git.sesse.net Git - nageru/blob - httpd.cpp

   1 #include "httpd.h"
   2
   3 #include <assert.h>
   4 #include <byteswap.h>
   5 #include <endian.h>
   6 #include <microhttpd.h>
   7 #include <netinet/in.h>
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <sys/time.h>
  11 #include <time.h>
  12 #include <memory>
  13
  14 #include "defs.h"
  15 #include "metacube2.h"
  16 #include "metrics.h"
  17
  18 struct MHD_Connection;
  19 struct MHD_Response;
  20
  21 using namespace std;
  22
  23 HTTPD::HTTPD()
  24 {
  25         global_metrics.add("num_connected_clients", &metric_num_connected_clients, Metrics::TYPE_GAUGE);
  26 }
  27
  28 HTTPD::~HTTPD()
  29 {
  30         if (mhd) {
  31                 MHD_quiesce_daemon(mhd);
  32                 for (Stream *stream : streams) {
  33                         stream->stop();
  34                 }
  35                 MHD_stop_daemon(mhd);
  36         }
  37 }
  38
  39 void HTTPD::start(int port)
  40 {
  41         mhd = MHD_start_daemon(MHD_USE_THREAD_PER_CONNECTION | MHD_USE_POLL_INTERNALLY | MHD_USE_DUAL_STACK,
  42                                port,
  43                                nullptr, nullptr,
  44                                &answer_to_connection_thunk, this,
  45                                MHD_OPTION_NOTIFY_COMPLETED, nullptr, this,
  46                                MHD_OPTION_END);
  47         if (mhd == nullptr) {
  48                 fprintf(stderr, "Warning: Could not open HTTP server. (Port already in use?)\n");
  49         }
  50 }
  51
  52 void HTTPD::add_data(const char *buf, size_t size, bool keyframe)
  53 {
  54         unique_lock<mutex> lock(streams_mutex);
  55         for (Stream *stream : streams) {
  56                 stream->add_data(buf, size, keyframe ? Stream::DATA_TYPE_KEYFRAME : Stream::DATA_TYPE_OTHER);
  57         }
  58 }
  59
  60 int HTTPD::answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  61                                       const char *url, const char *method,
  62                                       const char *version, const char *upload_data,
  63                                       size_t *upload_data_size, void **con_cls)
  64 {
  65         HTTPD *httpd = (HTTPD *)cls;
  66         return httpd->answer_to_connection(connection, url, method, version, upload_data, upload_data_size, con_cls);
  67 }
  68
  69 int HTTPD::answer_to_connection(MHD_Connection *connection,
  70                                 const char *url, const char *method,
  71                                 const char *version, const char *upload_data,
  72                                 size_t *upload_data_size, void **con_cls)
  73 {
  74         // See if the URL ends in “.metacube”.
  75         HTTPD::Stream::Framing framing;
  76         if (strstr(url, ".metacube") == url + strlen(url) - strlen(".metacube")) {
  77                 framing = HTTPD::Stream::FRAMING_METACUBE;
  78         } else {
  79                 framing = HTTPD::Stream::FRAMING_RAW;
  80         }
  81
  82         if (strcmp(url, "/metrics") == 0) {
  83                 string contents = global_metrics.serialize();
  84                 MHD_Response *response = MHD_create_response_from_buffer(
  85                         contents.size(), &contents[0], MHD_RESPMEM_MUST_COPY);
  86                 MHD_add_response_header(response, "Content-type", "text/plain");
  87                 int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
  88                 MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
  89                 return ret;
  90         }
  91
  92         HTTPD::Stream *stream = new HTTPD::Stream(this, framing);
  93         stream->add_data(header.data(), header.size(), Stream::DATA_TYPE_HEADER);
  94         {
  95                 unique_lock<mutex> lock(streams_mutex);
  96                 streams.insert(stream);
  97         }
  98         ++metric_num_connected_clients;
  99         *con_cls = stream;
 100
 101         // Does not strictly have to be equal to MUX_BUFFER_SIZE.
 102         MHD_Response *response = MHD_create_response_from_callback(
 103                 (size_t)-1, MUX_BUFFER_SIZE, &HTTPD::Stream::reader_callback_thunk, stream, &HTTPD::free_stream);
 104         // TODO: Content-type?
 105         if (framing == HTTPD::Stream::FRAMING_METACUBE) {
 106                 MHD_add_response_header(response, "Content-encoding", "metacube");
 107         }
 108
 109         int ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
 110         MHD_destroy_response(response);  // Only decreases the refcount; actual free is after the request is done.
 111
 112         return ret;
 113 }
 114
 115 void HTTPD::free_stream(void *cls)
 116 {
 117         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 118         HTTPD *httpd = stream->get_parent();
 119         {
 120                 unique_lock<mutex> lock(httpd->streams_mutex);
 121                 delete stream;
 122                 httpd->streams.erase(stream);
 123         }
 124         --httpd->metric_num_connected_clients;
 125 }
 126
 127 ssize_t HTTPD::Stream::reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max)
 128 {
 129         HTTPD::Stream *stream = (HTTPD::Stream *)cls;
 130         return stream->reader_callback(pos, buf, max);
 131 }
 132
 133 ssize_t HTTPD::Stream::reader_callback(uint64_t pos, char *buf, size_t max)
 134 {
 135         unique_lock<mutex> lock(buffer_mutex);
 136         has_buffered_data.wait(lock, [this]{ return should_quit || !buffered_data.empty(); });
 137         if (should_quit) {
 138                 return 0;
 139         }
 140
 141         ssize_t ret = 0;
 142         while (max > 0 && !buffered_data.empty()) {
 143                 const string &s = buffered_data.front();
 144                 assert(s.size() > used_of_buffered_data);
 145                 size_t len = s.size() - used_of_buffered_data;
 146                 if (max >= len) {
 147                         // Consume the entire (rest of the) string.
 148                         memcpy(buf, s.data() + used_of_buffered_data, len);
 149                         buf += len;
 150                         ret += len;
 151                         max -= len;
 152                         buffered_data.pop_front();
 153                         used_of_buffered_data = 0;
 154                 } else {
 155                         // We don't need the entire string; just use the first part of it.
 156                         memcpy(buf, s.data() + used_of_buffered_data, max);
 157                         buf += max;
 158                         used_of_buffered_data += max;
 159                         ret += max;
 160                         max = 0;
 161                 }
 162         }
 163
 164         return ret;
 165 }
 166
 167 void HTTPD::Stream::add_data(const char *buf, size_t buf_size, HTTPD::Stream::DataType data_type)
 168 {
 169         if (buf_size == 0) {
 170                 return;
 171         }
 172         if (data_type == DATA_TYPE_KEYFRAME) {
 173                 seen_keyframe = true;
 174         } else if (data_type == DATA_TYPE_OTHER && !seen_keyframe) {
 175                 // Start sending only once we see a keyframe.
 176                 return;
 177         }
 178
 179         unique_lock<mutex> lock(buffer_mutex);
 180
 181         if (framing == FRAMING_METACUBE) {
 182                 metacube2_block_header hdr;
 183                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 184                 hdr.size = htonl(buf_size);
 185                 int flags = 0;
 186                 if (data_type == DATA_TYPE_HEADER) {
 187                         flags |= METACUBE_FLAGS_HEADER;
 188                 } else if (data_type == DATA_TYPE_OTHER) {
 189                         flags |= METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START;
 190                 }
 191                 hdr.flags = htons(flags);
 192                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 193                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 194         }
 195         buffered_data.emplace_back(buf, buf_size);
 196
 197         // Send a Metacube2 timestamp every keyframe.
 198         if (framing == FRAMING_METACUBE && data_type == DATA_TYPE_KEYFRAME) {
 199                 timespec now;
 200                 clock_gettime(CLOCK_REALTIME, &now);
 201
 202                 metacube2_timestamp_packet packet;
 203                 packet.type = htobe64(METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP);
 204                 packet.tv_sec = htobe64(now.tv_sec);
 205                 packet.tv_nsec = htobe64(now.tv_nsec);
 206
 207                 metacube2_block_header hdr;
 208                 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
 209                 hdr.size = htonl(sizeof(packet));
 210                 hdr.flags = htons(METACUBE_FLAGS_METADATA);
 211                 hdr.csum = htons(metacube2_compute_crc(&hdr));
 212                 buffered_data.emplace_back((char *)&hdr, sizeof(hdr));
 213                 buffered_data.emplace_back((char *)&packet, sizeof(packet));
 214         }
 215
 216         has_buffered_data.notify_all();
 217 }
 218
 219 void HTTPD::Stream::stop()
 220 {
 221         unique_lock<mutex> lock(buffer_mutex);
 222         should_quit = true;
 223         has_buffered_data.notify_all();
 224 }