blame: Rename detection (take 2)

Signed-off-by: Fredrik Kuivinen <freku045@student.liu.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/blame.c b/blame.c
index 90338af..1fb5070 100644 (file)
--- a/blame.c
+++ b/blame.c
@@ -14,6 +14,7 @@
 #include "tree.h"
 #include "blob.h"
 #include "diff.h"
+#include "diffcore.h"
 #include "revision.h"
 
 #define DEBUG 0
@@ -34,7 +35,9 @@ struct util_info {
        char *buf;
        unsigned long size;
        int num_lines;
-//    const char* path;
+       const char* pathname;
+
+       void* topo_data;
 };
 
 struct chunk {
@@ -342,25 +345,34 @@ static int map_line(struct commit *commit, int line)
        return info->line_map[line];
 }
 
-static int fill_util_info(struct commit *commit, const char *path)
+static struct util_info* get_util(struct commit *commit)
 {
-       struct util_info *util;
-       if (commit->object.util)
-               return 0;
+       struct util_info *util = commit->object.util;
+
+       if (util)
+               return util;
 
        util = xmalloc(sizeof(struct util_info));
+       util->buf = NULL;
+       util->size = 0;
+       util->line_map = NULL;
+       util->num_lines = -1;
+       util->pathname = NULL;
+       commit->object.util = util;
+       return util;
+}
+
+static int fill_util_info(struct commit *commit)
+{
+       struct util_info *util = commit->object.util;
+
+       assert(util);
+       assert(util->pathname);
 
-       if (get_blob_sha1(commit->tree, path, util->sha1)) {
-               free(util);
+       if (get_blob_sha1(commit->tree, util->pathname, util->sha1))
                return 1;
-       } else {
-               util->buf = NULL;
-               util->size = 0;
-               util->line_map = NULL;
-               util->num_lines = -1;
-               commit->object.util = util;
+       else
                return 0;
-       }
 }
 
 static void alloc_line_map(struct commit *commit)
@@ -389,10 +401,11 @@ static void alloc_line_map(struct commit *commit)
 
 static void init_first_commit(struct commit* commit, const char* filename)
 {
-       struct util_info* util;
+       struct util_info* util = commit->object.util;
        int i;
 
-       if (fill_util_info(commit, filename))
+       util->pathname = filename;
+       if (fill_util_info(commit))
                die("fill_util_info failed");
 
        alloc_line_map(commit);
@@ -453,7 +466,7 @@ static void process_commits(struct rev_info *rev, const char *path,
                if(num_parents == 0)
                        *initial = commit;
 
-               if(fill_util_info(commit, path))
+               if (fill_util_info(commit))
                        continue;
 
                alloc_line_map(commit);
@@ -471,7 +484,7 @@ static void process_commits(struct rev_info *rev, const char *path,
                                printf("parent: %s\n",
                                       sha1_to_hex(parent->object.sha1));
 
-                       if(fill_util_info(parent, path)) {
+                       if (fill_util_info(parent)) {
                                num_parents--;
                                continue;
                        }
@@ -511,6 +524,135 @@ static void process_commits(struct rev_info *rev, const char *path,
        } while ((commit = get_revision(rev)) != NULL);
 }
 
+
+static int compare_tree_path(struct rev_info* revs,
+                            struct commit* c1, struct commit* c2)
+{
+       const char* paths[2];
+       struct util_info* util = c2->object.util;
+       paths[0] = util->pathname;
+       paths[1] = NULL;
+
+       diff_tree_setup_paths(get_pathspec(revs->prefix, paths));
+       return rev_compare_tree(c1->tree, c2->tree);
+}
+
+
+static int same_tree_as_empty_path(struct rev_info *revs, struct tree* t1,
+                                  const char* path)
+{
+       const char* paths[2];
+       paths[0] = path;
+       paths[1] = NULL;
+
+       diff_tree_setup_paths(get_pathspec(revs->prefix, paths));
+       return rev_same_tree_as_empty(t1);
+}
+
+static const char* find_rename(struct commit* commit, struct commit* parent)
+{
+       struct util_info* cutil = commit->object.util;
+       struct diff_options diff_opts;
+       const char *paths[1];
+       int i;
+
+       if (DEBUG) {
+               printf("find_rename commit: %s ",
+                      sha1_to_hex(commit->object.sha1));
+               puts(sha1_to_hex(parent->object.sha1));
+       }
+
+       diff_setup(&diff_opts);
+       diff_opts.recursive = 1;
+       diff_opts.detect_rename = DIFF_DETECT_RENAME;
+       paths[0] = NULL;
+       diff_tree_setup_paths(paths);
+       if (diff_setup_done(&diff_opts) < 0)
+               die("diff_setup_done failed");
+
+       diff_tree_sha1(commit->tree->object.sha1, parent->tree->object.sha1,
+                      "", &diff_opts);
+       diffcore_std(&diff_opts);
+
+       for (i = 0; i < diff_queued_diff.nr; i++) {
+               struct diff_filepair *p = diff_queued_diff.queue[i];
+
+               if (p->status == 'R' && !strcmp(p->one->path, cutil->pathname)) {
+                       if (DEBUG)
+                               printf("rename %s -> %s\n", p->one->path, p->two->path);
+                       return p->two->path;
+               }
+       }
+
+       return 0;
+}
+
+static void simplify_commit(struct rev_info *revs, struct commit *commit)
+{
+       struct commit_list **pp, *parent;
+
+       if (!commit->tree)
+               return;
+
+       if (!commit->parents) {
+               struct util_info* util = commit->object.util;
+               if (!same_tree_as_empty_path(revs, commit->tree,
+                                            util->pathname))
+                       commit->object.flags |= TREECHANGE;
+               return;
+       }
+
+       pp = &commit->parents;
+       while ((parent = *pp) != NULL) {
+               struct commit *p = parent->item;
+
+               if (p->object.flags & UNINTERESTING) {
+                       pp = &parent->next;
+                       continue;
+               }
+
+               parse_commit(p);
+               switch (compare_tree_path(revs, p, commit)) {
+               case REV_TREE_SAME:
+                       parent->next = NULL;
+                       commit->parents = parent;
+                       get_util(p)->pathname = get_util(commit)->pathname;
+                       return;
+
+               case REV_TREE_NEW:
+               {
+
+                       struct util_info* util = commit->object.util;
+                       if (revs->remove_empty_trees &&
+                           same_tree_as_empty_path(revs, p->tree,
+                                                   util->pathname)) {
+                               const char* new_name = find_rename(commit, p);
+                               if (new_name) {
+                                       struct util_info* putil = get_util(p);
+                                       if (!putil->pathname)
+                                               putil->pathname = strdup(new_name);
+                               } else {
+                                       *pp = parent->next;
+                                       continue;
+                               }
+                       }
+               }
+
+               /* fallthrough */
+               case REV_TREE_DIFFERENT:
+                       pp = &parent->next;
+                       if (!get_util(p)->pathname)
+                               get_util(p)->pathname =
+                                       get_util(commit)->pathname;
+                       continue;
+               }
+               die("bad tree compare for commit %s",
+                   sha1_to_hex(commit->object.sha1));
+       }
+       commit->object.flags |= TREECHANGE;
+}
+
+
 struct commit_info
 {
        char* author;
@@ -569,6 +711,18 @@ static const char* format_time(unsigned long time, const char* tz_str)
        return time_buf;
 }
 
+static void topo_setter(struct commit* c, void* data)
+{
+       struct util_info* util = c->object.util;
+       util->topo_data = data;
+}
+
+static void* topo_getter(struct commit* c)
+{
+       struct util_info* util = c->object.util;
+       return util->topo_data;
+}
+
 int main(int argc, const char **argv)
 {
        int i;
@@ -580,8 +734,8 @@ int main(int argc, const char **argv)
        int sha1_len = 8;
        int compability = 0;
        int options = 1;
+       struct commit* start_commit;
 
-       int num_args;
        const char* args[10];
        struct rev_info rev;
 
@@ -634,28 +788,29 @@ int main(int argc, const char **argv)
                strcpy(filename_buf, filename);
        filename = filename_buf;
 
-       {
-               struct commit* c;
-               if (get_sha1(commit, sha1))
-                       die("get_sha1 failed, commit '%s' not found", commit);
-               c = lookup_commit_reference(sha1);
-
-               if (fill_util_info(c, filename)) {
-                       printf("%s not found in %s\n", filename, commit);
-                       return 1;
-               }
+       if (get_sha1(commit, sha1))
+               die("get_sha1 failed, commit '%s' not found", commit);
+       start_commit = lookup_commit_reference(sha1);
+       get_util(start_commit)->pathname = filename;
+       if (fill_util_info(start_commit)) {
+               printf("%s not found in %s\n", filename, commit);
+               return 1;
        }
 
-       num_args = 0;
-       args[num_args++] = NULL;
-       args[num_args++] = "--topo-order";
-       args[num_args++] = "--remove-empty";
-       args[num_args++] = commit;
-       args[num_args++] = "--";
-       args[num_args++] = filename;
-       args[num_args] = NULL;
 
-       setup_revisions(num_args, args, &rev, "HEAD");
+       init_revisions(&rev);
+       rev.remove_empty_trees = 1;
+       rev.topo_order = 1;
+       rev.prune_fn = simplify_commit;
+       rev.topo_setter = topo_setter;
+       rev.topo_getter = topo_getter;
+       rev.limited = 1;
+
+       commit_list_insert(start_commit, &rev.commits);
+
+       args[0] = filename;
+       args[1] = NULL;
+       diff_tree_setup_paths(args);
        prepare_revision_walk(&rev);
        process_commits(&rev, filename, &initial);
 
@@ -665,17 +820,21 @@ int main(int argc, const char **argv)
 
        for (i = 0; i < num_blame_lines; i++) {
                struct commit *c = blame_lines[i];
+               struct util_info* u;
+
                if (!c)
                        c = initial;
 
+               u = c->object.util;
                get_commit_info(c, &ci);
                fwrite(sha1_to_hex(c->object.sha1), sha1_len, 1, stdout);
                if(compability)
                        printf("\t(%10s\t%10s\t%d)", ci.author,
                               format_time(ci.author_time, ci.author_tz), i+1);
                else
-                       printf(" (%-15.15s %10s %*d) ", ci.author,
-                              format_time(ci.author_time, ci.author_tz),
+                       printf(" %s (%-15.15s %10s %*d) ", u->pathname,
+                              ci.author, format_time(ci.author_time,
+                                                     ci.author_tz),
                               max_digits, i+1);
 
                if(i == num_blame_lines - 1) {