Merge branch 'maint'
[gitweb.git] / read-cache.c
index ec4dd5ae6c96c8114b75fdec415b2af816518e21..54573ce2ee3b2c70d5419716b20ade61683bc289 100644 (file)
 #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;
+struct cache_entry **active_cache;
 static time_t index_file_timestamp;
-unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
+unsigned int active_nr, active_alloc, active_cache_changed;
 
-struct cache_tree *active_cache_tree = NULL;
+struct cache_tree *active_cache_tree;
 
-int cache_errno = 0;
-
-static void *cache_mmap = NULL;
-static size_t cache_mmap_size = 0;
+static void *cache_mmap;
+static size_t cache_mmap_size;
 
 /*
  * This only updates the "non-critical" parts of the directory
@@ -59,20 +57,20 @@ static int ce_compare_data(struct cache_entry *ce, struct stat *st)
 
        if (fd >= 0) {
                unsigned char sha1[20];
-               if (!index_fd(sha1, fd, st, 0, NULL))
-                       match = memcmp(sha1, ce->sha1, 20);
+               if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name))
+                       match = hashcmp(sha1, ce->sha1);
                /* index_fd() closed the file descriptor already */
        }
        return match;
 }
 
-static int ce_compare_link(struct cache_entry *ce, unsigned long expected_size)
+static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
 {
        int match = -1;
        char *target;
        void *buffer;
        unsigned long size;
-       char type[10];
+       enum object_type type;
        int len;
 
        target = xmalloc(expected_size);
@@ -81,7 +79,7 @@ static int ce_compare_link(struct cache_entry *ce, unsigned long expected_size)
                free(target);
                return -1;
        }
-       buffer = read_sha1_file(ce->sha1, type, &size);
+       buffer = read_sha1_file(ce->sha1, &type, &size);
        if (!buffer) {
                free(target);
                return -1;
@@ -101,7 +99,7 @@ static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
                        return DATA_CHANGED;
                break;
        case S_IFLNK:
-               if (ce_compare_link(ce, st->st_size))
+               if (ce_compare_link(ce, xsize_t(st->st_size)))
                        return DATA_CHANGED;
                break;
        default:
@@ -125,7 +123,9 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
                        changed |= MODE_CHANGED;
                break;
        case S_IFLNK:
-               changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0;
+               if (!S_ISLNK(st->st_mode) &&
+                   (has_symlinks || !S_ISREG(st->st_mode)))
+                       changed |= TYPE_CHANGED;
                break;
        default:
                die("internal error: ce_mode is %o", ntohl(ce->ce_mode));
@@ -169,9 +169,11 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
        return changed;
 }
 
-int ce_match_stat(struct cache_entry *ce, struct stat *st, int ignore_valid)
+int ce_match_stat(struct cache_entry *ce, struct stat *st, int options)
 {
        unsigned int changed;
+       int ignore_valid = options & 01;
+       int assume_racy_is_modified = options & 02;
 
        /*
         * If it's marked as always valid in the index, it's
@@ -200,8 +202,12 @@ int ce_match_stat(struct cache_entry *ce, struct stat *st, int ignore_valid)
         */
        if (!changed &&
            index_file_timestamp &&
-           index_file_timestamp <= ntohl(ce->ce_mtime.sec))
-               changed |= ce_modified_check_fs(ce, st);
+           index_file_timestamp <= ntohl(ce->ce_mtime.sec)) {
+               if (assume_racy_is_modified)
+                       changed |= DATA_CHANGED;
+               else
+                       changed |= ce_modified_check_fs(ce, st);
+       }
 
        return changed;
 }
@@ -319,7 +325,7 @@ int remove_file_from_cache(const char *path)
        return 0;
 }
 
-int add_file_to_index(const char *path, int verbose)
+int add_file_to_cache(const char *path, int verbose)
 {
        int size, namelen;
        struct stat st;
@@ -338,19 +344,22 @@ int add_file_to_index(const char *path, int verbose)
        ce->ce_flags = htons(namelen);
        fill_stat_cache_info(ce, &st);
 
-       ce->ce_mode = create_ce_mode(st.st_mode);
-       if (!trust_executable_bit) {
-               /* If there is an existing entry, pick the mode bits
-                * from it.
+       if (trust_executable_bit && has_symlinks)
+               ce->ce_mode = create_ce_mode(st.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 = cache_name_pos(path, namelen);
-               if (pos >= 0)
-                       ce->ce_mode = active_cache[pos]->ce_mode;
+
+               ent = (0 <= pos) ? active_cache[pos] : NULL;
+               ce->ce_mode = ce_mode_from_stat(ent, st.st_mode);
        }
 
        if (index_path(ce->sha1, path, &st, 1))
                die("unable to index file %s", path);
-       if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD))
+       if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
                die("unable to add %s to index",path);
        if (verbose)
                printf("add '%s'\n", path);
@@ -476,6 +485,8 @@ static int has_file_name(const struct cache_entry *ce, int pos, int ok_to_replac
                        continue;
                if (p->name[len] != '/')
                        continue;
+               if (!ce_stage(p) && !p->ce_mode)
+                       continue;
                retval = -1;
                if (!ok_to_replace)
                        break;
@@ -508,26 +519,37 @@ static int has_dir_name(const struct cache_entry *ce, int pos, int ok_to_replace
 
                pos = cache_name_pos(name, ntohs(create_ce_flags(len, stage)));
                if (pos >= 0) {
-                       retval = -1;
-                       if (ok_to_replace)
-                               break;
-                       remove_cache_entry_at(pos);
-                       continue;
+                       /*
+                        * 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 (stage || active_cache[pos]->ce_mode) {
+                               retval = -1;
+                               if (!ok_to_replace)
+                                       break;
+                               remove_cache_entry_at(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.
                 */
-               pos = -pos-1;
                while (pos < active_nr) {
                        struct cache_entry *p = active_cache[pos];
                        if ((ce_namelen(p) <= len) ||
                            (p->name[len] != '/') ||
                            memcmp(p->name, name, len))
                                break; /* not our subdirectory */
-                       if (ce_stage(p) == stage)
+                       if (ce_stage(p) == stage && (stage || p->ce_mode))
                                /* 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
@@ -551,12 +573,21 @@ static int has_dir_name(const struct cache_entry *ce, int pos, int ok_to_replace
  */
 static int check_file_directory_conflict(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_stage(ce) && !ce->ce_mode)
+               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
+        * in the array.
         */
-       int retval = has_file_name(ce, pos, ok_to_replace);
+       retval = has_file_name(ce, pos, ok_to_replace);
+
        /*
         * Then check if the path might have a clashing sub-directory
         * before it.
@@ -601,7 +632,7 @@ int add_cache_entry(struct cache_entry *ce, int option)
        if (!skip_df_check &&
            check_file_directory_conflict(ce, pos, ok_to_replace)) {
                if (!ok_to_replace)
-                       return -1;
+                       return error("'%s' appears as both a file and as a directory", ce->name);
                pos = cache_name_pos(ce->name, ntohs(ce->ce_flags));
                pos = -pos-1;
        }
@@ -632,14 +663,15 @@ int add_cache_entry(struct cache_entry *ce, int option)
  * 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.
  */
-struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
+static struct cache_entry *refresh_cache_ent(struct cache_entry *ce, int really, int *err)
 {
        struct stat st;
        struct cache_entry *updated;
        int changed, size;
 
        if (lstat(ce->name, &st) < 0) {
-               cache_errno = errno;
+               if (err)
+                       *err = errno;
                return NULL;
        }
 
@@ -653,7 +685,8 @@ struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
        }
 
        if (ce_modified(ce, &st, really)) {
-               cache_errno = EINVAL;
+               if (err)
+                       *err = EINVAL;
                return NULL;
        }
 
@@ -685,6 +718,8 @@ int refresh_cache(unsigned int flags)
 
        for (i = 0; i < active_nr; i++) {
                struct cache_entry *ce, *new;
+               int cache_errno = 0;
+
                ce = active_cache[i];
                if (ce_stage(ce)) {
                        while ((i < active_nr) &&
@@ -698,7 +733,7 @@ int refresh_cache(unsigned int flags)
                        continue;
                }
 
-               new = refresh_cache_entry(ce, really);
+               new = refresh_cache_ent(ce, really, &cache_errno);
                if (new == ce)
                        continue;
                if (!new) {
@@ -726,6 +761,11 @@ int refresh_cache(unsigned int flags)
        return has_errors;
 }
 
+struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
+{
+       return refresh_cache_ent(ce, really, NULL);
+}
+
 static int verify_hdr(struct cache_header *hdr, unsigned long size)
 {
        SHA_CTX c;
@@ -738,7 +778,7 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
        SHA1_Init(&c);
        SHA1_Update(&c, hdr, size - 20);
        SHA1_Final(sha1, &c);
-       if (memcmp(sha1, (char *) hdr + size - 20, 20))
+       if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
                return error("bad index file sha1 signature");
        return 0;
 }
@@ -785,16 +825,16 @@ int read_cache_from(const char *path)
                die("index file open failed (%s)", strerror(errno));
        }
 
-       cache_mmap = MAP_FAILED;
        if (!fstat(fd, &st)) {
-               cache_mmap_size = st.st_size;
+               cache_mmap_size = xsize_t(st.st_size);
                errno = EINVAL;
                if (cache_mmap_size >= sizeof(struct cache_header) + 20)
-                       cache_mmap = mmap(NULL, cache_mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
-       }
+                       cache_mmap = xmmap(NULL, cache_mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+               else
+                       die("index file smaller than expected");
+       } else
+               die("cannot stat the open index (%s)", strerror(errno));
        close(fd);
-       if (cache_mmap == MAP_FAILED)
-               die("index file mmap failed (%s)", strerror(errno));
 
        hdr = cache_mmap;
        if (verify_hdr(hdr, cache_mmap_size) < 0)
@@ -836,6 +876,23 @@ int read_cache_from(const char *path)
        die("index file corrupt");
 }
 
+int discard_cache(void)
+{
+       int ret;
+
+       active_nr = active_cache_changed = 0;
+       index_file_timestamp = 0;
+       cache_tree_free(&active_cache_tree);
+       if (cache_mmap == NULL)
+               return 0;
+       ret = munmap(cache_mmap, cache_mmap_size);
+       cache_mmap = NULL;
+       cache_mmap_size = 0;
+
+       /* no need to throw away allocated active_cache */
+       return ret;
+}
+
 #define WRITE_BUFFER_SIZE 8192
 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
 static unsigned long write_buffer_len;
@@ -845,7 +902,7 @@ static int ce_write_flush(SHA_CTX *context, int fd)
        unsigned int buffered = write_buffer_len;
        if (buffered) {
                SHA1_Update(context, write_buffer, buffered);
-               if (write(fd, write_buffer, buffered) != buffered)
+               if (write_in_full(fd, write_buffer, buffered) != buffered)
                        return -1;
                write_buffer_len = 0;
        }
@@ -894,7 +951,7 @@ static int ce_flush(SHA_CTX *context, int fd)
 
        /* Flush first if not enough space for SHA1 signature */
        if (left + 20 > WRITE_BUFFER_SIZE) {
-               if (write(fd, write_buffer, left) != left)
+               if (write_in_full(fd, write_buffer, left) != left)
                        return -1;
                left = 0;
        }
@@ -902,7 +959,7 @@ static int ce_flush(SHA_CTX *context, int fd)
        /* Append the SHA1 signature at the end */
        SHA1_Final(write_buffer + left, context);
        left += 20;
-       return (write(fd, write_buffer, left) != left) ? -1 : 0;
+       return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
 }
 
 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
@@ -953,9 +1010,7 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
 {
        SHA_CTX c;
        struct cache_header hdr;
-       int i, removed, recent;
-       struct stat st;
-       time_t now;
+       int i, removed;
 
        for (i = removed = 0; i < entries; i++)
                if (!cache[i]->ce_mode)
@@ -987,60 +1042,11 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
                if (data &&
                    !write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sz) &&
                    !ce_write(&c, newfd, data, sz))
-                       ;
+                       free(data);
                else {
                        free(data);
                        return -1;
                }
        }
-
-       /*
-        * To prevent later ce_match_stat() from always falling into
-        * check_fs(), if we have too many entries that can trigger
-        * racily clean check, we are better off delaying the return.
-        * We arbitrarily say if more than 20 paths or 25% of total
-        * paths are very new, we delay the return until the index
-        * file gets a new timestamp.
-        *
-        * NOTE! NOTE! NOTE!
-        *
-        * This assumes that nobody is touching the working tree while
-        * we are updating the index.
-        */
-
-       /* Make sure that the new index file has st_mtime
-        * that is current enough -- ce_write() batches the data
-        * so it might not have written anything yet.
-        */
-       ce_write_flush(&c, newfd);
-
-       now = fstat(newfd, &st) ? 0 : st.st_mtime;
-       if (now) {
-               recent = 0;
-               for (i = 0; i < entries; i++) {
-                       struct cache_entry *ce = cache[i];
-                       time_t entry_time = (time_t) ntohl(ce->ce_mtime.sec);
-                       if (!ce->ce_mode)
-                               continue;
-                       if (now && now <= entry_time)
-                               recent++;
-               }
-               if (20 < recent && entries <= recent * 4) {
-#if 0
-                       fprintf(stderr, "entries    %d\n", entries);
-                       fprintf(stderr, "recent     %d\n", recent);
-                       fprintf(stderr, "now        %lu\n", now);
-#endif
-                       while (!fstat(newfd, &st) && st.st_mtime <= now) {
-                               off_t where = lseek(newfd, 0, SEEK_CUR);
-                               sleep(1);
-                               if ((where == (off_t) -1) ||
-                                   (write(newfd, "", 1) != 1) ||
-                                   (lseek(newfd, -1, SEEK_CUR) != where) ||
-                                   ftruncate(newfd, where))
-                                       break;
-                       }
-               }
-       }
        return ce_flush(&c, newfd);
 }