OpenTTD Source  20241121-master-g67a0fccfad
http_shared.h
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1 /*
2  * This file is part of OpenTTD.
3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
4  * OpenTTD 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.
5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
6  */
7 
12 #ifndef NETWORK_CORE_HTTP_SHARED_H
13 #define NETWORK_CORE_HTTP_SHARED_H
14 
15 #include "http.h"
16 
17 #include <condition_variable>
18 #include <mutex>
19 #include <vector>
20 
23 private:
25  class Callback {
26  public:
27  Callback(std::unique_ptr<char[]> data, size_t length) : data(std::move(data)), length(length), failure(false) {}
28  Callback() : data(nullptr), length(0), failure(true) {}
29 
30  std::unique_ptr<char[]> data;
31  size_t length;
32  bool failure;
33  };
34 
35 public:
39  void OnFailure()
40  {
41  std::lock_guard<std::mutex> lock(this->mutex);
42  this->queue.emplace_back();
43  }
44 
48  void OnReceiveData(std::unique_ptr<char[]> data, size_t length)
49  {
50  std::lock_guard<std::mutex> lock(this->mutex);
51  this->queue.emplace_back(std::move(data), length);
52  }
53 
59  void HandleQueue()
60  {
61  this->cancelled = callback->IsCancelled();
62 
63  std::lock_guard<std::mutex> lock(this->mutex);
64 
65  for (auto &item : this->queue) {
66  if (item.failure) {
67  this->callback->OnFailure();
68  } else {
69  this->callback->OnReceiveData(std::move(item.data), item.length);
70  }
71  }
72 
73  this->queue.clear();
74  this->queue_cv.notify_all();
75  }
76 
81  template <typename T>
82  void WaitTillEmptyOrCondition(T condition)
83  {
84  std::unique_lock<std::mutex> lock(this->mutex);
85 
86  while (!(queue.empty() || condition())) {
87  this->queue_cv.wait(lock);
88  }
89  }
90 
94  bool IsQueueEmpty()
95  {
96  std::lock_guard<std::mutex> lock(this->mutex);
97  return this->queue.empty();
98  }
99 
101 
103  {
104  std::lock_guard<std::mutex> lock(this->mutex);
105 
106  /* Clear the list and notify explicitly. */
107  queue.clear();
108  queue_cv.notify_all();
109  }
110 
111  std::atomic<bool> cancelled = false;
112 
113 private:
115  std::mutex mutex;
116  std::vector<Callback> queue;
117  std::condition_variable queue_cv;
118 };
119 
120 #endif /* NETWORK_CORE_HTTP_SHARED_H */
Entries on the queue for later handling.
Definition: http_shared.h:25
Converts a HTTPCallback to a Thread-Safe variant.
Definition: http_shared.h:22
HTTPCallback * callback
The callback to send data back on.
Definition: http_shared.h:114
std::mutex mutex
Mutex to protect the queue.
Definition: http_shared.h:115
std::condition_variable queue_cv
Condition variable to wait for the queue to be empty.
Definition: http_shared.h:117
void OnFailure()
Similar to HTTPCallback::OnFailure, but thread-safe.
Definition: http_shared.h:39
void OnReceiveData(std::unique_ptr< char[]> data, size_t length)
Similar to HTTPCallback::OnReceiveData, but thread-safe.
Definition: http_shared.h:48
bool IsQueueEmpty()
Check if the queue is empty.
Definition: http_shared.h:94
std::vector< Callback > queue
Queue of data to send back.
Definition: http_shared.h:116
void WaitTillEmptyOrCondition(T condition)
Wait till the queue is dequeued, or a condition is met.
Definition: http_shared.h:82
void HandleQueue()
Process everything on the queue.
Definition: http_shared.h:59
Basic functions to send and receive HTTP packets.
Callback for when the HTTP handler has something to tell us.
Definition: http.h:20
virtual bool IsCancelled() const =0
Check if there is a request to cancel the transfer.
virtual void OnFailure()=0
An error has occurred and the connection has been closed.
virtual void OnReceiveData(std::unique_ptr< char[]> data, size_t length)=0
We're receiving data.
std::mutex lock
synchronization for playback status fields
Definition: win32_m.cpp:35