projects / thirdparty / git.git / blame
| Commit | Line | Data |
|---|---|---|
| e83c5163 LT |
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 <errno.h> | |
| 11 | #include <sys/mman.h> | |
| 12 | ||
| 13 | #include <openssl/sha.h> | |
| 14 | #include <zlib.h> | |
| 15 | ||
| 16 | /* | |
| 17 | * Basic data structures for the directory cache | |
| 18 | * | |
| 19 | * NOTE NOTE NOTE! This is all in the native CPU byte format. It's | |
| 20 | * not even trying to be portable. It's trying to be efficient. It's | |
| 21 | * just a cache, after all. | |
| 22 | */ | |
| 23 | ||
| 24 | #define CACHE_SIGNATURE 0x44495243 /* "DIRC" */ | |
| 25 | struct cache_header { | |
| 26 | unsigned int signature; | |
| 27 | unsigned int version; | |
| 28 | unsigned int entries; | |
| 29 | unsigned char sha1[20]; | |
| 30 | }; | |
| 31 | ||
| 32 | /* | |
| 33 | * The "cache_time" is just the low 32 bits of the | |
| 34 | * time. It doesn't matter if it overflows - we only | |
| 35 | * check it for equality in the 32 bits we save. | |
| 36 | */ | |
| 37 | struct cache_time { | |
| 38 | unsigned int sec; | |
| 39 | unsigned int nsec; | |
| 40 | }; | |
| 41 | ||
| 42 | /* | |
| 43 | * dev/ino/uid/gid/size are also just tracked to the low 32 bits | |
| 44 | * Again - this is just a (very strong in practice) heuristic that | |
| 45 | * the inode hasn't changed. | |
| 46 | */ | |
| 47 | struct cache_entry { | |
| 48 | struct cache_time ctime; | |
| 49 | struct cache_time mtime; | |
| 50 | unsigned int st_dev; | |
| 51 | unsigned int st_ino; | |
| 52 | unsigned int st_mode; | |
| 53 | unsigned int st_uid; | |
| 54 | unsigned int st_gid; | |
| 55 | unsigned int st_size; | |
| 56 | unsigned char sha1[20]; | |
| 57 | unsigned short namelen; | |
| 58 | unsigned char name[0]; | |
| 59 | }; | |
| 60 | ||
| 61 | const char *sha1_file_directory; | |
| 62 | struct cache_entry **active_cache; | |
| 63 | unsigned int active_nr, active_alloc; | |
| 64 | ||
| 65 | #define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY" | |
| 66 | #define DEFAULT_DB_ENVIRONMENT ".dircache/objects" | |
| 67 | ||
| 68 | #define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7) | |
| 69 | #define ce_size(ce) cache_entry_size((ce)->namelen) | |
| 70 | ||
| 71 | #define alloc_nr(x) (((x)+16)*3/2) | |
| 72 | ||
| 73 | /* Initialize the cache information */ | |
| 74 | extern int read_cache(void); | |
| 75 | ||
| 76 | /* Return a statically allocated filename matching the sha1 signature */ | |
| 77 | extern char *sha1_file_name(unsigned char *sha1); | |
| 78 | ||
| 79 | /* Write a memory buffer out to the sha file */ | |
| 80 | extern int write_sha1_buffer(unsigned char *sha1, void *buf, unsigned int size); | |
| 81 | ||
| 82 | /* Read and unpack a sha1 file into memory, write memory to a sha1 file */ | |
| 83 | extern void * read_sha1_file(unsigned char *sha1, char *type, unsigned long *size); | |
| 84 | extern int write_sha1_file(char *buf, unsigned len); | |
| 85 | ||
| 86 | /* Convert to/from hex/sha1 representation */ | |
| 87 | extern int get_sha1_hex(char *hex, unsigned char *sha1); | |
| 88 | extern char *sha1_to_hex(unsigned char *sha1); /* static buffer! */ | |
| 89 | ||
| 90 | /* General helper functions */ | |
| 91 | extern void usage(const char *err); | |
| 92 | ||
| 93 | #endif /* CACHE_H */ |