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39
40#ifndef QHOSTINFO_P_H
41#define QHOSTINFO_P_H
42
43//
44// W A R N I N G
45// -------------
46//
47// This file is not part of the Qt API. It exists for the convenience
48// of the QHostInfo class. This header file may change from
49// version to version without notice, or even be removed.
50//
51// We mean it.
52//
53
54#include <QtNetwork/private/qtnetworkglobal_p.h>
55#include "QtCore/qcoreapplication.h"
56#include "private/qcoreapplication_p.h"
57#include "private/qmetaobject_p.h"
58#include "QtNetwork/qhostinfo.h"
59#include "QtCore/qmutex.h"
60#include "QtCore/qwaitcondition.h"
61#include "QtCore/qobject.h"
62#include "QtCore/qpointer.h"
63#include "QtCore/qthread.h"
64#if QT_CONFIG(thread)
65#include "QtCore/qthreadpool.h"
66#endif
67#include "QtCore/qrunnable.h"
68#include "QtCore/qlist.h"
69#include "QtCore/qqueue.h"
70#include <QElapsedTimer>
71#include <QCache>
72
73#include <QNetworkSession>
74#include <QSharedPointer>
75
76#include <atomic>
77
78QT_BEGIN_NAMESPACE
79
80
81class QHostInfoResult : public QObject
82{
83 Q_OBJECT
84public:
85 QHostInfoResult(const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj)
86 : receiver(receiver), slotObj(slotObj),
87 withContextObject(slotObj && receiver)
88 {
89 if (receiver)
90 moveToThread(thread: receiver->thread());
91 }
92
93 void postResultsReady(const QHostInfo &info);
94
95Q_SIGNALS:
96 void resultsReady(const QHostInfo &info);
97
98protected:
99 bool event(QEvent *event) override;
100
101private:
102 QHostInfoResult(const QHostInfoResult *other)
103 : receiver(other->receiver), slotObj(other->slotObj),
104 withContextObject(other->withContextObject)
105 {
106 // cleanup if the application terminates before results are delivered
107 connect(sender: QCoreApplication::instance(), signal: &QCoreApplication::aboutToQuit,
108 receiver: this, slot: &QObject::deleteLater);
109 // maintain thread affinity
110 moveToThread(thread: other->thread());
111 }
112
113 QPointer<const QObject> receiver = nullptr;
114 QtPrivate::QSlotObjectBase *slotObj = nullptr;
115 const bool withContextObject = false;
116};
117
118class QHostInfoAgent
119{
120public:
121 static QHostInfo fromName(const QString &hostName);
122private:
123 static QHostInfo lookup(const QString &hostName);
124 static QHostInfo reverseLookup(const QHostAddress &address);
125};
126
127class QHostInfoPrivate
128{
129public:
130 inline QHostInfoPrivate()
131 : err(QHostInfo::NoError),
132 errorStr(QLatin1String(QT_TRANSLATE_NOOP("QHostInfo", "Unknown error"))),
133 lookupId(0)
134 {
135 }
136 static int lookupHostImpl(const QString &name,
137 const QObject *receiver,
138 QtPrivate::QSlotObjectBase *slotObj,
139 const char *member);
140
141 QHostInfo::HostInfoError err;
142 QString errorStr;
143 QList<QHostAddress> addrs;
144 QString hostName;
145 int lookupId;
146};
147
148// These functions are outside of the QHostInfo class and strictly internal.
149// Do NOT use them outside of QAbstractSocket.
150QHostInfo Q_NETWORK_EXPORT qt_qhostinfo_lookup(const QString &name, QObject *receiver, const char *member, bool *valid, int *id);
151void Q_AUTOTEST_EXPORT qt_qhostinfo_clear_cache();
152void Q_AUTOTEST_EXPORT qt_qhostinfo_enable_cache(bool e);
153void Q_AUTOTEST_EXPORT qt_qhostinfo_cache_inject(const QString &hostname, const QHostInfo &resolution);
154
155class QHostInfoCache
156{
157public:
158 QHostInfoCache();
159 const int max_age; // seconds
160
161 QHostInfo get(const QString &name, bool *valid);
162 void put(const QString &name, const QHostInfo &info);
163 void clear();
164
165 bool isEnabled() { return enabled.load(m: std::memory_order_relaxed); }
166 // this function is currently only used for the auto tests
167 // and not usable by public API
168 void setEnabled(bool e) { enabled.store(i: e, m: std::memory_order_relaxed); }
169private:
170 std::atomic<bool> enabled;
171 struct QHostInfoCacheElement {
172 QHostInfo info;
173 QElapsedTimer age;
174 };
175 QCache<QString,QHostInfoCacheElement> cache;
176 QMutex mutex;
177};
178
179// the following classes are used for the (normal) case: We use multiple threads to lookup DNS
180
181class QHostInfoRunnable : public QRunnable
182{
183public:
184 QHostInfoRunnable(const QString &hn, int i, const QObject *receiver,
185 QtPrivate::QSlotObjectBase *slotObj);
186 void run() override;
187
188 QString toBeLookedUp;
189 int id;
190 QHostInfoResult resultEmitter;
191};
192
193
194class QHostInfoLookupManager
195{
196public:
197 QHostInfoLookupManager();
198 ~QHostInfoLookupManager();
199
200 void clear();
201
202 // called from QHostInfo
203 void scheduleLookup(QHostInfoRunnable *r);
204 void abortLookup(int id);
205
206 // called from QHostInfoRunnable
207 void lookupFinished(QHostInfoRunnable *r);
208 bool wasAborted(int id);
209
210 QHostInfoCache cache;
211
212 friend class QHostInfoRunnable;
213protected:
214#if QT_CONFIG(thread)
215 QList<QHostInfoRunnable*> currentLookups; // in progress
216 QList<QHostInfoRunnable*> postponedLookups; // postponed because in progress for same host
217#endif
218 QQueue<QHostInfoRunnable*> scheduledLookups; // not yet started
219 QList<QHostInfoRunnable*> finishedLookups; // recently finished
220 QList<int> abortedLookups; // ids of aborted lookups
221
222#if QT_CONFIG(thread)
223 QThreadPool threadPool;
224#endif
225 QMutex mutex;
226
227 bool wasDeleted;
228
229private:
230 void rescheduleWithMutexHeld();
231};
232
233QT_END_NAMESPACE
234
235#endif // QHOSTINFO_P_H
236

source code of qtbase/src/network/kernel/qhostinfo_p.h