diff --git a/commit.c b/commit.c
index 254c902716e08266a89a9df245bcda5808737b6a..caee5bc218f6db03ec4c8f16f39b892ebb7c762c 100644 (file)
--- a/commit.c
+++ b/commit.c
#include "commit.h"
#include "cache.h"
#include "commit.h"
#include "cache.h"
+struct sort_node
+{
+ /*
+ * the number of children of the associated commit
+ * that also occur in the list being sorted.
+ */
+ unsigned int indegree;
+
+ /*
+ * reference to original list item that we will re-use
+ * on output.
+ */
+ struct commit_list * list_item;
+
+};
+
const char *commit_type = "commit";
enum cmit_fmt get_commit_format(const char *arg)
const char *commit_type = "commit";
enum cmit_fmt get_commit_format(const char *arg)
if (!obj)
return NULL;
if (!obj)
return NULL;
- if (obj->type == tag_type)
- obj = ((struct tag *)obj)->tagged;
+ while (obj->type == tag_type)
+ obj = parse_object(((struct tag *)obj)->tagged->sha1);
+
return check_commit(obj, sha1);
}
return check_commit(obj, sha1);
}
return count;
}
return count;
}
+/*
+ * Performs an in-place topological sort on the list supplied.
+ */
+void sort_in_topological_order(struct commit_list ** list)
+{
+ struct commit_list * next = *list;
+ struct commit_list * work = NULL;
+ struct commit_list ** pptr = list;
+ struct sort_node * nodes;
+ struct sort_node * next_nodes;
+ int count = 0;
+
+ /* determine the size of the list */
+ while (next) {
+ next = next->next;
+ count++;
+ }
+ /* allocate an array to help sort the list */
+ nodes = xcalloc(count, sizeof(*nodes));
+ /* link the list to the array */
+ next_nodes = nodes;
+ next=*list;
+ while (next) {
+ next_nodes->list_item = next;
+ next->item->object.util = next_nodes;
+ next_nodes++;
+ next = next->next;
+ }
+ /* update the indegree */
+ next=*list;
+ while (next) {
+ struct commit_list * parents = next->item->parents;
+ while (parents) {
+ struct commit * parent=parents->item;
+ struct sort_node * pn = (struct sort_node *)parent->object.util;
+
+ if (pn)
+ pn->indegree++;
+ parents=parents->next;
+ }
+ next=next->next;
+ }
+ /*
+ * find the tips
+ *
+ * tips are nodes not reachable from any other node in the list
+ *
+ * the tips serve as a starting set for the work queue.
+ */
+ next=*list;
+ while (next) {
+ struct sort_node * node = (struct sort_node *)next->item->object.util;
+
+ if (node->indegree == 0) {
+ commit_list_insert(next->item, &work);
+ }
+ next=next->next;
+ }
+ /* process the list in topological order */
+ while (work) {
+ struct commit * work_item = pop_commit(&work);
+ struct sort_node * work_node = (struct sort_node *)work_item->object.util;
+ struct commit_list * parents = work_item->parents;
+
+ while (parents) {
+ struct commit * parent=parents->item;
+ struct sort_node * pn = (struct sort_node *)parent->object.util;
+
+ if (pn) {
+ /*
+ * parents are only enqueued for emission
+ * when all their children have been emitted thereby
+ * guaranteeing topological order.
+ */
+ pn->indegree--;
+ if (!pn->indegree)
+ commit_list_insert(parent, &work);
+ }
+ parents=parents->next;
+ }
+ /*
+ * work_item is a commit all of whose children
+ * have already been emitted. we can emit it now.
+ */
+ *pptr = work_node->list_item;
+ pptr = &(*pptr)->next;
+ *pptr = NULL;
+ work_item->object.util = NULL;
+ }
+ free(nodes);
+}