0ad/source/lib/res/file/file_cache.h
janwas 44901d38b9 # further documentation and improvements to lib/res/file code
FILE_CACHE_BLOCK flag used more safely (copied in afile_read)
add file_sector_size (set from sysdep code)
documented and organized FileFlags
moved publically visible file_buf* decls to file.h; add FileBufFlags
file_buf_get: moved to file_io and renamed because it is not a part of
the file_buf manager itself
FILE_BLOCK_SIZE no longer exposed to users - it's an implementation
detail. for alignment purposes, you should use file_sector_size (less
wasteful)
add page_aligned allocator (mmap)
write buffers now allocated via file_buf_alloc(FB_FROM_HEAP) (avoids
wasting cache space)
append trace runs into the trace file (-> better input data for archive
ordering)
document lib_errors.h
tex_load: add provision for file_flags, used by ogl_tex_load to prevent
caching file data

simulation, entitymanager: add perf measurements

This was SVN commit r3725.
2006-04-03 21:28:10 +00:00

84 lines
3.2 KiB
C

#ifndef FILE_CACHE_H__
#define FILE_CACHE_H__
struct BlockId
{
const char* atom_fn;
u32 block_num;
};
extern bool block_eq(BlockId b1, BlockId b2);
// create an id for use with the cache that uniquely identifies
// the block from the file <atom_fn> starting at <ofs>.
extern BlockId block_cache_make_id(const char* atom_fn, const off_t ofs);
extern void* block_cache_alloc(BlockId id);
extern void block_cache_mark_completed(BlockId id);
extern void* block_cache_find(BlockId id);
extern void block_cache_release(BlockId id);
// interpret file_io parameters (pbuf, size, flags, cb) and allocate a
// file buffer if necessary.
// called by file_io and afile_read.
extern LibError file_io_get_buf(FileIOBuf* pbuf, size_t size,
const char* atom_fn, uint flags, FileIOCB cb);
// inform us that the buffer address will be increased by <padding>-bytes.
// this happens when reading uncompressed files from archive: they
// start at unaligned offsets and file_io rounds offset down to
// next block boundary. the buffer therefore starts with padding, which
// is skipped so the user only sees their data.
// we make note of the new buffer address so that it can be freed correctly
// by passing the new padded buffer.
extern void file_buf_add_padding(FileIOBuf exact_buf, size_t exact_size, size_t padding);
// if buf is not in extant list, complain; otherwise, mark it as
// coming from the file <atom_fn>.
// this is needed in the following case: uncompressed reads from archive
// boil down to a file_io of the archive file. the buffer is therefore
// tagged with the archive filename instead of the desired filename.
// afile_read sets things right by calling this.
extern LibError file_buf_set_real_fn(FileIOBuf buf, const char* atom_fn);
// "give" <buf> to the cache, specifying its size and owner filename.
// since this data may be shared among users of the cache, it is made
// read-only (via MMU) to make sure no one can corrupt/change it.
//
// note: the reference added by file_buf_alloc still exists! it must
// still be file_buf_free-d after calling this.
extern LibError file_cache_add(FileIOBuf buf, size_t size,
const char* atom_fn, uint file_flags);
// check if the contents of the file <atom_fn> are in file cache.
// if not, return 0; otherwise, return buffer address and optionally
// pass back its size.
//
// note: does not call stats_cache because it does not know the file size
// in case of cache miss! doing so is left to the caller.
extern FileIOBuf file_cache_retrieve(const char* atom_fn, size_t* psize, uint fb_flags = 0);
// invalidate all data loaded from the file <fn>. this ensures the next
// load of this file gets the (presumably new) contents of the file,
// not previous stale cache contents.
// call after hotloading code detects file has been changed.
extern LibError file_cache_invalidate(const char* P_fn);
// reset entire state of the file cache to what it was after initialization.
// that means completely emptying the extant list and cache.
// used after simulating cache operation, which fills the cache with
// invalid data.
extern void file_cache_reset();
extern void file_cache_init();
extern void file_cache_shutdown();
#endif // #ifndef FILE_CACHE_H__