Unify httpd.cpp from Nageru and Futatabi (whitespace differences, and metrics support).

[nageru] / shared / httpd.h

diff --git a/shared/httpd.h b/shared/httpd.h
new file mode 100644 (file)
index 0000000..5b2b266
--- /dev/null
+++ b/shared/httpd.h
@@ -0,0 +1,118 @@
+#ifndef _HTTPD_H
+#define _HTTPD_H
+
+// A class dealing with stream output to HTTP.
+
+#include <atomic>
+#include <condition_variable>
+#include <deque>
+#include <functional>
+#include <mutex>
+#include <set>
+#include <stddef.h>
+#include <stdint.h>
+#include <string>
+#include <sys/types.h>
+#include <unordered_map>
+#include <utility>
+
+extern "C" {
+#include <libavutil/rational.h>
+}
+
+struct MHD_Connection;
+struct MHD_Daemon;
+
+class HTTPD {
+public:
+       // Returns a pair of content and content-type.
+       using EndpointCallback = std::function<std::pair<std::string, std::string>()>;
+
+       HTTPD();
+       ~HTTPD();
+
+       // Should be called before start().
+       void set_header(const std::string &data)
+       {
+               header = data;
+       }
+
+       // Should be called before start() (due to threading issues).
+       enum CORSPolicy {
+               NO_CORS_POLICY,
+               ALLOW_ALL_ORIGINS
+       };
+       void add_endpoint(const std::string &url, const EndpointCallback &callback, CORSPolicy cors_policy)
+       {
+               endpoints[url] = Endpoint{ callback, cors_policy };
+       }
+
+       void start(int port);
+       void stop();
+       void add_data(const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase);
+       int64_t get_num_connected_clients() const
+       {
+               return metric_num_connected_clients.load();
+       }
+
+private:
+       static int answer_to_connection_thunk(void *cls, MHD_Connection *connection,
+                                             const char *url, const char *method,
+                                             const char *version, const char *upload_data,
+                                             size_t *upload_data_size, void **con_cls);
+
+       int answer_to_connection(MHD_Connection *connection,
+                                const char *url, const char *method,
+                                const char *version, const char *upload_data,
+                                size_t *upload_data_size, void **con_cls);
+
+       static void free_stream(void *cls);
+
+       class Stream {
+       public:
+               enum Framing {
+                       FRAMING_RAW,
+                       FRAMING_METACUBE
+               };
+               Stream(HTTPD *parent, Framing framing)
+                       : parent(parent), framing(framing) {}
+
+               static ssize_t reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max);
+               ssize_t reader_callback(uint64_t pos, char *buf, size_t max);
+
+               enum DataType {
+                       DATA_TYPE_HEADER,
+                       DATA_TYPE_KEYFRAME,
+                       DATA_TYPE_OTHER
+               };
+               void add_data(const char *buf, size_t size, DataType data_type, int64_t time, AVRational timebase);
+               void stop();
+               HTTPD *get_parent() const { return parent; }
+
+       private:
+               HTTPD *parent;
+               Framing framing;
+
+               std::mutex buffer_mutex;
+               bool should_quit = false;  // Under <buffer_mutex>.
+               std::condition_variable has_buffered_data;
+               std::deque<std::string> buffered_data;  // Protected by <buffer_mutex>.
+               size_t used_of_buffered_data = 0;  // How many bytes of the first element of <buffered_data> that is already used. Protected by <mutex>.
+               size_t seen_keyframe = false;
+       };
+
+       MHD_Daemon *mhd = nullptr;
+       std::mutex streams_mutex;
+       std::set<Stream *> streams;  // Not owned.
+       struct Endpoint {
+               EndpointCallback callback;
+               CORSPolicy cors_policy;
+       };
+       std::unordered_map<std::string, Endpoint> endpoints;
+       std::string header;
+
+       // Metrics.
+       std::atomic<int64_t> metric_num_connected_clients{ 0 };
+};
+
+#endif  // !defined(_HTTPD_H)