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