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-rw-r--r--src/client/clientmedia.cpp639
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diff --git a/src/client/clientmedia.cpp b/src/client/clientmedia.cpp
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+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "clientmedia.h"
+#include "httpfetch.h"
+#include "client.h"
+#include "filecache.h"
+#include "filesys.h"
+#include "log.h"
+#include "porting.h"
+#include "settings.h"
+#include "util/hex.h"
+#include "util/serialize.h"
+#include "util/sha1.h"
+#include "util/string.h"
+
+static std::string getMediaCacheDir()
+{
+ return porting::path_cache + DIR_DELIM + "media";
+}
+
+/*
+ ClientMediaDownloader
+*/
+
+ClientMediaDownloader::ClientMediaDownloader():
+ m_media_cache(getMediaCacheDir()),
+ m_httpfetch_caller(HTTPFETCH_DISCARD)
+{
+}
+
+ClientMediaDownloader::~ClientMediaDownloader()
+{
+ if (m_httpfetch_caller != HTTPFETCH_DISCARD)
+ httpfetch_caller_free(m_httpfetch_caller);
+
+ for (auto &file_it : m_files)
+ delete file_it.second;
+
+ for (auto &remote : m_remotes)
+ delete remote;
+}
+
+void ClientMediaDownloader::addFile(const std::string &name, const std::string &sha1)
+{
+ assert(!m_initial_step_done); // pre-condition
+
+ // if name was already announced, ignore the new announcement
+ if (m_files.count(name) != 0) {
+ errorstream << "Client: ignoring duplicate media announcement "
+ << "sent by server: \"" << name << "\""
+ << std::endl;
+ return;
+ }
+
+ // if name is empty or contains illegal characters, ignore the file
+ if (name.empty() || !string_allowed(name, TEXTURENAME_ALLOWED_CHARS)) {
+ errorstream << "Client: ignoring illegal file name "
+ << "sent by server: \"" << name << "\""
+ << std::endl;
+ return;
+ }
+
+ // length of sha1 must be exactly 20 (160 bits), else ignore the file
+ if (sha1.size() != 20) {
+ errorstream << "Client: ignoring illegal SHA1 sent by server: "
+ << hex_encode(sha1) << " \"" << name << "\""
+ << std::endl;
+ return;
+ }
+
+ FileStatus *filestatus = new FileStatus();
+ filestatus->received = false;
+ filestatus->sha1 = sha1;
+ filestatus->current_remote = -1;
+ m_files.insert(std::make_pair(name, filestatus));
+}
+
+void ClientMediaDownloader::addRemoteServer(const std::string &baseurl)
+{
+ assert(!m_initial_step_done); // pre-condition
+
+ #ifdef USE_CURL
+
+ if (g_settings->getBool("enable_remote_media_server")) {
+ infostream << "Client: Adding remote server \""
+ << baseurl << "\" for media download" << std::endl;
+
+ RemoteServerStatus *remote = new RemoteServerStatus();
+ remote->baseurl = baseurl;
+ remote->active_count = 0;
+ remote->request_by_filename = false;
+ m_remotes.push_back(remote);
+ }
+
+ #else
+
+ infostream << "Client: Ignoring remote server \""
+ << baseurl << "\" because cURL support is not compiled in"
+ << std::endl;
+
+ #endif
+}
+
+void ClientMediaDownloader::step(Client *client)
+{
+ if (!m_initial_step_done) {
+ initialStep(client);
+ m_initial_step_done = true;
+ }
+
+ // Remote media: check for completion of fetches
+ if (m_httpfetch_active) {
+ bool fetched_something = false;
+ HTTPFetchResult fetch_result;
+
+ while (httpfetch_async_get(m_httpfetch_caller, fetch_result)) {
+ m_httpfetch_active--;
+ fetched_something = true;
+
+ // Is this a hashset (index.mth) or a media file?
+ if (fetch_result.request_id < m_remotes.size())
+ remoteHashSetReceived(fetch_result);
+ else
+ remoteMediaReceived(fetch_result, client);
+ }
+
+ if (fetched_something)
+ startRemoteMediaTransfers();
+
+ // Did all remote transfers end and no new ones can be started?
+ // If so, request still missing files from the minetest server
+ // (Or report that we have all files.)
+ if (m_httpfetch_active == 0) {
+ if (m_uncached_received_count < m_uncached_count) {
+ infostream << "Client: Failed to remote-fetch "
+ << (m_uncached_count-m_uncached_received_count)
+ << " files. Requesting them"
+ << " the usual way." << std::endl;
+ }
+ startConventionalTransfers(client);
+ }
+ }
+}
+
+void ClientMediaDownloader::initialStep(Client *client)
+{
+ // Check media cache
+ m_uncached_count = m_files.size();
+ for (auto &file_it : m_files) {
+ std::string name = file_it.first;
+ FileStatus *filestatus = file_it.second;
+ const std::string &sha1 = filestatus->sha1;
+
+ std::ostringstream tmp_os(std::ios_base::binary);
+ bool found_in_cache = m_media_cache.load(hex_encode(sha1), tmp_os);
+
+ // If found in cache, try to load it from there
+ if (found_in_cache) {
+ bool success = checkAndLoad(name, sha1,
+ tmp_os.str(), true, client);
+ if (success) {
+ filestatus->received = true;
+ m_uncached_count--;
+ }
+ }
+ }
+
+ assert(m_uncached_received_count == 0);
+
+ // Create the media cache dir if we are likely to write to it
+ if (m_uncached_count != 0) {
+ bool did = fs::CreateAllDirs(getMediaCacheDir());
+ if (!did) {
+ errorstream << "Client: "
+ << "Could not create media cache directory: "
+ << getMediaCacheDir()
+ << std::endl;
+ }
+ }
+
+ // If we found all files in the cache, report this fact to the server.
+ // If the server reported no remote servers, immediately start
+ // conventional transfers. Note: if cURL support is not compiled in,
+ // m_remotes is always empty, so "!USE_CURL" is redundant but may
+ // reduce the size of the compiled code
+ if (!USE_CURL || m_uncached_count == 0 || m_remotes.empty()) {
+ startConventionalTransfers(client);
+ }
+ else {
+ // Otherwise start off by requesting each server's sha1 set
+
+ // This is the first time we use httpfetch, so alloc a caller ID
+ m_httpfetch_caller = httpfetch_caller_alloc();
+ m_httpfetch_timeout = g_settings->getS32("curl_timeout");
+
+ // Set the active fetch limit to curl_parallel_limit or 84,
+ // whichever is greater. This gives us some leeway so that
+ // inefficiencies in communicating with the httpfetch thread
+ // don't slow down fetches too much. (We still want some limit
+ // so that when the first remote server returns its hash set,
+ // not all files are requested from that server immediately.)
+ // One such inefficiency is that ClientMediaDownloader::step()
+ // is only called a couple times per second, while httpfetch
+ // might return responses much faster than that.
+ // Note that httpfetch strictly enforces curl_parallel_limit
+ // but at no inter-thread communication cost. This however
+ // doesn't help with the aforementioned inefficiencies.
+ // The signifance of 84 is that it is 2*6*9 in base 13.
+ m_httpfetch_active_limit = g_settings->getS32("curl_parallel_limit");
+ m_httpfetch_active_limit = MYMAX(m_httpfetch_active_limit, 84);
+
+ // Write a list of hashes that we need. This will be POSTed
+ // to the server using Content-Type: application/octet-stream
+ std::string required_hash_set = serializeRequiredHashSet();
+
+ // minor fixme: this loop ignores m_httpfetch_active_limit
+
+ // another minor fixme, unlikely to matter in normal usage:
+ // these index.mth fetches do (however) count against
+ // m_httpfetch_active_limit when starting actual media file
+ // requests, so if there are lots of remote servers that are
+ // not responding, those will stall new media file transfers.
+
+ for (u32 i = 0; i < m_remotes.size(); ++i) {
+ assert(m_httpfetch_next_id == i);
+
+ RemoteServerStatus *remote = m_remotes[i];
+ actionstream << "Client: Contacting remote server \""
+ << remote->baseurl << "\"" << std::endl;
+
+ HTTPFetchRequest fetch_request;
+ fetch_request.url =
+ remote->baseurl + MTHASHSET_FILE_NAME;
+ fetch_request.caller = m_httpfetch_caller;
+ fetch_request.request_id = m_httpfetch_next_id; // == i
+ fetch_request.timeout = m_httpfetch_timeout;
+ fetch_request.connect_timeout = m_httpfetch_timeout;
+ fetch_request.post_data = required_hash_set;
+ fetch_request.extra_headers.emplace_back(
+ "Content-Type: application/octet-stream");
+ httpfetch_async(fetch_request);
+
+ m_httpfetch_active++;
+ m_httpfetch_next_id++;
+ m_outstanding_hash_sets++;
+ }
+ }
+}
+
+void ClientMediaDownloader::remoteHashSetReceived(
+ const HTTPFetchResult &fetch_result)
+{
+ u32 remote_id = fetch_result.request_id;
+ assert(remote_id < m_remotes.size());
+ RemoteServerStatus *remote = m_remotes[remote_id];
+
+ m_outstanding_hash_sets--;
+
+ if (fetch_result.succeeded) {
+ try {
+ // Server sent a list of file hashes that are
+ // available on it, try to parse the list
+
+ std::set<std::string> sha1_set;
+ deSerializeHashSet(fetch_result.data, sha1_set);
+
+ // Parsing succeeded: For every file that is
+ // available on this server, add this server
+ // to the available_remotes array
+
+ for(std::map<std::string, FileStatus*>::iterator
+ it = m_files.upper_bound(m_name_bound);
+ it != m_files.end(); ++it) {
+ FileStatus *f = it->second;
+ if (!f->received && sha1_set.count(f->sha1))
+ f->available_remotes.push_back(remote_id);
+ }
+ }
+ catch (SerializationError &e) {
+ infostream << "Client: Remote server \""
+ << remote->baseurl << "\" sent invalid hash set: "
+ << e.what() << std::endl;
+ }
+ }
+
+ // For compatibility: If index.mth is not found, assume that the
+ // server contains files named like the original files (not their sha1)
+
+ // Do NOT check for any particular response code (e.g. 404) here,
+ // because different servers respond differently
+
+ if (!fetch_result.succeeded && !fetch_result.timeout) {
+ infostream << "Client: Enabling compatibility mode for remote "
+ << "server \"" << remote->baseurl << "\"" << std::endl;
+ remote->request_by_filename = true;
+
+ // Assume every file is available on this server
+
+ for(std::map<std::string, FileStatus*>::iterator
+ it = m_files.upper_bound(m_name_bound);
+ it != m_files.end(); ++it) {
+ FileStatus *f = it->second;
+ if (!f->received)
+ f->available_remotes.push_back(remote_id);
+ }
+ }
+}
+
+void ClientMediaDownloader::remoteMediaReceived(
+ const HTTPFetchResult &fetch_result,
+ Client *client)
+{
+ // Some remote server sent us a file.
+ // -> decrement number of active fetches
+ // -> mark file as received if fetch succeeded
+ // -> try to load media
+
+ std::string name;
+ {
+ std::unordered_map<unsigned long, std::string>::iterator it =
+ m_remote_file_transfers.find(fetch_result.request_id);
+ assert(it != m_remote_file_transfers.end());
+ name = it->second;
+ m_remote_file_transfers.erase(it);
+ }
+
+ sanity_check(m_files.count(name) != 0);
+
+ FileStatus *filestatus = m_files[name];
+ sanity_check(!filestatus->received);
+ sanity_check(filestatus->current_remote >= 0);
+
+ RemoteServerStatus *remote = m_remotes[filestatus->current_remote];
+
+ filestatus->current_remote = -1;
+ remote->active_count--;
+
+ // If fetch succeeded, try to load media file
+
+ if (fetch_result.succeeded) {
+ bool success = checkAndLoad(name, filestatus->sha1,
+ fetch_result.data, false, client);
+ if (success) {
+ filestatus->received = true;
+ assert(m_uncached_received_count < m_uncached_count);
+ m_uncached_received_count++;
+ }
+ }
+}
+
+s32 ClientMediaDownloader::selectRemoteServer(FileStatus *filestatus)
+{
+ // Pre-conditions
+ assert(filestatus != NULL);
+ assert(!filestatus->received);
+ assert(filestatus->current_remote < 0);
+
+ if (filestatus->available_remotes.empty())
+ return -1;
+
+ // Of all servers that claim to provide the file (and haven't
+ // been unsuccessfully tried before), find the one with the
+ // smallest number of currently active transfers
+
+ s32 best = 0;
+ s32 best_remote_id = filestatus->available_remotes[best];
+ s32 best_active_count = m_remotes[best_remote_id]->active_count;
+
+ for (u32 i = 1; i < filestatus->available_remotes.size(); ++i) {
+ s32 remote_id = filestatus->available_remotes[i];
+ s32 active_count = m_remotes[remote_id]->active_count;
+ if (active_count < best_active_count) {
+ best = i;
+ best_remote_id = remote_id;
+ best_active_count = active_count;
+ }
+ }
+
+ filestatus->available_remotes.erase(
+ filestatus->available_remotes.begin() + best);
+
+ return best_remote_id;
+
+}
+
+void ClientMediaDownloader::startRemoteMediaTransfers()
+{
+ bool changing_name_bound = true;
+
+ for (std::map<std::string, FileStatus*>::iterator
+ files_iter = m_files.upper_bound(m_name_bound);
+ files_iter != m_files.end(); ++files_iter) {
+
+ // Abort if active fetch limit is exceeded
+ if (m_httpfetch_active >= m_httpfetch_active_limit)
+ break;
+
+ const std::string &name = files_iter->first;
+ FileStatus *filestatus = files_iter->second;
+
+ if (!filestatus->received && filestatus->current_remote < 0) {
+ // File has not been received yet and is not currently
+ // being transferred. Choose a server for it.
+ s32 remote_id = selectRemoteServer(filestatus);
+ if (remote_id >= 0) {
+ // Found a server, so start fetching
+ RemoteServerStatus *remote =
+ m_remotes[remote_id];
+
+ std::string url = remote->baseurl +
+ (remote->request_by_filename ? name :
+ hex_encode(filestatus->sha1));
+ verbosestream << "Client: "
+ << "Requesting remote media file "
+ << "\"" << name << "\" "
+ << "\"" << url << "\"" << std::endl;
+
+ HTTPFetchRequest fetch_request;
+ fetch_request.url = url;
+ fetch_request.caller = m_httpfetch_caller;
+ fetch_request.request_id = m_httpfetch_next_id;
+ fetch_request.timeout = 0; // no data timeout!
+ fetch_request.connect_timeout =
+ m_httpfetch_timeout;
+ httpfetch_async(fetch_request);
+
+ m_remote_file_transfers.insert(std::make_pair(
+ m_httpfetch_next_id,
+ name));
+
+ filestatus->current_remote = remote_id;
+ remote->active_count++;
+ m_httpfetch_active++;
+ m_httpfetch_next_id++;
+ }
+ }
+
+ if (filestatus->received ||
+ (filestatus->current_remote < 0 &&
+ !m_outstanding_hash_sets)) {
+ // If we arrive here, we conclusively know that we
+ // won't fetch this file from a remote server in the
+ // future. So update the name bound if possible.
+ if (changing_name_bound)
+ m_name_bound = name;
+ }
+ else
+ changing_name_bound = false;
+ }
+
+}
+
+void ClientMediaDownloader::startConventionalTransfers(Client *client)
+{
+ assert(m_httpfetch_active == 0); // pre-condition
+
+ if (m_uncached_received_count != m_uncached_count) {
+ // Some media files have not been received yet, use the
+ // conventional slow method (minetest protocol) to get them
+ std::vector<std::string> file_requests;
+ for (auto &file : m_files) {
+ if (!file.second->received)
+ file_requests.push_back(file.first);
+ }
+ assert((s32) file_requests.size() ==
+ m_uncached_count - m_uncached_received_count);
+ client->request_media(file_requests);
+ }
+}
+
+void ClientMediaDownloader::conventionalTransferDone(
+ const std::string &name,
+ const std::string &data,
+ Client *client)
+{
+ // Check that file was announced
+ std::map<std::string, FileStatus*>::iterator
+ file_iter = m_files.find(name);
+ if (file_iter == m_files.end()) {
+ errorstream << "Client: server sent media file that was"
+ << "not announced, ignoring it: \"" << name << "\""
+ << std::endl;
+ return;
+ }
+ FileStatus *filestatus = file_iter->second;
+ assert(filestatus != NULL);
+
+ // Check that file hasn't already been received
+ if (filestatus->received) {
+ errorstream << "Client: server sent media file that we already"
+ << "received, ignoring it: \"" << name << "\""
+ << std::endl;
+ return;
+ }
+
+ // Mark file as received, regardless of whether loading it works and
+ // whether the checksum matches (because at this point there is no
+ // other server that could send a replacement)
+ filestatus->received = true;
+ assert(m_uncached_received_count < m_uncached_count);
+ m_uncached_received_count++;
+
+ // Check that received file matches announced checksum
+ // If so, load it
+ checkAndLoad(name, filestatus->sha1, data, false, client);
+}
+
+bool ClientMediaDownloader::checkAndLoad(
+ const std::string &name, const std::string &sha1,
+ const std::string &data, bool is_from_cache, Client *client)
+{
+ const char *cached_or_received = is_from_cache ? "cached" : "received";
+ const char *cached_or_received_uc = is_from_cache ? "Cached" : "Received";
+ std::string sha1_hex = hex_encode(sha1);
+
+ // Compute actual checksum of data
+ std::string data_sha1;
+ {
+ SHA1 data_sha1_calculator;
+ data_sha1_calculator.addBytes(data.c_str(), data.size());
+ unsigned char *data_tmpdigest = data_sha1_calculator.getDigest();
+ data_sha1.assign((char*) data_tmpdigest, 20);
+ free(data_tmpdigest);
+ }
+
+ // Check that received file matches announced checksum
+ if (data_sha1 != sha1) {
+ std::string data_sha1_hex = hex_encode(data_sha1);
+ infostream << "Client: "
+ << cached_or_received_uc << " media file "
+ << sha1_hex << " \"" << name << "\" "
+ << "mismatches actual checksum " << data_sha1_hex
+ << std::endl;
+ return false;
+ }
+
+ // Checksum is ok, try loading the file
+ bool success = client->loadMedia(data, name);
+ if (!success) {
+ infostream << "Client: "
+ << "Failed to load " << cached_or_received << " media: "
+ << sha1_hex << " \"" << name << "\""
+ << std::endl;
+ return false;
+ }
+
+ verbosestream << "Client: "
+ << "Loaded " << cached_or_received << " media: "
+ << sha1_hex << " \"" << name << "\""
+ << std::endl;
+
+ // Update cache (unless we just loaded the file from the cache)
+ if (!is_from_cache)
+ m_media_cache.update(sha1_hex, data);
+
+ return true;
+}
+
+
+/*
+ Minetest Hashset File Format
+
+ All values are stored in big-endian byte order.
+ [u32] signature: 'MTHS'
+ [u16] version: 1
+ For each hash in set:
+ [u8*20] SHA1 hash
+
+ Version changes:
+ 1 - Initial version
+*/
+
+std::string ClientMediaDownloader::serializeRequiredHashSet()
+{
+ std::ostringstream os(std::ios::binary);
+
+ writeU32(os, MTHASHSET_FILE_SIGNATURE); // signature
+ writeU16(os, 1); // version
+
+ // Write list of hashes of files that have not been
+ // received (found in cache) yet
+ for (std::map<std::string, FileStatus*>::iterator
+ it = m_files.begin();
+ it != m_files.end(); ++it) {
+ if (!it->second->received) {
+ FATAL_ERROR_IF(it->second->sha1.size() != 20, "Invalid SHA1 size");
+ os << it->second->sha1;
+ }
+ }
+
+ return os.str();
+}
+
+void ClientMediaDownloader::deSerializeHashSet(const std::string &data,
+ std::set<std::string> &result)
+{
+ if (data.size() < 6 || data.size() % 20 != 6) {
+ throw SerializationError(
+ "ClientMediaDownloader::deSerializeHashSet: "
+ "invalid hash set file size");
+ }
+
+ const u8 *data_cstr = (const u8*) data.c_str();
+
+ u32 signature = readU32(&data_cstr[0]);
+ if (signature != MTHASHSET_FILE_SIGNATURE) {
+ throw SerializationError(
+ "ClientMediaDownloader::deSerializeHashSet: "
+ "invalid hash set file signature");
+ }
+
+ u16 version = readU16(&data_cstr[4]);
+ if (version != 1) {
+ throw SerializationError(
+ "ClientMediaDownloader::deSerializeHashSet: "
+ "unsupported hash set file version");
+ }
+
+ for (u32 pos = 6; pos < data.size(); pos += 20) {
+ result.insert(data.substr(pos, 20));
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 16:44:54 +0000