From 488a214a81a25c6397c56822ed1713f51dddc520 Mon Sep 17 00:00:00 2001
From: Lars Hjemli <hjemli@gmail.com>
Date: Thu, 19 Feb 2009 22:38:36 +0100
Subject: 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>

diff --git a/cgit.c b/cgit.c
index 64d95f9..411e421 100644
--- a/cgit.c
+++ b/cgit.c
@@ -206,6 +206,7 @@ static void prepare_context(struct cgit_context *ctx)
 	ctx->page.size = 0;
 	ctx->page.modified = time(NULL);
 	ctx->page.expires = ctx->page.modified;
+	ctx->page.etag = NULL;
 }
 
 struct refmatch {
diff --git a/cgit.h b/cgit.h
index 5f7af51..2bfbe7b 100644
--- a/cgit.h
+++ b/cgit.h
@@ -180,6 +180,7 @@ struct cgit_page {
 	char *mimetype;
 	char *charset;
 	char *filename;
+	char *etag;
 	char *title;
 };
 
diff --git a/ui-plain.c b/ui-plain.c
index 5addd9e..f73cd14 100644
--- a/ui-plain.c
+++ b/ui-plain.c
@@ -34,6 +34,7 @@ static void print_object(const unsigned char *sha1, const char *path)
 	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;
diff --git a/ui-shared.c b/ui-shared.c
index de77bbf..86a7d29 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -468,6 +468,8 @@ void cgit_print_http_headers(struct cgit_context *ctx)
 		      ctx->page.filename);
 	htmlf("Last-Modified: %s\n", http_date(ctx->page.modified));
 	htmlf("Expires: %s\n", http_date(ctx->page.expires));
+	if (ctx->page.etag)
+		htmlf("ETag: \"%s\"\n", ctx->page.etag);
 	html("\n");
 }
 
-- 
cgit v0.10.1


From 3ff58ddd51bcbcbc9b7649bad1a39aa98af4b49f Mon Sep 17 00:00:00 2001
From: Lars Hjemli <hjemli@gmail.com>
Date: Thu, 19 Feb 2009 23:24:15 +0100
Subject: Add support for HEAD requests

This is a quick 'n dirty hack which makes cgit honor HEAD requests.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

diff --git a/cgit.c b/cgit.c
index 411e421..dc1c2e4 100644
--- a/cgit.c
+++ b/cgit.c
@@ -430,6 +430,7 @@ static int calc_ttl()
 int main(int argc, const char **argv)
 {
 	const char *cgit_config_env = getenv("CGIT_CONFIG");
+	const char *method = getenv("REQUEST_METHOD");
 	const char *path;
 	char *qry;
 	int err, ttl;
@@ -476,6 +477,8 @@ int main(int argc, const char **argv)
 
 	ttl = calc_ttl();
 	ctx.page.expires += ttl*60;
+	if (method && !strcmp(method, "HEAD"))
+		ctx.cfg.nocache = 1;
 	if (ctx.cfg.nocache)
 		ctx.cfg.cache_size = 0;
 	err = cache_process(ctx.cfg.cache_size, ctx.cfg.cache_root,
diff --git a/ui-shared.c b/ui-shared.c
index 86a7d29..0dafc83 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -456,6 +456,8 @@ void cgit_print_age(time_t t, time_t max_relative, char *format)
 
 void cgit_print_http_headers(struct cgit_context *ctx)
 {
+	const char *method = getenv("REQUEST_METHOD");
+
 	if (ctx->page.mimetype && ctx->page.charset)
 		htmlf("Content-Type: %s; charset=%s\n", ctx->page.mimetype,
 		      ctx->page.charset);
@@ -471,6 +473,8 @@ void cgit_print_http_headers(struct cgit_context *ctx)
 	if (ctx->page.etag)
 		htmlf("ETag: \"%s\"\n", ctx->page.etag);
 	html("\n");
+	if (method && !strcmp(method, "HEAD"))
+		exit(0);
 }
 
 void cgit_print_docstart(struct cgit_context *ctx)
-- 
cgit v0.10.1