Abstract out the "name <email> date" handling of commit-tree.c
[gitweb.git] / commit.c
index a466f7da6648da80737805b392658c317772770b..caee5bc218f6db03ec4c8f16f39b892ebb7c762c 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -1,10 +1,42 @@
+#include <ctype.h>
 #include "tag.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";
 
-static struct commit *check_commit(struct object *obj, unsigned char *sha1)
+enum cmit_fmt get_commit_format(const char *arg)
+{
+       if (!*arg)
+               return CMIT_FMT_DEFAULT;
+       if (!strcmp(arg, "=raw"))
+               return CMIT_FMT_RAW;
+       if (!strcmp(arg, "=medium"))
+               return CMIT_FMT_MEDIUM;
+       if (!strcmp(arg, "=short"))
+               return CMIT_FMT_SHORT;
+       if (!strcmp(arg, "=full"))
+               return CMIT_FMT_FULL;
+       die("invalid --pretty format");
+}
+
+static struct commit *check_commit(struct object *obj, const unsigned char *sha1)
 {
        if (obj->type != commit_type) {
                error("Object %s is a %s, not a commit", 
@@ -14,18 +46,19 @@ static struct commit *check_commit(struct object *obj, unsigned char *sha1)
        return (struct commit *) obj;
 }
 
-struct commit *lookup_commit_reference(unsigned char *sha1)
+struct commit *lookup_commit_reference(const unsigned char *sha1)
 {
        struct object *obj = parse_object(sha1);
 
        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);
 }
 
-struct commit *lookup_commit(unsigned char *sha1)
+struct commit *lookup_commit(const unsigned char *sha1)
 {
        struct object *obj = lookup_object(sha1);
        if (!obj) {
@@ -62,6 +95,7 @@ int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 {
        void *bufptr = buffer;
        unsigned char parent[20];
+       struct commit_list **pptr;
 
        if (item->object.parsed)
                return 0;
@@ -71,11 +105,12 @@ int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
        if (item->tree)
                add_ref(&item->object, &item->tree->object);
        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
+       pptr = &item->parents;
        while (!memcmp(bufptr, "parent ", 7) &&
               !get_sha1_hex(bufptr + 7, parent)) {
                struct commit *new_parent = lookup_commit(parent);
                if (new_parent) {
-                       commit_list_insert(new_parent, &item->parents);
+                       pptr = &commit_list_insert(new_parent, pptr)->next;
                        add_ref(&item->object, &new_parent->object);
                }
                bufptr += 48;
@@ -129,7 +164,7 @@ void free_commit_list(struct commit_list *list)
        }
 }
 
-static void insert_by_date(struct commit_list **list, struct commit *item)
+struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 {
        struct commit_list **pp = list;
        struct commit_list *p;
@@ -139,7 +174,7 @@ static void insert_by_date(struct commit_list **list, struct commit *item)
                }
                pp = &p->next;
        }
-       commit_list_insert(item, pp);
+       return commit_list_insert(item, pp);
 }
 
        
@@ -147,7 +182,7 @@ void sort_by_date(struct commit_list **list)
 {
        struct commit_list *ret = NULL;
        while (*list) {
-               insert_by_date(&ret, (*list)->item);
+               insert_by_date((*list)->item, &ret);
                *list = (*list)->next;
        }
        *list = ret;
@@ -168,9 +203,254 @@ struct commit *pop_most_recent_commit(struct commit_list **list,
                parse_commit(commit);
                if (!(commit->object.flags & mark)) {
                        commit->object.flags |= mark;
-                       insert_by_date(list, commit);
+                       insert_by_date(commit, list);
                }
                parents = parents->next;
        }
        return ret;
 }
+
+/*
+ * Generic support for pretty-printing the header
+ */
+static int get_one_line(const char *msg, unsigned long len)
+{
+       int ret = 0;
+
+       while (len--) {
+               char c = *msg++;
+               ret++;
+               if (c == '\n')
+                       break;
+               if (!c)
+                       return 0;
+       }
+       return ret;
+}
+
+static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
+{
+       char *date;
+       unsigned int namelen;
+       unsigned long time;
+       int tz, ret;
+
+       date = strchr(line, '>');
+       if (!date)
+               return 0;
+       namelen = ++date - line;
+       time = strtoul(date, &date, 10);
+       tz = strtol(date, NULL, 10);
+
+       ret = sprintf(buf, "%s: %.*s\n", what, namelen, line);
+       if (fmt == CMIT_FMT_MEDIUM)
+               ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
+       return ret;
+}
+
+static int is_empty_line(const char *line, int len)
+{
+       while (len && isspace(line[len-1]))
+               len--;
+       return !len;
+}
+
+static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
+{
+       int offset = 0;
+       switch (parents) {
+       case 1:
+               break;
+       case 2:
+               /* Go back to the previous line: 40 characters of previous parent, and one '\n' */
+               offset = sprintf(buf, "Merge: %.40s\n", line-41);
+               /* Fallthrough */
+       default:
+               /* Replace the previous '\n' with a space */
+               buf[offset-1] = ' ';
+               offset += sprintf(buf + offset, "%.40s\n", line+7);
+       }
+       return offset;
+}
+
+unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
+{
+       int hdr = 1, body = 0;
+       unsigned long offset = 0;
+       int parents = 0;
+
+       for (;;) {
+               const char *line = msg;
+               int linelen = get_one_line(msg, len);
+
+               if (!linelen)
+                       break;
+
+               /*
+                * We want some slop for indentation and a possible
+                * final "...". Thus the "+ 20".
+                */
+               if (offset + linelen + 20 > space) {
+                       memcpy(buf + offset, "    ...\n", 8);
+                       offset += 8;
+                       break;
+               }
+
+               msg += linelen;
+               len -= linelen;
+               if (hdr) {
+                       if (linelen == 1) {
+                               hdr = 0;
+                               buf[offset++] = '\n';
+                               continue;
+                       }
+                       if (fmt == CMIT_FMT_RAW) {
+                               memcpy(buf + offset, line, linelen);
+                               offset += linelen;
+                               continue;
+                       }
+                       if (!memcmp(line, "parent ", 7)) {
+                               if (linelen != 48)
+                                       die("bad parent line in commit");
+                               offset += add_parent_info(fmt, buf + offset, line, ++parents);
+                       }
+                       if (!memcmp(line, "author ", 7))
+                               offset += add_user_info("Author", fmt, buf + offset, line + 7);
+                       if (fmt == CMIT_FMT_FULL) {
+                               if (!memcmp(line, "committer ", 10))
+                                       offset += add_user_info("Commit", fmt, buf + offset, line + 10);
+                       }
+                       continue;
+               }
+
+               if (is_empty_line(line, linelen)) {
+                       if (!body)
+                               continue;
+                       if (fmt == CMIT_FMT_SHORT)
+                               break;
+               } else {
+                       body = 1;
+               }
+               memset(buf + offset, ' ', 4);
+               memcpy(buf + offset + 4, line, linelen);
+               offset += linelen + 4;
+       }
+       /* Make sure there is an EOLN */
+       if (buf[offset - 1] != '\n')
+               buf[offset++] = '\n';
+       buf[offset] = '\0';
+       return offset;
+}
+
+struct commit *pop_commit(struct commit_list **stack)
+{
+       struct commit_list *top = *stack;
+       struct commit *item = top ? top->item : NULL;
+
+       if (top) {
+               *stack = top->next;
+               free(top);
+       }
+       return item;
+}
+
+int count_parents(struct commit * commit)
+{
+        int count = 0;
+        struct commit_list * parents = commit->parents;
+        for (count=0;parents; parents=parents->next,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);
+}