svn-gvsig-desktop / tags / v1_0_2_Build_916 / libraries / libIverUtiles / src / com / iver / utiles / bigfile / BigByteBuffer.java @ 12327
History | View | Annotate | Download (9.26 KB)
1 |
/*
|
---|---|
2 |
* Created on 11-jul-2005
|
3 |
*
|
4 |
* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana
|
5 |
*
|
6 |
* Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.
|
7 |
*
|
8 |
* This program is free software; you can redistribute it and/or
|
9 |
* modify it under the terms of the GNU General Public License
|
10 |
* as published by the Free Software Foundation; either version 2
|
11 |
* of the License, or (at your option) any later version.
|
12 |
*
|
13 |
* This program is distributed in the hope that it will be useful,
|
14 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
15 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
16 |
* GNU General Public License for more details.
|
17 |
*
|
18 |
* You should have received a copy of the GNU General Public License
|
19 |
* along with this program; if not, write to the Free Software
|
20 |
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
21 |
*
|
22 |
* For more information, contact:
|
23 |
*
|
24 |
* Generalitat Valenciana
|
25 |
* Conselleria d'Infraestructures i Transport
|
26 |
* Av. Blasco Ib??ez, 50
|
27 |
* 46010 VALENCIA
|
28 |
* SPAIN
|
29 |
*
|
30 |
* +34 963862235
|
31 |
* gvsig@gva.es
|
32 |
* www.gvsig.gva.es
|
33 |
*
|
34 |
* or
|
35 |
*
|
36 |
* IVER T.I. S.A
|
37 |
* Salamanca 50
|
38 |
* 46005 Valencia
|
39 |
* Spain
|
40 |
*
|
41 |
* +34 963163400
|
42 |
* dac@iver.es
|
43 |
*/
|
44 |
package com.iver.utiles.bigfile; |
45 |
|
46 |
import java.io.IOException; |
47 |
import java.nio.Buffer; |
48 |
import java.nio.ByteBuffer; |
49 |
import java.nio.ByteOrder; |
50 |
import java.nio.CharBuffer; |
51 |
import java.nio.DoubleBuffer; |
52 |
import java.nio.FloatBuffer; |
53 |
import java.nio.IntBuffer; |
54 |
import java.nio.LongBuffer; |
55 |
import java.nio.MappedByteBuffer; |
56 |
import java.nio.ShortBuffer; |
57 |
import java.nio.channels.FileChannel; |
58 |
|
59 |
/**
|
60 |
* @author Fjp
|
61 |
*
|
62 |
* Clase para trabajar con ficheros grandes. Mapea solo un trozo
|
63 |
* de fichero en memoria, y cuando intentas acceder fuera de esa
|
64 |
* zona, se ocupa de leer autom?ticamente el trozo que le falta.
|
65 |
*/
|
66 |
public class BigByteBuffer { |
67 |
|
68 |
private static long DEFAULT_SIZE = 50*1024*1024; // 50 Megas m?ximo |
69 |
|
70 |
MappedByteBuffer bb;
|
71 |
FileChannel fc;
|
72 |
long minAbs, maxAbs, posAbs;
|
73 |
int minRel, maxRel, posRel;
|
74 |
long sizeChunk, amountMem;
|
75 |
long fileSize;
|
76 |
FileChannel.MapMode mode;
|
77 |
|
78 |
/**
|
79 |
* Revisa la posici?n absoluta, y si hace falta, carga el buffer
|
80 |
* con la parte de fichero que toca.
|
81 |
* @throws IOException
|
82 |
*/
|
83 |
private void prepareBuffer(long posActual, int numBytesToRead) |
84 |
{ |
85 |
long desiredPos = posActual + numBytesToRead;
|
86 |
if ((desiredPos > maxAbs) || (posActual < minAbs))
|
87 |
{ |
88 |
// Quiero leer fuera:
|
89 |
sizeChunk = Math.min(fileSize-posActual, amountMem);
|
90 |
try {
|
91 |
ByteOrder lastOrder = bb.order();
|
92 |
bb = fc.map(mode, posActual, sizeChunk); |
93 |
minAbs = posActual; |
94 |
maxAbs = sizeChunk + posActual; |
95 |
bb.order(lastOrder); |
96 |
// System.out.println("BigByteBuffer: min=" + minAbs
|
97 |
// + " maxAbs=" + maxAbs + " posAbs = " + posAbs);
|
98 |
|
99 |
} catch (IOException e) { |
100 |
// TODO Auto-generated catch block
|
101 |
e.printStackTrace(); |
102 |
} |
103 |
|
104 |
} |
105 |
// Dejamos posAbs apuntando a donde va a quedar
|
106 |
// "a priori", antes de leer de verdad, que se hace
|
107 |
// al salir de esta funci?n.
|
108 |
posAbs = desiredPos; |
109 |
|
110 |
} |
111 |
|
112 |
public BigByteBuffer(FileChannel fc, FileChannel.MapMode mode, long amountMem) throws IOException |
113 |
{ |
114 |
this.amountMem = amountMem;
|
115 |
this.fc = fc;
|
116 |
this.fileSize = fc.size();
|
117 |
this.mode = mode;
|
118 |
sizeChunk = Math.min(fc.size(), amountMem);
|
119 |
bb = fc.map(mode, 0L, sizeChunk);
|
120 |
minAbs = 0;
|
121 |
maxAbs = sizeChunk; |
122 |
} |
123 |
public BigByteBuffer(FileChannel fc, FileChannel.MapMode mode) throws IOException |
124 |
{ |
125 |
this.amountMem = DEFAULT_SIZE;
|
126 |
this.fc = fc;
|
127 |
this.fileSize = fc.size();
|
128 |
this.mode = mode;
|
129 |
sizeChunk = Math.min(fc.size(), amountMem);
|
130 |
bb = fc.map(mode, 0L, sizeChunk);
|
131 |
minAbs = 0;
|
132 |
maxAbs = sizeChunk; |
133 |
} |
134 |
|
135 |
|
136 |
public synchronized byte get() { |
137 |
prepareBuffer(posAbs,1);
|
138 |
return bb.get();
|
139 |
} |
140 |
public synchronized ByteBuffer get(byte[] dst) |
141 |
{ |
142 |
prepareBuffer(posAbs, dst.length); |
143 |
return bb.get(dst);
|
144 |
} |
145 |
|
146 |
public synchronized char getChar() { |
147 |
prepareBuffer(posAbs,2);
|
148 |
return bb.getChar();
|
149 |
} |
150 |
|
151 |
public synchronized double getDouble() { |
152 |
prepareBuffer(posAbs,8);
|
153 |
return bb.getDouble();
|
154 |
} |
155 |
|
156 |
public synchronized float getFloat() { |
157 |
prepareBuffer(posAbs,4);
|
158 |
return bb.getFloat();
|
159 |
} |
160 |
|
161 |
public synchronized int getInt() { |
162 |
prepareBuffer(posAbs,4);
|
163 |
return bb.getInt();
|
164 |
} |
165 |
|
166 |
public synchronized long getLong() { |
167 |
prepareBuffer(posAbs,8);
|
168 |
return bb.getLong();
|
169 |
} |
170 |
|
171 |
public synchronized short getShort() { |
172 |
prepareBuffer(posAbs,2);
|
173 |
return bb.getShort();
|
174 |
} |
175 |
|
176 |
public boolean isDirect() { |
177 |
return bb.isDirect();
|
178 |
} |
179 |
|
180 |
public synchronized byte get(int index) { |
181 |
prepareBuffer(index,1);
|
182 |
return bb.get(index - (int) minAbs); |
183 |
} |
184 |
|
185 |
public synchronized char getChar(int index) { |
186 |
prepareBuffer(index,2);
|
187 |
return bb.getChar(index - (int) minAbs); |
188 |
} |
189 |
|
190 |
public synchronized double getDouble(int index) { |
191 |
prepareBuffer(index,8);
|
192 |
return bb.getDouble(index - (int) minAbs); |
193 |
} |
194 |
|
195 |
public synchronized float getFloat(int index) { |
196 |
prepareBuffer(index,4);
|
197 |
return bb.getFloat(index - (int) minAbs); |
198 |
} |
199 |
|
200 |
public synchronized int getInt(int index) { |
201 |
prepareBuffer(index,4);
|
202 |
return bb.getInt(index - (int) minAbs); |
203 |
} |
204 |
|
205 |
public synchronized long getLong(int index) { |
206 |
prepareBuffer(index,8);
|
207 |
return bb.getLong(index - (int) minAbs); |
208 |
} |
209 |
|
210 |
public synchronized short getShort(int index) { |
211 |
prepareBuffer(index,2);
|
212 |
return bb.getShort(index - (int) minAbs); |
213 |
} |
214 |
|
215 |
public ByteBuffer asReadOnlyBuffer() { |
216 |
return bb.asReadOnlyBuffer();
|
217 |
} |
218 |
|
219 |
public ByteBuffer compact() { |
220 |
return bb.compact();
|
221 |
} |
222 |
|
223 |
public ByteBuffer duplicate() { |
224 |
return bb.duplicate();
|
225 |
} |
226 |
|
227 |
public ByteBuffer slice() { |
228 |
return bb.slice();
|
229 |
} |
230 |
|
231 |
public synchronized ByteBuffer put(byte b) { |
232 |
prepareBuffer(posAbs,1);
|
233 |
return bb.put(b);
|
234 |
} |
235 |
|
236 |
public synchronized ByteBuffer putChar(char value) { |
237 |
prepareBuffer(posAbs,2);
|
238 |
return bb.putChar(value);
|
239 |
} |
240 |
|
241 |
public synchronized ByteBuffer putDouble(double value) { |
242 |
prepareBuffer(posAbs,8);
|
243 |
return bb.putDouble(value);
|
244 |
} |
245 |
|
246 |
public synchronized ByteBuffer putFloat(float value) { |
247 |
prepareBuffer(posAbs,4);
|
248 |
return bb.putFloat(value);
|
249 |
} |
250 |
|
251 |
public synchronized ByteBuffer putInt(int value) { |
252 |
prepareBuffer(posAbs,4);
|
253 |
return bb.putInt(value);
|
254 |
} |
255 |
|
256 |
public synchronized ByteBuffer put(int index, byte b) { |
257 |
prepareBuffer(index,1);
|
258 |
return bb.put(index- (int) minAbs, b); |
259 |
} |
260 |
|
261 |
public synchronized ByteBuffer putChar(int index, char value) { |
262 |
prepareBuffer(index,2);
|
263 |
return bb.putChar(index- (int) minAbs, value); |
264 |
} |
265 |
|
266 |
public synchronized ByteBuffer putDouble(int index, double value) { |
267 |
prepareBuffer(index,8);
|
268 |
return bb.putDouble(index- (int) minAbs, value); |
269 |
} |
270 |
|
271 |
public synchronized ByteBuffer putFloat(int index, float value) { |
272 |
prepareBuffer(index,4);
|
273 |
return bb.putFloat(index- (int) minAbs, value); |
274 |
} |
275 |
|
276 |
public synchronized ByteBuffer putInt(int index, int value) { |
277 |
prepareBuffer(index,4);
|
278 |
return bb.putInt(index- (int) minAbs, value); |
279 |
} |
280 |
|
281 |
public synchronized ByteBuffer putLong(int index, long value) { |
282 |
prepareBuffer(index,8);
|
283 |
return bb.putLong(index- (int) minAbs, value); |
284 |
} |
285 |
|
286 |
public synchronized ByteBuffer putShort(int index, short value) { |
287 |
prepareBuffer(index,2);
|
288 |
return bb.putShort(index- (int) minAbs, value); |
289 |
} |
290 |
|
291 |
public synchronized ByteBuffer putLong(long value) { |
292 |
prepareBuffer(posAbs,8);
|
293 |
return bb.putLong(value);
|
294 |
} |
295 |
|
296 |
public synchronized ByteBuffer putShort(short value) { |
297 |
prepareBuffer(posAbs,2);
|
298 |
return bb.putShort(value);
|
299 |
} |
300 |
|
301 |
public CharBuffer asCharBuffer() { |
302 |
return bb.asCharBuffer();
|
303 |
} |
304 |
|
305 |
public DoubleBuffer asDoubleBuffer() { |
306 |
return bb.asDoubleBuffer();
|
307 |
} |
308 |
|
309 |
public FloatBuffer asFloatBuffer() { |
310 |
return bb.asFloatBuffer();
|
311 |
} |
312 |
|
313 |
public IntBuffer asIntBuffer() { |
314 |
return bb.asIntBuffer();
|
315 |
} |
316 |
|
317 |
public LongBuffer asLongBuffer() { |
318 |
return bb.asLongBuffer();
|
319 |
} |
320 |
|
321 |
public ShortBuffer asShortBuffer() { |
322 |
return bb.asShortBuffer();
|
323 |
} |
324 |
|
325 |
public boolean isReadOnly() { |
326 |
return bb.isReadOnly();
|
327 |
} |
328 |
|
329 |
public final ByteOrder order() |
330 |
{ |
331 |
return bb.order();
|
332 |
} |
333 |
|
334 |
public final ByteBuffer order(ByteOrder bo) |
335 |
{ |
336 |
return bb.order(bo);
|
337 |
} |
338 |
public final long position() |
339 |
{ |
340 |
return posAbs;
|
341 |
} |
342 |
|
343 |
public synchronized final Buffer position(long newPosition) |
344 |
{ |
345 |
prepareBuffer(newPosition,0);
|
346 |
int relPos = (int) (newPosition - minAbs); |
347 |
// System.out.println("Position=" + newPosition);
|
348 |
return bb.position(relPos);
|
349 |
} |
350 |
|
351 |
} |