summaryrefslogtreecommitdiffstats
path: root/dom/base/CompressionStream.cpp
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--dom/base/CompressionStream.cpp252
1 files changed, 252 insertions, 0 deletions
diff --git a/dom/base/CompressionStream.cpp b/dom/base/CompressionStream.cpp
new file mode 100644
index 0000000000..72c3b55d52
--- /dev/null
+++ b/dom/base/CompressionStream.cpp
@@ -0,0 +1,252 @@
+/* -*- 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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/CompressionStream.h"
+
+#include "js/TypeDecls.h"
+#include "mozilla/Assertions.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"
+
+// See the zlib manual in https://www.zlib.net/manual.html or in
+// https://searchfox.org/mozilla-central/source/modules/zlib/src/zlib.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
+ // https://wicg.github.io/compression/#dom-compressionstream-compressionstream
+ // 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();
+
+ // https://wicg.github.io/compression/#compress-and-enqueue-a-chunk
+
+ // Step 1: If chunk is not a BufferSource type, then throw a TypeError.
+ // (ExtractSpanFromBufferSource does it)
+ Span<const uint8_t> input = ExtractSpanFromBufferSource(cx, aChunk, aRv);
+ if (aRv.Failed()) {
+ return;
+ }
+
+ // Step 2: Let buffer be the result of compressing chunk with cs's format
+ // and context.
+ // Step 3 - 5: (Done in CompressAndEnqueue)
+ CompressAndEnqueue(cx, input, ZLibFlush::No, aController, aRv);
+ }
+
+ // Step 4 of
+ // https://wicg.github.io/compression/#dom-compressionstream-compressionstream
+ // 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();
+
+ // https://wicg.github.io/compression/#compress-flush-and-enqueue
+
+ // 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:
+ // https://wicg.github.io/compression/#compress-and-enqueue-a-chunk
+ // https://wicg.github.io/compression/#compress-flush-and-enqueue
+ 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> 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 and vise versa, see above
+ MOZ_ASSERT_IF(err == Z_STREAM_END, aFlush == ZLibFlush::Yes);
+ MOZ_ASSERT_IF(aFlush == ZLibFlush::Yes, err == Z_STREAM_END);
+
+ // 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, 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);
+}
+
+// https://wicg.github.io/compression/#dom-compressionstream-compressionstream
+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