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/* -*- 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 "InputStreamLengthHelper.h"
#include "mozilla/dom/WorkerCommon.h"
#include "nsIAsyncInputStream.h"
#include "nsIInputStream.h"
#include "nsNetCID.h"
#include "nsServiceManagerUtils.h"
static NS_DEFINE_CID(kStreamTransportServiceCID, NS_STREAMTRANSPORTSERVICE_CID);
namespace mozilla {
namespace {
class AvailableEvent final : public Runnable {
public:
AvailableEvent(nsIInputStream* stream,
const std::function<void(int64_t aLength)>& aCallback)
: Runnable("mozilla::AvailableEvent"),
mStream(stream),
mCallback(aCallback),
mSize(-1) {
mCallbackTarget = GetCurrentSerialEventTarget();
MOZ_ASSERT(NS_IsMainThread());
}
NS_IMETHOD
Run() override {
// ping
if (!NS_IsMainThread()) {
uint64_t size = 0;
if (NS_WARN_IF(NS_FAILED(mStream->Available(&size)))) {
mSize = -1;
} else {
mSize = (int64_t)size;
}
mStream = nullptr;
nsCOMPtr<nsIRunnable> self(this); // overly cute
mCallbackTarget->Dispatch(self.forget(), NS_DISPATCH_NORMAL);
mCallbackTarget = nullptr;
return NS_OK;
}
// pong
std::function<void(int64_t aLength)> callback;
callback.swap(mCallback);
callback(mSize);
return NS_OK;
}
private:
nsCOMPtr<nsIInputStream> mStream;
std::function<void(int64_t aLength)> mCallback;
nsCOMPtr<nsIEventTarget> mCallbackTarget;
int64_t mSize;
};
} // namespace
/* static */
bool InputStreamLengthHelper::GetSyncLength(nsIInputStream* aStream,
int64_t* aLength) {
MOZ_ASSERT(aStream);
MOZ_ASSERT(aLength);
*aLength = -1;
// Sync length access.
nsCOMPtr<nsIInputStreamLength> streamLength = do_QueryInterface(aStream);
if (streamLength) {
int64_t length = -1;
nsresult rv = streamLength->Length(&length);
// All good!
if (NS_SUCCEEDED(rv)) {
*aLength = length;
return true;
}
// Already closed stream or an error occurred.
if (rv == NS_BASE_STREAM_CLOSED ||
NS_WARN_IF(rv == NS_ERROR_NOT_AVAILABLE) ||
NS_WARN_IF(rv != NS_BASE_STREAM_WOULD_BLOCK)) {
return true;
}
}
nsCOMPtr<nsIAsyncInputStreamLength> asyncStreamLength =
do_QueryInterface(aStream);
if (asyncStreamLength) {
// GetAsyncLength should be used.
return false;
}
// We cannot calculate the length of an async stream.
nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(aStream);
if (asyncStream) {
return false;
}
// For main-thread only, we want to avoid calling ::Available() for blocking
// streams.
if (NS_IsMainThread()) {
bool nonBlocking = false;
if (NS_WARN_IF(NS_FAILED(aStream->IsNonBlocking(&nonBlocking)))) {
// Let's return -1. There is nothing else we can do here.
return true;
}
if (!nonBlocking) {
return false;
}
}
// Fallback using available().
uint64_t available = 0;
nsresult rv = aStream->Available(&available);
if (NS_WARN_IF(NS_FAILED(rv))) {
// Let's return -1. There is nothing else we can do here.
return true;
}
*aLength = (int64_t)available;
return true;
}
/* static */
void InputStreamLengthHelper::GetAsyncLength(
nsIInputStream* aStream,
const std::function<void(int64_t aLength)>& aCallback) {
MOZ_ASSERT(aStream);
MOZ_ASSERT(aCallback);
// We don't want to allow this class to be used on workers because we are not
// using the correct Runnable types.
MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread() ||
!dom::IsCurrentThreadRunningWorker());
RefPtr<InputStreamLengthHelper> helper =
new InputStreamLengthHelper(aStream, aCallback);
// Let's be sure that we don't call ::Available() on main-thread.
if (NS_IsMainThread()) {
nsCOMPtr<nsIInputStreamLength> streamLength = do_QueryInterface(aStream);
nsCOMPtr<nsIAsyncInputStreamLength> asyncStreamLength =
do_QueryInterface(aStream);
if (!streamLength && !asyncStreamLength) {
// We cannot calculate the length of an async stream. We must fix the
// caller if this happens.
#ifdef DEBUG
nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(aStream);
MOZ_DIAGNOSTIC_ASSERT(!asyncStream);
#endif
bool nonBlocking = false;
if (NS_SUCCEEDED(aStream->IsNonBlocking(&nonBlocking)) && !nonBlocking) {
nsCOMPtr<nsIEventTarget> target =
do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
MOZ_ASSERT(target);
RefPtr<AvailableEvent> event = new AvailableEvent(aStream, aCallback);
target->Dispatch(event.forget(), NS_DISPATCH_NORMAL);
return;
}
}
}
// Let's go async in order to have similar behaviors for sync and async
// nsIInputStreamLength implementations.
GetCurrentSerialEventTarget()->Dispatch(helper, NS_DISPATCH_NORMAL);
}
InputStreamLengthHelper::InputStreamLengthHelper(
nsIInputStream* aStream,
const std::function<void(int64_t aLength)>& aCallback)
: Runnable("InputStreamLengthHelper"),
mStream(aStream),
mCallback(aCallback) {
MOZ_ASSERT(aStream);
MOZ_ASSERT(aCallback);
}
InputStreamLengthHelper::~InputStreamLengthHelper() = default;
NS_IMETHODIMP
InputStreamLengthHelper::Run() {
// Sync length access.
nsCOMPtr<nsIInputStreamLength> streamLength = do_QueryInterface(mStream);
if (streamLength) {
int64_t length = -1;
nsresult rv = streamLength->Length(&length);
// All good!
if (NS_SUCCEEDED(rv)) {
ExecCallback(length);
return NS_OK;
}
// Already closed stream or an error occurred.
if (rv == NS_BASE_STREAM_CLOSED ||
NS_WARN_IF(rv == NS_ERROR_NOT_AVAILABLE) ||
NS_WARN_IF(rv != NS_BASE_STREAM_WOULD_BLOCK)) {
ExecCallback(-1);
return NS_OK;
}
}
// Async length access.
nsCOMPtr<nsIAsyncInputStreamLength> asyncStreamLength =
do_QueryInterface(mStream);
if (asyncStreamLength) {
nsresult rv =
asyncStreamLength->AsyncLengthWait(this, GetCurrentSerialEventTarget());
if (NS_WARN_IF(NS_FAILED(rv))) {
ExecCallback(-1);
}
return NS_OK;
}
// Fallback using available().
uint64_t available = 0;
nsresult rv = mStream->Available(&available);
if (NS_WARN_IF(NS_FAILED(rv))) {
ExecCallback(-1);
return NS_OK;
}
ExecCallback((int64_t)available);
return NS_OK;
}
NS_IMETHODIMP
InputStreamLengthHelper::OnInputStreamLengthReady(
nsIAsyncInputStreamLength* aStream, int64_t aLength) {
ExecCallback(aLength);
return NS_OK;
}
void InputStreamLengthHelper::ExecCallback(int64_t aLength) {
MOZ_ASSERT(mCallback);
std::function<void(int64_t aLength)> callback;
callback.swap(mCallback);
callback(aLength);
}
NS_IMPL_ISUPPORTS_INHERITED(InputStreamLengthHelper, Runnable,
nsIInputStreamLengthCallback)
} // namespace mozilla