summaryrefslogtreecommitdiffstats
path: root/kftpgrabber/src/engine/speedlimiter.cpp
blob: 27b3a87aed852554191c4c287381bc16a0a2469d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
/*
 * This file is part of the KFTPGrabber project
 *
 * Copyright (C) 2003-2007 by the KFTPGrabber developers
 * Copyright (C) 2003-2007 Jernej Kos <kostko@jweb-network.net>
 *
 * This program 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; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * is provided AS IS, WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, and
 * NON-INFRINGEMENT.  See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Steet, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 *
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 */
#include "speedlimiter.h"
#include "misc/kftpconfig.h"

#include <kstaticdeleter.h>

using namespace KFTPCore;

namespace KFTPEngine {

static const int tickDelay = 250;
static int bucketSize = 1000 / tickDelay;

SpeedLimiter *SpeedLimiter::m_self = 0;
static KStaticDeleter<SpeedLimiter> staticSpeedLimiterDeleter;

SpeedLimiter *SpeedLimiter::self()
{
  if (!m_self) {
    staticSpeedLimiterDeleter.setObject(m_self, new SpeedLimiter());
  }
  
  return m_self;
}

SpeedLimiter::SpeedLimiter()
  : m_timer(false)
{
  // Reset limits and token debts
  m_limits[0] = 0;
  m_limits[1] = 0;
  
  m_tokenDebt[0] = 0;
  m_tokenDebt[1] = 0;
  
  // Subscribe to config updates and update the limits
  connect(Config::self(), SIGNAL(configChanged()), this, SLOT(updateLimits()));
  updateLimits();
}

SpeedLimiter::~SpeedLimiter()
{
  if (m_self == this)
    staticSpeedLimiterDeleter.setObject(m_self, 0, false);
}

void SpeedLimiter::updateLimits()
{
  setLimit(SpeedLimiter::Download, Config::downloadSpeedLimit() * 1024);
  setLimit(SpeedLimiter::Upload, Config::uploadSpeedLimit() * 1024);
}

void SpeedLimiter::setLimit(Type type, int limit)
{
  m_limits[type] = limit;
}

void SpeedLimiter::append(SpeedLimiterItem *item, Type type)
{
  m_objects[type].append(item);
  
  int limit = m_limits[type];
  if (limit > 0) {
    int tokens = limit * tickDelay / 1000;
    tokens /= m_objects[type].count();
    
    if (m_tokenDebt[type] > 0) {
      if (tokens >= m_tokenDebt[type]) {
        tokens -= m_tokenDebt[type];
        m_tokenDebt[type] = 0;
      } else {
        tokens = 0;
      }
    }
    
    item->m_availableBytes = tokens;
  } else {
    item->m_availableBytes = -1;
  }
  
  // Fire the timer if not running
  if (!m_timer) {
    startTimer(tickDelay);
    m_timer = true;
  }
}

void SpeedLimiter::remove(SpeedLimiterItem *item)
{
  remove(item, Download);
  remove(item, Upload);
}

void SpeedLimiter::remove(SpeedLimiterItem *item, Type type)
{
  if (m_objects[type].containsRef(item)) {
    int tokens = m_limits[type] * tickDelay / 1000;
    tokens /= m_objects[type].count();
    
    if (item->m_availableBytes < tokens)
      m_tokenDebt[type] += tokens - item->m_availableBytes;
    
    m_objects[type].removeRef(item);
  }
  
  item->m_availableBytes = -1;
}

void SpeedLimiter::timerEvent(TQTimerEvent*)
{
  TQPtrList<SpeedLimiterItem> pendingWakeup;
  
  for (int i = 0; i < 2; i++) {
    m_tokenDebt[i] = 0;
    
    int limit = m_limits[i];
    if (!limit) {
      // There is no limit, reset all items
      for (SpeedLimiterItem *item = m_objects[i].first(); item; item = m_objects[i].next()) {
        item->m_availableBytes = -1;
      }
      
      continue;
    }
    
    // If there are no objects, just skip it
    if (m_objects[i].isEmpty())
      continue;
    
    int tokens = limit * tickDelay / 1000;
    if (!tokens)
      tokens = 1;
    
    int maxTokens = tokens * bucketSize;
    
    // Get amount of tokens for each object
    int tokensPerObject = tokens / m_objects[i].count();
    if (!tokensPerObject)
      tokensPerObject = 1;
    
    tokens = 0;
    
    TQPtrList<SpeedLimiterItem> unsaturatedObjects;
    
    for (SpeedLimiterItem *item = m_objects[i].first(); item; item = m_objects[i].next()) {
      if (item->m_availableBytes == -1) {
        item->m_availableBytes = tokensPerObject;
        unsaturatedObjects.append(item);
      } else {
        item->m_availableBytes += tokensPerObject;
        
        if (item->m_availableBytes > maxTokens) {
          tokens += item->m_availableBytes - maxTokens;
          item->m_availableBytes = maxTokens;
        } else {
          unsaturatedObjects.append(item);
        }
      }
    }
    
    // Assign any left-overs to unsaturated sources
    while (tokens && !unsaturatedObjects.isEmpty()) {
      tokensPerObject = tokens / unsaturatedObjects.count();
      if (!tokensPerObject)
        break;
      
      tokens = 0;
      
      for (SpeedLimiterItem *item = unsaturatedObjects.first(); item; item = unsaturatedObjects.next()) {
        item->m_availableBytes += tokensPerObject;
        
        if (item->m_availableBytes > maxTokens) {
          tokens += item->m_availableBytes - maxTokens;
          item->m_availableBytes = maxTokens;
          unsaturatedObjects.removeRef(item);
        }
      }
    }
  }
  
  if (m_objects[0].isEmpty() && m_objects[1].isEmpty()) {
    killTimers();
    m_timer = false;
  }
}

SpeedLimiterItem::SpeedLimiterItem()
  : m_availableBytes(-1)
{
}

void SpeedLimiterItem::updateUsage(int bytes)
{
  // Ignore if there are no limits
  if (m_availableBytes == -1)
    return;
  
  if (bytes > m_availableBytes)
    m_availableBytes = 0;
  else
    m_availableBytes -= bytes;
}

}

#include "speedlimiter.moc"