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1
50 package org.apache.avalon.excalibur.pool;
51
52 import org.apache.avalon.framework.activity.Disposable;
53 import org.apache.avalon.framework.activity.Initializable;
54 import org.apache.avalon.framework.logger.AbstractLogEnabled;
55 import org.apache.avalon.framework.thread.SingleThreaded;
56
57
66 public class SingleThreadedPool
67 extends AbstractLogEnabled
68 implements Pool, Initializable, SingleThreaded, Resizable, Disposable
69 {
70 protected boolean m_initialized;
71 protected int m_count;
72 protected Poolable[] m_pool;
73 protected ObjectFactory m_factory;
74 protected PoolController m_controller;
75 protected int m_maximum;
76 protected int m_initial;
77
78 public SingleThreadedPool( final Class  clazz,
79 final int initial,
80 final int maximum ) throws Exception
81 {
82 this( new DefaultObjectFactory( clazz ), initial, maximum );
83 }
84
85 public SingleThreadedPool( final ObjectFactory factory,
86 final int initial,
87 final int maximum ) throws Exception
88 {
89 this( factory, null, initial, maximum );
90 }
91
92 public SingleThreadedPool( final ObjectFactory factory,
93 final PoolController controller,
94 final int initial,
95 final int maximum ) throws Exception
96 {
97 m_count = 0;
98 m_factory = factory;
99 m_controller = controller;
100 m_maximum = maximum;
101 m_initial = initial;
102 }
103
104 public void initialize()
105 throws Exception
106 {
107 m_initialized = true;
108
109 grow( m_maximum );
110 fill( m_initial );
111 }
112
113
118 public Poolable get() throws Exception
119 {
120 if( !m_initialized )
122 {
123 initialize();
124 }
125
126 if( null == m_pool && null != m_controller )
127 {
128 final int increase = m_controller.grow();
129 if( increase > 0 )
130 {
131 grow( increase );
132 }
133 }
134
135 if( 0 > m_count )
136 {
137 m_count = -1;
138 return (Poolable)m_factory.newInstance();
139 }
140 else if( 0 == m_count )
141 {
142 m_count--;
143 return m_pool[ 0 ];
144 }
145
146 final Poolable poolable = m_pool[ m_count ];
147 m_pool[ m_count ] = null;
148 m_count--;
149 return poolable;
150 }
151
152
157 public void put( final Poolable poolable )
158 {
159 if( poolable instanceof Recyclable )
160 {
161 ( (Recyclable)poolable ).recycle();
162 }
163
164 if( m_pool.length == ( m_count + 1 ) && null != m_controller )
165 {
166 final int decrease = m_controller.shrink();
167 if( decrease > 0 )
168 {
169 shrink( decrease );
170 }
171 }
172
173 if( m_pool.length > m_count + 1 )
174 {
175 m_count++;
176 m_pool[ m_count ] = poolable;
177 }
178 else
179 {
180 try
181 {
182 m_factory.decommission( poolable );
183 }
184 catch( Exception e )
185 {
186 if( ( getLogger() != null ) && ( getLogger().isDebugEnabled() ) )
188 {
189 getLogger().debug( "Error decommissioning object", e );
190 }
191 }
192 }
193 }
194
195
200 public final int getCapacity()
201 {
202 return m_pool.length;
203 }
204
205
211 public final int getSize()
212 {
213 return m_count;
214 }
215
216
221 public final int size()
222 {
223 return getSize();
224 }
225
226
229 public final void fill( final int fillSize ) throws Exception
230 {
231 final int size = Math.min( m_pool.length, fillSize );
232
233 for( int i = m_count; i < size; i++ )
234 {
235 m_pool[ i ] = (Poolable)m_factory.newInstance();
236 }
237
238 m_count = size - 1;
239 }
240
241
244 public final void grow( final int increase )
245 {
246 if( null == m_pool )
247 {
248 m_pool = new Poolable[ increase ];
249 return;
250 }
251
252 final Poolable[] poolables = new Poolable[ increase + m_pool.length ];
253 System.arraycopy( m_pool, 0, poolables, 0, m_pool.length );
254 m_pool = poolables;
255 }
256
257
260 public final void shrink( final int decrease )
261 {
262 final Poolable[] poolables = new Poolable[ m_pool.length - decrease ];
263 System.arraycopy( m_pool, 0, poolables, 0, poolables.length );
264 m_pool = poolables;
265 }
266
267
270 public void dispose()
271 {
272 while( m_count > 0 )
273 {
274 int i = m_count - 1;
275 try
276 {
277 m_factory.decommission( m_pool[ i ] );
278 }
279 catch( Exception e )
280 {
281 if( ( getLogger() != null ) && ( getLogger().isDebugEnabled() ) )
283 {
284 getLogger().debug( "Error decommissioning object", e );
285 }
286 }
287 m_pool[ i ] = null;
288 m_count--;
289 }
290 }
291 }
292 |
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