File: CompressionStreamEncoder.cpp

package info (click to toggle)
webkit2gtk 2.48.5-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 429,764 kB
  • sloc: cpp: 3,697,587; javascript: 194,444; ansic: 169,997; python: 46,499; asm: 19,295; ruby: 18,528; perl: 16,602; xml: 4,650; yacc: 2,360; sh: 2,098; java: 1,993; lex: 1,327; pascal: 366; makefile: 298
file content (160 lines) | stat: -rw-r--r-- 5,741 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
/*
 * Copyright (C) 2022-2024 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "CompressionStreamEncoder.h"

#include "BufferSource.h"
#include "Exception.h"
#include "SharedBuffer.h"
#include <JavaScriptCore/GenericTypedArrayViewInlines.h>
#include <JavaScriptCore/JSCInlines.h>
#include <JavaScriptCore/JSGenericTypedArrayViewInlines.h>

namespace WebCore {

ExceptionOr<RefPtr<Uint8Array>> CompressionStreamEncoder::encode(const BufferSource&& input)
{
    auto compressedDataCheck = compress(input.span());
    if (compressedDataCheck.hasException())
        return compressedDataCheck.releaseException();

    Ref compressedData = compressedDataCheck.releaseReturnValue();
    if (!compressedData->byteLength())
        return nullptr;

    return RefPtr { Uint8Array::create(WTFMove(compressedData)) };
}

ExceptionOr<RefPtr<Uint8Array>> CompressionStreamEncoder::flush()
{
    m_didFinish = true;

    auto compressedDataCheck = compress({ });
    if (compressedDataCheck.hasException())
        return compressedDataCheck.releaseException();

    Ref compressedData = compressedDataCheck.releaseReturnValue();
    if (!compressedData->byteLength())
        return nullptr;

    return RefPtr { Uint8Array::create(WTFMove(compressedData)) };
}

// The compression algorithm is broken up into 2 steps.
// 1. Compression of Data
// 2. Flush Remaining Data
//
// When avail_in is empty we can normally exit performing compression, but during the flush
// step we may have data buffered and will need to continue to keep flushing out the rest.
bool CompressionStreamEncoder::didDeflateFinish(int result) const
{
    return !m_zstream.getPlatformStream().avail_in && (!m_didFinish || (m_didFinish && result == Z_STREAM_END));
}

// See https://www.zlib.net/manual.html#Constants
static bool didDeflateFail(int result)
{
    return result != Z_OK && result != Z_STREAM_END && result != Z_BUF_ERROR;
}

ExceptionOr<Ref<JSC::ArrayBuffer>> CompressionStreamEncoder::compress(std::span<const uint8_t> input)
{
#if PLATFORM(COCOA)
    if (m_format == Formats::CompressionFormat::Brotli)
        return compressAppleCompressionFramework(input);
#endif
    return compressZlib(input);
}

static ZStream::Algorithm compressionAlgorithm(Formats::CompressionFormat format)
{
    switch (format) {
    case Formats::CompressionFormat::Brotli:
        RELEASE_ASSERT_NOT_REACHED();
    case Formats::CompressionFormat::Gzip:
        return ZStream::Algorithm::Gzip;
    case Formats::CompressionFormat::Zlib:
        return ZStream::Algorithm::Zlib;
    case Formats::CompressionFormat::Deflate:
        return ZStream::Algorithm::Deflate;
    }
    RELEASE_ASSERT_NOT_REACHED();
}

ExceptionOr<Ref<JSC::ArrayBuffer>> CompressionStreamEncoder::compressZlib(std::span<const uint8_t> input)
{
    size_t allocateSize = std::max(input.size(), startingAllocationSize);
    auto storage = SharedBufferBuilder();

    int result;    
    bool shouldCompress = true;

    if (!m_zstream.initializeIfNecessary(compressionAlgorithm(m_format), ZStream::Operation::Compression))
        return Exception { ExceptionCode::TypeError, "Initialization Failed."_s };

    m_zstream.getPlatformStream().next_in = const_cast<z_const Bytef*>(input.data());
    m_zstream.getPlatformStream().avail_in = input.size();

    while (shouldCompress) {
        Vector<uint8_t> output;
        if (!output.tryReserveInitialCapacity(allocateSize)) {
            allocateSize /= 4;

            if (allocateSize < startingAllocationSize)
                return Exception { ExceptionCode::OutOfMemoryError };

            continue;
        }

        output.grow(allocateSize);

        m_zstream.getPlatformStream().next_out = output.data();
        m_zstream.getPlatformStream().avail_out = output.size();

        result = deflate(&m_zstream.getPlatformStream(), m_didFinish ? Z_FINISH : Z_NO_FLUSH);

        if (didDeflateFail(result))
            return Exception { ExceptionCode::TypeError, "Failed to compress data."_s };

        if (didDeflateFinish(result)) {
            shouldCompress = false;
            output.shrink(allocateSize - m_zstream.getPlatformStream().avail_out);
        }
        else {
            if (allocateSize < maxAllocationSize)
                allocateSize *= 2;
        }

        storage.append(output);
    }

    RefPtr compressedData = storage.takeAsArrayBuffer();
    if (!compressedData)
        return Exception { ExceptionCode::OutOfMemoryError };

    return compressedData.releaseNonNull();
}

} // namespace WebCore