parse_object: try internal cache before reading object db

diff --git a/tag.c b/tag.c
index 4470d2bf78e1fbb00d00e487f41daa4373cf48e1..3aa186df628331e74e8a84d3cc2d313f4518a626 100644 (file)
--- a/tag.c
+++ b/tag.c
@@ -4,6 +4,9 @@
 #include "tree.h"
 #include "blob.h"
 
+#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
+#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
+
 const char *tag_type = "tag";
 
 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
@@ -28,51 +31,58 @@ struct tag *lookup_tag(const unsigned char *sha1)
                return create_object(sha1, OBJ_TAG, alloc_tag_node());
        if (!obj->type)
                obj->type = OBJ_TAG;
-        if (obj->type != OBJ_TAG) {
-                error("Object %s is a %s, not a tag",
-                      sha1_to_hex(sha1), typename(obj->type));
-                return NULL;
-        }
-        return (struct tag *) obj;
+       if (obj->type != OBJ_TAG) {
+               error("Object %s is a %s, not a tag",
+                     sha1_to_hex(sha1), typename(obj->type));
+               return NULL;
+       }
+       return (struct tag *) obj;
+}
+
+static unsigned long parse_tag_date(const char *buf, const char *tail)
+{
+       const char *dateptr;
+
+       while (buf < tail && *buf++ != '>')
+               /* nada */;
+       if (buf >= tail)
+               return 0;
+       dateptr = buf;
+       while (buf < tail && *buf++ != '\n')
+               /* nada */;
+       if (buf >= tail)
+               return 0;
+       /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
+       return strtoul(dateptr, NULL, 10);
 }
 
-int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
+int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
 {
-       int typelen, taglen;
        unsigned char sha1[20];
-       const char *type_line, *tag_line, *sig_line;
        char type[20];
-       const char *start = data;
+       const char *bufptr = data;
+       const char *tail = bufptr + size;
+       const char *nl;
 
-        if (item->object.parsed)
-                return 0;
-        item->object.parsed = 1;
+       if (item->object.parsed)
+               return 0;
+       item->object.parsed = 1;
 
        if (size < 64)
                return -1;
-       if (memcmp("object ", data, 7) || get_sha1_hex((char *) data + 7, sha1))
+       if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
                return -1;
+       bufptr += 48; /* "object " + sha1 + "\n" */
 
-       type_line = (char *) data + 48;
-       if (memcmp("\ntype ", type_line-1, 6))
+       if (prefixcmp(bufptr, "type "))
                return -1;
-
-       tag_line = memchr(type_line, '\n', size - (type_line - start));
-       if (!tag_line || memcmp("tag ", ++tag_line, 4))
+       bufptr += 5;
+       nl = memchr(bufptr, '\n', tail - bufptr);
+       if (!nl || sizeof(type) <= (nl - bufptr))
                return -1;
-
-       sig_line = memchr(tag_line, '\n', size - (tag_line - start));
-       if (!sig_line)
-               return -1;
-       sig_line++;
-
-       typelen = tag_line - type_line - strlen("type \n");
-       if (typelen >= 20)
-               return -1;
-       memcpy(type, type_line + 5, typelen);
-       type[typelen] = '\0';
-       taglen = sig_line - tag_line - strlen("tag \n");
-       item->tag = xmemdupz(tag_line + 4, taglen);
+       strncpy(type, bufptr, nl - bufptr);
+       type[nl - bufptr] = '\0';
+       bufptr = nl + 1;
 
        if (!strcmp(type, blob_type)) {
                item->tagged = &lookup_blob(sha1)->object;
@@ -87,6 +97,22 @@ int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
                item->tagged = NULL;
        }
 
+       if (bufptr + 4 < tail && !prefixcmp(bufptr, "tag "))
+               ;               /* good */
+       else
+               return -1;
+       bufptr += 4;
+       nl = memchr(bufptr, '\n', tail - bufptr);
+       if (!nl)
+               return -1;
+       item->tag = xmemdupz(bufptr, nl - bufptr);
+       bufptr = nl + 1;
+
+       if (bufptr + 7 < tail && !prefixcmp(bufptr, "tagger "))
+               item->date = parse_tag_date(bufptr, tail);
+       else
+               item->date = 0;
+
        return 0;
 }
 
@@ -112,3 +138,20 @@ int parse_tag(struct tag *item)
        free(data);
        return ret;
 }
+
+/*
+ * Look at a signed tag object, and return the offset where
+ * the embedded detached signature begins, or the end of the
+ * data when there is no such signature.
+ */
+size_t parse_signature(const char *buf, unsigned long size)
+{
+       char *eol;
+       size_t len = 0;
+       while (len < size && prefixcmp(buf + len, PGP_SIGNATURE) &&
+                       prefixcmp(buf + len, PGP_MESSAGE)) {
+               eol = memchr(buf + len, '\n', size - len);
+               len += eol ? eol - (buf + len) + 1 : size - len;
+       }
+       return len;
+}