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    rooted!(&in(cx) let mut js_object = ptr::null_mut::<JSObject>());
157    let array = {
158        let mut compression_context = cs.context.borrow_mut();
159        let buffer = compression_context
160            .compress(get_buffer_source_slice(buffer_source, cx.no_gc()))
161            .map_err(|_| Error::Operation(Some("Failed to compress a chunk of input".into())))?;
162
163        // Step 3. If buffer is empty, return.
164        if buffer.is_empty() {
165            return Ok(());
166        }
167        // Step 4. Let arrays be the result of splitting buffer into one or more non-empty pieces and
168        // converting them into Uint8Arrays.
169        // NOTE: We process the result in a single Uint8Array.
170        create_buffer_source::<Uint8>(cx, buffer, js_object.handle_mut())
171            .map_err(|_| Error::Type(c"Cannot convert byte sequence to Uint8Array".to_owned()))?
172    };
173    // Step 5. For each Uint8Array array of arrays, enqueue array in cs’s transform.
174    rooted!(&in(cx) let mut rval = UndefinedValue());
175    array.to_jsval(cx, rval.handle_mut());
176    controller.enqueue(cx, global, rval.handle())?;
177
178    Ok(())
179}
180
181/// <https://compression.spec.whatwg.org/#compress-flush-and-enqueue>
182pub(crate) fn compress_flush_and_enqueue(
183    cx: &mut JSContext,
184    global: &GlobalScope,
185    cs: &CompressionStream,
186    controller: &TransformStreamDefaultController,
187) -> Fallible<()> {
188    // Step 1. Let buffer be the result of compressing an empty input with cs’s format and context,
189    // with the finish flag.
190    // NOTE: In our implementation, the enum type of context already indicates the format.
191    rooted!(&in(cx) let mut js_object = ptr::null_mut::<JSObject>());
192    let array = {
193        let mut compression_context = cs.context.borrow_mut();
194        let buffer = compression_context.finalize().map_err(|_| {
195            Error::Operation(Some("Failed to finalize the compression stream".into()))
196        })?;
197
198        // Step 2. If buffer is empty, return.
199        if buffer.is_empty() {
200            return Ok(());
201        }
202        // Step 3. Let arrays be the result of splitting buffer into one or more non-empty pieces and
203        // converting them into Uint8Arrays.
204        // NOTE: We process the result in a single Uint8Array.
205        create_buffer_source::<Uint8>(cx, buffer, js_object.handle_mut())
206            .map_err(|_| Error::Type(c"Cannot convert byte sequence to Uint8Array".to_owned()))?
207    };
208    // Step 4. For each Uint8Array array of arrays, enqueue array in cs’s transform.
209    rooted!(&in(cx) let mut rval = UndefinedValue());
210    array.to_jsval(cx, rval.handle_mut());
211    controller.enqueue(cx, global, rval.handle())?;
212
213    Ok(())
214}
215
216/// An enum grouping encoders of differenct compression algorithms.
217enum Encoder {
218    #[cfg(feature = "brotli-compression-stream")]
219    Brotli(Box<BrotliEncoder<Vec<u8>>>),
220    Deflate(ZlibEncoder<Vec<u8>>),
221    DeflateRaw(DeflateEncoder<Vec<u8>>),
222    Gzip(GzEncoder<Vec<u8>>),
223}
224
225impl MallocSizeOf for Encoder {
226    fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
227        match self {
228            #[cfg(feature = "brotli-compression-stream")]
229            Encoder::Brotli(encoder) => encoder.shallow_size_of(ops),
230            Encoder::Deflate(encoder) => encoder.size_of(ops),
231            Encoder::DeflateRaw(encoder) => encoder.size_of(ops),
232            Encoder::Gzip(encoder) => encoder.size_of(ops),
233        }
234    }
235}
236
237/// <https://compression.spec.whatwg.org/#compressionstream-context>
238/// Used to encapsulate the logic of encoder.
239#[derive(MallocSizeOf)]
240struct CompressionContext {
241    encoder: Encoder,
242}
243
244impl CompressionContext {
245    fn new(format: CompressionFormat) -> Fallible<CompressionContext> {
246        let encoder = match format {
247            #[cfg(feature = "brotli-compression-stream")]
248            CompressionFormat::Brotli => Encoder::Brotli(Box::new(BrotliEncoder::new(
249                Vec::new(),
250                BROTLI_BUFFER_SIZE,
251                BROTLI_QUALITIY_LEVEL,
252                BROTLI_WINDOW_SIZE,
253            ))),
254            #[cfg(not(feature = "brotli-compression-stream"))]
255            CompressionFormat::Brotli => {
256                return Err(Error::NotSupported(Some("Brotli not supported".into())));
257            },
258            CompressionFormat::Deflate => {
259                Encoder::Deflate(ZlibEncoder::new(Vec::new(), Compression::default()))
260            },
261            CompressionFormat::Deflate_raw => {
262                Encoder::DeflateRaw(DeflateEncoder::new(Vec::new(), Compression::default()))
263            },
264            CompressionFormat::Gzip => {
265                Encoder::Gzip(GzEncoder::new(Vec::new(), Compression::default()))
266            },
267        };
268        Ok(CompressionContext { encoder })
269    }
270
271    fn compress(&mut self, chunk: &[u8]) -> Result<&[u8], io::Error> {
272        match &mut self.encoder {
273            #[cfg(feature = "brotli-compression-stream")]
274            Encoder::Brotli(encoder) => {
275                encoder.get_mut().clear();
276                encoder.write_all(chunk)?;
277                encoder.flush()?;
278                Ok(encoder.get_ref().as_slice())
279            },
280            Encoder::Deflate(encoder) => {
281                encoder.get_mut().clear();
282                encoder.write_all(chunk)?;
283                encoder.flush()?;
284                Ok(encoder.get_ref().as_slice())
285            },
286            Encoder::DeflateRaw(encoder) => {
287                encoder.get_mut().clear();
288                encoder.write_all(chunk)?;
289                encoder.flush()?;
290                Ok(encoder.get_ref().as_slice())
291            },
292            Encoder::Gzip(encoder) => {
293                encoder.get_mut().clear();
294                encoder.write_all(chunk)?;
295                encoder.flush()?;
296                Ok(encoder.get_ref().as_slice())
297            },
298        }
299    }
300
301    fn finalize(&mut self) -> Result<&[u8], io::Error> {
302        match &mut self.encoder {
303            #[cfg(feature = "brotli-compression-stream")]
304            Encoder::Brotli(encoder) => {
305                encoder.get_mut().clear();
306                let finished_encoder = std::mem::replace(
307                    encoder.borrow_mut(),
308                    BrotliEncoder::new(
309                        Vec::new(),
310                        BROTLI_BUFFER_SIZE,
311                        BROTLI_QUALITIY_LEVEL,
312                        BROTLI_WINDOW_SIZE,
313                    ),
314                );
315                *encoder.get_mut() = finished_encoder.into_inner();
316                Ok(encoder.get_ref().as_slice())
317            },
318            Encoder::Deflate(encoder) => {
319                encoder.get_mut().clear();
320                encoder.try_finish()?;
321                Ok(encoder.get_ref().as_slice())
322            },
323            Encoder::DeflateRaw(encoder) => {
324                encoder.get_mut().clear();
325                encoder.try_finish()?;
326                Ok(encoder.get_ref().as_slice())
327            },
328            Encoder::Gzip(encoder) => {
329                encoder.get_mut().clear();
330                encoder.try_finish()?;
331                Ok(encoder.get_ref().as_slice())
332            },
333        }
334    }
335}
script/dom/stream/compressionstream.rs

script/dom/stream/
compressionstream.rs
