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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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
#include "mozilla/dom/CompressionStream.h"
#include "js/TypeDecls.h"
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/dom/CompressionStreamBinding.h"
#include "mozilla/dom/ReadableStream.h"
#include "mozilla/dom/WritableStream.h"
#include "mozilla/dom/TransformStream.h"
#include "mozilla/dom/TextDecoderStream.h"
#include "mozilla/dom/TransformerCallbackHelpers.h"
#include "mozilla/dom/UnionTypes.h"
#include "ZLibHelper.h"
namespace mozilla::dom {
class CompressionStreamAlgorithms : public TransformerAlgorithmsWrapper {
public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(CompressionStreamAlgorithms,
TransformerAlgorithmsBase)
explicit CompressionStreamAlgorithms(CompressionFormat format) {
int8_t err = deflateInit2(&mZStream, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
ZLibWindowBits(format), 8 /* default memLevel */,
Z_DEFAULT_STRATEGY);
if (err == Z_MEM_ERROR) {
MOZ_CRASH("Out of memory");
}
MOZ_ASSERT(err == Z_OK);
}
// Step 3 of
// Let transformAlgorithm be an algorithm which takes a chunk argument and
// runs the compress and enqueue a chunk algorithm with this and chunk.
MOZ_CAN_RUN_SCRIPT
void TransformCallbackImpl(JS::Handle<JS::Value> aChunk,
TransformStreamDefaultController& aController,
ErrorResult& aRv) override {
AutoJSAPI jsapi;
if (!jsapi.Init(aController.GetParentObject())) {
aRv.ThrowUnknownError("Internal error");
return;
}
JSContext* cx = jsapi.cx();
// Step 1: If chunk is not a BufferSource type, then throw a TypeError.
RootedUnion<OwningArrayBufferViewOrArrayBuffer> bufferSource(cx);
if (!bufferSource.Init(cx, aChunk)) {
aRv.MightThrowJSException();
aRv.StealExceptionFromJSContext(cx);
return;
}
// Step 2: Let buffer be the result of compressing chunk with cs's format
// and context.
// Step 3 - 5: (Done in CompressAndEnqueue)
ProcessTypedArraysFixed(
bufferSource,
[&](const Span<uint8_t>& aData) MOZ_CAN_RUN_SCRIPT_BOUNDARY {
CompressAndEnqueue(cx, aData, ZLibFlush::No, aController, aRv);
});
}
// Step 4 of
// Let flushAlgorithm be an algorithm which takes no argument and runs the
// compress flush and enqueue algorithm with this.
MOZ_CAN_RUN_SCRIPT void FlushCallbackImpl(
TransformStreamDefaultController& aController,
ErrorResult& aRv) override {
AutoJSAPI jsapi;
if (!jsapi.Init(aController.GetParentObject())) {
aRv.ThrowUnknownError("Internal error");
return;
}
JSContext* cx = jsapi.cx();
// Step 1: Let buffer be the result of compressing an empty input with cs's
// format and context, with the finish flag.
// Step 2 - 4: (Done in CompressAndEnqueue)
CompressAndEnqueue(cx, Span<const uint8_t>(), ZLibFlush::Yes, aController,
aRv);
}
private:
// Shared by:
MOZ_CAN_RUN_SCRIPT void CompressAndEnqueue(
JSContext* aCx, Span<const uint8_t> aInput, ZLibFlush aFlush,
TransformStreamDefaultController& aController, ErrorResult& aRv) {
MOZ_ASSERT_IF(aFlush == ZLibFlush::Yes, !aInput.Length());
mZStream.avail_in = aInput.Length();
mZStream.next_in = const_cast<uint8_t*>(aInput.Elements());
JS::RootedVector<JSObject*> array(aCx);
do {
static uint16_t kBufferSize = 16384;
UniquePtr<uint8_t[], JS::FreePolicy> buffer(
static_cast<uint8_t*>(JS_malloc(aCx, kBufferSize)));
if (!buffer) {
aRv.ThrowTypeError("Out of memory");
return;
}
mZStream.avail_out = kBufferSize;
mZStream.next_out = buffer.get();
int8_t err = deflate(&mZStream, aFlush);
// From the manual: deflate() returns ...
switch (err) {
case Z_OK:
case Z_STREAM_END:
case Z_BUF_ERROR:
// * Z_OK if some progress has been made
// * Z_STREAM_END if all input has been consumed and all output has
// been produced (only when flush is set to Z_FINISH)
// * Z_BUF_ERROR if no progress is possible (for example avail_in or
// avail_out was zero). Note that Z_BUF_ERROR is not fatal, and
// deflate() can be called again with more input and more output space
// to continue compressing.
//
// (But of course no input should be given after Z_FINISH)
break;
case Z_STREAM_ERROR:
default:
// * Z_STREAM_ERROR if the stream state was inconsistent
// (which is fatal)
MOZ_ASSERT_UNREACHABLE("Unexpected compression error code");
aRv.ThrowTypeError("Unexpected compression error");
return;
}
// Stream should end only when flushed, see above
// The reverse is not true as zlib may have big data to be flushed that is
// larger than the buffer size
MOZ_ASSERT_IF(err == Z_STREAM_END, aFlush == ZLibFlush::Yes);
// At this point we either exhausted the input or the output buffer
MOZ_ASSERT(!mZStream.avail_in || !mZStream.avail_out);
size_t written = kBufferSize - mZStream.avail_out;
if (!written) {
break;
}
// Step 3: If buffer is empty, return.
// (We'll implicitly return when the array is empty.)
// Step 4: Split buffer into one or more non-empty pieces and convert them
// into Uint8Arrays.
// (The buffer is 'split' by having a fixed sized buffer above.)
JS::Rooted<JSObject*> view(aCx, nsJSUtils::MoveBufferAsUint8Array(
aCx, written, std::move(buffer)));
if (!view || !array.append(view)) {
JS_ClearPendingException(aCx);
aRv.ThrowTypeError("Out of memory");
return;
}
} while (mZStream.avail_out == 0);
// From the manual:
// If deflate returns with avail_out == 0, this function must be called
// again with the same value of the flush parameter and more output space
// (updated avail_out)
// Step 5: For each Uint8Array array, enqueue array in cs's transform.
for (const auto& view : array) {
JS::Rooted<JS::Value> value(aCx, JS::ObjectValue(*view));
aController.Enqueue(aCx, value, aRv);
if (aRv.Failed()) {
return;
}
}
}
~CompressionStreamAlgorithms() override { deflateEnd(&mZStream); };
z_stream mZStream = {};
};
NS_IMPL_CYCLE_COLLECTION_INHERITED(CompressionStreamAlgorithms,
TransformerAlgorithmsBase)
NS_IMPL_ADDREF_INHERITED(CompressionStreamAlgorithms, TransformerAlgorithmsBase)
NS_IMPL_RELEASE_INHERITED(CompressionStreamAlgorithms,
TransformerAlgorithmsBase)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CompressionStreamAlgorithms)
NS_INTERFACE_MAP_END_INHERITING(TransformerAlgorithmsBase)
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(CompressionStream, mGlobal, mStream)
NS_IMPL_CYCLE_COLLECTING_ADDREF(CompressionStream)
NS_IMPL_CYCLE_COLLECTING_RELEASE(CompressionStream)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CompressionStream)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
CompressionStream::CompressionStream(nsISupports* aGlobal,
TransformStream& aStream)
: mGlobal(aGlobal), mStream(&aStream) {}
CompressionStream::~CompressionStream() = default;
JSObject* CompressionStream::WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return CompressionStream_Binding::Wrap(aCx, this, aGivenProto);
}
already_AddRefed<CompressionStream> CompressionStream::Constructor(
const GlobalObject& aGlobal, CompressionFormat aFormat, ErrorResult& aRv) {
// Step 1: If format is unsupported in CompressionStream, then throw a
// TypeError.
// XXX: Skipped as we are using enum for this
// Step 2 - 4: (Done in CompressionStreamAlgorithms)
// Step 5: Set this's transform to a new TransformStream.
// Step 6: Set up this's transform with transformAlgorithm set to
// transformAlgorithm and flushAlgorithm set to flushAlgorithm.
auto algorithms = MakeRefPtr<CompressionStreamAlgorithms>(aFormat);
RefPtr<TransformStream> stream =
TransformStream::CreateGeneric(aGlobal, *algorithms, aRv);
if (aRv.Failed()) {
return nullptr;
}
return do_AddRef(new CompressionStream(aGlobal.GetAsSupports(), *stream));
}
already_AddRefed<ReadableStream> CompressionStream::Readable() const {
return do_AddRef(mStream->Readable());
}
already_AddRefed<WritableStream> CompressionStream::Writable() const {
return do_AddRef(mStream->Writable());
}
} // namespace mozilla::dom