Add support for ETag in 'plain' view

When downloading a blob identified by its path, the client might want
to know if the blob has been modified since a previous download of the
same path. To this end, an ETag containing the blob SHA1 seems to be
ideal.

Todo: add support for HEAD requests...

Suggested-by: Owen Taylor <otaylor@redhat.com>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/ui-plain.c b/ui-plain.c
index 5addd9e..f73cd14 100644
--- a/ui-plain.c
+++ b/ui-plain.c
@@ -1,79 +1,80 @@
 /* ui-plain.c: functions for output of plain blobs by path
  *
  * Copyright (C) 2008 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 #include "html.h"
 #include "ui-shared.h"
 
 char *curr_rev;
 char *match_path;
 int match;
 
 static void print_object(const unsigned char *sha1, const char *path)
 {
         enum object_type type;
         char *buf;
         unsigned long size;
 
         type = sha1_object_info(sha1, &size);
         if (type == OBJ_BAD) {
                 html_status(404, "Not found", 0);
                 return;
         }
 
         buf = read_sha1_file(sha1, &type, &size);
         if (!buf) {
                 html_status(404, "Not found", 0);
                 return;
         }
         ctx.page.mimetype = "text/plain";
         ctx.page.filename = fmt("%s", path);
         ctx.page.size = size;
+        ctx.page.etag = sha1_to_hex(sha1);
         cgit_print_http_headers(&ctx);
         html_raw(buf, size);
         match = 1;
 }
 
 static int walk_tree(const unsigned char *sha1, const char *base, int baselen,
                      const char *pathname, unsigned mode, int stage,
                      void *cbdata)
 {
         if (S_ISDIR(mode))
                 return READ_TREE_RECURSIVE;
 
         if (S_ISREG(mode))
                 print_object(sha1, pathname);
 
         return 0;
 }
 
 void cgit_print_plain(struct cgit_context *ctx)
 {
         const char *rev = ctx->qry.sha1;
         unsigned char sha1[20];
         struct commit *commit;
         const char *paths[] = {ctx->qry.path, NULL};
 
         if (!rev)
                 rev = ctx->qry.head;
 
         curr_rev = xstrdup(rev);
         if (get_sha1(rev, sha1)) {
                 html_status(404, "Not found", 0);
                 return;
         }
         commit = lookup_commit_reference(sha1);
         if (!commit || parse_commit(commit)) {
                 html_status(404, "Not found", 0);
                 return;
         }
         match_path = ctx->qry.path;
         read_tree_recursive(commit->tree, NULL, 0, 0, paths, walk_tree, NULL);
         if (!match)
                 html_status(404, "Not found", 0);
 }