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1
4 package com.tc.net.core;
5
6 import com.tc.config.schema.dynamic.ConfigItem;
7 import com.tc.config.schema.dynamic.ConfigItemListener;
8
9 import java.util.ArrayList  ;
10 import java.util.Arrays ;
11 import java.util.Iterator ;
12 import java.util.List ;
13 import java.util.NoSuchElementException ;
14
15 public class ConfigBasedConnectionAddressProvider implements ConnectionAddressProvider, ConfigItemListener {
16
17 private final ConfigItem source;
18
19 private int policy;
20 private List currentAddresses = new ArrayList ();
21 private int current = -1;
22
23 public ConfigBasedConnectionAddressProvider(ConfigItem source) {
24 this(ROUND_ROBIN, source);
25 }
26
27 private ConfigBasedConnectionAddressProvider(int policy, ConfigItem source) {
28 this.policy = policy;
29 this.source = source;
30
31 this.source.addListener(this);
32 this.currentAddresses.addAll(Arrays.asList((ConnectionInfo[]) source.getObject()));
33
34 init();
35 }
36
37 private void init() {
38 switch (policy) {
39 case ROUND_ROBIN:
40 if (currentAddresses.size() == 0) {
41 current = -1;
42 } else if (current < 0 || current >= currentAddresses.size()) {
43 current = 0;
44 }
45 break;
46 case LINEAR:
47 if (currentAddresses.size() == 0) {
48 current = -1;
49 } else if (current < 0) {
50 current = 0;
51 }
52 break;
53 default:
54 throw new AssertionError ("Unimplemented policy for ConnectionAddressProvider !");
55 }
56 }
57
58 public synchronized void valueChanged(Object oldValue, Object newValue) {
59 ConnectionInfo currentServer;
60
61 try {
62 currentServer = getConnectionInfo();
63 } catch (NoSuchElementException nsee) {
64 currentServer = null;
65 }
66
67 ConnectionInfo[] newAddresses = (ConnectionInfo[]) this.source.getObject();
68 this.currentAddresses.clear();
69 this.currentAddresses.addAll(Arrays.asList(newAddresses));
70
71 init();
72
73 Iterator iter = this.currentAddresses.iterator();
76 int pos = 0;
77 while (iter.hasNext()) {
78 if (currentServer != null && iter.next().equals(currentServer)) {
79 current = pos;
80 break;
81 }
82 ++pos;
83 }
84 }
85
86 private void reinit() {
87 current = -1;
88 init();
89 }
90
91 public String getHostname() {
92 return getConnectionInfo().getHostname();
93 }
94
95 public int getPortNumber() {
96 return getConnectionInfo().getPort();
97 }
98
99 public synchronized int getCount() {
100 return currentAddresses.size();
101 }
102
103 public synchronized boolean hasNext() {
104 switch (policy) {
105 case ROUND_ROBIN:
106 return currentAddresses.size() > 0;
107 case LINEAR:
108 return currentAddresses.size() > 0 && current < currentAddresses.size() - 1;
109 default:
110 return false;
111 }
112 }
113
114 public synchronized ConnectionInfo getConnectionInfo() {
115 if (current > -1 && current < currentAddresses.size()) { return (ConnectionInfo) currentAddresses.get(current); }
116 throw new NoSuchElementException ();
117 }
118
119 public synchronized ConnectionInfo next() {
120 goNext();
121 return getConnectionInfo();
122 }
123
124 private void goNext() {
125 switch (policy) {
126 case ROUND_ROBIN:
127 if (currentAddresses.size() == 0) {
128 current = -1;
129 } else if (current < 0 || current >= currentAddresses.size() - 1) {
130 current = 0;
131 } else {
132 current++;
133 }
134 break;
135 case LINEAR:
136 if (currentAddresses.size() == 0) {
137 current = -1;
138 } else if (current < currentAddresses.size()) {
139 current++;
140 }
141 break;
142 default:
143 throw new AssertionError ("Unimplemented policy for ConnectionAddressProvider !");
144 }
145 }
146
147 public synchronized void setPolicy(int policy) {
148 switch (policy) {
149 case ROUND_ROBIN:
150 case LINEAR:
151 this.policy = policy;
152 break;
153 default:
154 throw new AssertionError ("Unimplemented policy for ConnectionAddressProvider !");
155 }
156 reinit();
157 }
158
159 public String toString() {
160 return "ConnectionAddressProvider(current = " + current + ", policy = "
161 + (policy == ROUND_ROBIN ? "ROUND_ROBIN" : "LINEAR") + ")[" + currentAddresses + "]";
162 }
163 }
164 |
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