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128 lines
4.0 KiB
128 lines
4.0 KiB
#ifndef CACHE_H |
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#define CACHE_H |
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#include <stdio.h> |
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#include <sys/stat.h> |
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#include <fcntl.h> |
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#include <stddef.h> |
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#include <stdlib.h> |
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#include <stdarg.h> |
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#include <string.h> |
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#include <errno.h> |
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#include <sys/mman.h> |
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#include <netinet/in.h> |
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#include <openssl/sha.h> |
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#include <zlib.h> |
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/* |
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* Basic data structures for the directory cache |
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* |
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* NOTE NOTE NOTE! This is all in the native CPU byte format. It's |
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* not even trying to be portable. It's trying to be efficient. It's |
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* just a cache, after all. |
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*/ |
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#define CACHE_SIGNATURE 0x44495243 /* "DIRC" */ |
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struct cache_header { |
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unsigned int hdr_signature; |
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unsigned int hdr_version; |
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unsigned int hdr_entries; |
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unsigned char sha1[20]; |
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}; |
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/* |
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* The "cache_time" is just the low 32 bits of the |
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* time. It doesn't matter if it overflows - we only |
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* check it for equality in the 32 bits we save. |
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*/ |
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struct cache_time { |
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unsigned int sec; |
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unsigned int nsec; |
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}; |
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/* |
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* dev/ino/uid/gid/size are also just tracked to the low 32 bits |
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* Again - this is just a (very strong in practice) heuristic that |
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* the inode hasn't changed. |
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* |
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* We save the fields in big-endian order to allow using the |
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* index file over NFS transparently. |
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*/ |
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struct cache_entry { |
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struct cache_time ce_ctime; |
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struct cache_time ce_mtime; |
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unsigned int ce_dev; |
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unsigned int ce_ino; |
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unsigned int ce_mode; |
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unsigned int ce_uid; |
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unsigned int ce_gid; |
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unsigned int ce_size; |
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unsigned char sha1[20]; |
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unsigned short ce_flags; |
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char name[0]; |
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}; |
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#define CE_NAMEMASK (0x0fff) |
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#define CE_STAGEMASK (0x3000) |
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#define CE_STAGESHIFT 12 |
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#define create_ce_flags(len, stage) htons((len) | ((stage) << CE_STAGESHIFT)) |
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#define ce_namelen(ce) (CE_NAMEMASK & ntohs((ce)->ce_flags)) |
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#define ce_size(ce) cache_entry_size(ce_namelen(ce)) |
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#define ce_stage(ce) ((CE_STAGEMASK & ntohs((ce)->ce_flags)) >> CE_STAGESHIFT) |
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#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644) |
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#define create_ce_mode(mode) htonl(S_IFREG | ce_permissions(mode)) |
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#define cache_entry_size(len) ((offsetof(struct cache_entry,name) + (len) + 8) & ~7) |
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const char *sha1_file_directory; |
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struct cache_entry **active_cache; |
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unsigned int active_nr, active_alloc; |
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#define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY" |
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#define DEFAULT_DB_ENVIRONMENT ".git/objects" |
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#define alloc_nr(x) (((x)+16)*3/2) |
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/* Initialize and use the cache information */ |
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extern int read_cache(void); |
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extern int write_cache(int newfd, struct cache_entry **cache, int entries); |
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extern int cache_name_pos(const char *name, int namelen); |
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extern int add_cache_entry(struct cache_entry *ce, int ok_to_add); |
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extern int remove_file_from_cache(char *path); |
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extern int cache_match_stat(struct cache_entry *ce, struct stat *st); |
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#define MTIME_CHANGED 0x0001 |
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#define CTIME_CHANGED 0x0002 |
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#define OWNER_CHANGED 0x0004 |
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#define MODE_CHANGED 0x0008 |
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#define INODE_CHANGED 0x0010 |
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#define DATA_CHANGED 0x0020 |
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/* Return a statically allocated filename matching the sha1 signature */ |
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extern char *sha1_file_name(const unsigned char *sha1); |
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/* Write a memory buffer out to the sha file */ |
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extern int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size); |
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/* Read and unpack a sha1 file into memory, write memory to a sha1 file */ |
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extern void * map_sha1_file(const unsigned char *sha1, unsigned long *size); |
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extern void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size); |
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extern void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size); |
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extern int write_sha1_file(char *buf, unsigned len, unsigned char *return_sha1); |
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extern int check_sha1_signature(unsigned char *sha1, void *buf, unsigned long size, const char *type); |
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/* Convert to/from hex/sha1 representation */ |
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extern int get_sha1_hex(const char *hex, unsigned char *sha1); |
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extern char *sha1_to_hex(const unsigned char *sha1); /* static buffer result! */ |
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/* General helper functions */ |
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extern void usage(const char *err); |
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extern void die(const char *err, ...); |
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extern int error(const char *err, ...); |
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extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2); |
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#endif /* CACHE_H */
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