1 #ifndef MSP_IO_ZLIBCOMPRESSED_H_
2 #define MSP_IO_ZLIBCOMPRESSED_H_
6 #include <sigc++/trackable.h>
12 class zlib_error: public std::runtime_error
18 zlib_error(const std::string &, int);
19 ~zlib_error() throw() { }
21 int code() const throw() { return code_; }
25 Compresses or decompresses data with zlib. This class is a filter that
26 operates on top of another I/O object.
28 To ensure proper termination of the compressed data stream, the ZlibCompressed
29 object must be destroyed before the underlying object is closed.
31 class ZlibCompressed: public Base, public sigc::trackable
38 unsigned char *in_buffer;
39 unsigned char *out_buffer;
44 /** Creates a zlib de/compression object. The underlying object must be
45 open for reading or writing, not both. The level parameter determines
46 compression quality, ranging from 1 (fastest) to 9 (best compression). */
47 ZlibCompressed(Base &, unsigned level = 9);
49 /** Creates a zlib de/compression object. Mode must be either read or
50 write, and compatible with the underlying object. */
51 ZlibCompressed(Base &, Mode, unsigned level = 9);
57 virtual ~ZlibCompressed();
62 virtual unsigned do_write(const char *, unsigned);
65 /** Compresses data and writes it to the underlying object. Returns true if
66 progress was made, false otherwise. flush_mode can be any of zlib's flush
67 modes. If it is Z_FINISH, false is also returned when the stream has been
69 bool compress_data(int flush_mode);
72 virtual unsigned do_read(char *, unsigned);