1#ifndef CACHE_H 2#define CACHE_H 3 4#include <stdio.h> 5#include <sys/stat.h> 6#include <fcntl.h> 7#include <stddef.h> 8#include <stdlib.h> 9#include <stdarg.h> 10#include <string.h> 11#include <errno.h> 12#include <sys/mman.h> 13 14#include <openssl/sha.h> 15#include <zlib.h> 16 17/* 18 * Basic data structures for the directory cache 19 * 20 * NOTE NOTE NOTE! This is all in the native CPU byte format. It's 21 * not even trying to be portable. It's trying to be efficient. It's 22 * just a cache, after all. 23 */ 24 25#define CACHE_SIGNATURE 0x44495243/* "DIRC" */ 26struct cache_header { 27unsigned int signature; 28unsigned int version; 29unsigned int entries; 30unsigned char sha1[20]; 31}; 32 33/* 34 * The "cache_time" is just the low 32 bits of the 35 * time. It doesn't matter if it overflows - we only 36 * check it for equality in the 32 bits we save. 37 */ 38struct cache_time { 39unsigned int sec; 40unsigned int nsec; 41}; 42 43/* 44 * dev/ino/uid/gid/size are also just tracked to the low 32 bits 45 * Again - this is just a (very strong in practice) heuristic that 46 * the inode hasn't changed. 47 */ 48struct cache_entry { 49struct cache_time ctime; 50struct cache_time mtime; 51unsigned int st_dev; 52unsigned int st_ino; 53unsigned int st_mode; 54unsigned int st_uid; 55unsigned int st_gid; 56unsigned int st_size; 57unsigned char sha1[20]; 58unsigned short namelen; 59char name[0]; 60}; 61 62const char*sha1_file_directory; 63struct cache_entry **active_cache; 64unsigned int active_nr, active_alloc; 65 66#define DB_ENVIRONMENT"SHA1_FILE_DIRECTORY" 67#define DEFAULT_DB_ENVIRONMENT".dircache/objects" 68 69#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7) 70#define ce_size(ce) cache_entry_size((ce)->namelen) 71 72#define alloc_nr(x) (((x)+16)*3/2) 73 74/* Initialize and use the cache information */ 75externintread_cache(void); 76externintwrite_cache(int newfd,struct cache_entry **cache,int entries); 77externintcache_name_pos(const char*name,int namelen); 78externintadd_cache_entry(struct cache_entry *ce); 79externintremove_file_from_cache(char*path); 80externintcache_match_stat(struct cache_entry *ce,struct stat *st); 81 82#define MTIME_CHANGED 0x0001 83#define CTIME_CHANGED 0x0002 84#define OWNER_CHANGED 0x0004 85#define MODE_CHANGED 0x0008 86#define INODE_CHANGED 0x0010 87#define DATA_CHANGED 0x0020 88 89/* Return a statically allocated filename matching the sha1 signature */ 90externchar*sha1_file_name(unsigned char*sha1); 91 92/* Write a memory buffer out to the sha file */ 93externintwrite_sha1_buffer(unsigned char*sha1,void*buf,unsigned int size); 94 95/* Read and unpack a sha1 file into memory, write memory to a sha1 file */ 96externvoid*map_sha1_file(unsigned char*sha1,unsigned long*size); 97externvoid*unpack_sha1_file(void*map,unsigned long mapsize,char*type,unsigned long*size); 98externvoid*read_sha1_file(unsigned char*sha1,char*type,unsigned long*size); 99externintwrite_sha1_file(char*buf,unsigned len,unsigned char*return_sha1); 100externintcheck_sha1_signature(unsigned char*sha1,void*buf,unsigned long size); 101 102/* Convert to/from hex/sha1 representation */ 103externintget_sha1_hex(const char*hex,unsigned char*sha1); 104externchar*sha1_to_hex(const unsigned char*sha1);/* static buffer result! */ 105 106/* General helper functions */ 107externvoidusage(const char*err); 108externintcache_name_compare(const char*name1,int len1,const char*name2,int len2); 109 110#endif/* CACHE_H */