), NS_DISPATCH_NORMAL);
}
private:
~ReadCallback()
{}
// The worker is kept alive because of the sync event loop.
WorkerPrivate* mWorkerPrivate;
nsCOMPtr<nsIEventTarget> mEventTarget;
};
NS_IMPL_ADDREF(ReadCallback);
NS_IMPL_RELEASE(ReadCallback);
NS_INTERFACE_MAP_BEGIN(ReadCallback)
NS_INTERFACE_MAP_ENTRY(nsIInputStreamCallback)
NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIInputStreamCallback)
NS_INTERFACE_MAP_END
} // anonymous
nsresult
FileReaderSync::SyncRead(nsIInputStream* aStream, char* aBuffer,
uint32_t aBufferSize, uint32_t* aRead)
{
MOZ_ASSERT(aStream);
MOZ_ASSERT(aBuffer);
MOZ_ASSERT(aRead);
// Let's try to read, directly.
nsresult rv = aStream->Read(aBuffer, aBufferSize, aRead);
// Nothing else to read.
if (rv == NS_BASE_STREAM_CLOSED ||
(NS_SUCCEEDED(rv) && *aRead == 0)) {
return NS_OK;
}
// An error.
if (NS_FAILED(rv) && rv != NS_BASE_STREAM_WOULD_BLOCK) {
return rv;
}
// All good.
if (NS_SUCCEEDED(rv)) {
// Not enough data, let's read recursively.
if (*aRead != aBufferSize) {
uint32_t byteRead = 0;
rv = SyncRead(aStream, aBuffer + *aRead, aBufferSize - *aRead, &byteRead);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
*aRead += byteRead;
}
return NS_OK;
}
// We need to proceed async.
nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(aStream);
if (!asyncStream) {
return rv;
}
WorkerPrivate* workerPrivate = GetCurrentThreadWorkerPrivate();
MOZ_ASSERT(workerPrivate);
AutoSyncLoopHolder syncLoop(workerPrivate, Canceling);
nsCOMPtr<nsIEventTarget> syncLoopTarget = syncLoop.GetEventTarget();
if (!syncLoopTarget) {
// SyncLoop creation can fail if the worker is shutting down.
return NS_ERROR_DOM_INVALID_STATE_ERR;
}
RefPtr<ReadCallback> callback =
new ReadCallback(workerPrivate, syncLoopTarget);
nsCOMPtr<nsIEventTarget> target =
do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
MOZ_ASSERT(target);
rv = asyncStream->AsyncWait(callback, 0, aBufferSize, target);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
if (!syncLoop.Run()) {
return NS_ERROR_DOM_INVALID_STATE_ERR;
}
// Now, we can try to read again.
return SyncRead(aStream, aBuffer, aBufferSize, aRead);
}
nsresult
FileReaderSync::ConvertAsyncToSyncStream(uint64_t aStreamSize,
already_AddRefed<nsIInputStream> aAsyncStream,
nsIInputStream** aSyncStream)
{
nsCOMPtr<nsIInputStream> asyncInputStream = std::move(aAsyncStream);
// If the stream is not async, we just need it to be bufferable.
nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(asyncInputStream);
if (!asyncStream) {
return NS_NewBufferedInputStream(aSyncStream, asyncInputStream.forget(), 4096);
}
nsAutoCString buffer;
if (!buffer.SetLength(aStreamSize, fallible)) {
return NS_ERROR_OUT_OF_MEMORY;
}
uint32_t read;
nsresult rv =
SyncRead(asyncInputStream, buffer.BeginWriting(), aStreamSize, &read);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
if (read != aStreamSize) {
return NS_ERROR_FAILURE;
}
rv = NS_NewCStringInputStream(aSyncStream, std::move(buffer));
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
return NS_OK;
}