Make "rev-tree" able to read its own output again from the cache.

Also, add "date" information to the output so that you can do something
like this:

	rev-tree `cat .git/HEAD` | sort -nr | cut -d' ' -f2 | while read i; do cat-file commit $i; done

which basically becomes a "git log" (aka "git changes") where things are
sorted by time.

diff --git a/rev-tree.c b/rev-tree.c
index 21598d6..82bf5aa 100644 (file)
--- a/rev-tree.c
+++ b/rev-tree.c
@@ -1,3 +1,6 @@
+#define _XOPEN_SOURCE /* glibc2 needs this */
+#include <time.h>
+#include <ctype.h>
 #include "cache.h"
 
 /*
@@ -24,6 +27,7 @@ struct parent {
 struct revision {
        unsigned int flags;
        unsigned char sha1[20];
+       unsigned long date;
        struct parent *parent;
 };
 
@@ -97,6 +101,52 @@ static int add_relationship(struct revision *rev, unsigned char *parent_sha)
        return 1;
 }
 
+static unsigned long parse_time(const char *buf)
+{
+       char c, *p;
+       char buffer[100];
+       struct tm tm;
+       const char *formats[] = {
+               "%c",
+               "%a %b %d %T %y",
+               NULL
+       };
+       const char **fmt = formats;
+
+       p = buffer;
+       while (isspace(c = *buf))
+               buf++;
+       while ((c = *buf++) != '\n')
+               *p++ = c;
+       *p++ = 0;
+       buf = buffer;
+       memset(&tm, 0, sizeof(tm));
+       do {
+               const char *next = strptime(buf, *fmt, &tm);
+               fmt++;
+               if (next) {
+                       if (!*next)
+                               return mktime(&tm);
+                       buf = next;
+               }
+       } while (*buf && *fmt);
+       return mktime(&tm);
+}
+               
+
+static unsigned long parse_commit_date(const char *buf)
+{
+       if (memcmp(buf, "author", 6))
+               return 0;
+       while (*buf++ != '\n')
+               /* nada */;
+       if (memcmp(buf, "committer", 9))
+               return 0;
+       while (*buf++ != '>')
+               /* nada */;
+       return parse_time(buf);
+}
+
 static int parse_commit(unsigned char *sha1)
 {
        struct revision *rev = lookup_rev(sha1);
@@ -117,6 +167,8 @@ static int parse_commit(unsigned char *sha1)
                        parse_commit(parent);
                        buffer += 48;   /* "parent " + "hex sha1" + "\n" */
                }
+               rev->date = parse_commit_date(buffer);
+               free(buffer);
        }
        return 0;       
 }
@@ -124,20 +176,35 @@ static int parse_commit(unsigned char *sha1)
 static void read_cache_file(const char *path)
 {
        FILE *file = fopen(path, "r");
-       char line[100];
+       char line[500];
 
        if (!file)
                usage("bad revtree cache file (%s)", path);
 
        while (fgets(line, sizeof(line), file)) {
-               unsigned char sha1[20], parent[20];
+               unsigned long date;
+               unsigned char sha1[20];
                struct revision *rev;
-
-               if (get_sha1_hex(line, sha1) || get_sha1_hex(line + 41, parent))
-                       usage("bad rev-tree cache file %s", path);
+               const char *buf;
+
+               if (sscanf(line, "%lu", &date) != 1)
+                       break;
+               buf = strchr(line, ' ');
+               if (!buf)
+                       break;
+               if (get_sha1_hex(buf+1, sha1))
+                       break;
                rev = lookup_rev(sha1);
                rev->flags |= SEEN;
-               add_relationship(rev, parent);
+               rev->date = date;
+
+               /* parents? */
+               while ((buf = strchr(buf+1, ' ')) != NULL) {
+                       unsigned char parent[20];
+                       if (get_sha1_hex(buf + 1, parent))
+                               break;
+                       add_relationship(rev, parent);
+               }
        }
        fclose(file);
 }
@@ -244,7 +311,7 @@ int main(int argc, char **argv)
                if (!interesting(rev))
                        continue;
 
-               printf("%s:%d", sha1_to_hex(rev->sha1), marked(rev));
+               printf("%lu %s:%d", rev->date, sha1_to_hex(rev->sha1), marked(rev));
                p = rev->parent;
                while (p) {
                        printf(" %s:%d", sha1_to_hex(p->parent->sha1), marked(p->parent));