X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fio%2Fzlibcompressed.h;fp=source%2Fio%2Fzlibcompressed.h;h=1ee427413ddc1cc448338278fab543f19bbd2ca9;hb=8ed14b63ab6249e9fc2a3a691cf8ffbf49166deb;hp=0000000000000000000000000000000000000000;hpb=faeafc9d652ba6caa350ca95dff14408b036ccfb;p=libs%2Fcore.git

diff --git a/source/io/zlibcompressed.h b/source/io/zlibcompressed.h
new file mode 100644
index 0000000..1ee4274
--- /dev/null
+++ b/source/io/zlibcompressed.h
@@ -0,0 +1,68 @@
+#ifndef MSP_IO_ZLIBCOMPRESSED_H_
+#define MSP_IO_ZLIBCOMPRESSED_H_
+
+#include <stdexcept>
+#include <string>
+#include "base.h"
+
+namespace Msp {
+namespace IO {
+
+class zlib_error: public std::runtime_error
+{
+private:
+	int code_;
+
+public:
+	zlib_error(const std::string &, int);
+	~zlib_error() throw() { }
+
+	int code() const throw() { return code_; }
+};
+
+/**
+Compresses or decompresses data with zlib.  This class is a filter that
+operates on top of another I/O object.
+
+To ensure proper termination of the compressed data stream, the ZlibCompressed
+object must be destroyed before the underlying object is closed.
+*/
+class ZlibCompressed: public Base
+{
+private:
+	struct Private;
+
+	Base &below;
+	unsigned buffer_size;
+	unsigned char *in_buffer;
+	unsigned char *out_buffer;
+	Private *priv;
+
+public:
+	/** Creates a zlib de/compression object.  The underlying object must be
+	open for reading or writing, not both.  The level parameter determines
+	compression quality, ranging from 1 (fastest) to 9 (best compression). */
+	ZlibCompressed(Base &, unsigned level = 9);
+
+	virtual ~ZlibCompressed();
+
+	void flush();
+
+protected:
+	virtual unsigned do_write(const char *, unsigned);
+
+private:
+	/** Compresses data and writes it to the underlying object.  Returns true if
+	progress was made, false otherwise.  flush_mode can be any of zlib's flush
+	modes.  If it is Z_FINISH, false is also returned when the stream has been
+	terminated. */
+	bool compress_data(int flush_mode);
+
+public:
+	virtual unsigned do_read(char *, unsigned);
+};
+
+} // namespace IO
+} // namespace Msp
+
+#endif