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

script/dom/stream/
compressionstream.rs
