60 lines
1.7 KiB
C++
60 lines
1.7 KiB
C++
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#ifndef STAR_COMPRESSION_HPP
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#define STAR_COMPRESSION_HPP
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#include "StarIODevice.hpp"
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#include "StarString.hpp"
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namespace Star {
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STAR_CLASS(CompressedFile);
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// Zlib compression level, ranges from 0 to 9
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typedef int CompressionLevel;
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CompressionLevel const LowCompression = 2;
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CompressionLevel const MediumCompression = 5;
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CompressionLevel const HighCompression = 9;
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void compressData(ByteArray const& in, ByteArray& out, CompressionLevel compression = MediumCompression);
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ByteArray compressData(ByteArray const& in, CompressionLevel compression = MediumCompression);
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void uncompressData(ByteArray const& in, ByteArray& out);
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ByteArray uncompressData(ByteArray const& in);
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// Random access to a (potentially) compressed file.
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class CompressedFile : public IODevice {
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public:
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static CompressedFilePtr open(String const& filename, IOMode mode, CompressionLevel comp = MediumCompression);
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CompressedFile();
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CompressedFile(String filename);
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virtual ~CompressedFile();
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void setFilename(String filename);
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void setCompression(CompressionLevel compression);
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StreamOffset pos() override;
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// Only seek forward is supported on writes. Seek is emulated *slowly* on
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// reads.
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void seek(StreamOffset pos, IOSeek seek = IOSeek::Absolute) override;
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bool atEnd() override;
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size_t read(char* data, size_t len) override;
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size_t write(char const* data, size_t len) override;
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void open(IOMode mode) override;
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// Compression is ignored on read. Always truncates on write
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void open(IOMode mode, CompressionLevel compression);
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void sync() override;
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void close() override;
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private:
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String m_filename;
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void* m_file;
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CompressionLevel m_compression;
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};
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}
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#endif
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