Teach the revision walker to walk by reflogs with --walk-reflogs

When called with "--walk-reflogs", as long as there are reflogs
available, the walker will take this information into account, rather
than the parent information in the commit object.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Makefile b/Makefile
index 8432ab8ba1c69f1269808782b17e62ce92460b4e..1a29392a1254ef4f2a15d9abb88ccfc29b77f479 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -254,7 +254,7 @@ LIB_OBJS = \
        interpolate.o \
        lockfile.o \
        object.o pack-check.o patch-delta.o path.o pkt-line.o sideband.o \
-       reachable.o \
+       reachable.o reflog-walk.o \
        quote.o read-cache.o refs.o run-command.o dir.o object-refs.o \
        server-info.o setup.o sha1_file.o sha1_name.o strbuf.o \
        tag.o tree.o usage.o config.o environment.o ctype.o copy.o \

diff --git a/log-tree.c b/log-tree.c
index 35be33aaf73e0b53cb9ece09bba5f1e12de4b99d..f043ad3723eef60f4e3d7a7a95ba19c89d0bcebf 100644 (file)
--- a/log-tree.c
+++ b/log-tree.c
@@ -2,6 +2,7 @@
 #include "diff.h"
 #include "commit.h"
 #include "log-tree.h"
+#include "reflog-walk.h"
 
 static void show_parents(struct commit *commit, int abbrev)
 {
@@ -223,6 +224,8 @@ void show_log(struct rev_info *opt, const char *sep)
                printf("%s",
                       diff_get_color(opt->diffopt.color_diff, DIFF_RESET));
                putchar(opt->commit_format == CMIT_FMT_ONELINE ? ' ' : '\n');
+               if (opt->reflog_info)
+                       show_reflog_message(opt->reflog_info);
        }
 
        /*

diff --git a/reflog-walk.c b/reflog-walk.c
new file mode 100644 (file)
index 0000000..d4b49c7
--- /dev/null
+++ b/reflog-walk.c
@@ -0,0 +1,235 @@
+#include "cache.h"
+#include "commit.h"
+#include "refs.h"
+#include "diff.h"
+#include "revision.h"
+#include "path-list.h"
+
+struct complete_reflogs {
+       char *ref;
+       struct reflog_info {
+               unsigned char osha1[20], nsha1[20];
+               char *email;
+               unsigned long timestamp;
+               int tz;
+               char *message;
+       } *items;
+       int nr, alloc;
+};
+
+static int read_one_reflog(unsigned char *osha1, unsigned char *nsha1,
+               const char *email, unsigned long timestamp, int tz,
+               const char *message, void *cb_data)
+{
+       struct complete_reflogs *array = cb_data;
+       struct reflog_info *item;
+
+       if (array->nr >= array->alloc) {
+               array->alloc = alloc_nr(array->nr + 1);
+               array->items = xrealloc(array->items, array->alloc *
+                       sizeof(struct reflog_info));
+       }
+       item = array->items + array->nr;
+       memcpy(item->osha1, osha1, 20);
+       memcpy(item->nsha1, nsha1, 20);
+       item->email = xstrdup(email);
+       item->timestamp = timestamp;
+       item->tz = tz;
+       item->message = xstrdup(message);
+       array->nr++;
+       return 0;
+}
+
+static struct complete_reflogs *read_complete_reflog(const char *ref)
+{
+       struct complete_reflogs *reflogs =
+               xcalloc(sizeof(struct complete_reflogs), 1);
+       reflogs->ref = xstrdup(ref);
+       for_each_reflog_ent(ref, read_one_reflog, reflogs);
+       if (reflogs->nr == 0) {
+               unsigned char sha1[20];
+               const char *name = resolve_ref(ref, sha1, 1, NULL);
+               if (name)
+                       for_each_reflog_ent(name, read_one_reflog, reflogs);
+       }
+       if (reflogs->nr == 0) {
+               int len = strlen(ref);
+               char *refname = xmalloc(len + 12);
+               sprintf(refname, "refs/%s", ref);
+               for_each_reflog_ent(refname, read_one_reflog, reflogs);
+               if (reflogs->nr == 0) {
+                       sprintf(refname, "refs/heads/%s", ref);
+                       for_each_reflog_ent(refname, read_one_reflog, reflogs);
+               }
+               free(refname);
+       }
+       return reflogs;
+}
+
+static int get_reflog_recno_by_time(struct complete_reflogs *array,
+       unsigned long timestamp)
+{
+       int i;
+       for (i = array->nr - 1; i >= 0; i++)
+               if (timestamp >= array->items[i].timestamp)
+                       return i;
+       return -1;
+}
+
+struct commit_info_lifo {
+       struct commit_info {
+               struct commit *commit;
+               void *util;
+       } *items;
+       int nr, alloc;
+};
+
+static struct commit_info *get_commit_info(struct commit *commit,
+               struct commit_info_lifo *lifo, int pop)
+{
+       int i;
+       for (i = 0; i < lifo->nr; i++)
+               if (lifo->items[i].commit == commit) {
+                       struct commit_info *result = &lifo->items[i];
+                       if (pop) {
+                               if (i + 1 < lifo->nr)
+                                       memmove(lifo->items + i,
+                                               lifo->items + i + 1,
+                                               (lifo->nr - i) *
+                                               sizeof(struct commit_info));
+                               lifo->nr--;
+                       }
+                       return result;
+               }
+       return NULL;
+}
+
+static void add_commit_info(struct commit *commit, void *util,
+               struct commit_info_lifo *lifo)
+{
+       struct commit_info *info;
+       if (lifo->nr >= lifo->alloc) {
+               lifo->alloc = alloc_nr(lifo->nr + 1);
+               lifo->items = xrealloc(lifo->items,
+                       lifo->alloc * sizeof(struct commit_info));
+       }
+       info = lifo->items + lifo->nr;
+       info->commit = commit;
+       info->util = util;
+       lifo->nr++;
+}
+
+struct commit_reflog {
+       int flag, recno;
+       struct complete_reflogs *reflogs;
+};
+
+struct reflog_walk_info {
+       struct commit_info_lifo reflogs;
+       struct path_list complete_reflogs;
+       struct commit_reflog *last_commit_reflog;
+};
+
+void init_reflog_walk(struct reflog_walk_info** info)
+{
+       *info = xcalloc(sizeof(struct reflog_walk_info), 1);
+}
+
+void add_reflog_for_walk(struct reflog_walk_info *info,
+               struct commit *commit, const char *name)
+{
+       unsigned long timestamp = 0;
+       int recno = -1;
+       struct path_list_item *item;
+       struct complete_reflogs *reflogs;
+       char *branch, *at = strchr(name, '@');
+       struct commit_reflog *commit_reflog;
+
+       branch = xstrdup(name);
+       if (at && at[1] == '{') {
+               char *ep;
+               branch[at - name] = '\0';
+               recno = strtoul(at + 2, &ep, 10);
+               if (*ep != '}') {
+                       recno = -1;
+                       timestamp = approxidate(at + 2);
+               }
+       } else
+               recno = 0;
+
+       item = path_list_lookup(branch, &info->complete_reflogs);
+       if (item)
+               reflogs = item->util;
+       else {
+               reflogs = read_complete_reflog(branch);
+               if (!reflogs || reflogs->nr == 0)
+                       die("No reflogs found for '%s'", branch);
+               path_list_insert(branch, &info->complete_reflogs)->util
+                       = reflogs;
+       }
+
+       commit_reflog = xcalloc(sizeof(struct commit_reflog), 1);
+       if (recno < 0) {
+               commit_reflog->flag = 1;
+               commit_reflog->recno = get_reflog_recno_by_time(reflogs, timestamp);
+               if (commit_reflog->recno < 0) {
+                       free(branch);
+                       free(commit_reflog);
+                       return;
+               }
+       } else
+               commit_reflog->recno = reflogs->nr - recno - 1;
+       commit_reflog->reflogs = reflogs;
+
+       add_commit_info(commit, commit_reflog, &info->reflogs);
+}
+
+void fake_reflog_parent(struct reflog_walk_info *info, struct commit *commit)
+{
+       struct commit_info *commit_info =
+               get_commit_info(commit, &info->reflogs, 0);
+       struct commit_reflog *commit_reflog;
+       struct reflog_info *reflog;
+
+       info->last_commit_reflog = NULL;
+       if (!commit_info)
+               return;
+
+       commit_reflog = commit_info->util;
+       if (commit_reflog->recno < 0) {
+               commit->parents = NULL;
+               return;
+       }
+
+       reflog = &commit_reflog->reflogs->items[commit_reflog->recno];
+       info->last_commit_reflog = commit_reflog;
+       commit_reflog->recno--;
+       commit_info->commit = (struct commit *)parse_object(reflog->osha1);
+       if (!commit_info->commit) {
+               commit->parents = NULL;
+               return;
+       }
+
+       commit->parents = xcalloc(sizeof(struct commit_list), 1);
+       commit->parents->item = commit_info->commit;
+       commit->object.flags &= ~(ADDED | SEEN | SHOWN);
+}
+
+void show_reflog_message(struct reflog_walk_info* info)
+{
+       if (info && info->last_commit_reflog) {
+               struct commit_reflog *commit_reflog = info->last_commit_reflog;
+               struct reflog_info *info;
+
+               printf("Reflog: %s@{", commit_reflog->reflogs->ref);
+               info = &commit_reflog->reflogs->items[commit_reflog->recno + 1];
+               if (commit_reflog->flag)
+                       printf("%s", show_rfc2822_date(info->timestamp,
+                                               info->tz));
+               else
+                       printf("%d", commit_reflog->reflogs->nr
+                                       - 2 - commit_reflog->recno);
+               printf("} (%s)\nReflog message: %s",
+                       info->email, info->message);
+       }
+}

diff --git a/reflog-walk.h b/reflog-walk.h
new file mode 100644 (file)
index 0000000..787996b
--- /dev/null
+++ b/reflog-walk.h
@@ -0,0 +1,11 @@
+#ifndef REFLOG_WALK_H
+#define REFLOG_WALK_H
+
+extern void init_reflog_walk(struct reflog_walk_info** info);
+extern void add_reflog_for_walk(struct reflog_walk_info *info,
+               struct commit *commit, const char *name);
+extern void fake_reflog_parent(struct reflog_walk_info *info,
+               struct commit *commit);
+extern void show_reflog_message(struct reflog_walk_info* info);
+
+#endif

diff --git a/revision.c b/revision.c
index f2ddd95e29e5eaef2cb4beb28c34921396d94fdf..ebd025064c82a3f6190a83e808e8bcf73478dacc 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -7,6 +7,7 @@
 #include "refs.h"
 #include "revision.h"
 #include "grep.h"
+#include "reflog-walk.h"
 
 static char *path_name(struct name_path *path, const char *name)
 {
@@ -116,6 +117,9 @@ void mark_parents_uninteresting(struct commit *commit)
 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 {
        add_object_array(obj, name, &revs->pending);
+       if (revs->reflog_info && obj->type == OBJ_COMMIT)
+               add_reflog_for_walk(revs->reflog_info,
+                               (struct commit *)obj, name);
 }
 
 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
@@ -864,6 +868,10 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                handle_reflog(revs, flags);
                                continue;
                        }
+                       if (!strcmp(arg, "--walk-reflogs")) {
+                               init_reflog_walk(&revs->reflog_info);
+                               continue;
+                       }
                        if (!strcmp(arg, "--not")) {
                                flags ^= UNINTERESTING;
                                continue;
@@ -1210,6 +1218,9 @@ static struct commit *get_revision_1(struct rev_info *revs)
                revs->commits = entry->next;
                free(entry);
 
+               if (revs->reflog_info)
+                       fake_reflog_parent(revs->reflog_info, commit);
+
                /*
                 * If we haven't done the list limiting, we need to look at
                 * the parents here. We also need to do the date-based limiting

diff --git a/revision.h b/revision.h
index 8f7907d7abdb764317612d868f58ab88f7175b59..d93481f68f53a657fe4b174e4a12777efe6a74bb 100644 (file)
--- a/revision.h
+++ b/revision.h
@@ -89,6 +89,8 @@ struct rev_info {
 
        topo_sort_set_fn_t topo_setter;
        topo_sort_get_fn_t topo_getter;
+
+       struct reflog_walk_info *reflog_info;
 };
 
 #define REV_TREE_SAME          0