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1
21 package com.db4o.foundation.network;
22
23 import java.io.*;
24
25 import com.db4o.*;
26 import com.db4o.foundation.*;
27
28
32 class ByteBuffer4 {
33
34 private final int DISCARD_BUFFER_SIZE = 500;
35 protected byte[] i_cache;
36 private boolean i_closed = false;
37 protected int i_readOffset;
38 protected int i_timeout;
39 protected int i_writeOffset;
40 protected final Lock4 i_lock = new Lock4();
41
42 public ByteBuffer4(int timeout) {
43 i_timeout = timeout;
44 }
45
46 protected int available() {
47 return i_writeOffset - i_readOffset;
48 }
49
50 protected void checkDiscardCache() {
51 if (i_readOffset == i_writeOffset && i_cache.length > DISCARD_BUFFER_SIZE) {
52 i_cache = null;
53 i_readOffset = 0;
54 i_writeOffset = 0;
55 }
56 }
57
58 void close() {
59 i_closed = true;
60 }
61
62 protected void makefit(int length) {
63 if (i_cache == null) {
64 i_cache = new byte[length];
65 } else {
66 if (i_writeOffset + length > i_cache.length) {
68 if (i_writeOffset + length - i_readOffset <= i_cache.length) {
70 byte[] temp = new byte[i_cache.length];
71 System.arraycopy(i_cache, i_readOffset, temp, 0, i_cache.length - i_readOffset);
72 i_cache = temp;
73 i_writeOffset -= i_readOffset;
74 i_readOffset = 0;
75
76 } else {
78 byte[] temp = new byte[i_writeOffset + length];
79 System.arraycopy(i_cache, 0, temp, 0, i_cache.length);
80 i_cache = temp;
81 }
82 }
83 }
84 }
85
86 public int read() throws IOException {
87 try{
88 Integer  ret = (Integer )i_lock.run(new Closure4() {
89 public Object run() throws Exception {
90 waitForAvailable();
91 int retVal = i_cache[i_readOffset++];
92 checkDiscardCache();
93 return new Integer (retVal);
94 }
95
96 });
97 return ret.intValue();
98 }catch(IOException iex){
99 throw iex;
100 }catch(Exception bex){
101 }
103 return -1;
104 }
105
106 public int read(final byte[] a_bytes, final int a_offset, final int a_length) throws IOException {
107 try{
108 Integer ret = (Integer )i_lock.run(new Closure4() {
109 public Object run() throws Exception {
110 waitForAvailable();
111 int avail = available();
112 int length = a_length;
113 if (avail < a_length) {
114 length = avail;
115 }
116 System.arraycopy(i_cache, i_readOffset, a_bytes, a_offset, length);
117 i_readOffset += length;
118 checkDiscardCache();
119 return new Integer (avail);
120 }
121
122 });
123 return ret.intValue();
124 }catch(IOException iex){
125 throw iex;
126 }catch(Exception bex){
127 }
129 return -1;
130 }
131
132 public void setTimeout(int timeout) {
133 i_timeout = timeout;
134 }
135
136 protected void waitForAvailable() throws IOException {
137 while (available() == 0) {
138 try {
139 i_lock.snooze(i_timeout);
140 } catch (Exception e) {
141 throw new IOException(Messages.get(55));
142 }
143 }
144 if (i_closed) {
145 throw new IOException(Messages.get(35));
146 }
147
148 }
149
150 public void write(byte[] bytes) {
151 write(bytes, 0, bytes.length);
152 }
153
154 public void write(final byte[] bytes, final int off, final int len) {
155 try {
156 i_lock.run(new Closure4() {
157 public Object run() throws Exception {
158 makefit(len);
159 System.arraycopy(bytes, off, i_cache, i_writeOffset, len);
160 i_writeOffset += len;
161 i_lock.awake();
162 return null;
163 }
164 });
165 } catch (Exception e) {
166
167
169 }
170 }
171
172 public void write(final int i) {
173 try {
174 i_lock.run(new Closure4() {
175 public Object run() throws Exception {
176 makefit(1);
177 i_cache[i_writeOffset++] = (byte) i;
178 i_lock.awake();
179 return null;
180 }
181 });
182 } catch (Exception e) {
183
184
186 }
187 }
188 }
189 |
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