Documentation updates.
[gitweb.git] / fsck-cache.c
index 5dca6dbc04b0bf40cd654f05766f7daa6fac75b4..e53d01a40ffd98f1cb3a571776b0e050551938f1 100644 (file)
-#include "cache.h"
-
 #include <sys/types.h>
 #include <dirent.h>
 
-struct needs {
-       unsigned char parent[20];
-       unsigned char needs[20];
-       char tag[10];
-};
-
-struct seen {
-       unsigned char sha1[20];
-       char tag[10];
-       unsigned needed;
-};
-
-static struct needs *needs;
-static struct seen *seen;
-
-static int nr_seen, alloc_seen, nr_needs, alloc_needs;
+#include "cache.h"
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "tag.h"
+#include "refs.h"
+#include "pack.h"
+
+#define REACHABLE 0x0001
+
+static int show_root = 0;
+static int show_tags = 0;
+static int show_unreachable = 0;
+static int standalone = 0;
+static int check_full = 0;
+static int check_strict = 0;
+static int keep_cache_objects = 0; 
+static unsigned char head_sha1[20];
 
-/*
- * These two functions build up a graph in memory about
- * what objects we've referenced, and found, and types..
- */
-static int compare_seen(const void *s1, const void *s2)
+static void check_connectivity(void)
 {
-       return memcmp(s1, s2, 20);
-}
+       int i;
 
-static int lookup_seen(unsigned char *sha1, char *tag)
-{
-       int first = 0, last = nr_seen;
+       /* Look up all the requirements, warn about missing objects.. */
+       for (i = 0; i < nr_objs; i++) {
+               struct object *obj = objs[i];
+               struct object_list *refs;
+
+               if (!obj->parsed) {
+                       if (!standalone && has_sha1_file(obj->sha1))
+                               ; /* it is in pack */
+                       else
+                               printf("missing %s %s\n",
+                                      obj->type, sha1_to_hex(obj->sha1));
+                       continue;
+               }
 
-       while (last > first) {
-               int next = (last + first) / 2;
-               struct seen *s = seen + next;
-               int cmp = memcmp(sha1, s->sha1, 20);
+               for (refs = obj->refs; refs; refs = refs->next) {
+                       if (refs->item->parsed ||
+                           (!standalone && has_sha1_file(refs->item->sha1)))
+                               continue;
+                       printf("broken link from %7s %s\n",
+                              obj->type, sha1_to_hex(obj->sha1));
+                       printf("              to %7s %s\n",
+                              refs->item->type, sha1_to_hex(refs->item->sha1));
+               }
 
-               if (cmp < 0) {
-                       last = next;
+               if (show_unreachable && !(obj->flags & REACHABLE)) {
+                       printf("unreachable %s %s\n",
+                              obj->type, sha1_to_hex(obj->sha1));
                        continue;
                }
-               if (cmp > 0) {
-                       first = next+1;
-                       continue;
+
+               if (!obj->used) {
+                       printf("dangling %s %s\n", obj->type, 
+                              sha1_to_hex(obj->sha1));
                }
-               if (strcmp(tag, s->tag))
-                       break;
-               s->needed++;
-               return 1;
        }
-       return 0;
 }
 
-static void check_connectivity(void)
+/*
+ * The entries in a tree are ordered in the _path_ order,
+ * which means that a directory entry is ordered by adding
+ * a slash to the end of it.
+ *
+ * So a directory called "a" is ordered _after_ a file
+ * called "a.c", because "a/" sorts after "a.c".
+ */
+#define TREE_UNORDERED (-1)
+#define TREE_HAS_DUPS  (-2)
+
+static int verify_ordered(struct tree_entry_list *a, struct tree_entry_list *b)
 {
-       int i;
+       int len1 = strlen(a->name);
+       int len2 = strlen(b->name);
+       int len = len1 < len2 ? len1 : len2;
+       unsigned char c1, c2;
+       int cmp;
+
+       cmp = memcmp(a->name, b->name, len);
+       if (cmp < 0)
+               return 0;
+       if (cmp > 0)
+               return TREE_UNORDERED;
+
+       /*
+        * Ok, the first <len> characters are the same.
+        * Now we need to order the next one, but turn
+        * a '\0' into a '/' for a directory entry.
+        */
+       c1 = a->name[len];
+       c2 = b->name[len];
+       if (!c1 && !c2)
+               /*
+                * git-write-tree used to write out a nonsense tree that has
+                * entries with the same name, one blob and one tree.  Make
+                * sure we do not have duplicate entries.
+                */
+               return TREE_HAS_DUPS;
+       if (!c1 && a->directory)
+               c1 = '/';
+       if (!c2 && b->directory)
+               c2 = '/';
+       return c1 < c2 ? 0 : TREE_UNORDERED;
+}
 
-       /* Sort the "seen" tags for quicker lookup */
-       qsort(seen, nr_seen, sizeof(struct seen), compare_seen);
+static int fsck_tree(struct tree *item)
+{
+       int retval;
+       int has_full_path = 0;
+       int has_zero_pad = 0;
+       int has_bad_modes = 0;
+       int has_dup_entries = 0;
+       int not_properly_sorted = 0;
+       struct tree_entry_list *entry, *last;
+
+       last = NULL;
+       for (entry = item->entries; entry; entry = entry->next) {
+               if (strchr(entry->name, '/'))
+                       has_full_path = 1;
+               has_zero_pad |= entry->zeropad;
+
+               switch (entry->mode) {
+               /*
+                * Standard modes.. 
+                */
+               case S_IFREG | 0755:
+               case S_IFREG | 0644:
+               case S_IFLNK:
+               case S_IFDIR:
+                       break;
+               /*
+                * This is nonstandard, but we had a few of these
+                * early on when we honored the full set of mode
+                * bits..
+                */
+               case S_IFREG | 0664:
+                       if (!check_strict)
+                               break;
+               default:
+                       has_bad_modes = 1;
+               }
 
-       /* Look up all the requirements, warn about missing objects.. */
-       for (i = 0; i < nr_needs; i++) {
-               struct needs *n = needs + i;
-               char hex[60];
+               if (last) {
+                       switch (verify_ordered(last, entry)) {
+                       case TREE_UNORDERED:
+                               not_properly_sorted = 1;
+                               break;
+                       case TREE_HAS_DUPS:
+                               has_dup_entries = 1;
+                               break;
+                       default:
+                               break;
+                       }
+               }
 
-               if (lookup_seen(n->needs, n->tag))
-                       continue;
-               strcpy(hex, sha1_to_hex(n->parent));
+               last = entry;
        }
 
-       /* Tell the user about things not referenced.. */
-       for (i = 0; i < nr_seen; i++) {
-               struct seen *s = seen + i;
-
-               if (s->needed)
-                       continue;
-               printf("unreferenced %s: %s\n", s->tag, sha1_to_hex(s->sha1));
+       retval = 0;
+       if (has_full_path) {
+               fprintf(stderr, "warning: git-fsck-cache: tree %s "
+                       "has full pathnames in it\n", 
+                       sha1_to_hex(item->object.sha1));
        }
-}
-
-static void mark_needs_sha1(unsigned char *parent, const char * tag, unsigned char *child)
-{
-       struct needs *n;
-
-       if (nr_needs == alloc_needs) {
-               alloc_needs = alloc_nr(alloc_needs);
-               needs = realloc(needs, alloc_needs*sizeof(struct needs));
+       if (has_zero_pad) {
+               fprintf(stderr, "warning: git-fsck-cache: tree %s "
+                       "has zero-padded file modes in it\n",
+                       sha1_to_hex(item->object.sha1));
+       }
+       if (has_bad_modes) {
+               fprintf(stderr, "warning: git-fsck-cache: tree %s "
+                       "has bad file modes in it\n",
+                       sha1_to_hex(item->object.sha1));
+       }
+       if (has_dup_entries) {
+               fprintf(stderr, "error: git-fsck-cache: tree %s "
+                       "has duplicate file entries\n",
+                       sha1_to_hex(item->object.sha1));
+               retval = -1;
        }
-       n = needs + nr_needs;
-       nr_needs++;
-       memcpy(n->parent, parent, 20);
-       memcpy(n->needs, child, 20);
-       strncpy(n->tag, tag, sizeof(n->tag));
+       if (not_properly_sorted) {
+               fprintf(stderr, "error: git-fsck-cache: tree %s "
+                       "is not properly sorted\n",
+                       sha1_to_hex(item->object.sha1));
+               retval = -1;
+       }
+       return retval;
 }
 
-static int mark_sha1_seen(unsigned char *sha1, char *tag)
+static int fsck_commit(struct commit *commit)
 {
-       struct seen *s;
-
-       if (nr_seen == alloc_seen) {
-               alloc_seen = alloc_nr(alloc_seen);
-               seen = realloc(seen, alloc_seen*sizeof(struct seen));
-       }
-       s = seen + nr_seen;
-       memset(s, 0, sizeof(s));
-       nr_seen++;
-       memcpy(s->sha1, sha1, 20);
-       strncpy(s->tag, tag, sizeof(s->tag));
-       
-       return 0;
-}
+       char *buffer = commit->buffer;
+       unsigned char sha1[20];
 
-static int fsck_tree(unsigned char *sha1, void *data, unsigned long size)
-{
-       int warn_old_tree = 1;
-
-       while (size) {
-               int len = 1+strlen(data);
-               unsigned char *file_sha1 = data + len;
-               char *path = strchr(data, ' ');
-               unsigned int mode;
-               if (size < len + 20 || !path || sscanf(data, "%o", &mode) != 1)
+       if (memcmp(buffer, "tree ", 5))
+               return -1;
+       if (get_sha1_hex(buffer+5, sha1) || buffer[45] != '\n')
+               return -1;
+       buffer += 46;
+       while (!memcmp(buffer, "parent ", 7)) {
+               if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
                        return -1;
-
-               /* Warn about trees that don't do the recursive thing.. */
-               if (warn_old_tree && strchr(path, '/')) {
-                       fprintf(stderr, "warning: fsck-cache: tree %s has full pathnames in it\n", sha1_to_hex(sha1));
-                       warn_old_tree = 0;
-               }
-
-               data += len + 20;
-               size -= len + 20;
-               mark_needs_sha1(sha1, S_ISDIR(mode) ? "tree" : "blob", file_sha1);
+               buffer += 48;
        }
+       if (memcmp(buffer, "author ", 7))
+               return -1;
+       free(commit->buffer);
+       commit->buffer = NULL;
+       if (!commit->tree)
+               return -1;
+       if (!commit->parents && show_root)
+               printf("root %s\n", sha1_to_hex(commit->object.sha1));
+       if (!commit->date)
+               printf("bad commit date in %s\n", 
+                      sha1_to_hex(commit->object.sha1));
        return 0;
 }
 
-static int fsck_commit(unsigned char *sha1, void *data, unsigned long size)
+static int fsck_tag(struct tag *tag)
 {
-       int parents;
-       unsigned char tree_sha1[20];
-       unsigned char parent_sha1[20];
+       struct object *tagged = tag->tagged;
 
-       if (memcmp(data, "tree ", 5))
+       if (!tagged) {
+               printf("bad object in tag %s\n", sha1_to_hex(tag->object.sha1));
                return -1;
-       if (get_sha1_hex(data + 5, tree_sha1) < 0)
-               return -1;
-       mark_needs_sha1(sha1, "tree", tree_sha1);
-       data += 5 + 40 + 1;     /* "tree " + <hex sha1> + '\n' */
-       parents = 0;
-       while (!memcmp(data, "parent ", 7)) {
-               if (get_sha1_hex(data + 7, parent_sha1) < 0)
-                       return -1;
-               mark_needs_sha1(sha1, "commit", parent_sha1);
-               data += 7 + 40 + 1;     /* "parent " + <hex sha1> + '\n' */
-               parents++;
        }
-       if (!parents)
-               printf("root: %s\n", sha1_to_hex(sha1));
+       if (!show_tags)
+               return 0;
+
+       printf("tagged %s %s", tagged->type, sha1_to_hex(tagged->sha1));
+       printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
        return 0;
 }
 
-static int fsck_entry(unsigned char *sha1, char *tag, void *data, unsigned long size)
+static int fsck_sha1(unsigned char *sha1)
 {
-       if (!strcmp(tag, "blob")) {
-               /* Nothing to check */;
-       } else if (!strcmp(tag, "tree")) {
-               if (fsck_tree(sha1, data, size) < 0)
-                       return -1;
-       } else if (!strcmp(tag, "commit")) {
-               if (fsck_commit(sha1, data, size) < 0)
-                       return -1;
-       } else
+       struct object *obj = parse_object(sha1);
+       if (!obj)
                return -1;
-       return mark_sha1_seen(sha1, tag);
+       if (obj->type == blob_type)
+               return 0;
+       if (obj->type == tree_type)
+               return fsck_tree((struct tree *) obj);
+       if (obj->type == commit_type)
+               return fsck_commit((struct commit *) obj);
+       if (obj->type == tag_type)
+               return fsck_tag((struct tag *) obj);
+       return -1;
 }
 
-static int fsck_name(char *hex)
-{
+/*
+ * This is the sorting chunk size: make it reasonably
+ * big so that we can sort well..
+ */
+#define MAX_SHA1_ENTRIES (1024)
+
+struct sha1_entry {
+       unsigned long ino;
        unsigned char sha1[20];
-       if (!get_sha1_hex(hex, sha1)) {
-               unsigned long mapsize;
-               void *map = map_sha1_file(sha1, &mapsize);
-               if (map) {
-                       char type[100];
-                       unsigned long size;
-                       void *buffer = NULL;
-                       if (!check_sha1_signature(sha1, map, mapsize))
-                               buffer = unpack_sha1_file(map, mapsize, type, &size);
-                       munmap(map, mapsize);
-                       if (buffer && !fsck_entry(sha1, type, buffer, size))
-                               return 0;
-               }
+};
+
+static struct {
+       unsigned long nr;
+       struct sha1_entry *entry[MAX_SHA1_ENTRIES];
+} sha1_list;
+
+static int ino_compare(const void *_a, const void *_b)
+{
+       const struct sha1_entry *a = _a, *b = _b;
+       unsigned long ino1 = a->ino, ino2 = b->ino;
+       return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
+}
+
+static void fsck_sha1_list(void)
+{
+       int i, nr = sha1_list.nr;
+
+       qsort(sha1_list.entry, nr, sizeof(struct sha1_entry *), ino_compare);
+       for (i = 0; i < nr; i++) {
+               struct sha1_entry *entry = sha1_list.entry[i];
+               unsigned char *sha1 = entry->sha1;
+
+               sha1_list.entry[i] = NULL;
+               if (fsck_sha1(sha1) < 0)
+                       fprintf(stderr, "bad sha1 entry '%s'\n", sha1_to_hex(sha1));
+               free(entry);
        }
-       return -1;
+       sha1_list.nr = 0;
+}
+
+static void add_sha1_list(unsigned char *sha1, unsigned long ino)
+{
+       struct sha1_entry *entry = xmalloc(sizeof(*entry));
+       int nr;
+
+       entry->ino = ino;
+       memcpy(entry->sha1, sha1, 20);
+       nr = sha1_list.nr;
+       if (nr == MAX_SHA1_ENTRIES) {
+               fsck_sha1_list();
+               nr = 0;
+       }
+       sha1_list.entry[nr] = entry;
+       sha1_list.nr = ++nr;
 }
 
 static int fsck_dir(int i, char *path)
@@ -204,12 +314,12 @@ static int fsck_dir(int i, char *path)
        struct dirent *de;
 
        if (!dir) {
-               fprintf(stderr, "missing sha1 directory '%s'", path);
-               return -1;
+               return error("missing sha1 directory '%s'", path);
        }
 
        while ((de = readdir(dir)) != NULL) {
                char name[100];
+               unsigned char sha1[20];
                int len = strlen(de->d_name);
 
                switch (len) {
@@ -223,8 +333,10 @@ static int fsck_dir(int i, char *path)
                case 38:
                        sprintf(name, "%02x", i);
                        memcpy(name+2, de->d_name, len+1);
-                       if (!fsck_name(name))
-                               continue;
+                       if (get_sha1_hex(name, sha1) < 0)
+                               break;
+                       add_sha1_list(sha1, de->d_ino);
+                       continue;
                }
                fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
        }
@@ -232,19 +344,194 @@ static int fsck_dir(int i, char *path)
        return 0;
 }
 
-int main(int argc, char **argv)
+static int default_refs = 0;
+
+static int fsck_handle_ref(const char *refname, const unsigned char *sha1)
 {
-       int i;
-       char *sha1_dir;
+       struct object *obj;
 
-       if (argc != 1)
-               usage("fsck-cache");
-       sha1_dir = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
+       obj = lookup_object(sha1);
+       if (!obj) {
+               if (!standalone && has_sha1_file(sha1)) {
+                       default_refs++;
+                       return 0; /* it is in a pack */
+               }
+               error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
+               /* We'll continue with the rest despite the error.. */
+               return 0;
+       }
+       default_refs++;
+       obj->used = 1;
+       mark_reachable(obj, REACHABLE);
+       return 0;
+}
+
+static void get_default_heads(void)
+{
+       for_each_ref(fsck_handle_ref);
+       if (!default_refs)
+               die("No default references");
+}
+
+static void fsck_object_dir(const char *path)
+{
+       int i;
        for (i = 0; i < 256; i++) {
                static char dir[4096];
-               sprintf(dir, "%s/%02x", sha1_dir, i);
+               sprintf(dir, "%s/%02x", path, i);
                fsck_dir(i, dir);
        }
+       fsck_sha1_list();
+}
+
+static int fsck_head_link(void)
+{
+       int fd, count;
+       char hex[40];
+       unsigned char sha1[20];
+       static char path[PATH_MAX], link[PATH_MAX];
+       const char *git_dir;
+
+       git_dir = gitenv(GIT_DIR_ENVIRONMENT);
+       if (!git_dir) git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
+
+       snprintf(path, sizeof(path), "%s/HEAD", git_dir);
+       if (readlink(path, link, sizeof(link)) < 0)
+               return error("HEAD is not a symlink");
+       if (strncmp("refs/heads/", link, 11))
+               return error("HEAD points to something strange (%s)", link);
+       fd = open(path, O_RDONLY);
+       if (fd < 0)
+               return error("HEAD: %s", strerror(errno));
+       count = read(fd, hex, sizeof(hex));
+       close(fd);
+       if (count < 0)
+               return error("HEAD: %s", strerror(errno));
+       if (count < 40 || get_sha1_hex(hex, sha1))
+               return error("HEAD: not a valid git pointer");
+       return 0;
+}
+
+int main(int argc, char **argv)
+{
+       int i, heads;
+
+       for (i = 1; i < argc; i++) {
+               const char *arg = argv[i];
+
+               if (!strcmp(arg, "--unreachable")) {
+                       show_unreachable = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--tags")) {
+                       show_tags = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--root")) {
+                       show_root = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--cache")) {
+                       keep_cache_objects = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--standalone")) {
+                       standalone = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--full")) {
+                       check_full = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--strict")) {
+                       check_strict = 1;
+                       continue;
+               }
+               if (*arg == '-')
+                       usage("git-fsck-cache [--tags] [--root] [[--unreachable] [--cache] [--standalone | --full] [--strict] <head-sha1>*]");
+       }
+
+       if (standalone && check_full)
+               die("Only one of --standalone or --full can be used.");
+       if (standalone)
+               putenv("GIT_ALTERNATE_OBJECT_DIRECTORIES=");
+
+       fsck_head_link();
+       fsck_object_dir(get_object_directory());
+       if (check_full) {
+               struct alternate_object_database *alt;
+               struct packed_git *p;
+               prepare_alt_odb();
+               for (alt = alt_odb_list; alt; alt = alt->next) {
+                       char namebuf[PATH_MAX];
+                       int namelen = alt->name - alt->base;
+                       memcpy(namebuf, alt->base, namelen);
+                       namebuf[namelen - 1] = 0;
+                       fsck_object_dir(namebuf);
+               }
+               prepare_packed_git();
+               for (p = packed_git; p; p = p->next)
+                       /* verify gives error messages itself */
+                       verify_pack(p, 0);
+
+               for (p = packed_git; p; p = p->next) {
+                       int num = num_packed_objects(p);
+                       for (i = 0; i < num; i++) {
+                               unsigned char sha1[20];
+                               nth_packed_object_sha1(p, i, sha1);
+                               if (fsck_sha1(sha1) < 0)
+                                       fprintf(stderr, "bad sha1 entry '%s'\n", sha1_to_hex(sha1));
+
+                       }
+               }
+       }
+
+       heads = 0;
+       for (i = 1; i < argc; i++) {
+               const char *arg = argv[i]; 
+
+               if (*arg == '-')
+                       continue;
+
+               if (!get_sha1(arg, head_sha1)) {
+                       struct object *obj = lookup_object(head_sha1);
+
+                       /* Error is printed by lookup_object(). */
+                       if (!obj)
+                               continue;
+
+                       obj->used = 1;
+                       mark_reachable(obj, REACHABLE);
+                       heads++;
+                       continue;
+               }
+               error("expected sha1, got %s", arg);
+       }
+
+       /*
+        * If we've not been given any explicit head information, do the
+        * default ones from .git/refs. We also consider the index file
+        * in this case (ie this implies --cache).
+        */
+       if (!heads) {
+               get_default_heads();
+               keep_cache_objects = 1;
+       }
+
+       if (keep_cache_objects) {
+               int i;
+               read_cache();
+               for (i = 0; i < active_nr; i++) {
+                       struct blob *blob = lookup_blob(active_cache[i]->sha1);
+                       struct object *obj;
+                       if (!blob)
+                               continue;
+                       obj = &blob->object;
+                       obj->used = 1;
+                       mark_reachable(obj, REACHABLE);
+               }
+       }
+
        check_connectivity();
        return 0;
 }