osb/source/core/StarCompression.hpp
2024-02-25 15:46:47 +01:00

57 lines
1.6 KiB
C++

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