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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-14 04:37:59 (GMT)
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-14 04:37:59 (GMT)
commit458754a9fe2c2e889e38d1f4f53d5d457eba6faa (patch)
treeb65f86cddbb4086dc6b9b0a14ec8a935c45c6c3d /revision.h
parentf864ba7448564d06e8076d1b6a66eca00a337d8c (diff)
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Use common "revision.h" header for both fsck and rev-tree.
It's really a very generic thing: the notion of one sha1 revision referring to another one. "fsck" uses it for all nodes, and "rev-tree" only tracks commit-node relationships, but the code was already the same - now we just make that explicit by moving it to a common header file.
Diffstat (limited to 'revision.h')
-rw-r--r--revision.h114
1 files changed, 114 insertions, 0 deletions
diff --git a/revision.h b/revision.h
new file mode 100644
index 0000000..4f140ca
--- /dev/null
+++ b/revision.h
@@ -0,0 +1,114 @@
+#ifndef REVISION_H
+#define REVISION_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 marked(rev) ((rev)->flags & 0xffff)
+#define SEEN 0x10000
+#define USED 0x20000
+#define REACHABLE 0x40000
+
+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;
+ }
+}
+
+#endif /* REVISION_H */