Update tutorial a bit for scripted helpers.
[gitweb.git] / update-cache.c
index 893ba8679d5764ba84627558d567268ff2500558..d2f79fa4535d3ec718b60a13a9a8c67d74323d8e 100644 (file)
@@ -3,23 +3,17 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
-#include <signal.h>
 #include "cache.h"
 
 /*
  * Default to not allowing changes to the list of files. The
  * tool doesn't actually care, but this makes it harder to add
  * files to the revision control by mistake by doing something
- * like "update-cache *" and suddenly having all the object
+ * like "git-update-cache *" and suddenly having all the object
  * files be revision controlled.
  */
-static int allow_add = 0, allow_remove = 0, not_new = 0;
-
-/*
- * update-cache --refresh may not touch anything at all, in which case
- * writing 1.6MB of the same thing is a waste.
- */
-static int cache_changed = 0;
+static int allow_add = 0, allow_remove = 0, allow_replace = 0, not_new = 0;
+static int force_remove;
 
 /* Three functions to allow overloaded pointer return; see linux/err.h */
 static inline void *ERR_PTR(long error)
@@ -37,41 +31,29 @@ static inline long IS_ERR(const void *ptr)
        return (unsigned long)ptr > (unsigned long)-1000L;
 }
 
-/*
- * 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.
- */
-static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
-{
-       ce->ce_ctime.sec = htonl(st->st_ctime);
-       ce->ce_mtime.sec = htonl(st->st_mtime);
-#ifdef NSEC
-       ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
-       ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
-#endif
-       ce->ce_dev = htonl(st->st_dev);
-       ce->ce_ino = htonl(st->st_ino);
-       ce->ce_uid = htonl(st->st_uid);
-       ce->ce_gid = htonl(st->st_gid);
-       ce->ce_size = htonl(st->st_size);
-}
-
-static int add_file_to_cache_1(char *path)
+static int add_file_to_cache(char *path)
 {
-       int size, namelen;
+       int size, namelen, option, status;
        struct cache_entry *ce;
        struct stat st;
        int fd;
-       unsigned int len;
-       char target[1024];
-
-       if (lstat(path, &st) < 0) {
-               if (errno == ENOENT || errno == ENOTDIR) {
+       char *target;
+
+       status = lstat(path, &st);
+       if (status < 0 || S_ISDIR(st.st_mode)) {
+               /* When we used to have "path" and now we want to add
+                * "path/file", we need a way to remove "path" before
+                * being able to add "path/file".  However,
+                * "git-update-cache --remove path" would not work.
+                * --force-remove can be used but this is more user
+                * friendly, especially since we can do the opposite
+                * case just fine without --force-remove.
+                */
+               if (status == 0 || (errno == ENOENT || errno == ENOTDIR)) {
                        if (allow_remove)
                                return remove_file_from_cache(path);
                }
-               return -1;
+               return error("open(\"%s\"): %s", path, strerror(errno));
        }
        namelen = strlen(path);
        size = cache_entry_size(namelen);
@@ -90,42 +72,21 @@ static int add_file_to_cache_1(char *path)
                        return -1;
                break;
        case S_IFLNK:
-               len = readlink(path, target, sizeof(target));
-               if (len == -1 || len+1 > sizeof(target))
+               target = xmalloc(st.st_size+1);
+               if (readlink(path, target, st.st_size+1) != st.st_size) {
+                       free(target);
                        return -1;
-               if (write_sha1_file(target, len, "blob", ce->sha1))
+               }
+               if (write_sha1_file(target, st.st_size, "blob", ce->sha1))
                        return -1;
+               free(target);
                break;
        default:
                return -1;
        }
-       if (!cache_changed) {
-               /* If we have not smudged the cache, be careful
-                * to keep it clean.  Find out if we have a matching
-                * cache entry that add_cache_entry would replace with,
-                * and if it matches then do not bother calling it.
-                */
-               int pos = cache_name_pos(ce->name, namelen);
-               if ((0 <= pos) &&
-                   !memcmp(active_cache[pos], ce, sizeof(*ce))) {
-                       free(ce);
-                       /* magic to tell add_file_to_cache that
-                        * we have not updated anything.
-                        */
-                       return 999;
-               }
-       }
-       return add_cache_entry(ce, allow_add);
-}
-
-static int add_file_to_cache(char *path)
-{
-       int ret = add_file_to_cache_1(path);
-       if (ret == 0)
-               cache_changed = 1;
-       else if (ret == 999)
-               ret = 0;
-       return ret;
+       option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
+       option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
+       return add_cache_entry(ce, option);
 }
 
 static int match_data(int fd, void *buffer, unsigned long size)
@@ -150,7 +111,7 @@ static int compare_data(struct cache_entry *ce, unsigned long expected_size)
        if (fd >= 0) {
                void *buffer;
                unsigned long size;
-               char type[10];
+               char type[20];
 
                buffer = read_sha1_file(ce->sha1, type, &size);
                if (buffer) {
@@ -163,6 +124,33 @@ static int compare_data(struct cache_entry *ce, unsigned long expected_size)
        return match;
 }
 
+static int compare_link(struct cache_entry *ce, unsigned long expected_size)
+{
+       int match = -1;
+       char *target;
+       void *buffer;
+       unsigned long size;
+       char type[10];
+       int len;
+
+       target = xmalloc(expected_size);
+       len = readlink(ce->name, target, expected_size);
+       if (len != expected_size) {
+               free(target);
+               return -1;
+       }
+       buffer = read_sha1_file(ce->sha1, type, &size);
+       if (!buffer) {
+               free(target);
+               return -1;
+       }
+       if (size == expected_size)
+               match = memcmp(buffer, target, size);
+       free(buffer);
+       free(target);
+       return match;
+}
+
 /*
  * "refresh" does not calculate a new sha1 file or bring the
  * cache up-to-date for mode/content changes. But what it
@@ -171,7 +159,7 @@ static int compare_data(struct cache_entry *ce, unsigned long expected_size)
  * 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 "read-tree",
+ * 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)
@@ -183,7 +171,7 @@ static struct cache_entry *refresh_entry(struct cache_entry *ce)
        if (lstat(ce->name, &st) < 0)
                return ERR_PTR(-errno);
 
-       changed = cache_match_stat(ce, &st);
+       changed = ce_match_stat(ce, &st);
        if (!changed)
                return ce;
 
@@ -194,10 +182,19 @@ static struct cache_entry *refresh_entry(struct cache_entry *ce)
        if (changed & (MODE_CHANGED | TYPE_CHANGED))
                return ERR_PTR(-EINVAL);
 
-       if (compare_data(ce, st.st_size))
+       switch (st.st_mode & S_IFMT) {
+       case S_IFREG:
+               if (compare_data(ce, st.st_size))
+                       return ERR_PTR(-EINVAL);
+               break;
+       case S_IFLNK:
+               if (compare_link(ce, st.st_size))
+                       return ERR_PTR(-EINVAL);
+               break;
+       default:
                return ERR_PTR(-EINVAL);
+       }
 
-       cache_changed = 1;
        size = ce_size(ce);
        updated = xmalloc(size);
        memcpy(updated, ce, size);
@@ -231,6 +228,10 @@ static int refresh_cache(void)
                        }
                        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;
@@ -238,13 +239,42 @@ static int refresh_cache(void)
 
 /*
  * We fundamentally don't like some paths: we don't want
- * dot or dot-dot anywhere, and in fact, we don't even want
- * any other dot-files (.git or anything else). They
- * are hidden, for chist sake.
+ * 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;
+}
+
 static int verify_path(char *path)
 {
        char c;
@@ -256,8 +286,15 @@ static int verify_path(char *path)
                if (c == '/') {
 inside:
                        c = *path++;
-                       if (c != '/' && c != '.' && c != '\0')
+                       switch (c) {
+                       default:
                                continue;
+                       case '/': case '\0':
+                               break;
+                       case '.':
+                               if (verify_dotfile(path))
+                                       continue;
+                       }
                        return 0;
                }
                c = *path++;
@@ -266,7 +303,7 @@ static int verify_path(char *path)
 
 static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
 {
-       int size, len;
+       int size, len, option;
        unsigned int mode;
        unsigned char sha1[20];
        struct cache_entry *ce;
@@ -278,7 +315,6 @@ static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
        if (!verify_path(arg3))
                return -1;
 
-       cache_changed = 1;
        len = strlen(arg3);
        size = cache_entry_size(len);
        ce = xmalloc(size);
@@ -288,39 +324,22 @@ static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
        memcpy(ce->name, arg3, len);
        ce->ce_flags = htons(len);
        ce->ce_mode = create_ce_mode(mode);
-       return add_cache_entry(ce, allow_add);
-}
-
-static const char *lockfile_name = NULL;
-
-static void remove_lock_file(void)
-{
-       if (lockfile_name)
-               unlink(lockfile_name);
+       option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
+       option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
+       return add_cache_entry(ce, option);
 }
 
-static void remove_lock_file_on_signal(int signo)
-{
-       remove_lock_file();
-}
+static struct cache_file cache_file;
 
 int main(int argc, char **argv)
 {
        int i, newfd, entries, has_errors = 0;
        int allow_options = 1;
-       static char lockfile[MAXPATHLEN+1];
-       const char *indexfile = get_index_file();
-
-       snprintf(lockfile, sizeof(lockfile), "%s.lock", indexfile);
 
-       newfd = open(lockfile, O_RDWR | O_CREAT | O_EXCL, 0600);
+       newfd = hold_index_file_for_update(&cache_file, get_index_file());
        if (newfd < 0)
                die("unable to create new cachefile");
 
-       signal(SIGINT, remove_lock_file_on_signal);
-       atexit(remove_lock_file);
-       lockfile_name = lockfile;
-
        entries = read_cache();
        if (entries < 0)
                die("cache corrupted");
@@ -337,6 +356,10 @@ int main(int argc, char **argv)
                                allow_add = 1;
                                continue;
                        }
+                       if (!strcmp(path, "--replace")) {
+                               allow_replace = 1;
+                               continue;
+                       }
                        if (!strcmp(path, "--remove")) {
                                allow_remove = 1;
                                continue;
@@ -346,17 +369,15 @@ int main(int argc, char **argv)
                                continue;
                        }
                        if (!strcmp(path, "--cacheinfo")) {
-                               if (i+3 >= argc || add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
-                                       die("update-cache: --cacheinfo <mode> <sha1> <path>");
+                               if (i+3 >= argc)
+                                       die("git-update-cache: --cacheinfo <mode> <sha1> <path>");
+                               if (add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
+                                       die("git-update-cache: --cacheinfo cannot add %s", argv[i+3]);
                                i += 3;
                                continue;
                        }
                        if (!strcmp(path, "--force-remove")) {
-                               if (argc <= i + 1)
-                                       die("update-cache: --force-remove <path>");
-                               if (remove_file_from_cache(argv[i+1]))
-                                       die("update-cache: --force-remove cannot remove %s", argv[i+1]);
-                               i++;
+                               force_remove = 1;
                                continue;
                        }
 
@@ -370,16 +391,17 @@ int main(int argc, char **argv)
                        fprintf(stderr, "Ignoring path %s\n", argv[i]);
                        continue;
                }
+               if (force_remove) {
+                       if (remove_file_from_cache(path))
+                               die("git-update-cache: --force-remove cannot remove %s", path);
+                       continue;
+               }
                if (add_file_to_cache(path))
                        die("Unable to add %s to database", path);
        }
-
-       if (!cache_changed)
-               unlink(lockfile);
-       else if (write_cache(newfd, active_cache, active_nr) ||
-                rename(lockfile, indexfile))
+       if (write_cache(newfd, active_cache, active_nr) ||
+           commit_index_file(&cache_file))
                die("Unable to write new cachefile");
 
-       lockfile_name = NULL;
        return has_errors ? 1 : 0;
 }