X-Git-Url: https://git.octo.it/?p=git.git;a=blobdiff_plain;f=read-cache.c;h=c499c5185678b6b4ac35d57d1ab0b36cc2ff056b;hp=a917ab0cfe1547d1070f2567a41295c96f97b249;hb=HEAD;hpb=b9895c06882c0e395a2d22c3649e53bd342b535e diff --git a/read-cache.c b/read-cache.c index a917ab0c..c499c518 100644 --- a/read-cache.c +++ b/read-cache.c @@ -4,11 +4,26 @@ * Copyright (C) Linus Torvalds, 2005 */ #include "cache.h" +#include "cache-tree.h" + +/* Index extensions. + * + * The first letter should be 'A'..'Z' for extensions that are not + * necessary for a correct operation (i.e. optimization data). + * When new extensions are added that _needs_ to be understood in + * order to correctly interpret the index file, pick character that + * is outside the range, to cause the reader to abort. + */ + +#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) ) +#define CACHE_EXT_TREE 0x54524545 /* "TREE" */ struct cache_entry **active_cache = NULL; static time_t index_file_timestamp; unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0; +struct cache_tree *active_cache_tree = NULL; + /* * This only updates the "non-critical" parts of the directory * cache, ie the parts that aren't tracked by GIT, and only used @@ -332,6 +347,70 @@ int ce_path_match(const struct cache_entry *ce, const char **pathspec) } /* + * We fundamentally don't like some paths: we don't want + * dot or dot-dot anywhere, and for obvious reasons don't + * want to recurse into ".git" either. + * + * Also, we don't want double slashes or slashes at the + * end that can make pathnames ambiguous. + */ +static int verify_dotfile(const char *rest) +{ + /* + * The first character was '.', but that + * has already been discarded, we now test + * the rest. + */ + switch (*rest) { + /* "." is not allowed */ + case '\0': case '/': + return 0; + + /* + * ".git" followed by NUL or slash is bad. This + * shares the path end test with the ".." case. + */ + case 'g': + if (rest[1] != 'i') + break; + if (rest[2] != 't') + break; + rest += 2; + /* fallthrough */ + case '.': + if (rest[1] == '\0' || rest[1] == '/') + return 0; + } + return 1; +} + +int verify_path(const char *path) +{ + char c; + + goto inside; + for (;;) { + if (!c) + return 1; + if (c == '/') { +inside: + c = *path++; + switch (c) { + default: + continue; + case '/': case '\0': + break; + case '.': + if (verify_dotfile(path)) + continue; + } + return 0; + } + c = *path++; + } +} + +/* * Do we have another file that has the beginning components being a * proper superset of the name we're trying to add? */ @@ -472,6 +551,8 @@ int add_cache_entry(struct cache_entry *ce, int option) if (!ok_to_add) return -1; + if (!verify_path(ce->name)) + return -1; if (!skip_df_check && check_file_directory_conflict(ce, pos, ok_to_replace)) { @@ -496,6 +577,123 @@ int add_cache_entry(struct cache_entry *ce, int option) return 0; } +/* Three functions to allow overloaded pointer return; see linux/err.h */ +static inline void *ERR_PTR(long error) +{ + return (void *) error; +} + +static inline long PTR_ERR(const void *ptr) +{ + return (long) ptr; +} + +static inline long IS_ERR(const void *ptr) +{ + return (unsigned long)ptr > (unsigned long)-1000L; +} + +/* + * "refresh" does not calculate a new sha1 file or bring the + * cache up-to-date for mode/content changes. But what it + * _does_ do is to "re-match" the stat information of a file + * with the cache, so that you can refresh the cache for a + * file that hasn't been changed but where the stat entry is + * out of date. + * + * For example, you'd want to do this after doing a "git-read-tree", + * to link up the stat cache details with the proper files. + */ +static struct cache_entry *refresh_entry(struct cache_entry *ce, int really) +{ + struct stat st; + struct cache_entry *updated; + int changed, size; + + if (lstat(ce->name, &st) < 0) + return ERR_PTR(-errno); + + changed = ce_match_stat(ce, &st, really); + if (!changed) { + if (really && assume_unchanged && + !(ce->ce_flags & htons(CE_VALID))) + ; /* mark this one VALID again */ + else + return NULL; + } + + if (ce_modified(ce, &st, really)) + return ERR_PTR(-EINVAL); + + size = ce_size(ce); + updated = xmalloc(size); + memcpy(updated, ce, size); + fill_stat_cache_info(updated, &st); + + /* In this case, if really is not set, we should leave + * CE_VALID bit alone. Otherwise, paths marked with + * --no-assume-unchanged (i.e. things to be edited) will + * reacquire CE_VALID bit automatically, which is not + * really what we want. + */ + if (!really && assume_unchanged && !(ce->ce_flags & htons(CE_VALID))) + updated->ce_flags &= ~htons(CE_VALID); + + return updated; +} + +int refresh_cache(unsigned int flags) +{ + int i; + int has_errors = 0; + int really = (flags & REFRESH_REALLY) != 0; + int allow_unmerged = (flags & REFRESH_UNMERGED) != 0; + int quiet = (flags & REFRESH_QUIET) != 0; + int not_new = (flags & REFRESH_IGNORE_MISSING) != 0; + + for (i = 0; i < active_nr; i++) { + struct cache_entry *ce, *new; + ce = active_cache[i]; + if (ce_stage(ce)) { + while ((i < active_nr) && + ! strcmp(active_cache[i]->name, ce->name)) + i++; + i--; + if (allow_unmerged) + continue; + printf("%s: needs merge\n", ce->name); + has_errors = 1; + continue; + } + + new = refresh_entry(ce, really); + if (!new) + continue; + if (IS_ERR(new)) { + if (not_new && PTR_ERR(new) == -ENOENT) + continue; + if (really && PTR_ERR(new) == -EINVAL) { + /* If we are doing --really-refresh that + * means the index is not valid anymore. + */ + ce->ce_flags &= ~htons(CE_VALID); + active_cache_changed = 1; + } + if (quiet) + continue; + printf("%s: needs update\n", ce->name); + has_errors = 1; + continue; + } + active_cache_changed = 1; + /* You can NOT just free active_cache[i] here, since it + * might not be necessarily malloc()ed but can also come + * from mmap(). */ + active_cache[i] = new; + } + return has_errors; +} + static int verify_hdr(struct cache_header *hdr, unsigned long size) { SHA_CTX c; @@ -513,6 +711,22 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size) return 0; } +static int read_index_extension(const char *ext, void *data, unsigned long sz) +{ + switch (CACHE_EXT(ext)) { + case CACHE_EXT_TREE: + active_cache_tree = cache_tree_read(data, sz); + break; + default: + if (*ext < 'A' || 'Z' < *ext) + return error("index uses %.4s extension, which we do not understand", + ext); + fprintf(stderr, "ignoring %.4s extension\n", ext); + break; + } + return 0; +} + int read_cache(void) { int fd, i; @@ -561,6 +775,22 @@ int read_cache(void) active_cache[i] = ce; } index_file_timestamp = st.st_mtime; + while (offset <= size - 20 - 8) { + /* After an array of active_nr index entries, + * there can be arbitrary number of extended + * sections, each of which is prefixed with + * extension name (4-byte) and section length + * in 4-byte network byte order. + */ + unsigned long extsize; + memcpy(&extsize, map + offset + 4, 4); + extsize = ntohl(extsize); + if (read_index_extension(map + offset, + map + offset + 8, extsize) < 0) + goto unmap; + offset += 8; + offset += extsize; + } return active_nr; unmap: @@ -595,6 +825,17 @@ static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len) return 0; } +static int write_index_ext_header(SHA_CTX *context, int fd, + unsigned int ext, unsigned int sz) +{ + ext = htonl(ext); + sz = htonl(sz); + if ((ce_write(context, fd, &ext, 4) < 0) || + (ce_write(context, fd, &sz, 4) < 0)) + return -1; + return 0; +} + static int ce_flush(SHA_CTX *context, int fd) { unsigned int left = write_buffer_len; @@ -691,5 +932,19 @@ int write_cache(int newfd, struct cache_entry **cache, int entries) if (ce_write(&c, newfd, ce, ce_size(ce)) < 0) return -1; } + + /* Write extension data here */ + if (active_cache_tree) { + unsigned long sz; + void *data = cache_tree_write(active_cache_tree, &sz); + if (data && + !write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sz) && + !ce_write(&c, newfd, data, sz)) + ; + else { + free(data); + return -1; + } + } return ce_flush(&c, newfd); }