X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=fsck-cache.c;h=e7014a064e1a1562b35b7c5c95fb0e9843a54ebd;hb=bcee6fd8e7164aa7a4170f109af8347d88f0175e;hp=c35acaa82c93824f952327e12727d0c92edc5bd7;hpb=4e6616ab77ed6a53f857d4b1082c4dc4140f34f5;p=git.git

diff --git a/fsck-cache.c b/fsck-cache.c
index c35acaa8..e7014a06 100644
--- a/fsck-cache.c
+++ b/fsck-cache.c
@@ -4,17 +4,157 @@
 #include <dirent.h>
 
 /*
- * These two functions should build up a graph in memory about
- * what objects we've referenced, and found, and types..
+ * The low 16 bits of the "flags" field shows whether
+ * a commit is part of the path to the root for that
+ * parent.
  *
- * Right now we don't do that kind of reachability checking. Yet.
+ * Bit 16 is an internal flag that we've seen the
+ * definition for this rev, and not just seen it as
+ * a parent target.
  */
-static void mark_needs_sha1(unsigned char *parent, const char * type, unsigned char *child)
+#define MAX_COMMITS (16)
+#define marked(rev)	((rev)->flags & 0xffff)
+#define SEEN 0x10000
+#define USED 0x20000
+#define REACHABLE 0x40000
+
+static int show_unreachable = 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;
+
+	/* If we've been here already, don't bother */
+	if (rev->flags & REACHABLE)
+		return;
+	rev->flags |= REACHABLE | USED;
+	while (p) {
+		mark_reachable(p->parent);
+		p = p->next;
+	}
+}
+
+static void check_connectivity(void)
+{
+	int i;
+
+	/* Look up all the requirements, warn about missing objects.. */
+	for (i = 0; i < nr_revs; i++) {
+		struct revision *rev = revs[i];
+
+		if (show_unreachable && !(rev->flags & REACHABLE)) {
+			printf("unreachable %s\n", sha1_to_hex(rev->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;
+		}
+	}
+}
+
+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)
 {
+	struct revision *rev = lookup_rev(sha1);
+
+	rev->flags |= SEEN;
 	return 0;
 }
 
@@ -64,7 +204,7 @@ static int fsck_commit(unsigned char *sha1, void *data, unsigned long size)
 		parents++;
 	}
 	if (!parents)
-		printf("root: %s\n", sha1_to_hex(sha1));
+		printf("root %s\n", sha1_to_hex(sha1));
 	return 0;
 }
 
@@ -109,8 +249,7 @@ 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) {
@@ -139,16 +278,38 @@ static int fsck_dir(int i, char *path)
 
 int main(int argc, char **argv)
 {
-	int i;
+	int i, heads;
 	char *sha1_dir;
 
-	if (argc != 1)
-		usage("fsck-cache");
 	sha1_dir = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
 	for (i = 0; i < 256; i++) {
 		static char dir[4096];
 		sprintf(dir, "%s/%02x", sha1_dir, i);
 		fsck_dir(i, dir);
 	}
+
+	heads = 0;
+	for (i = 1; i < argc; i++) {
+		if (!strcmp(argv[i], "--unreachable")) {
+			show_unreachable = 1;
+			continue;
+		}
+		if (!get_sha1_hex(argv[i], head_sha1)) {
+			mark_reachable(lookup_rev(head_sha1));
+			heads++;
+			continue;
+		}
+		error("fsck-cache [[--unreachable] <head-sha1>*]");
+	}
+
+	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;
 }