[PATCH] git-fsck-cache: Gracefully handle non-commit IDs
[git.git] / fsck-cache.c
index bb2b867..164fc2e 100644 (file)
 #include <sys/types.h>
 #include <dirent.h>
 
-/*
- * The low 16 bits of the "flags" field shows whether
- * a commit is part of the path to the root for that
- * parent.
- *
- * Bit 16 is an internal flag that we've seen the
- * definition for this rev, and not just seen it as
- * a parent target.
- */
-#define MAX_COMMITS (16)
-#define marked(rev)    ((rev)->flags & 0xffff)
-#define SEEN 0x10000
-#define USED 0x20000
-#define REACHABLE 0x40000
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "tag.h"
 
+#define REACHABLE 0x0001
+
+static int show_root = 0;
+static int show_tags = 0;
 static int show_unreachable = 0;
-static int head_supplied = 0;
 static unsigned char head_sha1[20];
 
-struct parent {
-       struct revision *parent;
-       struct parent *next;
-};
-
-struct revision {
-       unsigned int flags;
-       unsigned char sha1[20];
-       unsigned long date;
-       struct parent *parent;
-};
-
-static struct revision **revs;
-static int nr_revs, rev_allocs;
-
-static int find_rev(unsigned char *sha1)
-{
-       int first = 0, last = nr_revs;
-
-       while (first < last) {
-               int next = (first + last) / 2;
-               struct revision *rev = revs[next];
-               int cmp;
-
-               cmp = memcmp(sha1, rev->sha1, 20);
-               if (!cmp)
-                       return next;
-               if (cmp < 0) {
-                       last = next;
-                       continue;
-               }
-               first = next+1;
-       }
-       return -first-1;
-}
-
-static struct revision *lookup_rev(unsigned char *sha1)
-{
-       int pos = find_rev(sha1);
-       struct revision *n;
-
-       if (pos >= 0)
-               return revs[pos];
-       
-       pos = -pos-1;
-
-       if (rev_allocs == nr_revs) {
-               rev_allocs = alloc_nr(rev_allocs);
-               revs = realloc(revs, rev_allocs * sizeof(struct revision *));
-       }
-       n = malloc(sizeof(struct revision));
-
-       n->flags = 0;
-       memcpy(n->sha1, sha1, 20);
-       n->parent = NULL;
-
-       /* Insert it into the right place */
-       memmove(revs + pos + 1, revs + pos, (nr_revs - pos) * sizeof(struct revision *));
-       revs[pos] = n;
-       nr_revs++;
-
-       return n;
-}
-
-static struct revision *add_relationship(struct revision *rev, unsigned char *needs)
-{
-       struct revision *parent_rev = lookup_rev(needs);
-       struct parent **pp = &rev->parent, *p;
-
-       while ((p = *pp) != NULL) {
-               if (p->parent == parent_rev)
-                       return parent_rev;
-               pp = &p->next;
-       }
-
-       p = malloc(sizeof(*p));
-       p->parent = parent_rev;
-       p->next = NULL;
-       *pp = p;
-       return parent_rev;
-}
-
-static void mark_reachable(struct revision *rev)
-{
-       struct parent *p = rev->parent;
-
-       rev->flags |= REACHABLE | USED;
-       while (p) {
-               mark_reachable(p->parent);
-               p = p->next;
-       }
-}
-
 static void check_connectivity(void)
 {
        int i;
 
-       if (head_supplied)
-               mark_reachable(lookup_rev(head_sha1));
-
        /* Look up all the requirements, warn about missing objects.. */
-       for (i = 0; i < nr_revs; i++) {
-               struct revision *rev = revs[i];
+       for (i = 0; i < nr_objs; i++) {
+               struct object *obj = objs[i];
+               struct object_list *refs;
 
-               if (show_unreachable && !(rev->flags & REACHABLE)) {
-                       printf("unreachable %s\n", sha1_to_hex(rev->sha1));
+               if (show_unreachable && !(obj->flags & REACHABLE)) {
+                       printf("unreachable %s %s\n", obj->type, sha1_to_hex(obj->sha1));
                        continue;
                }
 
-               switch (rev->flags & (SEEN | USED)) {
-               case 0:
-                       printf("bad %s\n", sha1_to_hex(rev->sha1));
-                       break;
-               case USED:
-                       printf("missing %s\n", sha1_to_hex(rev->sha1));
-                       break;
-               case SEEN:
-                       printf("dangling %s\n", sha1_to_hex(rev->sha1));
-                       break;
+               if (!obj->parsed) {
+                       printf("missing %s %s\n", obj->type, 
+                              sha1_to_hex(obj->sha1));
+               }
+               if (!obj->used) {
+                       printf("dangling %s %s\n", obj->type, 
+                              sha1_to_hex(obj->sha1));
+               }
+               for (refs = obj->refs; refs; refs = refs->next) {
+                       if (!refs->item->parsed) {
+                               printf("broken link from %s\n",
+                                      sha1_to_hex(obj->sha1));
+                               printf("              to %s\n",
+                                      sha1_to_hex(refs->item->sha1));
+                       }
                }
        }
 }
 
-static void mark_needs_sha1(unsigned char *parent, const char * tag, unsigned char *child)
-{
-       struct revision * child_rev = add_relationship(lookup_rev(parent), child);
-       child_rev->flags |= USED;
-}
-
-static int mark_sha1_seen(unsigned char *sha1, char *tag)
+static int fsck_tree(struct tree *item)
 {
-       struct revision *rev = lookup_rev(sha1);
-
-       rev->flags |= SEEN;
-       return 0;
-}
-
-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)
-                       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);
+       if (item->has_full_path) {
+               fprintf(stderr, "warning: fsck-cache: tree %s "
+                       "has full pathnames in it\n", 
+                       sha1_to_hex(item->object.sha1));
        }
        return 0;
 }
 
-static int fsck_commit(unsigned char *sha1, void *data, unsigned long size)
+static int fsck_commit(struct commit *commit)
 {
-       int parents;
-       unsigned char tree_sha1[20];
-       unsigned char parent_sha1[20];
-
-       if (memcmp(data, "tree ", 5))
-               return -1;
-       if (get_sha1_hex(data + 5, tree_sha1) < 0)
+       if (!commit->tree)
                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 (!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_entry(unsigned char *sha1, char *tag, void *data, unsigned long size)
+static int fsck_tag(struct tag *tag)
 {
-       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
-               return -1;
-       return mark_sha1_seen(sha1, tag);
+       if (!show_tags)
+               return 0;
+
+       printf("tagged %s %s",
+              tag->tagged->type,
+              sha1_to_hex(tag->tagged->sha1));
+       printf(" (%s) in %s\n",
+              tag->tag, sha1_to_hex(tag->object.sha1));
+       return 0;
 }
 
 static int fsck_name(char *hex)
 {
        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;
-               }
+               struct object *obj = parse_object(sha1);
+               if (!obj)
+                       return -1;
+               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;
 }
@@ -279,22 +137,27 @@ static int fsck_dir(int i, char *path)
 
 int main(int argc, char **argv)
 {
-       int i;
+       int i, heads;
        char *sha1_dir;
 
        for (i = 1; i < argc; i++) {
-               if (!strcmp(argv[i], "--unreachable")) {
+               const char *arg = argv[i];
+
+               if (!strcmp(arg, "--unreachable")) {
                        show_unreachable = 1;
                        continue;
                }
-               if (!get_sha1_hex(argv[i], head_sha1)) {
-                       head_supplied = 1;
+               if (!strcmp(arg, "--tags")) {
+                       show_tags = 1;
                        continue;
                }
-               usage("fsck-cache [[--unreachable] <head-sha1>]");
+               if (!strcmp(arg, "--root")) {
+                       show_root = 1;
+                       continue;
+               }
+               if (*arg == '-')
+                       usage("fsck-cache [--tags] [[--unreachable] <head-sha1>*]");
        }
-       if (show_unreachable && !head_supplied)
-               usage("unable to do reachability checks without a head");
 
        sha1_dir = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
        for (i = 0; i < 256; i++) {
@@ -302,6 +165,39 @@ int main(int argc, char **argv)
                sprintf(dir, "%s/%02x", sha1_dir, i);
                fsck_dir(i, dir);
        }
+
+       heads = 0;
+       for (i = 1; i < argc; i++) {
+               const char *arg = argv[i]; 
+
+               if (*arg == '-')
+                       continue;
+
+               if (!get_sha1_hex(arg, head_sha1)) {
+                       struct commit *commit = lookup_commit(head_sha1);
+                       struct object *obj;
+
+                       /* Error is printed by lookup_commit(). */
+                       if (!commit)
+                               continue;
+
+                       obj = &commit->object;
+                       obj->used = 1;
+                       mark_reachable(obj, REACHABLE);
+                       heads++;
+                       continue;
+               }
+               error("expected sha1, got %s", arg);
+       }
+
+       if (!heads) {
+               if (show_unreachable) {
+                       fprintf(stderr, "unable to do reachability without a head\n");
+                       show_unreachable = 0; 
+               }
+               fprintf(stderr, "expect dangling commits - potential heads - due to lack of head information\n");
+       }
+
        check_connectivity();
        return 0;
 }