journal-gatewayd: allow pipelining

The request must not be answered immediately (at first call to
response_handler()), but on the second. This is also important
for authentication, which cannot be performed on the first call.

Before:

% wget -O/dev/null -S https://localhost:19531/
--2012-11-28 18:29:43--  https://localhost:19531/
Resolving localhost (localhost)... 127.0.0.1
Connecting to localhost (localhost)|127.0.0.1|:19531... connected.
HTTP request sent, awaiting response...
  HTTP/1.1 301 Moved Permanently
  Connection: close
  Content-Length: 87
  Location: /browse
  Content-Type: text/html
  Date: Wed, 28 Nov 2012 17:29:44 GMT
Location: /browse [following]
--2012-11-28 18:29:43--  https://localhost:19531/browse
Connecting to localhost (localhost)|127.0.0.1|:19531... connected.
HTTP request sent, awaiting response...
  HTTP/1.1 200 OK
  Connection: close
  Content-Length: 23260
  Content-Type: text/html
  Date: Wed, 28 Nov 2012 17:29:44 GMT
Length: 23260 (23K) [text/html]

After:

% wget --no-check-certificate -O/dev/null -S https://localhost:19531/
--2012-11-28 18:30:05--  https://localhost:19531/
Resolving localhost (localhost)... 127.0.0.1
Connecting to localhost (localhost)|127.0.0.1|:19531... connected.
HTTP request sent, awaiting response...
  HTTP/1.1 301 Moved Permanently
  Content-Length: 87
  Location: /browse
  Content-Type: text/html
  Date: Wed, 28 Nov 2012 17:30:05 GMT
Location: /browse [following]
--2012-11-28 18:30:05--  https://localhost:19531/browse
Reusing existing connection to localhost:19531.
HTTP request sent, awaiting response...
  HTTP/1.1 200 OK
  Content-Length: 23260
  Content-Type: text/html
  Date: Wed, 28 Nov 2012 17:30:06 GMT
Length: 23260 (23K) [text/html]

1 files changed, 18 insertions, 22 deletions

diff --git a/src/journal/journal-gatewayd.c b/src/journal/journal-gatewayd.c
index 613b5394a..23939ccbc 100644
--- a/src/journal/journal-gatewayd.c
+++ b/src/journal/journal-gatewayd.c
@@ -482,18 +482,14 @@ static int request_parse_arguments(
 
 static int request_handler_entries(
                 struct MHD_Connection *connection,
-                void **connection_cls) {
+                void *connection_cls) {
 
         struct MHD_Response *response;
-        RequestMeta *m;
+        RequestMeta *m = connection_cls;
         int r;
 
         assert(connection);
-        assert(connection_cls);
-
-        m = request_meta(connection_cls);
-        if (!m)
-                return respond_oom(connection);
+        assert(m);
 
         r = open_journal(m);
         if (r < 0)
@@ -651,15 +647,11 @@ static int request_handler_fields(
                 void *connection_cls) {
 
         struct MHD_Response *response;
-        RequestMeta *m;
+        RequestMeta *m = connection_cls;
         int r;
 
         assert(connection);
-        assert(connection_cls);
-
-        m = request_meta(connection_cls);
-        if (!m)
-                return respond_oom(connection);
+        assert(m);
 
         r = open_journal(m);
         if (r < 0)
@@ -750,10 +742,10 @@ static int request_handler_file(
 
 static int request_handler_machine(
                 struct MHD_Connection *connection,
-                void **connection_cls) {
+                void *connection_cls) {
 
         struct MHD_Response *response;
-        RequestMeta *m;
+        RequestMeta *m = connection_cls;
         int r;
         _cleanup_free_ char* hostname = NULL, *os_name = NULL;
         uint64_t cutoff_from, cutoff_to, usage;
@@ -762,10 +754,7 @@ static int request_handler_machine(
         const char *v = "bare";
 
         assert(connection);
-
-        m = request_meta(connection_cls);
-        if (!m)
-                return respond_oom(connection);
+        assert(m);
 
         r = open_journal(m);
         if (r < 0)
@@ -840,26 +829,33 @@ static int request_handler(
                 void **connection_cls) {
 
         assert(connection);
+        assert(connection_cls);
         assert(url);
         assert(method);
 
         if (!streq(method, "GET"))
                 return MHD_NO;
 
+        if (!*connection_cls) {
+                if (!request_meta(connection_cls))
+                        return respond_oom(connection);
+                return MHD_YES;
+        }
+
         if (streq(url, "/"))
                 return request_handler_redirect(connection, "/browse");
 
         if (streq(url, "/entries"))
-                return request_handler_entries(connection, connection_cls);
+                return request_handler_entries(connection, *connection_cls);
 
         if (startswith(url, "/fields/"))
-                return request_handler_fields(connection, url + 8, connection_cls);
+                return request_handler_fields(connection, url + 8, *connection_cls);
 
         if (streq(url, "/browse"))
                 return request_handler_file(connection, DOCUMENT_ROOT "/browse.html", "text/html");
 
         if (streq(url, "/machine"))
-                return request_handler_machine(connection, connection_cls);
+                return request_handler_machine(connection, *connection_cls);
 
         return respond_error(connection, MHD_HTTP_NOT_FOUND, "Not found.\n");
 }