asset_internal.h

#ifndef __LIBDRAGON_ASSET_INTERNAL_H
#define __LIBDRAGON_ASSET_INTERNAL_H
 
#include <stdint.h>
#include <stdio.h>
 
#define ASSET_MAGIC                 "DCA"   
#define ASSET_FLAG_WINSIZE_MASK     0x0007  
#define ASSET_FLAG_WINSIZE_16K      0x0000  
#define ASSET_FLAG_WINSIZE_8K       0x0001  
#define ASSET_FLAG_WINSIZE_4K       0x0002  
#define ASSET_FLAG_WINSIZE_2K       0x0003  
#define ASSET_FLAG_WINSIZE_32K      0x0004  
#define ASSET_FLAG_WINSIZE_64K      0x0005  
#define ASSET_FLAG_WINSIZE_128K     0x0006  
#define ASSET_FLAG_WINSIZE_256K     0x0007  
#define ASSET_FLAG_INPLACE          0x0100  
#define ASSET_ALIGNMENT             32
 
__attribute__((used))
static inline int asset_winsize_from_flags(uint16_t flags) {
    flags &= ASSET_FLAG_WINSIZE_MASK;
    if (flags & 4) 
        return (2*1024) << flags;
    else
        return (16*1024) >> flags;
}
 
__attribute__((used))
static int asset_winsize_to_flags(int winsize) {
    if (winsize == 16*1024)  return ASSET_FLAG_WINSIZE_16K;
    if (winsize == 8*1024)   return ASSET_FLAG_WINSIZE_8K;
    if (winsize == 4*1024)   return ASSET_FLAG_WINSIZE_4K;
    if (winsize == 2*1024)   return ASSET_FLAG_WINSIZE_2K;
    if (winsize == 32*1024)  return ASSET_FLAG_WINSIZE_32K;
    if (winsize == 64*1024)  return ASSET_FLAG_WINSIZE_64K;
    if (winsize == 128*1024) return ASSET_FLAG_WINSIZE_128K;
    if (winsize == 256*1024) return ASSET_FLAG_WINSIZE_256K;
    return -1;
}
 
typedef struct {
    char magic[3];          
    uint8_t version;        
    uint16_t algo;          
    uint16_t flags;         
    uint32_t cmp_size;      
    uint32_t orig_size;     
    uint32_t inplace_margin; 
} asset_header_t;
 
_Static_assert(sizeof(asset_header_t) == 20, "invalid sizeof(asset_header_t)");
 
typedef struct {
    int state_size;     
 
    void (*decompress_init)(void *state, FILE *fp, int winsize);
 
    ssize_t (*decompress_read)(void *state, void *buf, size_t len);
 
    void (*decompress_reset)(void *state);
 
    void* (*decompress_full)(const char *fn, FILE *fp, size_t cmp_size, size_t len);
 
    int (*decompress_full_inplace)(const uint8_t *in, size_t cmp_size, uint8_t *out, size_t len);
} asset_compression_t;
 
 
FILE *must_fopen(const char *fn);
 
#endif