Make "convert-cache" able to handle the really old archive formats

This includes the old-style "flat tree" object, and the old broken
date format. Well, enough of the date format to convert the sparse
archive, at least.

diff --git a/convert-cache.c b/convert-cache.c
index 97e9952..35191df 100644 (file)
--- a/convert-cache.c
+++ b/convert-cache.c
@@ -1,3 +1,6 @@
+#define _XOPEN_SOURCE /* glibc2 needs this */
+#include <time.h>
+#include <ctype.h>
 #include "cache.h"
 
 struct entry {
@@ -46,11 +49,6 @@ static struct entry *lookup_entry(unsigned char *sha1)
        return insert_new(sha1, low);
 }
 
-static void convert_blob(void *buffer, unsigned long size)
-{
-       /* Nothing to do */
-}
-
 static void convert_binary_sha1(void *buffer)
 {
        struct entry *entry = convert_entry(buffer);
@@ -68,8 +66,80 @@ static void convert_ascii_sha1(void *buffer)
        memcpy(buffer, sha1_to_hex(entry->new_sha1), 40);
 }
 
-static void convert_tree(void *buffer, unsigned long size)
+#define ORIG_OFFSET (40)
+
+static int prepend_integer(char *buffer, unsigned val, int i)
+{
+       buffer[--i] = '\0';
+       do {
+               buffer[--i] = '0' + (val % 10);
+               val /= 10;
+       } while (val);
+       return i;
+}
+
+
+static int write_subdirectory(void *buffer, unsigned long size, const char *base, int baselen, unsigned char *result_sha1)
 {
+       char *new = malloc(size + ORIG_OFFSET);
+       unsigned long newlen = ORIG_OFFSET;
+       unsigned long used;
+       int i;
+
+       used = 0;
+       while (size) {
+               int len = 21 + strlen(buffer);
+               char *path = strchr(buffer, ' ');
+               unsigned char *sha1;
+               unsigned int mode;
+               char *slash, *origpath;
+
+               if (!path || sscanf(buffer, "%o", &mode) != 1)
+                       die("bad tree conversion");
+               path++;
+               if (memcmp(path, base, baselen))
+                       break;
+               origpath = path;
+               path += baselen;
+               slash = strchr(path, '/');
+               if (!slash) {
+                       newlen += sprintf(new + newlen, "%o %s", mode, path);
+                       new[newlen++] = '\0';
+                       memcpy(new + newlen, buffer + len - 20, 20);
+                       newlen += 20;
+
+                       used += len;
+                       size -= len;
+                       buffer += len;
+                       continue;
+               }
+
+               newlen += sprintf(new + newlen, "%o %.*s", S_IFDIR, slash - path, path);
+               new[newlen++] = 0;
+               sha1 = (unsigned char *)(new + newlen);
+               newlen += 20;
+
+               len = write_subdirectory(buffer, size, origpath, slash-origpath+1, sha1);
+
+               used += len;
+               size -= len;
+               buffer += len;
+       }
+
+       i = prepend_integer(new, newlen - ORIG_OFFSET, ORIG_OFFSET);
+       i -= 5;
+       memcpy(new + i, "tree ", 5);
+
+       write_sha1_file(new + i, newlen - i, result_sha1);
+       free(new);
+       return used;
+}
+
+static void convert_tree(void *buffer, unsigned long size, unsigned char *result_sha1)
+{
+       void *orig_buffer = buffer;
+       unsigned long orig_size = size;
+
        while (size) {
                int len = 1+strlen(buffer);
 
@@ -81,16 +151,140 @@ static void convert_tree(void *buffer, unsigned long size)
                size -= len;
                buffer += len;
        }
+
+       write_subdirectory(orig_buffer, orig_size, "", 0, result_sha1);
+}
+
+static unsigned long parse_oldstyle_date(const char *buf)
+{
+       char c, *p;
+       char buffer[100];
+       struct tm tm;
+       const char *formats[] = {
+               "%c",
+               "%a %b %d %T",
+               "%Z",
+               "%Y",
+               " %Y",
+               NULL
+       };
+       /* We only ever did two timezones in the bad old format .. */
+       const char *timezones[] = {
+               "PDT", "PST", 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);
+               if (next) {
+                       if (!*next)
+                               return mktime(&tm);
+                       buf = next;
+               } else {
+                       const char **p = timezones;
+                       while (isspace(*buf))
+                               buf++;
+                       while (*p) {
+                               if (!memcmp(buf, *p, strlen(*p))) {
+                                       buf += strlen(*p);
+                                       break;
+                               }
+                               p++;
+                       }
+               }
+               fmt++;
+       } while (*buf && *fmt);
+       printf("left: %s\n", buf);
+       return mktime(&tm);                             
+}
+
+static int convert_date_line(char *dst, void **buf, unsigned long *sp)
+{
+       unsigned long size = *sp;
+       char *line = *buf;
+       char *next = strchr(line, '\n');
+       char *date = strchr(line, '>');
+       int len;
+
+       if (!next || !date)
+               die("missing or bad author/committer line %s", line);
+       next++; date += 2;
+
+       *buf = next;
+       *sp = size - (next - line);
+
+       len = date - line;
+       memcpy(dst, line, len);
+       dst += len;
+
+       /* Is it already in new format? */
+       if (isdigit(*date)) {
+               int datelen = next - date;
+               memcpy(dst, date, datelen);
+               printf("new format date '%.*s'?\n", datelen-1, date);
+               return len + datelen;
+       }
+
+       return len + sprintf(dst, "%lu -0700\n", parse_oldstyle_date(date));
 }
 
-static void convert_commit(void *buffer, unsigned long size)
+static void convert_date(void *buffer, unsigned long size, unsigned char *result_sha1)
 {
+       char *new = malloc(size + ORIG_OFFSET + 100);
+       unsigned long newlen = ORIG_OFFSET;
+       int i;
+
+       // "tree <sha1>\n"
+       memcpy(new + newlen, buffer, 46);
+       newlen += 46;
+       buffer += 46;
+       size -= 46;
+
+       // "parent <sha1>\n"
+       while (!memcmp(buffer, "parent ", 7)) {
+               memcpy(new + newlen, buffer, 48);
+               newlen += 48;
+               buffer += 48;
+               size -= 48;
+       }
+
+       // "author xyz <xyz> date"
+       newlen += convert_date_line(new + newlen, &buffer, &size);
+       // "committer xyz <xyz> date"
+       newlen += convert_date_line(new + newlen, &buffer, &size);
+
+       // Rest
+       memcpy(new + newlen, buffer, size);
+       newlen += size;
+
+       i = prepend_integer(new, newlen - ORIG_OFFSET, ORIG_OFFSET);
+       i -= 7;
+       memcpy(new + i, "commit ", 7);
+
+       write_sha1_file(new + i, newlen - i, result_sha1);
+       free(new);      
+}
+
+static void convert_commit(void *buffer, unsigned long size, unsigned char *result_sha1)
+{
+       void *orig_buffer = buffer;
+       unsigned long orig_size = size;
+
        convert_ascii_sha1(buffer+5);
        buffer += 46;    /* "tree " + "hex sha1" + "\n" */
        while (!memcmp(buffer, "parent ", 7)) {
                convert_ascii_sha1(buffer+7);
                buffer += 48;
        }
+       convert_date(orig_buffer, orig_size, result_sha1);
 }
 
 static struct entry * convert_entry(unsigned char *sha1)
@@ -110,15 +304,14 @@ static struct entry * convert_entry(unsigned char *sha1)
        offset = sprintf(buffer, "%s %lu", type, size)+1;
        memcpy(buffer + offset, data, size);
        
-       if (!strcmp(type, "blob"))
-               convert_blob(buffer + offset, size);
-       else if (!strcmp(type, "tree"))
-               convert_tree(buffer + offset, size);
+       if (!strcmp(type, "blob")) {
+               write_sha1_file(buffer, size + offset, entry->new_sha1);
+       } else if (!strcmp(type, "tree"))
+               convert_tree(buffer + offset, size, entry->new_sha1);
        else if (!strcmp(type, "commit"))
-               convert_commit(buffer + offset, size);
+               convert_commit(buffer + offset, size, entry->new_sha1);
        else
                die("unknown object type '%s' in %s", type, sha1_to_hex(sha1));
-       write_sha1_file(buffer, size + offset, entry->new_sha1);
        entry->converted = 1;
        free(buffer);
        return entry;