Add an HTTP endpoint for enumerating channels and one for getting only their colors...

[nageru] / httpd.cpp

diff --git a/httpd.cpp b/httpd.cpp
index 858d9522c9354f1ea275cd0e859e5fef60d30636..811e095dc9541a442742e02c7d7454b0284cc207 100644 (file)
--- a/httpd.cpp
+++ b/httpd.cpp
@@ -13,6 +13,7 @@
 
 #include "defs.h"
 #include "metacube2.h"
+#include "metrics.h"
 
 struct MHD_Connection;
 struct MHD_Response;
@@ -21,6 +22,7 @@ using namespace std;
 
 HTTPD::HTTPD()
 {
+       global_metrics.add("num_connected_clients", &metric_num_connected_clients, Metrics::TYPE_GAUGE);
 }
 
 HTTPD::~HTTPD()
@@ -77,22 +79,42 @@ int HTTPD::answer_to_connection(MHD_Connection *connection,
                framing = HTTPD::Stream::FRAMING_RAW;
        }
 
+       if (strcmp(url, "/metrics") == 0) {
+               string contents = global_metrics.serialize();
+               MHD_Response *response = MHD_create_response_from_buffer(
+                       contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
+               MHD_add_response_header(response, "Content-type", "text/plain");
+               int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
+               MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
+               return ret;
+       }
+       if (endpoints.count(url)) {
+               pair<string, string> contents_and_type = endpoints[url]();
+               MHD_Response *response = MHD_create_response_from_buffer(
+                       contents_and_type.first.size(), &contents_and_type.first[0], MHD_RESPMEM_MUST_COPY);
+               MHD_add_response_header(response, "Content-type", contents_and_type.second.c_str());
+               int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
+               MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
+               return ret;
+       }
+
        HTTPD::Stream *stream = new HTTPD::Stream(this, framing);
        stream->add_data(header.data(), header.size(), Stream::DATA_TYPE_HEADER);
        {
                unique_lock<mutex> lock(streams_mutex);
                streams.insert(stream);
        }
+       ++metric_num_connected_clients;
        *con_cls = stream;
 
        // Does not strictly have to be equal to MUX_BUFFER_SIZE.
        MHD_Response *response = MHD_create_response_from_callback(
                (size_t)-1, MUX_BUFFER_SIZE, &HTTPD::Stream::reader_callback_thunk, stream, &HTTPD::free_stream);
-
        // TODO: Content-type?
        if (framing == HTTPD::Stream::FRAMING_METACUBE) {
                MHD_add_response_header(response, "Content-encoding", "metacube");
        }
+
        int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
        MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 
@@ -108,6 +130,7 @@ void HTTPD::free_stream(void *cls)
                delete stream;
                httpd->streams.erase(stream);
        }
+       --httpd->metric_num_connected_clients;
 }
 
 ssize_t HTTPD::Stream::reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max)