2 * Copyright (c) 2011 Sveriges Television AB <info@casparcg.com>
4 * This file is part of CasparCG (www.casparcg.com).
6 * CasparCG is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * CasparCG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with CasparCG. If not, see <http://www.gnu.org/licenses/>.
19 * Author: Helge Norberg, helge.norberg@svt.se
24 #include "polling_filesystem_monitor.h"
31 #include <boost/thread.hpp>
32 #include <boost/filesystem/fstream.hpp>
33 #include <boost/filesystem/convenience.hpp>
35 #include <tbb/atomic.h>
36 #include <tbb/concurrent_queue.h>
43 class exception_protected_handler
45 filesystem_monitor_handler handler_;
47 exception_protected_handler(const filesystem_monitor_handler& handler)
52 void operator()(filesystem_event event, const boost::filesystem::wpath& file)
56 boost::this_thread::interruption_point();
57 handler_(event, file);
58 boost::this_thread::interruption_point();
60 catch (const boost::thread_interrupted&)
66 CASPAR_LOG_CURRENT_EXCEPTION();
71 class directory_monitor
73 bool report_already_existing_;
74 boost::filesystem::wpath folder_;
75 filesystem_event events_mask_;
76 filesystem_monitor_handler handler_;
77 initial_files_handler initial_files_handler_;
78 bool first_scan_ = true;
79 std::map<boost::filesystem::wpath, std::time_t> files_;
80 std::map<boost::filesystem::wpath, uintmax_t> being_written_sizes_;
83 bool report_already_existing,
84 const boost::filesystem::wpath& folder,
85 filesystem_event events_mask,
86 const filesystem_monitor_handler& handler,
87 const initial_files_handler& initial_files_handler)
88 : report_already_existing_(report_already_existing)
90 , events_mask_(events_mask)
91 , handler_(exception_protected_handler(handler))
92 , initial_files_handler_(initial_files_handler)
98 if (static_cast<int>(events_mask_ & filesystem_event::MODIFIED) == 0)
101 for (auto& file : files_)
102 handler_(filesystem_event::MODIFIED, file.first);
105 void reemmit(const boost::filesystem::wpath& file)
107 if (static_cast<int>(events_mask_ & filesystem_event::MODIFIED) == 0)
110 if (files_.find(file) != files_.end() && boost::filesystem::exists(file))
111 handler_(filesystem_event::MODIFIED, file);
114 void scan(const boost::function<bool ()>& should_abort)
116 static const std::time_t NO_LONGER_WRITING_AGE = 3; // Assume std::time_t is expressed in seconds
117 using namespace boost::filesystem;
119 bool interested_in_removed = static_cast<int>(events_mask_ & filesystem_event::REMOVED) > 0;
120 bool interested_in_created = static_cast<int>(events_mask_ & filesystem_event::CREATED) > 0;
121 bool interested_in_modified = static_cast<int>(events_mask_ & filesystem_event::MODIFIED) > 0;
123 auto filenames = cpplinq::from(files_).select(keys());
124 std::set<wpath> removed_files(filenames.begin(), filenames.end());
125 std::set<wpath> initial_files;
127 for (boost::filesystem::wrecursive_directory_iterator iter(folder_); iter != boost::filesystem::wrecursive_directory_iterator(); ++iter)
132 auto& path = iter->path();
134 if (is_directory(path))
137 auto now = std::time(nullptr);
138 std::time_t current_mtime;
142 current_mtime = last_write_time(path);
146 // Probably removed, will be captured the next round.
150 auto time_since_written_to = now - current_mtime;
151 bool no_longer_being_written_to = time_since_written_to >= NO_LONGER_WRITING_AGE;
152 auto previous_it = files_.find(path);
153 bool already_known = previous_it != files_.end();
155 if (already_known && no_longer_being_written_to)
157 bool modified = previous_it->second != current_mtime;
159 if (modified && can_read_file(path))
161 if (interested_in_modified)
162 handler_(filesystem_event::MODIFIED, path);
164 files_[path] = current_mtime;
165 being_written_sizes_.erase(path);
168 else if (no_longer_being_written_to && can_read_file(path))
170 if (interested_in_created && (report_already_existing_ || !first_scan_))
171 handler_(filesystem_event::CREATED, path);
174 initial_files.insert(path);
176 files_.insert(std::make_pair(path, current_mtime));
177 being_written_sizes_.erase(path);
180 removed_files.erase(path);
183 for (auto& path : removed_files)
186 being_written_sizes_.erase(path);
188 if (interested_in_removed)
189 handler_(filesystem_event::REMOVED, path);
193 initial_files_handler_(initial_files);
198 bool can_read_file(const boost::filesystem::wpath& file)
200 boost::filesystem::wifstream stream(file);
202 return stream.is_open();
206 class polling_filesystem_monitor : public filesystem_monitor
208 directory_monitor root_monitor_;
209 boost::thread scanning_thread_;
210 tbb::atomic<bool> running_;
211 int scan_interval_millis_;
212 std::promise<void> initial_scan_completion_;
213 tbb::concurrent_queue<boost::filesystem::wpath> to_reemmit_;
214 tbb::atomic<bool> reemmit_all_;
216 polling_filesystem_monitor(
217 const boost::filesystem::wpath& folder_to_watch,
218 filesystem_event events_of_interest_mask,
219 bool report_already_existing,
220 int scan_interval_millis,
221 const filesystem_monitor_handler& handler,
222 const initial_files_handler& initial_files_handler)
223 : root_monitor_(report_already_existing, folder_to_watch, events_of_interest_mask, handler, initial_files_handler)
224 , scan_interval_millis_(scan_interval_millis)
227 reemmit_all_ = false;
228 scanning_thread_ = boost::thread([this] { scanner(); });
231 virtual ~polling_filesystem_monitor()
234 scanning_thread_.interrupt();
235 scanning_thread_.join();
238 virtual std::future<void> initial_files_processed()
240 return initial_scan_completion_.get_future();
243 virtual void reemmit_all()
248 virtual void reemmit(const boost::filesystem::wpath& file)
250 to_reemmit_.push(file);
255 ensure_gpf_handler_installed_for_thread("polling_filesystem_monitor");
257 bool running = scan(false);
258 initial_scan_completion_.set_value();
264 bool scan(bool sleep)
269 boost::this_thread::sleep_for(boost::chrono::milliseconds(scan_interval_millis_));
271 if (reemmit_all_.fetch_and_store(false))
272 root_monitor_.reemmit_all();
275 boost::filesystem::wpath file;
277 while (to_reemmit_.try_pop(file))
278 root_monitor_.reemmit(file);
281 root_monitor_.scan([=] { return !running_; });
283 catch (const boost::thread_interrupted&)
288 CASPAR_LOG_CURRENT_EXCEPTION();
295 struct polling_filesystem_monitor_factory::impl
297 int scan_interval_millis;
299 impl(int scan_interval_millis)
300 : scan_interval_millis(scan_interval_millis)
305 polling_filesystem_monitor_factory::polling_filesystem_monitor_factory(int scan_interval_millis)
306 : impl_(new impl(scan_interval_millis))
310 polling_filesystem_monitor_factory::~polling_filesystem_monitor_factory()
314 filesystem_monitor::ptr polling_filesystem_monitor_factory::create(
315 const boost::filesystem::wpath& folder_to_watch,
316 filesystem_event events_of_interest_mask,
317 bool report_already_existing,
318 const filesystem_monitor_handler& handler,
319 const initial_files_handler& initial_files_handler)
321 return spl::make_shared<polling_filesystem_monitor>(
323 events_of_interest_mask,
324 report_already_existing,
325 impl_->scan_interval_millis,
327 initial_files_handler);