OpenShot Library | libopenshot-audio  0.1.9
juce_NetworkServiceDiscovery.cpp
1 /*
2  ==============================================================================
3 
4  This file is part of the JUCE library.
5  Copyright (c) 2017 - ROLI Ltd.
6 
7  JUCE is an open source library subject to commercial or open-source
8  licensing.
9 
10  The code included in this file is provided under the terms of the ISC license
11  http://www.isc.org/downloads/software-support-policy/isc-license. Permission
12  To use, copy, modify, and/or distribute this software for any purpose with or
13  without fee is hereby granted provided that the above copyright notice and
14  this permission notice appear in all copies.
15 
16  JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
17  EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
18  DISCLAIMED.
19 
20  ==============================================================================
21 */
22 
23 namespace juce
24 {
25 
27  const String& serviceDescription,
28  int broadcastPortToUse, int connectionPort,
29  RelativeTime minTimeBetweenBroadcasts)
30  : Thread ("Discovery_broadcast"),
31  message (serviceTypeUID), broadcastPort (broadcastPortToUse),
32  minInterval (minTimeBetweenBroadcasts)
33 {
34  message.setAttribute ("id", Uuid().toString());
35  message.setAttribute ("name", serviceDescription);
36  message.setAttribute ("address", String());
37  message.setAttribute ("port", connectionPort);
38 
39  startThread (2);
40 }
41 
43 {
44  stopThread (2000);
45  socket.shutdown();
46 }
47 
48 void NetworkServiceDiscovery::Advertiser::run()
49 {
50  if (! socket.bindToPort (0))
51  {
52  jassertfalse;
53  return;
54  }
55 
56  while (! threadShouldExit())
57  {
58  sendBroadcast();
59  wait ((int) minInterval.inMilliseconds());
60  }
61 }
62 
63 void NetworkServiceDiscovery::Advertiser::sendBroadcast()
64 {
65  auto localAddress = IPAddress::getLocalAddress();
66  message.setAttribute ("address", localAddress.toString());
67  auto broadcastAddress = IPAddress::getInterfaceBroadcastAddress (localAddress);
68  auto data = message.createDocument ({}, true, false);
69  socket.write (broadcastAddress.toString(), broadcastPort, data.toRawUTF8(), (int) data.getNumBytesAsUTF8());
70 }
71 
72 //==============================================================================
74  : Thread ("Discovery_listen"), serviceTypeUID (serviceType)
75 {
76  socket.bindToPort (broadcastPort);
77  startThread (2);
78 }
79 
81 {
82  socket.shutdown();
83  stopThread (2000);
84 }
85 
86 void NetworkServiceDiscovery::AvailableServiceList::run()
87 {
88  while (! threadShouldExit())
89  {
90  if (socket.waitUntilReady (true, 200) == 1)
91  {
92  char buffer[1024];
93  auto bytesRead = socket.read (buffer, sizeof (buffer) - 1, false);
94 
95  if (bytesRead > 10)
96  if (auto xml = parseXML (String (CharPointer_UTF8 (buffer),
97  CharPointer_UTF8 (buffer + bytesRead))))
98  if (xml->hasTagName (serviceTypeUID))
99  handleMessage (*xml);
100  }
101 
102  removeTimedOutServices();
103  }
104 }
105 
106 std::vector<NetworkServiceDiscovery::Service> NetworkServiceDiscovery::AvailableServiceList::getServices() const
107 {
108  const ScopedLock sl (listLock);
109  auto listCopy = services;
110  return listCopy;
111 }
112 
113 void NetworkServiceDiscovery::AvailableServiceList::handleAsyncUpdate()
114 {
115  if (onChange != nullptr)
116  onChange();
117 }
118 
119 void NetworkServiceDiscovery::AvailableServiceList::handleMessage (const XmlElement& xml)
120 {
121  Service service;
122  service.instanceID = xml.getStringAttribute ("id");
123 
124  if (service.instanceID.trim().isNotEmpty())
125  {
126  service.description = xml.getStringAttribute ("name");
127  service.address = IPAddress (xml.getStringAttribute ("address"));
128  service.port = xml.getIntAttribute ("port");
129  service.lastSeen = Time::getCurrentTime();
130 
131  handleMessage (service);
132  }
133 }
134 
135 static void sortServiceList (std::vector<NetworkServiceDiscovery::Service>& services)
136 {
137  auto compareServices = [] (const NetworkServiceDiscovery::Service& s1,
139  {
140  return s1.instanceID < s2.instanceID;
141  };
142 
143  std::sort (services.begin(), services.end(), compareServices);
144 }
145 
146 void NetworkServiceDiscovery::AvailableServiceList::handleMessage (const Service& service)
147 {
148  const ScopedLock sl (listLock);
149 
150  for (auto& s : services)
151  {
152  if (s.instanceID == service.instanceID)
153  {
154  if (s.description != service.description
155  || s.address != service.address
156  || s.port != service.port)
157  {
158  s = service;
160  }
161 
162  s.lastSeen = service.lastSeen;
163  return;
164  }
165  }
166 
167  services.push_back (service);
168  sortServiceList (services);
170 }
171 
172 void NetworkServiceDiscovery::AvailableServiceList::removeTimedOutServices()
173 {
174  const double timeoutSeconds = 5.0;
175  auto oldestAllowedTime = Time::getCurrentTime() - RelativeTime::seconds (timeoutSeconds);
176 
177  const ScopedLock sl (listLock);
178 
179  auto oldEnd = std::end (services);
180  auto newEnd = std::remove_if (std::begin (services), oldEnd,
181  [=] (const Service& s) { return s.lastSeen < oldestAllowedTime; });
182 
183  if (newEnd != oldEnd)
184  {
185  services.erase (newEnd, oldEnd);
187  }
188 }
189 
190 } // namespace juce
std::vector< Service > getServices() const
Returns a list of the currently known services.
Contains information about a service that has been found on the network.
bool stopThread(int timeOutMilliseconds)
Attempts to stop the thread running.
bool bindToPort(int localPortNumber)
Binds the socket to the specified local port.
Represents an IP address.
bool isNotEmpty() const noexcept
Returns true if the string contains at least one character.
Definition: juce_String.h:306
void triggerAsyncUpdate()
Causes the callback to be triggered at a later time.
Used to build a tree of elements representing an XML document.
String instanceID
A UUID that identifies the particular instance of the Advertiser class.
The JUCE String class!
Definition: juce_String.h:42
void shutdown()
Closes the underlying socket object.
int getIntAttribute(StringRef attributeName, int defaultReturnValue=0) const
Returns the value of a named attribute as an integer.
static Time JUCE_CALLTYPE getCurrentTime() noexcept
Returns a Time object that is set to the current system time.
Definition: juce_Time.cpp:218
A relative measure of time.
IPAddress address
The IP address of the advertiser.
std::function< void()> onChange
A lambda that can be set to recieve a callback when the list changes.
Advertiser(const String &serviceTypeUID, const String &serviceDescription, int broadcastPort, int connectionPort, RelativeTime minTimeBetweenBroadcasts=RelativeTime::seconds(1.5))
Creates and starts an Advertiser thread, broadcasting with the given properties.
int64 inMilliseconds() const noexcept
Returns the number of milliseconds this time represents.
A universally unique 128-bit identifier.
Definition: juce_Uuid.h:42
static RelativeTime seconds(double seconds) noexcept
Creates a new RelativeTime object representing a number of seconds.
int waitUntilReady(bool readyForReading, int timeoutMsecs)
Waits until the socket is ready for reading or writing.
int read(void *destBuffer, int maxBytesToRead, bool blockUntilSpecifiedAmountHasArrived)
Reads bytes from the socket.
Time lastSeen
The time of the last ping received from the advertiser.
void setAttribute(const Identifier &attributeName, const String &newValue)
Adds a named attribute to the element.
bool threadShouldExit() const
Checks whether the thread has been told to stop running.
Encapsulates a thread.
Definition: juce_Thread.h:46
int write(const String &remoteHostname, int remotePortNumber, const void *sourceBuffer, int numBytesToWrite)
Writes bytes to the socket from a buffer.
static IPAddress getLocalAddress(bool includeIPv6=false)
Returns the first &#39;real&#39; address for the local machine.
String createDocument(StringRef dtdToUse, bool allOnOneLine=false, bool includeXmlHeader=true, StringRef encodingType="UTF-8", int lineWrapLength=60) const
Returns an XML text document that represents this element.
const String & getStringAttribute(StringRef attributeName) const noexcept
Returns the value of a named attribute.
AvailableServiceList(const String &serviceTypeUID, int broadcastPort)
Creates an AvailableServiceList that will bind to the given port number and watch the network for Adv...
String trim() const
Returns a copy of this string with any whitespace characters removed from the start and end...
static IPAddress getInterfaceBroadcastAddress(const IPAddress &interfaceAddress)
If the IPAdress is the address of an interface on the machine, returns the associated broadcast addre...
Automatically locks and unlocks a mutex object.
int port
The port number of the advertiser.
bool wait(int timeOutMilliseconds) const
Suspends the execution of this thread until either the specified timeout period has elapsed...
String description
The service description as sent by the Advertiser.
Wraps a pointer to a null-terminated UTF-8 character string, and provides various methods to operate ...
void startThread()
Starts the thread running.