0ad/source/lib/file/archive/codec.h
janwas a859562ea7 improvements and fixes:
- properly differentiate between buffer/offset alignment and length
alignment (relevant since block size has been increased to 256k)
- use VfsPath for most game paths instead of CStr
- clean up timer interface and implementation
- self-tests no longer crash
- file_cache.cpp: fix for the case where allocation fails (prevent
deleter from seeing a null pointer)
- allocators: move all shared_ptr-related stuff to its own component;
add DummySharedPtr
- codec: disable checksums (important for performance at work)
- File: made into an interface class to avoid export problems. not
entirely sure about this..
- vfs_path.h, path.h, os_path.h: proper fix for using
fs::change_extension and similar utility functions with derivatives of
basic_path
- lib_api: automatically link against import lib if building lib/ as a
DLL
- path_util: remove unused functions (this component is deprecated)
- compiler.h: add INLINE
- Xeromyces.cpp: pass PIVFS so that GetXMBPath works in self-test
(should do this mostly everywhere rather than have one singleton g_VFS)

This was SVN commit r5537.
2008-01-07 20:03:19 +00:00

75 lines
2.3 KiB
C

/**
* =========================================================================
* File : codec.h
* Project : 0 A.D.
* Description :
* =========================================================================
*/
// license: GPL; see lib/license.txt
#ifndef INCLUDED_CODEC
#define INCLUDED_CODEC
// rationale: this layer allows for other compression methods/libraries
// besides ZLib. it also simplifies the interface for user code and
// does error checking, etc.
#define CODEC_COMPUTE_CHECKSUM 0
struct ICodec
{
public:
/**
* note: the implementation should not check whether any data remains -
* codecs are sometimes destroyed without completing a transfer.
**/
virtual ~ICodec();
/**
* @return an upper bound on the output size for the given amount of input.
* this is used when allocating a single buffer for the whole operation.
**/
virtual size_t MaxOutputSize(size_t inSize) const = 0;
/**
* clear all previous state and prepare for reuse.
*
* this is as if the object were destroyed and re-created, but more
* efficient since it avoids reallocating a considerable amount of
* memory (about 200KB for LZ).
**/
virtual LibError Reset() = 0;
/**
* process (i.e. compress or decompress) data.
*
* @param outSize bytes remaining in the output buffer; shall not be zero.
* @param inConsumed, outProduced how many bytes in the input and
* output buffers were used. either or both of these can be zero if
* the input size is small or there's not enough output space.
**/
virtual LibError Process(const u8* in, size_t inSize, u8* out, size_t outSize, size_t& inConsumed, size_t& outProduced) = 0;
/**
* flush buffers and make sure all output has been produced.
*
* @param checksum over all input data.
* @return error status for the entire operation.
**/
virtual LibError Finish(u32& checksum) = 0;
/**
* update a checksum to reflect the contents of a buffer.
*
* @param checksum the initial value (must be 0 on first call)
* @return the new checksum. note: after all data has been seen, this is
* identical to the what Finish would return.
**/
virtual u32 UpdateChecksum(u32 checksum, const u8* in, size_t inSize) const = 0;
};
typedef shared_ptr<ICodec> PICodec;
#endif // #ifndef INCLUDED_CODEC