script/dom/stream/
compressionstream.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4
5#[cfg(feature = "brotli-compression-stream")]
6use std::borrow::BorrowMut;
7use std::cell::RefCell;
8use std::io::{self, Write};
9use std::ptr;
10
11#[cfg(feature = "brotli-compression-stream")]
12use brotli::CompressorWriter as BrotliEncoder;
13use dom_struct::dom_struct;
14use flate2::Compression;
15use flate2::write::{DeflateEncoder, GzEncoder, ZlibEncoder};
16use js::context::JSContext;
17use js::jsapi::JSObject;
18use js::jsval::UndefinedValue;
19use js::rust::{HandleObject as SafeHandleObject, HandleValue as SafeHandleValue};
20use js::typedarray::Uint8;
21#[cfg(feature = "brotli-compression-stream")]
22use malloc_size_of::MallocShallowSizeOf;
23use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
24use script_bindings::reflector::{Reflector, reflect_dom_object_with_proto};
25
26use crate::dom::bindings::buffer_source::{create_buffer_source, get_buffer_source_slice};
27use crate::dom::bindings::codegen::Bindings::CompressionStreamBinding::{
28    CompressionFormat, CompressionStreamMethods,
29};
30use crate::dom::bindings::codegen::UnionTypes::ArrayBufferViewOrArrayBuffer;
31use crate::dom::bindings::conversions::{FromJSValConvertible, ToJSValConvertible};
32use crate::dom::bindings::error::{Error, Fallible};
33use crate::dom::bindings::root::{Dom, DomRoot};
34use crate::dom::stream::transformstreamdefaultcontroller::TransformerType;
35use crate::dom::types::{
36    GlobalScope, ReadableStream, TransformStream, TransformStreamDefaultController, WritableStream,
37};
38
39#[cfg(feature = "brotli-compression-stream")]
40pub(crate) const BROTLI_BUFFER_SIZE: usize = 4096;
41#[cfg(feature = "brotli-compression-stream")]
42const BROTLI_QUALITIY_LEVEL: u32 = 5;
43#[cfg(feature = "brotli-compression-stream")]
44const BROTLI_WINDOW_SIZE: u32 = 22;
45
46/// <https://compression.spec.whatwg.org/#compressionstream>
47#[dom_struct]
48pub(crate) struct CompressionStream {
49    reflector_: Reflector,
50
51    /// <https://streams.spec.whatwg.org/#generictransformstream>
52    transform: Dom<TransformStream>,
53
54    /// <https://compression.spec.whatwg.org/#compressionstream-format>
55    format: CompressionFormat,
56
57    // <https://compression.spec.whatwg.org/#compressionstream-context>
58    #[no_trace]
59    context: RefCell<CompressionContext>,
60}
61
62impl CompressionStream {
63    fn new_inherited(
64        transform: &TransformStream,
65        format: CompressionFormat,
66    ) -> Fallible<CompressionStream> {
67        Ok(CompressionStream {
68            reflector_: Reflector::new(),
69            transform: Dom::from_ref(transform),
70            format,
71            context: RefCell::new(CompressionContext::new(format)?),
72        })
73    }
74    #[cfg_attr(crown, expect(crown::unrooted_must_root))] // reflect will only be called on the box which is fine
75    fn new_with_proto(
76        cx: &mut JSContext,
77        global: &GlobalScope,
78        proto: Option<SafeHandleObject>,
79        transform: &TransformStream,
80        format: CompressionFormat,
81    ) -> Fallible<DomRoot<CompressionStream>> {
82        Ok(reflect_dom_object_with_proto(
83            cx,
84            Box::new(CompressionStream::new_inherited(transform, format)?),
85            global,
86            proto,
87        ))
88    }
89}
90
91impl CompressionStreamMethods<crate::DomTypeHolder> for CompressionStream {
92    /// <https://compression.spec.whatwg.org/#dom-compressionstream-compressionstream>
93    fn Constructor(
94        cx: &mut JSContext,
95        global: &GlobalScope,
96        proto: Option<SafeHandleObject>,
97        format: CompressionFormat,
98    ) -> Fallible<DomRoot<CompressionStream>> {
99        // Step 1. If format is unsupported in CompressionStream, then throw a TypeError.
100        // NOTE: All of "brotli", "deflate", "deflate-raw" and "gzip" are supported.
101
102        // Step 2. Set this’s format to format.
103        // Step 5. Set this’s transform to a new TransformStream.
104        let transform = TransformStream::new_with_proto(cx, global, None);
105        let compression_stream =
106            CompressionStream::new_with_proto(cx, global, proto, &transform, format)?;
107
108        // Step 3. Let transformAlgorithm be an algorithm which takes a chunk argument and runs the
109        // compress and enqueue a chunk algorithm with this and chunk.
110        // Step 4. Let flushAlgorithm be an algorithm which takes no argument and runs the compress
111        // flush and enqueue algorithm with this.
112
113        // Step 6. Set up this’s transform with transformAlgorithm set to transformAlgorithm and
114        // flushAlgorithm set to flushAlgorithm.
115        transform.set_up(
116            cx,
117            global,
118            TransformerType::Compressor(compression_stream.as_traced()),
119        )?;
120
121        Ok(compression_stream)
122    }
123
124    /// <https://streams.spec.whatwg.org/#dom-generictransformstream-readable>
125    fn Readable(&self) -> DomRoot<ReadableStream> {
126        // The readable getter steps are to return this’s transform.[[readable]].
127        self.transform.get_readable()
128    }
129
130    /// <https://streams.spec.whatwg.org/#dom-generictransformstream-writable>
131    fn Writable(&self) -> DomRoot<WritableStream> {
132        // The writable getter steps are to return this’s transform.[[writable]].
133        self.transform.get_writable()
134    }
135}
136
137/// <https://compression.spec.whatwg.org/#compress-and-enqueue-a-chunk>
138pub(crate) fn compress_and_enqueue_a_chunk(
139    cx: &mut JSContext,
140    global: &GlobalScope,
141    cs: &CompressionStream,
142    chunk: SafeHandleValue,
143    controller: &TransformStreamDefaultController,
144) -> Fallible<()> {
145    // Step 1. If chunk is not a BufferSource type, then throw a TypeError.
146    let conversion_result =
147        ArrayBufferViewOrArrayBuffer::from_jsval(cx, chunk, ()).map_err(|_| {
148            Error::Type(c"Unable to convert chunk into ArrayBuffer or ArrayBufferView".to_owned())
149        })?;
150    let buffer_source = conversion_result.get_success_value().ok_or_else(|| {
151        Error::Type(c"Unable to convert chunk into ArrayBuffer or ArrayBufferView".to_owned())
152    })?;
153
154    // Step 2. Let buffer be the result of compressing chunk with cs’s format and context.
155    // NOTE: In our implementation, the enum type of context already indicates the format.
156    let buffer = {
157        let mut compression_context = cs.context.borrow_mut();
158        let buffer = compression_context
159            .compress(get_buffer_source_slice(buffer_source, cx.no_gc()))
160            .map_err(|_| Error::Operation(Some("Failed to compress a chunk of input".into())))?;
161
162        // Step 3. If buffer is empty, return.
163        if buffer.is_empty() {
164            return Ok(());
165        }
166        buffer
167    };
168
169    // Step 4. Let arrays be the result of splitting buffer into one or more non-empty pieces and
170    // converting them into Uint8Arrays.
171    // Step 5. For each Uint8Array array of arrays, enqueue array in cs’s transform.
172    // NOTE: We process the result in a single Uint8Array.
173    rooted!(&in(cx) let mut js_object = ptr::null_mut::<JSObject>());
174    let buffer_source = create_buffer_source::<Uint8>(cx, &buffer, js_object.handle_mut())
175        .map_err(|_| Error::Type(c"Cannot convert byte sequence to Uint8Array".to_owned()))?;
176    rooted!(&in(cx) let mut rval = UndefinedValue());
177    buffer_source.to_jsval(cx, rval.handle_mut());
178    controller.enqueue(cx, global, rval.handle())?;
179
180    Ok(())
181}
182
183/// <https://compression.spec.whatwg.org/#compress-flush-and-enqueue>
184pub(crate) fn compress_flush_and_enqueue(
185    cx: &mut JSContext,
186    global: &GlobalScope,
187    cs: &CompressionStream,
188    controller: &TransformStreamDefaultController,
189) -> Fallible<()> {
190    // Step 1. Let buffer be the result of compressing an empty input with cs’s format and context,
191    // with the finish flag.
192    // NOTE: In our implementation, the enum type of context already indicates the format.
193    let buffer = {
194        let mut compression_context = cs.context.borrow_mut();
195        let buffer = compression_context.finalize().map_err(|_| {
196            Error::Operation(Some("Failed to finalize the compression stream".into()))
197        })?;
198
199        // Step 2. If buffer is empty, return.
200        if buffer.is_empty() {
201            return Ok(());
202        }
203        buffer
204    };
205
206    // Step 3. Let arrays be the result of splitting buffer into one or more non-empty pieces and
207    // converting them into Uint8Arrays.
208    // Step 4. For each Uint8Array array of arrays, enqueue array in cs’s transform.
209    // NOTE: We process the result in a single Uint8Array.
210    rooted!(&in(cx) let mut js_object = ptr::null_mut::<JSObject>());
211    let buffer_source = create_buffer_source::<Uint8>(cx, &buffer, js_object.handle_mut())
212        .map_err(|_| Error::Type(c"Cannot convert byte sequence to Uint8Array".to_owned()))?;
213    rooted!(&in(cx) let mut rval = UndefinedValue());
214    buffer_source.to_jsval(cx, rval.handle_mut());
215    controller.enqueue(cx, global, rval.handle())?;
216
217    Ok(())
218}
219
220/// An enum grouping encoders of differenct compression algorithms.
221enum Encoder {
222    #[cfg(feature = "brotli-compression-stream")]
223    Brotli(Box<BrotliEncoder<Vec<u8>>>),
224    Deflate(ZlibEncoder<Vec<u8>>),
225    DeflateRaw(DeflateEncoder<Vec<u8>>),
226    Gzip(GzEncoder<Vec<u8>>),
227}
228
229impl MallocSizeOf for Encoder {
230    fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
231        match self {
232            #[cfg(feature = "brotli-compression-stream")]
233            Encoder::Brotli(encoder) => encoder.shallow_size_of(ops),
234            Encoder::Deflate(encoder) => encoder.size_of(ops),
235            Encoder::DeflateRaw(encoder) => encoder.size_of(ops),
236            Encoder::Gzip(encoder) => encoder.size_of(ops),
237        }
238    }
239}
240
241/// <https://compression.spec.whatwg.org/#compressionstream-context>
242/// Used to encapsulate the logic of encoder.
243#[derive(MallocSizeOf)]
244struct CompressionContext {
245    encoder: Encoder,
246}
247
248impl CompressionContext {
249    fn new(format: CompressionFormat) -> Fallible<CompressionContext> {
250        let encoder = match format {
251            #[cfg(feature = "brotli-compression-stream")]
252            CompressionFormat::Brotli => Encoder::Brotli(Box::new(BrotliEncoder::new(
253                Vec::new(),
254                BROTLI_BUFFER_SIZE,
255                BROTLI_QUALITIY_LEVEL,
256                BROTLI_WINDOW_SIZE,
257            ))),
258            #[cfg(not(feature = "brotli-compression-stream"))]
259            CompressionFormat::Brotli => {
260                return Err(Error::NotSupported(Some("Brotli not supported".into())));
261            },
262            CompressionFormat::Deflate => {
263                Encoder::Deflate(ZlibEncoder::new(Vec::new(), Compression::default()))
264            },
265            CompressionFormat::Deflate_raw => {
266                Encoder::DeflateRaw(DeflateEncoder::new(Vec::new(), Compression::default()))
267            },
268            CompressionFormat::Gzip => {
269                Encoder::Gzip(GzEncoder::new(Vec::new(), Compression::default()))
270            },
271        };
272        Ok(CompressionContext { encoder })
273    }
274
275    fn compress(&mut self, chunk: &[u8]) -> Result<Vec<u8>, io::Error> {
276        let mut result = Vec::new();
277
278        match &mut self.encoder {
279            #[cfg(feature = "brotli-compression-stream")]
280            Encoder::Brotli(encoder) => {
281                encoder.write_all(chunk)?;
282                encoder.flush()?;
283                result.append(encoder.get_mut());
284            },
285            Encoder::Deflate(encoder) => {
286                encoder.write_all(chunk)?;
287                encoder.flush()?;
288                result.append(encoder.get_mut());
289            },
290            Encoder::DeflateRaw(encoder) => {
291                encoder.write_all(chunk)?;
292                encoder.flush()?;
293                result.append(encoder.get_mut());
294            },
295            Encoder::Gzip(encoder) => {
296                encoder.write_all(chunk)?;
297                encoder.flush()?;
298                result.append(encoder.get_mut());
299            },
300        }
301
302        Ok(result)
303    }
304
305    fn finalize(&mut self) -> Result<Vec<u8>, io::Error> {
306        let mut result = Vec::new();
307
308        match &mut self.encoder {
309            #[cfg(feature = "brotli-compression-stream")]
310            Encoder::Brotli(encoder) => {
311                let encoder = std::mem::replace(
312                    encoder.borrow_mut(),
313                    BrotliEncoder::new(
314                        Vec::new(),
315                        BROTLI_BUFFER_SIZE,
316                        BROTLI_QUALITIY_LEVEL,
317                        BROTLI_WINDOW_SIZE,
318                    ),
319                );
320                result = encoder.into_inner();
321            },
322            Encoder::Deflate(encoder) => {
323                encoder.try_finish()?;
324                result.append(encoder.get_mut());
325            },
326            Encoder::DeflateRaw(encoder) => {
327                encoder.try_finish()?;
328                result.append(encoder.get_mut());
329            },
330            Encoder::Gzip(encoder) => {
331                encoder.try_finish()?;
332                result.append(encoder.get_mut());
333            },
334        }
335
336        Ok(result)
337    }
338}
script/dom/stream/compressionstream.rs

script/dom/stream/
compressionstream.rs
