]> git.sesse.net Git - cubemap/blobdiff - httpinput.cpp
Use C++11 std::mutex and std::lock_guard instead of our RAII wrapper.
[cubemap] / httpinput.cpp
index f92ac13ca9ca010f1b2a8efb2d45cba68c40b12f..05ff37ce4ab2c1032a251a8a574d1741c854f17d 100644 (file)
@@ -1,4 +1,3 @@
-#include <stdio.h>
 #include <assert.h>
 #include <errno.h>
 #include <netdb.h>
@@ -9,7 +8,10 @@
 #include <string.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
+#include <sys/time.h>
+#include <time.h>
 #include <unistd.h>
+#include <math.h>
 #include <map>
 #include <string>
 #include <utility>
 
 #include "httpinput.h"
 #include "log.h"
-#include "metacube.h"
+#include "metacube2.h"
 #include "parse.h"
 #include "serverpool.h"
 #include "state.pb.h"
+#include "stream.h"
+#include "timespec.h"
 #include "util.h"
 #include "version.h"
 
 using namespace std;
 
+namespace {
+
+string host_header(const string &host, const string &port)
+{
+       if (port == "http" || atoi(port.c_str()) == 80) {
+               return host;
+       } else {
+               return host + ":" + port;
+       }
+}
+
+}  // namespace
+
 extern ServerPool *servers;
-         
-HTTPInput::HTTPInput(const string &url)
+
+HTTPInput::HTTPInput(const string &url, Input::Encoding encoding)
        : state(NOT_CONNECTED),
          url(url),
-         has_metacube_header(false),
-         sock(-1)
+         encoding(encoding)
 {
+       stats.url = url;
+       stats.bytes_received = 0;
+       stats.data_bytes_received = 0;
+       stats.metadata_bytes_received = 0;
+       stats.connect_time = -1;
+       stats.latency_sec = HUGE_VAL;
 }
 
 HTTPInput::HTTPInput(const InputProto &serialized)
        : state(State(serialized.state())),
          url(serialized.url()),
+         encoding(serialized.is_metacube_encoded() ?
+                  Input::INPUT_ENCODING_METACUBE :
+                  Input::INPUT_ENCODING_RAW),
          request(serialized.request()),
          request_bytes_sent(serialized.request_bytes_sent()),
          response(serialized.response()),
          http_header(serialized.http_header()),
+         stream_header(serialized.stream_header()),
          has_metacube_header(serialized.has_metacube_header()),
          sock(serialized.sock())
 {
        pending_data.resize(serialized.pending_data().size());
        memcpy(&pending_data[0], serialized.pending_data().data(), serialized.pending_data().size());
 
-       string protocol;
-       parse_url(url, &protocol, &host, &port, &path);  // Don't care if it fails.
+       string protocol, user;
+       parse_url(url, &protocol, &user, &host, &port, &path);  // Don't care if it fails.
 
-       // Older versions stored the extra \r\n in the HTTP header.
-       // Strip it if we find it.
-       if (http_header.size() >= 4 &&
-           memcmp(http_header.data() + http_header.size() - 4, "\r\n\r\n", 4) == 0) {
-               http_header.resize(http_header.size() - 2);
+       stats.url = url;
+       stats.bytes_received = serialized.bytes_received();
+       stats.data_bytes_received = serialized.data_bytes_received();
+       stats.metadata_bytes_received = serialized.metadata_bytes_received();
+       if (serialized.has_connect_time()) {
+               stats.connect_time = serialized.connect_time();
+       } else {
+               stats.connect_time = time(nullptr);
        }
+       if (serialized.has_latency_sec()) {
+               stats.latency_sec = serialized.latency_sec();
+       } else {
+               stats.latency_sec = HUGE_VAL;
+       }
+
+       last_verbose_connection.tv_sec = -3600;
+       last_verbose_connection.tv_nsec = 0;
 }
 
 void HTTPInput::close_socket()
 {
-       safe_close(sock);
+       if (sock != -1) {
+               safe_close(sock);
+               sock = -1;
+       }
+
+       lock_guard<mutex> lock(stats_mutex);
+       stats.connect_time = -1;
 }
 
 InputProto HTTPInput::serialize() const
@@ -74,27 +117,41 @@ InputProto HTTPInput::serialize() const
        serialized.set_request_bytes_sent(request_bytes_sent);
        serialized.set_response(response);
        serialized.set_http_header(http_header);
+       serialized.set_stream_header(stream_header);
        serialized.set_pending_data(string(pending_data.begin(), pending_data.end()));
        serialized.set_has_metacube_header(has_metacube_header);
        serialized.set_sock(sock);
+       serialized.set_bytes_received(stats.bytes_received);
+       serialized.set_data_bytes_received(stats.data_bytes_received);
+       if (isfinite(stats.latency_sec)) {
+               serialized.set_latency_sec(stats.latency_sec);
+       }
+       serialized.set_connect_time(stats.connect_time);
+       if (encoding == Input::INPUT_ENCODING_METACUBE) {
+               serialized.set_is_metacube_encoded(true);
+       } else {
+               assert(encoding == Input::INPUT_ENCODING_RAW);
+               serialized.set_is_metacube_encoded(false);
+       }
        return serialized;
 }
 
 int HTTPInput::lookup_and_connect(const string &host, const string &port)
 {
        addrinfo *ai;
-       int err = getaddrinfo(host.c_str(), port.c_str(), NULL, &ai);
-       if (err == -1) {
-               log(WARNING, "[%s] Lookup of '%s' failed (%s).",
-                       url.c_str(), host.c_str(), gai_strerror(err));
-               freeaddrinfo(ai);
+       int err = getaddrinfo(host.c_str(), port.c_str(), nullptr, &ai);
+       if (err != 0) {
+               if (!suppress_logging) {
+                       log(WARNING, "[%s] Lookup of '%s' failed (%s).",
+                               url.c_str(), host.c_str(), gai_strerror(err));
+               }
                return -1;
        }
 
        addrinfo *base_ai = ai;
 
        // Connect to everything in turn until we have a socket.
-       while (ai && !should_stop()) {
+       for ( ; ai && !should_stop(); ai = ai->ai_next) {
                int sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
                if (sock == -1) {
                        // Could be e.g. EPROTONOSUPPORT. The show must go on.
@@ -125,7 +182,7 @@ int HTTPInput::lookup_and_connect(const string &host, const string &port)
 
                // Wait for the connect to complete, or an error to happen.
                for ( ;; ) {
-                       bool complete = wait_for_activity(sock, POLLIN | POLLOUT, NULL);
+                       bool complete = wait_for_activity(sock, POLLIN | POLLOUT, nullptr);
                        if (should_stop()) {
                                safe_close(sock);
                                return -1;
@@ -152,63 +209,52 @@ int HTTPInput::lookup_and_connect(const string &host, const string &port)
                }
 
                safe_close(sock);
-               ai = ai->ai_next;
        }
 
        // Give the last one as error.
-       log(WARNING, "[%s] Connect to '%s' failed (%s)",
-               url.c_str(), host.c_str(), strerror(errno));
+       if (!suppress_logging) {
+               log(WARNING, "[%s] Connect to '%s' failed (%s)",
+                       url.c_str(), host.c_str(), strerror(errno));
+       }
        freeaddrinfo(base_ai);
        return -1;
 }
        
-bool HTTPInput::parse_response(const std::string &request)
+bool HTTPInput::parse_response(const string &request)
 {
        vector<string> lines = split_lines(response);
        if (lines.empty()) {
-               log(WARNING, "[%s] Empty HTTP response from input.", url.c_str());
+               if (!suppress_logging) {
+                       log(WARNING, "[%s] Empty HTTP response from input.", url.c_str());
+               }
                return false;
        }
 
        vector<string> first_line_tokens = split_tokens(lines[0]);
        if (first_line_tokens.size() < 2) {
-               log(WARNING, "[%s] Malformed response line '%s' from input.",
-                       url.c_str(), lines[0].c_str());
+               if (!suppress_logging) {
+                       log(WARNING, "[%s] Malformed response line '%s' from input.",
+                               url.c_str(), lines[0].c_str());
+               }
                return false;
        }
 
        int response = atoi(first_line_tokens[1].c_str());
        if (response != 200) {
-               log(WARNING, "[%s] Non-200 response '%s' from input.",
-                       url.c_str(), lines[0].c_str());
+               if (!suppress_logging) {
+                       log(WARNING, "[%s] Non-200 response '%s' from input.",
+                               url.c_str(), lines[0].c_str());
+               }
                return false;
        }
 
-       multimap<string, string> parameters;
-       for (size_t i = 1; i < lines.size(); ++i) {
-               size_t split = lines[i].find(":");
-               if (split == string::npos) {
-                       log(WARNING, "[%s] Ignoring malformed HTTP response line '%s'",
-                               url.c_str(), lines[i].c_str());
-                       continue;
-               }
-
-               string key(lines[i].begin(), lines[i].begin() + split);
-
-               // Skip any spaces after the colon.
-               do {
-                       ++split;
-               } while (split < lines[i].size() && lines[i][split] == ' ');
-
-               string value(lines[i].begin() + split, lines[i].end());
-
-               // Remove “Content-encoding: metacube”.
-               // TODO: Make case-insensitive.
-               if (key == "Content-encoding" && value == "metacube") {
-                       continue;
-               }
+       multimap<string, string> parameters = extract_headers(lines, url);
 
-               parameters.insert(make_pair(key, value));
+       // Remove “Content-encoding: metacube”.
+       // TODO: Make case-insensitive.
+       const auto encoding_it = parameters.find("Content-encoding");
+       if (encoding_it != parameters.end() && encoding_it->second == "metacube") {
+               parameters.erase(encoding_it);
        }
 
        // Change “Server: foo” to “Server: metacube/0.1 (reflecting: foo)”
@@ -217,13 +263,11 @@ bool HTTPInput::parse_response(const std::string &request)
        if (parameters.count("Server") == 0) {
                parameters.insert(make_pair("Server", SERVER_IDENTIFICATION));
        } else {
-               for (multimap<string, string>::iterator it = parameters.begin();
-                    it != parameters.end();
-                    ++it) {
-                       if (it->first != "Server") {
+               for (auto &key_and_value : parameters) {
+                       if (key_and_value.first != "Server") {
                                continue;
                        }
-                       it->second = SERVER_IDENTIFICATION " (reflecting: " + it->second + ")";
+                       key_and_value.second = SERVER_IDENTIFICATION " (reflecting: " + key_and_value.second + ")";
                }
        }
 
@@ -234,14 +278,12 @@ bool HTTPInput::parse_response(const std::string &request)
 
        // Construct the new HTTP header.
        http_header = "HTTP/1.0 200 OK\r\n";
-       for (multimap<string, string>::iterator it = parameters.begin();
-            it != parameters.end();
-            ++it) {
-               http_header.append(it->first + ": " + it->second + "\r\n");
+       for (const auto &key_and_value : parameters) {
+               http_header.append(key_and_value.first + ": " + key_and_value.second + "\r\n");
        }
 
-       for (size_t i = 0; i < stream_ids.size(); ++i) {
-               servers->set_header(stream_ids[i], http_header, "");
+       for (int stream_index : stream_indices) {
+               servers->set_header(stream_index, http_header, stream_header);
        }
 
        return true;
@@ -249,11 +291,45 @@ bool HTTPInput::parse_response(const std::string &request)
 
 void HTTPInput::do_work()
 {
+       timespec last_activity;
+
+       // TODO: Make the timeout persist across restarts.
+       if (state == SENDING_REQUEST || state == RECEIVING_HEADER || state == RECEIVING_DATA) {
+               int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
+               assert(err != -1);
+       }
+
        while (!should_stop()) {
                if (state == SENDING_REQUEST || state == RECEIVING_HEADER || state == RECEIVING_DATA) {
-                       bool activity = wait_for_activity(sock, (state == SENDING_REQUEST) ? POLLOUT : POLLIN, NULL);
-                       if (!activity) {
-                               // Most likely, should_stop was set.
+                       // Give the socket 30 seconds since last activity before we time out.
+                       static const int timeout_secs = 30;
+
+                       timespec now;
+                       int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &now);
+                       assert(err != -1);
+
+                       timespec elapsed = clock_diff(last_activity, now);
+                       if (elapsed.tv_sec >= timeout_secs) {
+                               // Timeout!
+                               if (!suppress_logging) {
+                                       log(ERROR, "[%s] Timeout after %d seconds, closing.", url.c_str(), elapsed.tv_sec);
+                               }
+                               state = CLOSING_SOCKET;
+                               continue;
+                       }
+
+                       // Basically calculate (30 - (now - last_activity)) = (30 + (last_activity - now)).
+                       // Add a second of slack to account for differences between clocks.
+                       timespec timeout = clock_diff(now, last_activity);
+                       timeout.tv_sec += timeout_secs + 1;
+                       assert(timeout.tv_sec > 0 || (timeout.tv_sec >= 0 && timeout.tv_nsec > 0));
+
+                       bool activity = wait_for_activity(sock, (state == SENDING_REQUEST) ? POLLOUT : POLLIN, &timeout);
+                       if (activity) {
+                               err = clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
+                               assert(err != -1);
+                       } else {
+                               // OK. Most likely, should_stop was set, or we have timed out.
                                continue;
                        }
                }
@@ -264,18 +340,46 @@ void HTTPInput::do_work()
                        request_bytes_sent = 0;
                        response.clear();
                        pending_data.clear();
-                       for (size_t i = 0; i < stream_ids.size(); ++i) {
-                               servers->set_header(stream_ids[i], "", "");
+                       has_metacube_header = false;
+                       for (int stream_index : stream_indices) {
+                               servers->set_header(stream_index, "", "");
                        }
 
                        {
-                               string protocol;  // Thrown away.
-                               if (!parse_url(url, &protocol, &host, &port, &path)) {
-                                       log(WARNING, "[%s] Failed to parse URL '%s'", url.c_str(), url.c_str());
+                               string protocol, user;  // Thrown away.
+                               if (!parse_url(url, &protocol, &user, &host, &port, &path)) {
+                                       if (!suppress_logging) {
+                                               log(WARNING, "[%s] Failed to parse URL '%s'", url.c_str(), url.c_str());
+                                       }
                                        break;
                                }
+
+                               // Remove the brackets around IPv6 address literals.
+                               // TODO: See if we can join this with the code in parse_ip_address(),
+                               // or maybe even more it into parse_url().
+                               if (!host.empty() && host[0] == '[' && host[host.size() - 1] == ']') {
+                                       host = host.substr(1, host.size() - 2);
+                               }
                        }
 
+                       if (suppress_logging) {
+                               // See if there's more than one minute since last time we made a connection
+                               // with logging enabled. If so, turn it on again.
+                               timespec now;
+                               int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &now);
+                               assert(err != -1);
+
+                               double elapsed = now.tv_sec - last_verbose_connection.tv_sec +
+                                       1e-9 * (now.tv_nsec - last_verbose_connection.tv_nsec);
+                               if (elapsed > 60.0) {
+                                       suppress_logging = false;
+                               }
+                       }
+                       if (!suppress_logging) {
+                               int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &last_verbose_connection);
+                               assert(err != -1);
+                       }
+                       ++num_connection_attempts;
                        sock = lookup_and_connect(host, port);
                        if (sock != -1) {
                                // Yay, successful connect. Try to set it as nonblocking.
@@ -285,9 +389,13 @@ void HTTPInput::do_work()
                                        state = CLOSING_SOCKET;
                                } else {
                                        state = SENDING_REQUEST;
-                                       request = "GET " + path + " HTTP/1.0\r\nUser-Agent: cubemap\r\n\r\n";
+                                       request = "GET " + path + " HTTP/1.0\r\nHost: " + host_header(host, port) + "\r\nUser-Agent: cubemap\r\n\r\n";
                                        request_bytes_sent = 0;
                                }
+
+                               lock_guard<mutex> lock(stats_mutex);
+                               stats.connect_time = time(nullptr);
+                               clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
                        }
                        break;
                case SENDING_REQUEST: {
@@ -328,8 +436,10 @@ void HTTPInput::do_work()
 
                        if (ret == 0) {
                                // This really shouldn't happen...
-                               log(ERROR, "[%s] Socket unexpectedly closed while reading header",
-                                          url.c_str());
+                               if (!suppress_logging) {
+                                       log(ERROR, "[%s] Socket unexpectedly closed while reading header",
+                                                  url.c_str());
+                               }
                                state = CLOSING_SOCKET;
                                continue;
                        }
@@ -337,7 +447,9 @@ void HTTPInput::do_work()
                        RequestParseStatus status = wait_for_double_newline(&response, buf, ret);
                        
                        if (status == RP_OUT_OF_SPACE) {
-                               log(WARNING, "[%s] Sever sent overlong HTTP response!", url.c_str());
+                               if (!suppress_logging) {
+                                       log(WARNING, "[%s] Server sent overlong HTTP response!", url.c_str());
+                               }
                                state = CLOSING_SOCKET;
                                continue;
                        } else if (status == RP_NOT_FINISHED_YET) {
@@ -350,8 +462,8 @@ void HTTPInput::do_work()
                        if (status == RP_EXTRA_DATA) {
                                char *ptr = static_cast<char *>(
                                        memmem(response.data(), response.size(), "\r\n\r\n", 4));
-                               assert(ptr != NULL);
-                               extra_data = string(ptr, &response[0] + response.size());
+                               assert(ptr != nullptr);
+                               extra_data = string(ptr + 4, &response[0] + response.size());
                                response.resize(ptr - response.data());
                        }
 
@@ -364,8 +476,16 @@ void HTTPInput::do_work()
                                process_data(&extra_data[0], extra_data.size());
                        }
 
-                       log(INFO, "[%s] Connected to '%s', receiving data.",
-                                  url.c_str(), url.c_str());
+                       if (!suppress_logging) {
+                               if (encoding == Input::INPUT_ENCODING_RAW) {
+                                       log(INFO, "[%s] Connected to '%s', receiving raw data.",
+                                                  url.c_str(), url.c_str());
+                               } else {
+                                       assert(encoding == Input::INPUT_ENCODING_METACUBE);
+                                       log(INFO, "[%s] Connected to '%s', receiving data.",
+                                                  url.c_str(), url.c_str());
+                               }
+                       }
                        state = RECEIVING_DATA;
                        break;
                }
@@ -385,12 +505,28 @@ void HTTPInput::do_work()
 
                        if (ret == 0) {
                                // This really shouldn't happen...
-                               log(ERROR, "[%s] Socket unexpectedly closed while reading header",
-                                          url.c_str());
+                               if (!suppress_logging) {
+                                       log(ERROR, "[%s] Socket unexpectedly closed while reading data",
+                                                  url.c_str());
+                               }
                                state = CLOSING_SOCKET;
                                continue;
                        }
 
+                       num_connection_attempts = 0;  // Reset, since we have a successful read.
+                       if (suppress_logging) {
+                               // This was suppressed earlier, so print it out now.
+                               if (encoding == Input::INPUT_ENCODING_RAW) {
+                                       log(INFO, "[%s] Connected to '%s', receiving raw data.",
+                                                  url.c_str(), url.c_str());
+                               } else {
+                                       assert(encoding == Input::INPUT_ENCODING_METACUBE);
+                                       log(INFO, "[%s] Connected to '%s', receiving data.",
+                                                  url.c_str(), url.c_str());
+                               }
+                               suppress_logging = false;
+                       }
+
                        process_data(buf, ret);
                        break;
                }
@@ -407,7 +543,15 @@ void HTTPInput::do_work()
                // or the connection just got closed.
                // The earlier steps have already given the error message, if any.
                if (state == NOT_CONNECTED && !should_stop()) {
-                       log(INFO, "[%s] Waiting 0.2 second and restarting...", url.c_str());
+                       if (!suppress_logging) {
+                               log(INFO, "[%s] Waiting 0.2 seconds and restarting...", url.c_str());
+                       }
+
+                       if (num_connection_attempts >= 3 && !suppress_logging) {
+                               log(INFO, "[%s] %d failed connection attempts, suppressing logging for one minute.",
+                                       url.c_str(), num_connection_attempts);
+                               suppress_logging = true;
+                       }
                        timespec timeout_ts;
                        timeout_ts.tv_sec = 0;
                        timeout_ts.tv_nsec = 200000000;
@@ -418,11 +562,24 @@ void HTTPInput::do_work()
 
 void HTTPInput::process_data(char *ptr, size_t bytes)
 {
+       {
+               lock_guard<mutex> lock(stats_mutex);
+               stats.bytes_received += bytes;
+       }
+
+       if (encoding == Input::INPUT_ENCODING_RAW) {
+               for (int stream_index : stream_indices) {
+                       servers->add_data(stream_index, ptr, bytes, /*metacube_flags=*/0);
+               }
+               return;
+       }
+
+       assert(encoding == Input::INPUT_ENCODING_METACUBE);
        pending_data.insert(pending_data.end(), ptr, ptr + bytes);
 
        for ( ;; ) {
                // If we don't have enough data (yet) for even the Metacube header, just return.
-               if (pending_data.size() < sizeof(metacube_block_header)) {
+               if (pending_data.size() < sizeof(metacube2_block_header)) {
                        return;
                }
 
@@ -431,13 +588,13 @@ void HTTPInput::process_data(char *ptr, size_t bytes)
                if (!has_metacube_header) {
                        char *ptr = static_cast<char *>(
                                memmem(pending_data.data(), pending_data.size(),
-                                      METACUBE_SYNC, strlen(METACUBE_SYNC)));
-                       if (ptr == NULL) {
+                                      METACUBE2_SYNC, strlen(METACUBE2_SYNC)));
+                       if (ptr == nullptr) {
                                // OK, so we didn't find the sync marker. We know then that
                                // we do not have the _full_ marker in the buffer, but we
                                // could have N-1 bytes. Drop everything before that,
                                // and then give up.
-                               drop_pending_data(pending_data.size() - (strlen(METACUBE_SYNC) - 1));
+                               drop_pending_data(pending_data.size() - (strlen(METACUBE2_SYNC) - 1));
                                return;
                        } else {
                                // Yay, we found the header. Drop everything (if anything) before it.
@@ -445,40 +602,72 @@ void HTTPInput::process_data(char *ptr, size_t bytes)
                                has_metacube_header = true;
 
                                // Re-check that we have the entire header; we could have dropped data.
-                               if (pending_data.size() < sizeof(metacube_block_header)) {
+                               if (pending_data.size() < sizeof(metacube2_block_header)) {
                                        return;
                                }
                        }
                }
 
                // Now it's safe to read the header.
-               metacube_block_header *hdr = reinterpret_cast<metacube_block_header *>(pending_data.data());    
-               assert(memcmp(hdr->sync, METACUBE_SYNC, sizeof(hdr->sync)) == 0);
-               uint32_t size = ntohl(hdr->size);
-               uint32_t flags = ntohl(hdr->flags);
+               metacube2_block_header hdr;
+               memcpy(&hdr, pending_data.data(), sizeof(hdr));
+               assert(memcmp(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync)) == 0);
+               uint32_t size = ntohl(hdr.size);
+               uint16_t flags = ntohs(hdr.flags);
+               uint16_t expected_csum = metacube2_compute_crc(&hdr);
+
+               if (expected_csum != ntohs(hdr.csum)) {
+                       log(WARNING, "[%s] Metacube checksum failed (expected 0x%x, got 0x%x), "
+                               "not reading block claiming to be %d bytes (flags=%x).",
+                               url.c_str(), expected_csum, ntohs(hdr.csum),
+                               size, flags);
+
+                       // Drop only the first byte, and let the rest of the code handle resync.
+                       pending_data.erase(pending_data.begin(), pending_data.begin() + 1);
+                       has_metacube_header = false;
+                       continue;
+               }
+               if (size > 10485760) {
+                       log(WARNING, "[%s] Metacube block of %d bytes (flags=%x); corrupted header??",
+                               url.c_str(), size, flags);
+               }
 
                // See if we have the entire block. If not, wait for more data.
-               if (pending_data.size() < sizeof(metacube_block_header) + size) {
+               if (pending_data.size() < sizeof(metacube2_block_header) + size) {
                        return;
                }
 
-               // Send this block on to the data.
-               char *inner_data = pending_data.data() + sizeof(metacube_block_header);
-               if (flags & METACUBE_FLAGS_HEADER) {
-                       string header(inner_data, inner_data + size);
-                       for (size_t i = 0; i < stream_ids.size(); ++i) {
-                               servers->set_header(stream_ids[i], http_header, header);
+               // See if this is a metadata block. If so, we don't want to send it on,
+               // but rather process it ourselves.
+               // TODO: Keep metadata when sending on to other Metacube users.
+               if (flags & METACUBE_FLAGS_METADATA) {
+                       {
+                               lock_guard<mutex> lock(stats_mutex);
+                               stats.metadata_bytes_received += size;
                        }
-               } else { 
-                       for (size_t i = 0; i < stream_ids.size(); ++i) {
-                               servers->add_data(stream_ids[i], inner_data, size);
+                       process_metacube_metadata_block(hdr, pending_data.data() + sizeof(hdr), size);
+               } else {
+                       // Send this block on to the servers.
+                       {
+                               lock_guard<mutex> lock(stats_mutex);
+                               stats.data_bytes_received += size;
+                       }
+                       char *inner_data = pending_data.data() + sizeof(metacube2_block_header);
+                       if (flags & METACUBE_FLAGS_HEADER) {
+                               stream_header = string(inner_data, inner_data + size);
+                               for (int stream_index : stream_indices) {
+                                       servers->set_header(stream_index, http_header, stream_header);
+                               }
+                       }
+                       for (int stream_index : stream_indices) {
+                               servers->add_data(stream_index, inner_data, size, flags);
                        }
                }
 
                // Consume the block. This isn't the most efficient way of dealing with things
                // should we have many blocks, but these routines don't need to be too efficient
                // anyway.
-               pending_data.erase(pending_data.begin(), pending_data.begin() + sizeof(metacube_block_header) + size);
+               pending_data.erase(pending_data.begin(), pending_data.begin() + sizeof(metacube2_block_header) + size);
                has_metacube_header = false;
        }
 }
@@ -488,8 +677,52 @@ void HTTPInput::drop_pending_data(size_t num_bytes)
        if (num_bytes == 0) {
                return;
        }
-       log(WARNING, "[%s] Dropping %lld junk bytes from stream, maybe it is not a Metacube stream?",
+       log(WARNING, "[%s] Dropping %lld junk bytes; not a Metacube2 stream, or data was dropped from the middle of the stream.",
                url.c_str(), (long long)num_bytes);
+       assert(pending_data.size() >= num_bytes);
        pending_data.erase(pending_data.begin(), pending_data.begin() + num_bytes);
 }
 
+void HTTPInput::add_destination(int stream_index)
+{
+       stream_indices.push_back(stream_index);
+       servers->set_header(stream_index, http_header, stream_header);
+}
+
+InputStats HTTPInput::get_stats() const
+{
+       lock_guard<mutex> lock(stats_mutex);
+       return stats;
+}
+
+void HTTPInput::process_metacube_metadata_block(const metacube2_block_header &hdr, const char *payload, uint32_t payload_size)
+{
+       if (payload_size < sizeof(uint64_t)) {
+               log(WARNING, "[%s] Undersized Metacube metadata block (%d bytes); corrupted header?",
+                       url.c_str(), payload_size);
+               return;
+       }
+
+       uint64_t type = be64toh(*(const uint64_t *)payload);
+       if (type != METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP) {
+               // Unknown metadata block, ignore.
+               return;
+       }
+
+       timespec now;
+       clock_gettime(CLOCK_REALTIME, &now);
+
+       const metacube2_timestamp_packet *pkt = (const metacube2_timestamp_packet *)payload;
+       if (payload_size != sizeof(*pkt)) {
+               log(WARNING, "[%s] Metacube timestamp block of wrong size (%d bytes); ignoring.",
+                       url.c_str(), payload_size);
+               return;
+       }
+
+       double elapsed = now.tv_sec - be64toh(pkt->tv_sec) +
+               1e-9 * (now.tv_nsec - long(be64toh(pkt->tv_nsec)));
+       {
+               lock_guard<mutex> lock(stats_mutex);
+               stats.latency_sec = elapsed;
+       }
+}