aboutsummaryrefslogtreecommitdiffstats
path: root/hicn-light/src/strategies/rnd.c
blob: 37f3f6f3051bf9de7dc3192694ea2f5b712fb030 (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
/*
 * Copyright (c) 2017-2019 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <src/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include <parc/assert/parc_Assert.h>

#include <parc/algol/parc_HashMap.h>
#include <parc/algol/parc_Memory.h>

#include <src/strategies/rnd.h>

static void _strategyRnd_ReceiveObject(StrategyImpl *strategy,
                                       const NumberSet *egressId,
                                       const Message *objectMessage, Ticks rtt);
static void _strategyRnd_OnTimeout(StrategyImpl *strategy,
                                   const NumberSet *egressId);
static NumberSet *_strategyRnd_LookupNexthop(StrategyImpl *strategy,
                                             const Message *interestMessage);
static NumberSet *_strategyRnd_ReturnNexthops(StrategyImpl *strategy);
static unsigned _strategyRnd_CountNexthops(StrategyImpl *strategy);
static void _strategyRnd_AddNexthop(StrategyImpl *strategy,
                                    unsigned connectionId);
static void _strategyRnd_RemoveNexthop(StrategyImpl *strategy,
                                       unsigned connectionId);
static void _strategyRnd_ImplDestroy(StrategyImpl **strategyPtr);
static strategy_type _strategyRnd_GetStrategy(StrategyImpl *strategy);

static StrategyImpl _template = {
    .context = NULL,
    .receiveObject = &_strategyRnd_ReceiveObject,
    .onTimeout = &_strategyRnd_OnTimeout,
    .lookupNexthop = &_strategyRnd_LookupNexthop,
    .returnNexthops = &_strategyRnd_ReturnNexthops,
    .countNexthops = &_strategyRnd_CountNexthops,
    .addNexthop = &_strategyRnd_AddNexthop,
    .removeNexthop = &_strategyRnd_RemoveNexthop,
    .destroy = &_strategyRnd_ImplDestroy,
    .getStrategy = &_strategyRnd_GetStrategy,
};

struct strategy_rnd;
typedef struct strategy_rnd StrategyRnd;

struct strategy_rnd {
  NumberSet *nexthops;
};

StrategyImpl *strategyRnd_Create() {
  StrategyRnd *strategy = parcMemory_AllocateAndClear(sizeof(StrategyRnd));
  parcAssertNotNull(strategy, "parcMemory_AllocateAndClear(%zu) returned NULL",
                    sizeof(StrategyRnd));

  strategy->nexthops = numberSet_Create();
  srand(time(NULL));

  StrategyImpl *impl = parcMemory_AllocateAndClear(sizeof(StrategyImpl));
  parcAssertNotNull(impl, "parcMemory_AllocateAndClear(%zu) returned NULL",
                    sizeof(StrategyImpl));
  memcpy(impl, &_template, sizeof(StrategyImpl));
  impl->context = strategy;
  return impl;
}

// =======================================================
// Dispatch API

strategy_type _strategyRnd_GetStrategy(StrategyImpl *strategy) {
  return SET_STRATEGY_RANDOM;
}

static int _select_Nexthop(StrategyRnd *strategy) {
  unsigned len = numberSet_Length(strategy->nexthops);
  if (len == 0) {
    return -1;
  }

  int rnd = (rand() % len);
  return numberSet_GetItem(strategy->nexthops, rnd);
}

static void _strategyRnd_ReceiveObject(StrategyImpl *strategy,
                                       const NumberSet *egressId,
                                       const Message *objectMessage,
                                       Ticks rtt) {}

static void _strategyRnd_OnTimeout(StrategyImpl *strategy,
                                   const NumberSet *egressId) {}

static NumberSet *_strategyRnd_LookupNexthop(StrategyImpl *strategy,
                                             const Message *interestMessage) {
  StrategyRnd *srnd = (StrategyRnd *)strategy->context;

  unsigned in_connection = message_GetIngressConnectionId(interestMessage);
  unsigned nexthopSize = numberSet_Length(srnd->nexthops);

  NumberSet *out = numberSet_Create();
  if ((nexthopSize == 0) ||
      ((nexthopSize == 1) &&
       numberSet_Contains(srnd->nexthops, in_connection))) {
    // there are no output faces or the input face is also the only output face.
    // return null to avoid loops
    return out;
  }

  unsigned out_connection;
  do {
    out_connection = _select_Nexthop(srnd);
  } while (out_connection == in_connection);

  if (out_connection == -1) {
    return out;
  }

  numberSet_Add(out, out_connection);
  return out;
}

static NumberSet *_strategyRnd_ReturnNexthops(StrategyImpl *strategy) {
  StrategyRnd *srnd = (StrategyRnd *)strategy->context;
  return srnd->nexthops;
}

unsigned _strategyRnd_CountNexthops(StrategyImpl *strategy) {
  StrategyRnd *srnd = (StrategyRnd *)strategy->context;
  return numberSet_Length(srnd->nexthops);
}

static void _strategyRnd_AddNexthop(StrategyImpl *strategy,
                                    unsigned connectionId) {
  StrategyRnd *srnd = (StrategyRnd *)strategy->context;
  if (!numberSet_Contains(srnd->nexthops, connectionId)) {
    numberSet_Add(srnd->nexthops, connectionId);
  }
}

static void _strategyRnd_RemoveNexthop(StrategyImpl *strategy,
                                       unsigned connectionId) {
  StrategyRnd *srnd = (StrategyRnd *)strategy->context;

  if (numberSet_Contains(srnd->nexthops, connectionId)) {
    numberSet_Remove(srnd->nexthops, connectionId);
  }
}

static void _strategyRnd_ImplDestroy(StrategyImpl **strategyPtr) {
  parcAssertNotNull(strategyPtr, "Parameter must be non-null double pointer");
  parcAssertNotNull(*strategyPtr,
                    "Parameter must dereference to non-null pointer");

  StrategyImpl *impl = *strategyPtr;
  StrategyRnd *strategy = (StrategyRnd *)impl->context;

  numberSet_Release(&(strategy->nexthops));

  parcMemory_Deallocate((void **)&strategy);
  parcMemory_Deallocate((void **)&impl);
  *strategyPtr = NULL;
}