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#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 */
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