LibCompress: Introduce generic de/compressor using zlib

This compressor decompressor is capable of handling zlib, gzip and deflate all in one.
Author: https://github.com/devgianlu Commit: c4b76bea13 Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3755 Reviewed-by: https://github.com/gmta ✅ Reviewed-by: https://github.com/trflynn89
2025-08-24 11:21:34 +00:00 · 2025-03-01 17:33:52 +01:00 · 2025-03-01 17:33:52 +01:00 · c4b76bea13 · 2025-03-19 12:48:58 +00:00
commit c4b76bea13
parent 1c836588d9
3 changed files with 322 additions and 1 deletions
--- a/Libraries/LibCompress/GenericZlib.h
+++ b/Libraries/LibCompress/GenericZlib.h
@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2025, Altomani Gianluca <altomanigianluca@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/ByteBuffer.h>
+#include <AK/FixedArray.h>
+#include <AK/MaybeOwned.h>
+#include <AK/MemoryStream.h>
+#include <AK/Stream.h>
+
+extern "C" {
+typedef struct z_stream_s z_stream;
+}
+
+namespace Compress {
+
+enum class GenericZlibCompressionLevel : u8 {
+    Fastest,
+    Default,
+    Best,
+};
+
+class GenericZlibDecompressor : public Stream {
+    AK_MAKE_NONCOPYABLE(GenericZlibDecompressor);
+
+public:
+    ~GenericZlibDecompressor() override;
+
+    virtual ErrorOr<Bytes> read_some(Bytes) override;
+    virtual ErrorOr<size_t> write_some(ReadonlyBytes) override;
+    virtual bool is_eof() const override;
+    virtual bool is_open() const override;
+    virtual void close() override;
+
+protected:
+    GenericZlibDecompressor(AK::FixedArray<u8>, MaybeOwned<Stream>, z_stream*);
+
+    static ErrorOr<z_stream*> new_z_stream(int window_bits);
+
+private:
+    MaybeOwned<Stream> m_stream;
+    z_stream* m_zstream;
+
+    bool m_eof { false };
+
+    AK::FixedArray<u8> m_buffer;
+};
+
+class GenericZlibCompressor : public Stream {
+    AK_MAKE_NONCOPYABLE(GenericZlibCompressor);
+
+public:
+    ~GenericZlibCompressor() override;
+
+    virtual ErrorOr<Bytes> read_some(Bytes) override;
+    virtual ErrorOr<size_t> write_some(ReadonlyBytes) override;
+    virtual bool is_eof() const override;
+    virtual bool is_open() const override;
+    virtual void close() override;
+    ErrorOr<void> finish();
+
+protected:
+    GenericZlibCompressor(AK::FixedArray<u8>, MaybeOwned<Stream>, z_stream*);
+
+    static ErrorOr<z_stream*> new_z_stream(int window_bits, GenericZlibCompressionLevel compression_level);
+
+private:
+    MaybeOwned<Stream> m_stream;
+    z_stream* m_zstream;
+
+    AK::FixedArray<u8> m_buffer;
+};
+
+template<class T>
+ErrorOr<ByteBuffer> decompress_all(ReadonlyBytes bytes)
+{
+    auto input_stream = make<AK::FixedMemoryStream>(bytes);
+    auto deflate_stream = TRY(T::create(MaybeOwned<Stream>(move(input_stream))));
+    return TRY(deflate_stream->read_until_eof(4096));
+}
+
+template<class T>
+ErrorOr<ByteBuffer> compress_all(ReadonlyBytes bytes, GenericZlibCompressionLevel compression_level)
+{
+    auto output_stream = TRY(try_make<AllocatingMemoryStream>());
+    auto gzip_stream = TRY(T::create(MaybeOwned { *output_stream }, compression_level));
+
+    TRY(gzip_stream->write_until_depleted(bytes));
+    TRY(gzip_stream->finish());
+
+    auto buffer = TRY(ByteBuffer::create_uninitialized(output_stream->used_buffer_size()));
+    TRY(output_stream->read_until_filled(buffer.bytes()));
+
+    return buffer;
+}
+
+}