diff options
Diffstat (limited to 'read-cache.c')
| -rw-r--r-- | read-cache.c | 2308 |
1 files changed, 2308 insertions, 0 deletions
diff --git a/read-cache.c b/read-cache.c new file mode 100644 index 0000000000..36ff89f29e --- /dev/null +++ b/read-cache.c @@ -0,0 +1,2308 @@ +/* + * GIT - The information manager from hell + * + * Copyright (C) Linus Torvalds, 2005 + */ +#define NO_THE_INDEX_COMPATIBILITY_MACROS +#include "cache.h" +#include "lockfile.h" +#include "cache-tree.h" +#include "refs.h" +#include "dir.h" +#include "tree.h" +#include "commit.h" +#include "blob.h" +#include "resolve-undo.h" +#include "strbuf.h" +#include "varint.h" +#include "split-index.h" +#include "sigchain.h" +#include "utf8.h" + +static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, + unsigned int options); + +/* Mask for the name length in ce_flags in the on-disk index */ + +#define CE_NAMEMASK (0x0fff) + +/* 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" */ +#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */ +#define CACHE_EXT_LINK 0x6c696e6b /* "link" */ + +/* changes that can be kept in $GIT_DIR/index (basically all extensions) */ +#define EXTMASK (RESOLVE_UNDO_CHANGED | CACHE_TREE_CHANGED | \ + CE_ENTRY_ADDED | CE_ENTRY_REMOVED | CE_ENTRY_CHANGED | \ + SPLIT_INDEX_ORDERED) + +struct index_state the_index; +static const char *alternate_index_output; + +static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) +{ + istate->cache[nr] = ce; + add_name_hash(istate, ce); +} + +static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) +{ + struct cache_entry *old = istate->cache[nr]; + + replace_index_entry_in_base(istate, old, ce); + remove_name_hash(istate, old); + free(old); + set_index_entry(istate, nr, ce); + ce->ce_flags |= CE_UPDATE_IN_BASE; + istate->cache_changed |= CE_ENTRY_CHANGED; +} + +void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name) +{ + struct cache_entry *old = istate->cache[nr], *new; + int namelen = strlen(new_name); + + new = xmalloc(cache_entry_size(namelen)); + copy_cache_entry(new, old); + new->ce_flags &= ~CE_HASHED; + new->ce_namelen = namelen; + new->index = 0; + memcpy(new->name, new_name, namelen + 1); + + cache_tree_invalidate_path(istate, old->name); + remove_index_entry_at(istate, nr); + add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); +} + +void fill_stat_data(struct stat_data *sd, struct stat *st) +{ + sd->sd_ctime.sec = (unsigned int)st->st_ctime; + sd->sd_mtime.sec = (unsigned int)st->st_mtime; + sd->sd_ctime.nsec = ST_CTIME_NSEC(*st); + sd->sd_mtime.nsec = ST_MTIME_NSEC(*st); + sd->sd_dev = st->st_dev; + sd->sd_ino = st->st_ino; + sd->sd_uid = st->st_uid; + sd->sd_gid = st->st_gid; + sd->sd_size = st->st_size; +} + +int match_stat_data(const struct stat_data *sd, struct stat *st) +{ + int changed = 0; + + if (sd->sd_mtime.sec != (unsigned int)st->st_mtime) + changed |= MTIME_CHANGED; + if (trust_ctime && check_stat && + sd->sd_ctime.sec != (unsigned int)st->st_ctime) + changed |= CTIME_CHANGED; + +#ifdef USE_NSEC + if (check_stat && sd->sd_mtime.nsec != ST_MTIME_NSEC(*st)) + changed |= MTIME_CHANGED; + if (trust_ctime && check_stat && + sd->sd_ctime.nsec != ST_CTIME_NSEC(*st)) + changed |= CTIME_CHANGED; +#endif + + if (check_stat) { + if (sd->sd_uid != (unsigned int) st->st_uid || + sd->sd_gid != (unsigned int) st->st_gid) + changed |= OWNER_CHANGED; + if (sd->sd_ino != (unsigned int) st->st_ino) + changed |= INODE_CHANGED; + } + +#ifdef USE_STDEV + /* + * st_dev breaks on network filesystems where different + * clients will have different views of what "device" + * the filesystem is on + */ + if (check_stat && sd->sd_dev != (unsigned int) st->st_dev) + changed |= INODE_CHANGED; +#endif + + if (sd->sd_size != (unsigned int) st->st_size) + changed |= DATA_CHANGED; + + return changed; +} + +/* + * This only updates the "non-critical" parts of the directory + * cache, ie the parts that aren't tracked by GIT, and only used + * to validate the cache. + */ +void fill_stat_cache_info(struct cache_entry *ce, struct stat *st) +{ + fill_stat_data(&ce->ce_stat_data, st); + + if (assume_unchanged) + ce->ce_flags |= CE_VALID; + + if (S_ISREG(st->st_mode)) + ce_mark_uptodate(ce); +} + +static int ce_compare_data(const struct cache_entry *ce, struct stat *st) +{ + int match = -1; + int fd = open(ce->name, O_RDONLY); + + if (fd >= 0) { + unsigned char sha1[20]; + if (!index_fd(sha1, fd, st, OBJ_BLOB, ce->name, 0)) + match = hashcmp(sha1, ce->sha1); + /* index_fd() closed the file descriptor already */ + } + return match; +} + +static int ce_compare_link(const struct cache_entry *ce, size_t expected_size) +{ + int match = -1; + void *buffer; + unsigned long size; + enum object_type type; + struct strbuf sb = STRBUF_INIT; + + if (strbuf_readlink(&sb, ce->name, expected_size)) + return -1; + + buffer = read_sha1_file(ce->sha1, &type, &size); + if (buffer) { + if (size == sb.len) + match = memcmp(buffer, sb.buf, size); + free(buffer); + } + strbuf_release(&sb); + return match; +} + +static int ce_compare_gitlink(const struct cache_entry *ce) +{ + unsigned char sha1[20]; + + /* + * We don't actually require that the .git directory + * under GITLINK directory be a valid git directory. It + * might even be missing (in case nobody populated that + * sub-project). + * + * If so, we consider it always to match. + */ + if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0) + return 0; + return hashcmp(sha1, ce->sha1); +} + +static int ce_modified_check_fs(const struct cache_entry *ce, struct stat *st) +{ + switch (st->st_mode & S_IFMT) { + case S_IFREG: + if (ce_compare_data(ce, st)) + return DATA_CHANGED; + break; + case S_IFLNK: + if (ce_compare_link(ce, xsize_t(st->st_size))) + return DATA_CHANGED; + break; + case S_IFDIR: + if (S_ISGITLINK(ce->ce_mode)) + return ce_compare_gitlink(ce) ? DATA_CHANGED : 0; + default: + return TYPE_CHANGED; + } + return 0; +} + +static int ce_match_stat_basic(const struct cache_entry *ce, struct stat *st) +{ + unsigned int changed = 0; + + if (ce->ce_flags & CE_REMOVE) + return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED; + + switch (ce->ce_mode & S_IFMT) { + case S_IFREG: + changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; + /* We consider only the owner x bit to be relevant for + * "mode changes" + */ + if (trust_executable_bit && + (0100 & (ce->ce_mode ^ st->st_mode))) + changed |= MODE_CHANGED; + break; + case S_IFLNK: + if (!S_ISLNK(st->st_mode) && + (has_symlinks || !S_ISREG(st->st_mode))) + changed |= TYPE_CHANGED; + break; + case S_IFGITLINK: + /* We ignore most of the st_xxx fields for gitlinks */ + if (!S_ISDIR(st->st_mode)) + changed |= TYPE_CHANGED; + else if (ce_compare_gitlink(ce)) + changed |= DATA_CHANGED; + return changed; + default: + die("internal error: ce_mode is %o", ce->ce_mode); + } + + changed |= match_stat_data(&ce->ce_stat_data, st); + + /* Racily smudged entry? */ + if (!ce->ce_stat_data.sd_size) { + if (!is_empty_blob_sha1(ce->sha1)) + changed |= DATA_CHANGED; + } + + return changed; +} + +static int is_racy_timestamp(const struct index_state *istate, + const struct cache_entry *ce) +{ + return (!S_ISGITLINK(ce->ce_mode) && + istate->timestamp.sec && +#ifdef USE_NSEC + /* nanosecond timestamped files can also be racy! */ + (istate->timestamp.sec < ce->ce_stat_data.sd_mtime.sec || + (istate->timestamp.sec == ce->ce_stat_data.sd_mtime.sec && + istate->timestamp.nsec <= ce->ce_stat_data.sd_mtime.nsec)) +#else + istate->timestamp.sec <= ce->ce_stat_data.sd_mtime.sec +#endif + ); +} + +int ie_match_stat(const struct index_state *istate, + const struct cache_entry *ce, struct stat *st, + unsigned int options) +{ + unsigned int changed; + int ignore_valid = options & CE_MATCH_IGNORE_VALID; + int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE; + int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY; + + /* + * If it's marked as always valid in the index, it's + * valid whatever the checked-out copy says. + * + * skip-worktree has the same effect with higher precedence + */ + if (!ignore_skip_worktree && ce_skip_worktree(ce)) + return 0; + if (!ignore_valid && (ce->ce_flags & CE_VALID)) + return 0; + + /* + * Intent-to-add entries have not been added, so the index entry + * by definition never matches what is in the work tree until it + * actually gets added. + */ + if (ce->ce_flags & CE_INTENT_TO_ADD) + return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED; + + changed = ce_match_stat_basic(ce, st); + + /* + * Within 1 second of this sequence: + * echo xyzzy >file && git-update-index --add file + * running this command: + * echo frotz >file + * would give a falsely clean cache entry. The mtime and + * length match the cache, and other stat fields do not change. + * + * We could detect this at update-index time (the cache entry + * being registered/updated records the same time as "now") + * and delay the return from git-update-index, but that would + * effectively mean we can make at most one commit per second, + * which is not acceptable. Instead, we check cache entries + * whose mtime are the same as the index file timestamp more + * carefully than others. + */ + if (!changed && is_racy_timestamp(istate, ce)) { + if (assume_racy_is_modified) + changed |= DATA_CHANGED; + else + changed |= ce_modified_check_fs(ce, st); + } + + return changed; +} + +int ie_modified(const struct index_state *istate, + const struct cache_entry *ce, + struct stat *st, unsigned int options) +{ + int changed, changed_fs; + + changed = ie_match_stat(istate, ce, st, options); + if (!changed) + return 0; + /* + * If the mode or type has changed, there's no point in trying + * to refresh the entry - it's not going to match + */ + if (changed & (MODE_CHANGED | TYPE_CHANGED)) + return changed; + + /* + * Immediately after read-tree or update-index --cacheinfo, + * the length field is zero, as we have never even read the + * lstat(2) information once, and we cannot trust DATA_CHANGED + * returned by ie_match_stat() which in turn was returned by + * ce_match_stat_basic() to signal that the filesize of the + * blob changed. We have to actually go to the filesystem to + * see if the contents match, and if so, should answer "unchanged". + * + * The logic does not apply to gitlinks, as ce_match_stat_basic() + * already has checked the actual HEAD from the filesystem in the + * subproject. If ie_match_stat() already said it is different, + * then we know it is. + */ + if ((changed & DATA_CHANGED) && + (S_ISGITLINK(ce->ce_mode) || ce->ce_stat_data.sd_size != 0)) + return changed; + + changed_fs = ce_modified_check_fs(ce, st); + if (changed_fs) + return changed | changed_fs; + return 0; +} + +int base_name_compare(const char *name1, int len1, int mode1, + const char *name2, int len2, int mode2) +{ + unsigned char c1, c2; + int len = len1 < len2 ? len1 : len2; + int cmp; + + cmp = memcmp(name1, name2, len); + if (cmp) + return cmp; + c1 = name1[len]; + c2 = name2[len]; + if (!c1 && S_ISDIR(mode1)) + c1 = '/'; + if (!c2 && S_ISDIR(mode2)) + c2 = '/'; + return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; +} + +/* + * df_name_compare() is identical to base_name_compare(), except it + * compares conflicting directory/file entries as equal. Note that + * while a directory name compares as equal to a regular file, they + * then individually compare _differently_ to a filename that has + * a dot after the basename (because '\0' < '.' < '/'). + * + * This is used by routines that want to traverse the git namespace + * but then handle conflicting entries together when possible. + */ +int df_name_compare(const char *name1, int len1, int mode1, + const char *name2, int len2, int mode2) +{ + int len = len1 < len2 ? len1 : len2, cmp; + unsigned char c1, c2; + + cmp = memcmp(name1, name2, len); + if (cmp) + return cmp; + /* Directories and files compare equal (same length, same name) */ + if (len1 == len2) + return 0; + c1 = name1[len]; + if (!c1 && S_ISDIR(mode1)) + c1 = '/'; + c2 = name2[len]; + if (!c2 && S_ISDIR(mode2)) + c2 = '/'; + if (c1 == '/' && !c2) + return 0; + if (c2 == '/' && !c1) + return 0; + return c1 - c2; +} + +int name_compare(const char *name1, size_t len1, const char *name2, size_t len2) +{ + size_t min_len = (len1 < len2) ? len1 : len2; + int cmp = memcmp(name1, name2, min_len); + if (cmp) + return cmp; + if (len1 < len2) + return -1; + if (len1 > len2) + return 1; + return 0; +} + +int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2) +{ + int cmp; + + cmp = name_compare(name1, len1, name2, len2); + if (cmp) + return cmp; + + if (stage1 < stage2) + return -1; + if (stage1 > stage2) + return 1; + return 0; +} + +static int index_name_stage_pos(const struct index_state *istate, const char *name, int namelen, int stage) +{ + int first, last; + + first = 0; + last = istate->cache_nr; + while (last > first) { + int next = (last + first) >> 1; + struct cache_entry *ce = istate->cache[next]; + int cmp = cache_name_stage_compare(name, namelen, stage, ce->name, ce_namelen(ce), ce_stage(ce)); + if (!cmp) + return next; + if (cmp < 0) { + last = next; + continue; + } + first = next+1; + } + return -first-1; +} + +int index_name_pos(const struct index_state *istate, const char *name, int namelen) +{ + return index_name_stage_pos(istate, name, namelen, 0); +} + +/* Remove entry, return true if there are more entries to go.. */ +int remove_index_entry_at(struct index_state *istate, int pos) +{ + struct cache_entry *ce = istate->cache[pos]; + + record_resolve_undo(istate, ce); + remove_name_hash(istate, ce); + save_or_free_index_entry(istate, ce); + istate->cache_changed |= CE_ENTRY_REMOVED; + istate->cache_nr--; + if (pos >= istate->cache_nr) + return 0; + memmove(istate->cache + pos, + istate->cache + pos + 1, + (istate->cache_nr - pos) * sizeof(struct cache_entry *)); + return 1; +} + +/* + * Remove all cache entries marked for removal, that is where + * CE_REMOVE is set in ce_flags. This is much more effective than + * calling remove_index_entry_at() for each entry to be removed. + */ +void remove_marked_cache_entries(struct index_state *istate) +{ + struct cache_entry **ce_array = istate->cache; + unsigned int i, j; + + for (i = j = 0; i < istate->cache_nr; i++) { + if (ce_array[i]->ce_flags & CE_REMOVE) { + remove_name_hash(istate, ce_array[i]); + save_or_free_index_entry(istate, ce_array[i]); + } + else + ce_array[j++] = ce_array[i]; + } + if (j == istate->cache_nr) + return; + istate->cache_changed |= CE_ENTRY_REMOVED; + istate->cache_nr = j; +} + +int remove_file_from_index(struct index_state *istate, const char *path) +{ + int pos = index_name_pos(istate, path, strlen(path)); + if (pos < 0) + pos = -pos-1; + cache_tree_invalidate_path(istate, path); + while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path)) + remove_index_entry_at(istate, pos); + return 0; +} + +static int compare_name(struct cache_entry *ce, const char *path, int namelen) +{ + return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen); +} + +static int index_name_pos_also_unmerged(struct index_state *istate, + const char *path, int namelen) +{ + int pos = index_name_pos(istate, path, namelen); + struct cache_entry *ce; + + if (pos >= 0) + return pos; + + /* maybe unmerged? */ + pos = -1 - pos; + if (pos >= istate->cache_nr || + compare_name((ce = istate->cache[pos]), path, namelen)) + return -1; + + /* order of preference: stage 2, 1, 3 */ + if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr && + ce_stage((ce = istate->cache[pos + 1])) == 2 && + !compare_name(ce, path, namelen)) + pos++; + return pos; +} + +static int different_name(struct cache_entry *ce, struct cache_entry *alias) +{ + int len = ce_namelen(ce); + return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len); +} + +/* + * If we add a filename that aliases in the cache, we will use the + * name that we already have - but we don't want to update the same + * alias twice, because that implies that there were actually two + * different files with aliasing names! + * + * So we use the CE_ADDED flag to verify that the alias was an old + * one before we accept it as + */ +static struct cache_entry *create_alias_ce(struct index_state *istate, + struct cache_entry *ce, + struct cache_entry *alias) +{ + int len; + struct cache_entry *new; + + if (alias->ce_flags & CE_ADDED) + die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name); + + /* Ok, create the new entry using the name of the existing alias */ + len = ce_namelen(alias); + new = xcalloc(1, cache_entry_size(len)); + memcpy(new->name, alias->name, len); + copy_cache_entry(new, ce); + save_or_free_index_entry(istate, ce); + return new; +} + +void set_object_name_for_intent_to_add_entry(struct cache_entry *ce) +{ + unsigned char sha1[20]; + if (write_sha1_file("", 0, blob_type, sha1)) + die("cannot create an empty blob in the object database"); + hashcpy(ce->sha1, sha1); +} + +int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags) +{ + int size, namelen, was_same; + mode_t st_mode = st->st_mode; + struct cache_entry *ce, *alias; + unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE|CE_MATCH_RACY_IS_DIRTY; + int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND); + int pretend = flags & ADD_CACHE_PRETEND; + int intent_only = flags & ADD_CACHE_INTENT; + int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE| + (intent_only ? ADD_CACHE_NEW_ONLY : 0)); + + if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode)) + return error("%s: can only add regular files, symbolic links or git-directories", path); + + namelen = strlen(path); + if (S_ISDIR(st_mode)) { + while (namelen && path[namelen-1] == '/') + namelen--; + } + size = cache_entry_size(namelen); + ce = xcalloc(1, size); + memcpy(ce->name, path, namelen); + ce->ce_namelen = namelen; + if (!intent_only) + fill_stat_cache_info(ce, st); + else + ce->ce_flags |= CE_INTENT_TO_ADD; + + if (trust_executable_bit && has_symlinks) + ce->ce_mode = create_ce_mode(st_mode); + else { + /* If there is an existing entry, pick the mode bits and type + * from it, otherwise assume unexecutable regular file. + */ + struct cache_entry *ent; + int pos = index_name_pos_also_unmerged(istate, path, namelen); + + ent = (0 <= pos) ? istate->cache[pos] : NULL; + ce->ce_mode = ce_mode_from_stat(ent, st_mode); + } + + /* When core.ignorecase=true, determine if a directory of the same name but differing + * case already exists within the Git repository. If it does, ensure the directory + * case of the file being added to the repository matches (is folded into) the existing + * entry's directory case. + */ + if (ignore_case) { + const char *startPtr = ce->name; + const char *ptr = startPtr; + while (*ptr) { + while (*ptr && *ptr != '/') + ++ptr; + if (*ptr == '/') { + struct cache_entry *foundce; + ++ptr; + foundce = index_dir_exists(istate, ce->name, ptr - ce->name - 1); + if (foundce) { + memcpy((void *)startPtr, foundce->name + (startPtr - ce->name), ptr - startPtr); + startPtr = ptr; + } + } + } + } + + alias = index_file_exists(istate, ce->name, ce_namelen(ce), ignore_case); + if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) { + /* Nothing changed, really */ + if (!S_ISGITLINK(alias->ce_mode)) + ce_mark_uptodate(alias); + alias->ce_flags |= CE_ADDED; + + free(ce); + return 0; + } + if (!intent_only) { + if (index_path(ce->sha1, path, st, HASH_WRITE_OBJECT)) { + free(ce); + return error("unable to index file %s", path); + } + } else + set_object_name_for_intent_to_add_entry(ce); + + if (ignore_case && alias && different_name(ce, alias)) + ce = create_alias_ce(istate, ce, alias); + ce->ce_flags |= CE_ADDED; + + /* It was suspected to be racily clean, but it turns out to be Ok */ + was_same = (alias && + !ce_stage(alias) && + !hashcmp(alias->sha1, ce->sha1) && + ce->ce_mode == alias->ce_mode); + + if (pretend) + free(ce); + else if (add_index_entry(istate, ce, add_option)) { + free(ce); + return error("unable to add %s to index", path); + } + if (verbose && !was_same) + printf("add '%s'\n", path); + return 0; +} + +int add_file_to_index(struct index_state *istate, const char *path, int flags) +{ + struct stat st; + if (lstat(path, &st)) + die_errno("unable to stat '%s'", path); + return add_to_index(istate, path, &st, flags); +} + +struct cache_entry *make_cache_entry(unsigned int mode, + const unsigned char *sha1, const char *path, int stage, + unsigned int refresh_options) +{ + int size, len; + struct cache_entry *ce, *ret; + + if (!verify_path(path)) { + error("Invalid path '%s'", path); + return NULL; + } + + len = strlen(path); + size = cache_entry_size(len); + ce = xcalloc(1, size); + + hashcpy(ce->sha1, sha1); + memcpy(ce->name, path, len); + ce->ce_flags = create_ce_flags(stage); + ce->ce_namelen = len; + ce->ce_mode = create_ce_mode(mode); + + ret = refresh_cache_entry(ce, refresh_options); + if (ret != ce) + free(ce); + return ret; +} + +int ce_same_name(const struct cache_entry *a, const struct cache_entry *b) +{ + int len = ce_namelen(a); + return ce_namelen(b) == len && !memcmp(a->name, b->name, len); +} + +/* + * 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. + */ + + /* "." is not allowed */ + if (*rest == '\0' || is_dir_sep(*rest)) + return 0; + + switch (*rest) { + /* + * ".git" followed by NUL or slash is bad. This + * shares the path end test with the ".." case. + */ + case 'g': + case 'G': + if (rest[1] != 'i' && rest[1] != 'I') + break; + if (rest[2] != 't' && rest[2] != 'T') + break; + rest += 2; + /* fallthrough */ + case '.': + if (rest[1] == '\0' || is_dir_sep(rest[1])) + return 0; + } + return 1; +} + +int verify_path(const char *path) +{ + char c; + + if (has_dos_drive_prefix(path)) + return 0; + + goto inside; + for (;;) { + if (!c) + return 1; + if (is_dir_sep(c)) { +inside: + if (protect_hfs && is_hfs_dotgit(path)) + return 0; + if (protect_ntfs && is_ntfs_dotgit(path)) + return 0; + c = *path++; + if ((c == '.' && !verify_dotfile(path)) || + is_dir_sep(c) || c == '\0') + 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? + */ +static int has_file_name(struct index_state *istate, + const struct cache_entry *ce, int pos, int ok_to_replace) +{ + int retval = 0; + int len = ce_namelen(ce); + int stage = ce_stage(ce); + const char *name = ce->name; + + while (pos < istate->cache_nr) { + struct cache_entry *p = istate->cache[pos++]; + + if (len >= ce_namelen(p)) + break; + if (memcmp(name, p->name, len)) + break; + if (ce_stage(p) != stage) + continue; + if (p->name[len] != '/') + continue; + if (p->ce_flags & CE_REMOVE) + continue; + retval = -1; + if (!ok_to_replace) + break; + remove_index_entry_at(istate, --pos); + } + return retval; +} + +/* + * Do we have another file with a pathname that is a proper + * subset of the name we're trying to add? + */ +static int has_dir_name(struct index_state *istate, + const struct cache_entry *ce, int pos, int ok_to_replace) +{ + int retval = 0; + int stage = ce_stage(ce); + const char *name = ce->name; + const char *slash = name + ce_namelen(ce); + + for (;;) { + int len; + + for (;;) { + if (*--slash == '/') + break; + if (slash <= ce->name) + return retval; + } + len = slash - name; + + pos = index_name_stage_pos(istate, name, len, stage); + if (pos >= 0) { + /* + * Found one, but not so fast. This could + * be a marker that says "I was here, but + * I am being removed". Such an entry is + * not a part of the resulting tree, and + * it is Ok to have a directory at the same + * path. + */ + if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) { + retval = -1; + if (!ok_to_replace) + break; + remove_index_entry_at(istate, pos); + continue; + } + } + else + pos = -pos-1; + + /* + * Trivial optimization: if we find an entry that + * already matches the sub-directory, then we know + * we're ok, and we can exit. + */ + while (pos < istate->cache_nr) { + struct cache_entry *p = istate->cache[pos]; + if ((ce_namelen(p) <= len) || + (p->name[len] != '/') || + memcmp(p->name, name, len)) + break; /* not our subdirectory */ + if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE)) + /* + * p is at the same stage as our entry, and + * is a subdirectory of what we are looking + * at, so we cannot have conflicts at our + * level or anything shorter. + */ + return retval; + pos++; + } + } + return retval; +} + +/* We may be in a situation where we already have path/file and path + * is being added, or we already have path and path/file is being + * added. Either one would result in a nonsense tree that has path + * twice when git-write-tree tries to write it out. Prevent it. + * + * If ok-to-replace is specified, we remove the conflicting entries + * from the cache so the caller should recompute the insert position. + * When this happens, we return non-zero. + */ +static int check_file_directory_conflict(struct index_state *istate, + const struct cache_entry *ce, + int pos, int ok_to_replace) +{ + int retval; + + /* + * When ce is an "I am going away" entry, we allow it to be added + */ + if (ce->ce_flags & CE_REMOVE) + return 0; + + /* + * We check if the path is a sub-path of a subsequent pathname + * first, since removing those will not change the position + * in the array. + */ + retval = has_file_name(istate, ce, pos, ok_to_replace); + + /* + * Then check if the path might have a clashing sub-directory + * before it. + */ + return retval + has_dir_name(istate, ce, pos, ok_to_replace); +} + +static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option) +{ + int pos; + int ok_to_add = option & ADD_CACHE_OK_TO_ADD; + int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; + int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; + int new_only = option & ADD_CACHE_NEW_ONLY; + + if (!(option & ADD_CACHE_KEEP_CACHE_TREE)) + cache_tree_invalidate_path(istate, ce->name); + pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce)); + + /* existing match? Just replace it. */ + if (pos >= 0) { + if (!new_only) + replace_index_entry(istate, pos, ce); + return 0; + } + pos = -pos-1; + + /* + * Inserting a merged entry ("stage 0") into the index + * will always replace all non-merged entries.. + */ + if (pos < istate->cache_nr && ce_stage(ce) == 0) { + while (ce_same_name(istate->cache[pos], ce)) { + ok_to_add = 1; + if (!remove_index_entry_at(istate, pos)) + break; + } + } + + if (!ok_to_add) + return -1; + if (!verify_path(ce->name)) + return error("Invalid path '%s'", ce->name); + + if (!skip_df_check && + check_file_directory_conflict(istate, ce, pos, ok_to_replace)) { + if (!ok_to_replace) + return error("'%s' appears as both a file and as a directory", + ce->name); + pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce)); + pos = -pos-1; + } + return pos + 1; +} + +int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option) +{ + int pos; + + if (option & ADD_CACHE_JUST_APPEND) + pos = istate->cache_nr; + else { + int ret; + ret = add_index_entry_with_check(istate, ce, option); + if (ret <= 0) + return ret; + pos = ret - 1; + } + + /* Make sure the array is big enough .. */ + ALLOC_GROW(istate->cache, istate->cache_nr + 1, istate->cache_alloc); + + /* Add it in.. */ + istate->cache_nr++; + if (istate->cache_nr > pos + 1) + memmove(istate->cache + pos + 1, + istate->cache + pos, + (istate->cache_nr - pos - 1) * sizeof(ce)); + set_index_entry(istate, pos, ce); + istate->cache_changed |= CE_ENTRY_ADDED; + return 0; +} + +/* + * "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_cache_ent(struct index_state *istate, + struct cache_entry *ce, + unsigned int options, int *err, + int *changed_ret) +{ + struct stat st; + struct cache_entry *updated; + int changed, size; + int refresh = options & CE_MATCH_REFRESH; + int ignore_valid = options & CE_MATCH_IGNORE_VALID; + int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE; + int ignore_missing = options & CE_MATCH_IGNORE_MISSING; + + if (!refresh || ce_uptodate(ce)) + return ce; + + /* + * CE_VALID or CE_SKIP_WORKTREE means the user promised us + * that the change to the work tree does not matter and told + * us not to worry. + */ + if (!ignore_skip_worktree && ce_skip_worktree(ce)) { + ce_mark_uptodate(ce); + return ce; + } + if (!ignore_valid && (ce->ce_flags & CE_VALID)) { + ce_mark_uptodate(ce); + return ce; + } + + if (has_symlink_leading_path(ce->name, ce_namelen(ce))) { + if (ignore_missing) + return ce; + if (err) + *err = ENOENT; + return NULL; + } + + if (lstat(ce->name, &st) < 0) { + if (ignore_missing && errno == ENOENT) + return ce; + if (err) + *err = errno; + return NULL; + } + + changed = ie_match_stat(istate, ce, &st, options); + if (changed_ret) + *changed_ret = changed; + if (!changed) { + /* + * The path is unchanged. If we were told to ignore + * valid bit, then we did the actual stat check and + * found that the entry is unmodified. If the entry + * is not marked VALID, this is the place to mark it + * valid again, under "assume unchanged" mode. + */ + if (ignore_valid && assume_unchanged && + !(ce->ce_flags & CE_VALID)) + ; /* mark this one VALID again */ + else { + /* + * We do not mark the index itself "modified" + * because CE_UPTODATE flag is in-core only; + * we are not going to write this change out. + */ + if (!S_ISGITLINK(ce->ce_mode)) + ce_mark_uptodate(ce); + return ce; + } + } + + if (ie_modified(istate, ce, &st, options)) { + if (err) + *err = EINVAL; + return NULL; + } + + size = ce_size(ce); + updated = xmalloc(size); + memcpy(updated, ce, size); + fill_stat_cache_info(updated, &st); + /* + * If ignore_valid 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 (!ignore_valid && assume_unchanged && + !(ce->ce_flags & CE_VALID)) + updated->ce_flags &= ~CE_VALID; + + /* istate->cache_changed is updated in the caller */ + return updated; +} + +static void show_file(const char * fmt, const char * name, int in_porcelain, + int * first, const char *header_msg) +{ + if (in_porcelain && *first && header_msg) { + printf("%s\n", header_msg); + *first = 0; + } + printf(fmt, name); +} + +int refresh_index(struct index_state *istate, unsigned int flags, + const struct pathspec *pathspec, + char *seen, const char *header_msg) +{ + 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; + int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0; + int first = 1; + int in_porcelain = (flags & REFRESH_IN_PORCELAIN); + unsigned int options = (CE_MATCH_REFRESH | + (really ? CE_MATCH_IGNORE_VALID : 0) | + (not_new ? CE_MATCH_IGNORE_MISSING : 0)); + const char *modified_fmt; + const char *deleted_fmt; + const char *typechange_fmt; + const char *added_fmt; + const char *unmerged_fmt; + + modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n"); + deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n"); + typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n"); + added_fmt = (in_porcelain ? "A\t%s\n" : "%s needs update\n"); + unmerged_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n"); + for (i = 0; i < istate->cache_nr; i++) { + struct cache_entry *ce, *new; + int cache_errno = 0; + int changed = 0; + int filtered = 0; + + ce = istate->cache[i]; + if (ignore_submodules && S_ISGITLINK(ce->ce_mode)) + continue; + + if (pathspec && !ce_path_match(ce, pathspec, seen)) + filtered = 1; + + if (ce_stage(ce)) { + while ((i < istate->cache_nr) && + ! strcmp(istate->cache[i]->name, ce->name)) + i++; + i--; + if (allow_unmerged) + continue; + if (!filtered) + show_file(unmerged_fmt, ce->name, in_porcelain, + &first, header_msg); + has_errors = 1; + continue; + } + + if (filtered) + continue; + + new = refresh_cache_ent(istate, ce, options, &cache_errno, &changed); + if (new == ce) + continue; + if (!new) { + const char *fmt; + + if (really && cache_errno == EINVAL) { + /* If we are doing --really-refresh that + * means the index is not valid anymore. + */ + ce->ce_flags &= ~CE_VALID; + ce->ce_flags |= CE_UPDATE_IN_BASE; + istate->cache_changed |= CE_ENTRY_CHANGED; + } + if (quiet) + continue; + + if (cache_errno == ENOENT) + fmt = deleted_fmt; + else if (ce->ce_flags & CE_INTENT_TO_ADD) + fmt = added_fmt; /* must be before other checks */ + else if (changed & TYPE_CHANGED) + fmt = typechange_fmt; + else + fmt = modified_fmt; + show_file(fmt, + ce->name, in_porcelain, &first, header_msg); + has_errors = 1; + continue; + } + + replace_index_entry(istate, i, new); + } + return has_errors; +} + +static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, + unsigned int options) +{ + return refresh_cache_ent(&the_index, ce, options, NULL, NULL); +} + + +/***************************************************************** + * Index File I/O + *****************************************************************/ + +#define INDEX_FORMAT_DEFAULT 3 + +static unsigned int get_index_format_default(void) +{ + char *envversion = getenv("GIT_INDEX_VERSION"); + char *endp; + int value; + unsigned int version = INDEX_FORMAT_DEFAULT; + + if (!envversion) { + if (!git_config_get_int("index.version", &value)) + version = value; + if (version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < version) { + warning(_("index.version set, but the value is invalid.\n" + "Using version %i"), INDEX_FORMAT_DEFAULT); + return INDEX_FORMAT_DEFAULT; + } + return version; + } + + version = strtoul(envversion, &endp, 10); + if (*endp || + version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < version) { + warning(_("GIT_INDEX_VERSION set, but the value is invalid.\n" + "Using version %i"), INDEX_FORMAT_DEFAULT); + version = INDEX_FORMAT_DEFAULT; + } + return version; +} + +/* + * dev/ino/uid/gid/size are also just tracked to the low 32 bits + * Again - this is just a (very strong in practice) heuristic that + * the inode hasn't changed. + * + * We save the fields in big-endian order to allow using the + * index file over NFS transparently. + */ +struct ondisk_cache_entry { + struct cache_time ctime; + struct cache_time mtime; + uint32_t dev; + uint32_t ino; + uint32_t mode; + uint32_t uid; + uint32_t gid; + uint32_t size; + unsigned char sha1[20]; + uint16_t flags; + char name[FLEX_ARRAY]; /* more */ +}; + +/* + * This struct is used when CE_EXTENDED bit is 1 + * The struct must match ondisk_cache_entry exactly from + * ctime till flags + */ +struct ondisk_cache_entry_extended { + struct cache_time ctime; + struct cache_time mtime; + uint32_t dev; + uint32_t ino; + uint32_t mode; + uint32_t uid; + uint32_t gid; + uint32_t size; + unsigned char sha1[20]; + uint16_t flags; + uint16_t flags2; + char name[FLEX_ARRAY]; /* more */ +}; + +/* These are only used for v3 or lower */ +#define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7) +#define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len) +#define ondisk_cache_entry_extended_size(len) align_flex_name(ondisk_cache_entry_extended,len) +#define ondisk_ce_size(ce) (((ce)->ce_flags & CE_EXTENDED) ? \ + ondisk_cache_entry_extended_size(ce_namelen(ce)) : \ + ondisk_cache_entry_size(ce_namelen(ce))) + +static int verify_hdr(struct cache_header *hdr, unsigned long size) +{ + git_SHA_CTX c; + unsigned char sha1[20]; + int hdr_version; + + if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) + return error("bad signature"); + hdr_version = ntohl(hdr->hdr_version); + if (hdr_version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < hdr_version) + return error("bad index version %d", hdr_version); + git_SHA1_Init(&c); + git_SHA1_Update(&c, hdr, size - 20); + git_SHA1_Final(sha1, &c); + if (hashcmp(sha1, (unsigned char *)hdr + size - 20)) + return error("bad index file sha1 signature"); + return 0; +} + +static int read_index_extension(struct index_state *istate, + const char *ext, void *data, unsigned long sz) +{ + switch (CACHE_EXT(ext)) { + case CACHE_EXT_TREE: + istate->cache_tree = cache_tree_read(data, sz); + break; + case CACHE_EXT_RESOLVE_UNDO: + istate->resolve_undo = resolve_undo_read(data, sz); + break; + case CACHE_EXT_LINK: + if (read_link_extension(istate, data, sz)) + return -1; + 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 hold_locked_index(struct lock_file *lk, int die_on_error) +{ + return hold_lock_file_for_update(lk, get_index_file(), + die_on_error + ? LOCK_DIE_ON_ERROR + : 0); +} + +int read_index(struct index_state *istate) +{ + return read_index_from(istate, get_index_file()); +} + +static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk, + unsigned int flags, + const char *name, + size_t len) +{ + struct cache_entry *ce = xmalloc(cache_entry_size(len)); + + ce->ce_stat_data.sd_ctime.sec = get_be32(&ondisk->ctime.sec); + ce->ce_stat_data.sd_mtime.sec = get_be32(&ondisk->mtime.sec); + ce->ce_stat_data.sd_ctime.nsec = get_be32(&ondisk->ctime.nsec); + ce->ce_stat_data.sd_mtime.nsec = get_be32(&ondisk->mtime.nsec); + ce->ce_stat_data.sd_dev = get_be32(&ondisk->dev); + ce->ce_stat_data.sd_ino = get_be32(&ondisk->ino); + ce->ce_mode = get_be32(&ondisk->mode); + ce->ce_stat_data.sd_uid = get_be32(&ondisk->uid); + ce->ce_stat_data.sd_gid = get_be32(&ondisk->gid); + ce->ce_stat_data.sd_size = get_be32(&ondisk->size); + ce->ce_flags = flags & ~CE_NAMEMASK; + ce->ce_namelen = len; + ce->index = 0; + hashcpy(ce->sha1, ondisk->sha1); + memcpy(ce->name, name, len); + ce->name[len] = '\0'; + return ce; +} + +/* + * Adjacent cache entries tend to share the leading paths, so it makes + * sense to only store the differences in later entries. In the v4 + * on-disk format of the index, each on-disk cache entry stores the + * number of bytes to be stripped from the end of the previous name, + * and the bytes to append to the result, to come up with its name. + */ +static unsigned long expand_name_field(struct strbuf *name, const char *cp_) +{ + const unsigned char *ep, *cp = (const unsigned char *)cp_; + size_t len = decode_varint(&cp); + + if (name->len < len) + die("malformed name field in the index"); + strbuf_remove(name, name->len - len, len); + for (ep = cp; *ep; ep++) + ; /* find the end */ + strbuf_add(name, cp, ep - cp); + return (const char *)ep + 1 - cp_; +} + +static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk, + unsigned long *ent_size, + struct strbuf *previous_name) +{ + struct cache_entry *ce; + size_t len; + const char *name; + unsigned int flags; + + /* On-disk flags are just 16 bits */ + flags = get_be16(&ondisk->flags); + len = flags & CE_NAMEMASK; + + if (flags & CE_EXTENDED) { + struct ondisk_cache_entry_extended *ondisk2; + int extended_flags; + ondisk2 = (struct ondisk_cache_entry_extended *)ondisk; + extended_flags = get_be16(&ondisk2->flags2) << 16; + /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */ + if (extended_flags & ~CE_EXTENDED_FLAGS) + die("Unknown index entry format %08x", extended_flags); + flags |= extended_flags; + name = ondisk2->name; + } + else + name = ondisk->name; + + if (!previous_name) { + /* v3 and earlier */ + if (len == CE_NAMEMASK) + len = strlen(name); + ce = cache_entry_from_ondisk(ondisk, flags, name, len); + + *ent_size = ondisk_ce_size(ce); + } else { + unsigned long consumed; + consumed = expand_name_field(previous_name, name); + ce = cache_entry_from_ondisk(ondisk, flags, + previous_name->buf, + previous_name->len); + + *ent_size = (name - ((char *)ondisk)) + consumed; + } + return ce; +} + +static void check_ce_order(struct index_state *istate) +{ + unsigned int i; + + for (i = 1; i < istate->cache_nr; i++) { + struct cache_entry *ce = istate->cache[i - 1]; + struct cache_entry *next_ce = istate->cache[i]; + int name_compare = strcmp(ce->name, next_ce->name); + + if (0 < name_compare) + die("unordered stage entries in index"); + if (!name_compare) { + if (!ce_stage(ce)) + die("multiple stage entries for merged file '%s'", + ce->name); + if (ce_stage(ce) > ce_stage(next_ce)) + die("unordered stage entries for '%s'", + ce->name); + } + } +} + +/* remember to discard_cache() before reading a different cache! */ +int do_read_index(struct index_state *istate, const char *path, int must_exist) +{ + int fd, i; + struct stat st; + unsigned long src_offset; + struct cache_header *hdr; + void *mmap; + size_t mmap_size; + struct strbuf previous_name_buf = STRBUF_INIT, *previous_name; + + if (istate->initialized) + return istate->cache_nr; + + istate->timestamp.sec = 0; + istate->timestamp.nsec = 0; + fd = open(path, O_RDONLY); + if (fd < 0) { + if (!must_exist && errno == ENOENT) + return 0; + die_errno("%s: index file open failed", path); + } + + if (fstat(fd, &st)) + die_errno("cannot stat the open index"); + + mmap_size = xsize_t(st.st_size); + if (mmap_size < sizeof(struct cache_header) + 20) + die("index file smaller than expected"); + + mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + if (mmap == MAP_FAILED) + die_errno("unable to map index file"); + close(fd); + + hdr = mmap; + if (verify_hdr(hdr, mmap_size) < 0) + goto unmap; + + hashcpy(istate->sha1, (const unsigned char *)hdr + mmap_size - 20); + istate->version = ntohl(hdr->hdr_version); + istate->cache_nr = ntohl(hdr->hdr_entries); + istate->cache_alloc = alloc_nr(istate->cache_nr); + istate->cache = xcalloc(istate->cache_alloc, sizeof(*istate->cache)); + istate->initialized = 1; + + if (istate->version == 4) + previous_name = &previous_name_buf; + else + previous_name = NULL; + + src_offset = sizeof(*hdr); + for (i = 0; i < istate->cache_nr; i++) { + struct ondisk_cache_entry *disk_ce; + struct cache_entry *ce; + unsigned long consumed; + + disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset); + ce = create_from_disk(disk_ce, &consumed, previous_name); + set_index_entry(istate, i, ce); + + src_offset += consumed; + } + strbuf_release(&previous_name_buf); + istate->timestamp.sec = st.st_mtime; + istate->timestamp.nsec = ST_MTIME_NSEC(st); + + while (src_offset <= mmap_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. + */ + uint32_t extsize; + memcpy(&extsize, (char *)mmap + src_offset + 4, 4); + extsize = ntohl(extsize); + if (read_index_extension(istate, + (const char *) mmap + src_offset, + (char *) mmap + src_offset + 8, + extsize) < 0) + goto unmap; + src_offset += 8; + src_offset += extsize; + } + munmap(mmap, mmap_size); + return istate->cache_nr; + +unmap: + munmap(mmap, mmap_size); + die("index file corrupt"); +} + +int read_index_from(struct index_state *istate, const char *path) +{ + struct split_index *split_index; + int ret; + + /* istate->initialized covers both .git/index and .git/sharedindex.xxx */ + if (istate->initialized) + return istate->cache_nr; + + ret = do_read_index(istate, path, 0); + split_index = istate->split_index; + if (!split_index || is_null_sha1(split_index->base_sha1)) { + check_ce_order(istate); + return ret; + } + + if (split_index->base) + discard_index(split_index->base); + else + split_index->base = xcalloc(1, sizeof(*split_index->base)); + ret = do_read_index(split_index->base, + git_path("sharedindex.%s", + sha1_to_hex(split_index->base_sha1)), 1); + if (hashcmp(split_index->base_sha1, split_index->base->sha1)) + die("broken index, expect %s in %s, got %s", + sha1_to_hex(split_index->base_sha1), + git_path("sharedindex.%s", + sha1_to_hex(split_index->base_sha1)), + sha1_to_hex(split_index->base->sha1)); + merge_base_index(istate); + check_ce_order(istate); + return ret; +} + +int is_index_unborn(struct index_state *istate) +{ + return (!istate->cache_nr && !istate->timestamp.sec); +} + +int discard_index(struct index_state *istate) +{ + int i; + + for (i = 0; i < istate->cache_nr; i++) { + if (istate->cache[i]->index && + istate->split_index && + istate->split_index->base && + istate->cache[i]->index <= istate->split_index->base->cache_nr && + istate->cache[i] == istate->split_index->base->cache[istate->cache[i]->index - 1]) + continue; + free(istate->cache[i]); + } + resolve_undo_clear_index(istate); + istate->cache_nr = 0; + istate->cache_changed = 0; + istate->timestamp.sec = 0; + istate->timestamp.nsec = 0; + free_name_hash(istate); + cache_tree_free(&(istate->cache_tree)); + istate->initialized = 0; + free(istate->cache); + istate->cache = NULL; + istate->cache_alloc = 0; + discard_split_index(istate); + return 0; +} + +int unmerged_index(const struct index_state *istate) +{ + int i; + for (i = 0; i < istate->cache_nr; i++) { + if (ce_stage(istate->cache[i])) + return 1; + } + return 0; +} + +#define WRITE_BUFFER_SIZE 8192 +static unsigned char write_buffer[WRITE_BUFFER_SIZE]; +static unsigned long write_buffer_len; + +static int ce_write_flush(git_SHA_CTX *context, int fd) +{ + unsigned int buffered = write_buffer_len; + if (buffered) { + git_SHA1_Update(context, write_buffer, buffered); + if (write_in_full(fd, write_buffer, buffered) != buffered) + return -1; + write_buffer_len = 0; + } + return 0; +} + +static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len) +{ + while (len) { + unsigned int buffered = write_buffer_len; + unsigned int partial = WRITE_BUFFER_SIZE - buffered; + if (partial > len) + partial = len; + memcpy(write_buffer + buffered, data, partial); + buffered += partial; + if (buffered == WRITE_BUFFER_SIZE) { + write_buffer_len = buffered; + if (ce_write_flush(context, fd)) + return -1; + buffered = 0; + } + write_buffer_len = buffered; + len -= partial; + data = (char *) data + partial; + } + return 0; +} + +static int write_index_ext_header(git_SHA_CTX *context, int fd, + unsigned int ext, unsigned int sz) +{ + ext = htonl(ext); + sz = htonl(sz); + return ((ce_write(context, fd, &ext, 4) < 0) || + (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0; +} + +static int ce_flush(git_SHA_CTX *context, int fd, unsigned char *sha1) +{ + unsigned int left = write_buffer_len; + + if (left) { + write_buffer_len = 0; + git_SHA1_Update(context, write_buffer, left); + } + + /* Flush first if not enough space for SHA1 signature */ + if (left + 20 > WRITE_BUFFER_SIZE) { + if (write_in_full(fd, write_buffer, left) != left) + return -1; + left = 0; + } + + /* Append the SHA1 signature at the end */ + git_SHA1_Final(write_buffer + left, context); + hashcpy(sha1, write_buffer + left); + left += 20; + return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0; +} + +static void ce_smudge_racily_clean_entry(struct cache_entry *ce) +{ + /* + * The only thing we care about in this function is to smudge the + * falsely clean entry due to touch-update-touch race, so we leave + * everything else as they are. We are called for entries whose + * ce_stat_data.sd_mtime match the index file mtime. + * + * Note that this actually does not do much for gitlinks, for + * which ce_match_stat_basic() always goes to the actual + * contents. The caller checks with is_racy_timestamp() which + * always says "no" for gitlinks, so we are not called for them ;-) + */ + struct stat st; + + if (lstat(ce->name, &st) < 0) + return; + if (ce_match_stat_basic(ce, &st)) + return; + if (ce_modified_check_fs(ce, &st)) { + /* This is "racily clean"; smudge it. Note that this + * is a tricky code. At first glance, it may appear + * that it can break with this sequence: + * + * $ echo xyzzy >frotz + * $ git-update-index --add frotz + * $ : >frotz + * $ sleep 3 + * $ echo filfre >nitfol + * $ git-update-index --add nitfol + * + * but it does not. When the second update-index runs, + * it notices that the entry "frotz" has the same timestamp + * as index, and if we were to smudge it by resetting its + * size to zero here, then the object name recorded + * in index is the 6-byte file but the cached stat information + * becomes zero --- which would then match what we would + * obtain from the filesystem next time we stat("frotz"). + * + * However, the second update-index, before calling + * this function, notices that the cached size is 6 + * bytes and what is on the filesystem is an empty + * file, and never calls us, so the cached size information + * for "frotz" stays 6 which does not match the filesystem. + */ + ce->ce_stat_data.sd_size = 0; + } +} + +/* Copy miscellaneous fields but not the name */ +static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk, + struct cache_entry *ce) +{ + short flags; + + ondisk->ctime.sec = htonl(ce->ce_stat_data.sd_ctime.sec); + ondisk->mtime.sec = htonl(ce->ce_stat_data.sd_mtime.sec); + ondisk->ctime.nsec = htonl(ce->ce_stat_data.sd_ctime.nsec); + ondisk->mtime.nsec = htonl(ce->ce_stat_data.sd_mtime.nsec); + ondisk->dev = htonl(ce->ce_stat_data.sd_dev); + ondisk->ino = htonl(ce->ce_stat_data.sd_ino); + ondisk->mode = htonl(ce->ce_mode); + ondisk->uid = htonl(ce->ce_stat_data.sd_uid); + ondisk->gid = htonl(ce->ce_stat_data.sd_gid); + ondisk->size = htonl(ce->ce_stat_data.sd_size); + hashcpy(ondisk->sha1, ce->sha1); + + flags = ce->ce_flags & ~CE_NAMEMASK; + flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce)); + ondisk->flags = htons(flags); + if (ce->ce_flags & CE_EXTENDED) { + struct ondisk_cache_entry_extended *ondisk2; + ondisk2 = (struct ondisk_cache_entry_extended *)ondisk; + ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16); + return ondisk2->name; + } + else { + return ondisk->name; + } +} + +static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce, + struct strbuf *previous_name) +{ + int size; + struct ondisk_cache_entry *ondisk; + int saved_namelen = saved_namelen; /* compiler workaround */ + char *name; + int result; + + if (ce->ce_flags & CE_STRIP_NAME) { + saved_namelen = ce_namelen(ce); + ce->ce_namelen = 0; + } + + if (!previous_name) { + size = ondisk_ce_size(ce); + ondisk = xcalloc(1, size); + name = copy_cache_entry_to_ondisk(ondisk, ce); + memcpy(name, ce->name, ce_namelen(ce)); + } else { + int common, to_remove, prefix_size; + unsigned char to_remove_vi[16]; + for (common = 0; + (ce->name[common] && + common < previous_name->len && + ce->name[common] == previous_name->buf[common]); + common++) + ; /* still matching */ + to_remove = previous_name->len - common; + prefix_size = encode_varint(to_remove, to_remove_vi); + + if (ce->ce_flags & CE_EXTENDED) + size = offsetof(struct ondisk_cache_entry_extended, name); + else + size = offsetof(struct ondisk_cache_entry, name); + size += prefix_size + (ce_namelen(ce) - common + 1); + + ondisk = xcalloc(1, size); + name = copy_cache_entry_to_ondisk(ondisk, ce); + memcpy(name, to_remove_vi, prefix_size); + memcpy(name + prefix_size, ce->name + common, ce_namelen(ce) - common); + + strbuf_splice(previous_name, common, to_remove, + ce->name + common, ce_namelen(ce) - common); + } + if (ce->ce_flags & CE_STRIP_NAME) { + ce->ce_namelen = saved_namelen; + ce->ce_flags &= ~CE_STRIP_NAME; + } + + result = ce_write(c, fd, ondisk, size); + free(ondisk); + return result; +} + +/* + * This function verifies if index_state has the correct sha1 of the + * index file. Don't die if we have any other failure, just return 0. + */ +static int verify_index_from(const struct index_state *istate, const char *path) +{ + int fd; + ssize_t n; + struct stat st; + unsigned char sha1[20]; + + if (!istate->initialized) + return 0; + + fd = open(path, O_RDONLY); + if (fd < 0) + return 0; + + if (fstat(fd, &st)) + goto out; + + if (st.st_size < sizeof(struct cache_header) + 20) + goto out; + + n = pread_in_full(fd, sha1, 20, st.st_size - 20); + if (n != 20) + goto out; + + if (hashcmp(istate->sha1, sha1)) + goto out; + + close(fd); + return 1; + +out: + close(fd); + return 0; +} + +static int verify_index(const struct index_state *istate) +{ + return verify_index_from(istate, get_index_file()); +} + +static int has_racy_timestamp(struct index_state *istate) +{ + int entries = istate->cache_nr; + int i; + + for (i = 0; i < entries; i++) { + struct cache_entry *ce = istate->cache[i]; + if (is_racy_timestamp(istate, ce)) + return 1; + } + return 0; +} + +/* + * Opportunistically update the index but do not complain if we can't + */ +void update_index_if_able(struct index_state *istate, struct lock_file *lockfile) +{ + if ((istate->cache_changed || has_racy_timestamp(istate)) && + verify_index(istate) && + write_locked_index(istate, lockfile, COMMIT_LOCK)) + rollback_lock_file(lockfile); +} + +static int do_write_index(struct index_state *istate, int newfd, + int strip_extensions) +{ + git_SHA_CTX c; + struct cache_header hdr; + int i, err, removed, extended, hdr_version; + struct cache_entry **cache = istate->cache; + int entries = istate->cache_nr; + struct stat st; + struct strbuf previous_name_buf = STRBUF_INIT, *previous_name; + + for (i = removed = extended = 0; i < entries; i++) { + if (cache[i]->ce_flags & CE_REMOVE) + removed++; + + /* reduce extended entries if possible */ + cache[i]->ce_flags &= ~CE_EXTENDED; + if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) { + extended++; + cache[i]->ce_flags |= CE_EXTENDED; + } + } + + if (!istate->version) { + istate->version = get_index_format_default(); + if (getenv("GIT_TEST_SPLIT_INDEX")) + init_split_index(istate); + } + + /* demote version 3 to version 2 when the latter suffices */ + if (istate->version == 3 || istate->version == 2) + istate->version = extended ? 3 : 2; + + hdr_version = istate->version; + + hdr.hdr_signature = htonl(CACHE_SIGNATURE); + hdr.hdr_version = htonl(hdr_version); + hdr.hdr_entries = htonl(entries - removed); + + git_SHA1_Init(&c); + if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0) + return -1; + + previous_name = (hdr_version == 4) ? &previous_name_buf : NULL; + for (i = 0; i < entries; i++) { + struct cache_entry *ce = cache[i]; + if (ce->ce_flags & CE_REMOVE) + continue; + if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce)) + ce_smudge_racily_clean_entry(ce); + if (is_null_sha1(ce->sha1)) { + static const char msg[] = "cache entry has null sha1: %s"; + static int allow = -1; + + if (allow < 0) + allow = git_env_bool("GIT_ALLOW_NULL_SHA1", 0); + if (allow) + warning(msg, ce->name); + else + return error(msg, ce->name); + } + if (ce_write_entry(&c, newfd, ce, previous_name) < 0) + return -1; + } + strbuf_release(&previous_name_buf); + + /* Write extension data here */ + if (!strip_extensions && istate->split_index) { + struct strbuf sb = STRBUF_INIT; + + err = write_link_extension(&sb, istate) < 0 || + write_index_ext_header(&c, newfd, CACHE_EXT_LINK, + sb.len) < 0 || + ce_write(&c, newfd, sb.buf, sb.len) < 0; + strbuf_release(&sb); + if (err) + return -1; + } + if (!strip_extensions && istate->cache_tree) { + struct strbuf sb = STRBUF_INIT; + + cache_tree_write(&sb, istate->cache_tree); + err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0 + || ce_write(&c, newfd, sb.buf, sb.len) < 0; + strbuf_release(&sb); + if (err) + return -1; + } + if (!strip_extensions && istate->resolve_undo) { + struct strbuf sb = STRBUF_INIT; + + resolve_undo_write(&sb, istate->resolve_undo); + err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO, + sb.len) < 0 + || ce_write(&c, newfd, sb.buf, sb.len) < 0; + strbuf_release(&sb); + if (err) + return -1; + } + + if (ce_flush(&c, newfd, istate->sha1) || fstat(newfd, &st)) + return -1; + istate->timestamp.sec = (unsigned int)st.st_mtime; + istate->timestamp.nsec = ST_MTIME_NSEC(st); + return 0; +} + +void set_alternate_index_output(const char *name) +{ + alternate_index_output = name; +} + +static int commit_locked_index(struct lock_file *lk) +{ + if (alternate_index_output) + return commit_lock_file_to(lk, alternate_index_output); + else + return commit_lock_file(lk); +} + +static int do_write_locked_index(struct index_state *istate, struct lock_file *lock, + unsigned flags) +{ + int ret = do_write_index(istate, lock->fd, 0); + if (ret) + return ret; + assert((flags & (COMMIT_LOCK | CLOSE_LOCK)) != + (COMMIT_LOCK | CLOSE_LOCK)); + if (flags & COMMIT_LOCK) + return commit_locked_index(lock); + else if (flags & CLOSE_LOCK) + return close_lock_file(lock); + else + return ret; +} + +static int write_split_index(struct index_state *istate, + struct lock_file *lock, + unsigned flags) +{ + int ret; + prepare_to_write_split_index(istate); + ret = do_write_locked_index(istate, lock, flags); + finish_writing_split_index(istate); + return ret; +} + +static char *temporary_sharedindex; + +static void remove_temporary_sharedindex(void) +{ + if (temporary_sharedindex) { + unlink_or_warn(temporary_sharedindex); + free(temporary_sharedindex); + temporary_sharedindex = NULL; + } +} + +static void remove_temporary_sharedindex_on_signal(int signo) +{ + remove_temporary_sharedindex(); + sigchain_pop(signo); + raise(signo); +} + +static int write_shared_index(struct index_state *istate, + struct lock_file *lock, unsigned flags) +{ + struct split_index *si = istate->split_index; + static int installed_handler; + int fd, ret; + + temporary_sharedindex = git_pathdup("sharedindex_XXXXXX"); + fd = mkstemp(temporary_sharedindex); + if (fd < 0) { + free(temporary_sharedindex); + temporary_sharedindex = NULL; + hashclr(si->base_sha1); + return do_write_locked_index(istate, lock, flags); + } + if (!installed_handler) { + atexit(remove_temporary_sharedindex); + sigchain_push_common(remove_temporary_sharedindex_on_signal); + } + move_cache_to_base_index(istate); + ret = do_write_index(si->base, fd, 1); + close(fd); + if (ret) { + remove_temporary_sharedindex(); + return ret; + } + ret = rename(temporary_sharedindex, + git_path("sharedindex.%s", sha1_to_hex(si->base->sha1))); + free(temporary_sharedindex); + temporary_sharedindex = NULL; + if (!ret) + hashcpy(si->base_sha1, si->base->sha1); + return ret; +} + +int write_locked_index(struct index_state *istate, struct lock_file *lock, + unsigned flags) +{ + struct split_index *si = istate->split_index; + + if (!si || alternate_index_output || + (istate->cache_changed & ~EXTMASK)) { + if (si) + hashclr(si->base_sha1); + return do_write_locked_index(istate, lock, flags); + } + + if (getenv("GIT_TEST_SPLIT_INDEX")) { + int v = si->base_sha1[0]; + if ((v & 15) < 6) + istate->cache_changed |= SPLIT_INDEX_ORDERED; + } + if (istate->cache_changed & SPLIT_INDEX_ORDERED) { + int ret = write_shared_index(istate, lock, flags); + if (ret) + return ret; + } + + return write_split_index(istate, lock, flags); +} + +/* + * Read the index file that is potentially unmerged into given + * index_state, dropping any unmerged entries. Returns true if + * the index is unmerged. Callers who want to refuse to work + * from an unmerged state can call this and check its return value, + * instead of calling read_cache(). + */ +int read_index_unmerged(struct index_state *istate) +{ + int i; + int unmerged = 0; + + read_index(istate); + for (i = 0; i < istate->cache_nr; i++) { + struct cache_entry *ce = istate->cache[i]; + struct cache_entry *new_ce; + int size, len; + + if (!ce_stage(ce)) + continue; + unmerged = 1; + len = ce_namelen(ce); + size = cache_entry_size(len); + new_ce = xcalloc(1, size); + memcpy(new_ce->name, ce->name, len); + new_ce->ce_flags = create_ce_flags(0) | CE_CONFLICTED; + new_ce->ce_namelen = len; + new_ce->ce_mode = ce->ce_mode; + if (add_index_entry(istate, new_ce, 0)) + return error("%s: cannot drop to stage #0", + new_ce->name); + } + return unmerged; +} + +/* + * Returns 1 if the path is an "other" path with respect to + * the index; that is, the path is not mentioned in the index at all, + * either as a file, a directory with some files in the index, + * or as an unmerged entry. + * + * We helpfully remove a trailing "/" from directories so that + * the output of read_directory can be used as-is. + */ +int index_name_is_other(const struct index_state *istate, const char *name, + int namelen) +{ + int pos; + if (namelen && name[namelen - 1] == '/') + namelen--; + pos = index_name_pos(istate, name, namelen); + if (0 <= pos) + return 0; /* exact match */ + pos = -pos - 1; + if (pos < istate->cache_nr) { + struct cache_entry *ce = istate->cache[pos]; + if (ce_namelen(ce) == namelen && + !memcmp(ce->name, name, namelen)) + return 0; /* Yup, this one exists unmerged */ + } + return 1; +} + +void *read_blob_data_from_index(struct index_state *istate, const char *path, unsigned long *size) +{ + int pos, len; + unsigned long sz; + enum object_type type; + void *data; + + len = strlen(path); + pos = index_name_pos(istate, path, len); + if (pos < 0) { + /* + * We might be in the middle of a merge, in which + * case we would read stage #2 (ours). + */ + int i; + for (i = -pos - 1; + (pos < 0 && i < istate->cache_nr && + !strcmp(istate->cache[i]->name, path)); + i++) + if (ce_stage(istate->cache[i]) == 2) + pos = i; + } + if (pos < 0) + return NULL; + data = read_sha1_file(istate->cache[pos]->sha1, &type, &sz); + if (!data || type != OBJ_BLOB) { + free(data); + return NULL; + } + if (size) + *size = sz; + return data; +} + +void stat_validity_clear(struct stat_validity *sv) +{ + free(sv->sd); + sv->sd = NULL; +} + +int stat_validity_check(struct stat_validity *sv, const char *path) +{ + struct stat st; + + if (stat(path, &st) < 0) + return sv->sd == NULL; + if (!sv->sd) + return 0; + return S_ISREG(st.st_mode) && !match_stat_data(sv->sd, &st); +} + +void stat_validity_update(struct stat_validity *sv, int fd) +{ + struct stat st; + + if (fstat(fd, &st) < 0 || !S_ISREG(st.st_mode)) + stat_validity_clear(sv); + else { + if (!sv->sd) + sv->sd = xcalloc(1, sizeof(struct stat_data)); + fill_stat_data(sv->sd, &st); + } +} |