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1
30
31
32 package org.hsqldb.persist;
33
34 import java.io.DataInputStream  ;
35 import java.io.FileNotFoundException ;
36 import java.io.IOException ;
37 import java.io.InputStream ;
38
39 import org.hsqldb.Database;
40 import org.hsqldb.lib.HsqlByteArrayInputStream;
41
42
52 class ScaledRAFileInJar implements ScaledRAInterface {
53
54 DataInputStream file;
55 final String fileName;
56 long fileLength;
57 boolean bufferDirty = true;
58 byte[] buffer = new byte[4096];
59 HsqlByteArrayInputStream ba = new HsqlByteArrayInputStream(buffer);
60 long bufferOffset;
61
62 long seekPosition;
64 long realPosition;
65
66 ScaledRAFileInJar(String name) throws FileNotFoundException , IOException {
67
68 fileName = name;
69
70 resetStream();
71 file.skip(DataFileCache.LONG_FREE_POS_POS);
72
73 fileLength = file.readLong();
74
75 resetStream();
76 }
77
78 public long length() throws IOException {
79 return fileLength;
80 }
81
82
87 public void seek(long position) throws IOException {
88 seekPosition = position;
89 }
90
91 public long getFilePointer() throws IOException {
92 return seekPosition;
93 }
94
95 private void readIntoBuffer() throws IOException {
96
97 long filePos = seekPosition;
98
99 bufferDirty = false;
100
101 long subOffset = filePos % buffer.length;
102 long readLength = fileLength - (filePos - subOffset);
103
104 if (readLength <= 0) {
105 throw new IOException ("read beyond end of file");
106 }
107
108 if (readLength > buffer.length) {
109 readLength = buffer.length;
110 }
111
112 fileSeek(filePos - subOffset);
113 file.readFully(buffer, 0, (int) readLength);
114
115 bufferOffset = filePos - subOffset;
116 realPosition = bufferOffset + readLength;
117 }
118
119 public int read() throws IOException {
120
121 if (seekPosition >= fileLength) {
122 return -1;
123 }
124
125 if (bufferDirty || seekPosition < bufferOffset
126 || seekPosition >= bufferOffset + buffer.length) {
127 readIntoBuffer();
128 }
129
130 ba.reset();
131 ba.skip(seekPosition - bufferOffset);
132
133 int val = ba.read();
134
135 seekPosition++;
136
137 return val;
138 }
139
140 public long readLong() throws IOException {
141
142 long hi = readInt();
143 long lo = readInt();
144
145 return (hi << 32) + (lo & 0xffffffffL);
146 }
147
148 public int readInt() throws IOException {
149
150 if (bufferDirty || seekPosition < bufferOffset
151 || seekPosition >= bufferOffset + buffer.length) {
152 readIntoBuffer();
153 }
154
155 ba.reset();
156 ba.skip(seekPosition - bufferOffset);
157
158 int val = ba.readInt();
159
160 seekPosition += 4;
161
162 return val;
163 }
164
165 public void read(byte[] b, int offset, int length) throws IOException {
166
167 if (bufferDirty || seekPosition < bufferOffset
168 || seekPosition >= bufferOffset + buffer.length) {
169 readIntoBuffer();
170 }
171
172 ba.reset();
173 ba.skip(seekPosition - bufferOffset);
174
175 int bytesRead = ba.read(b, offset, length);
176
177 seekPosition += bytesRead;
178
179 if (bytesRead < length) {
180 if (seekPosition != realPosition) {
181 fileSeek(seekPosition);
182 }
183
184 file.readFully(b, offset + bytesRead, length - bytesRead);
185
186 seekPosition += (length - bytesRead);
187 realPosition = seekPosition;
188 }
189 }
190
191 public void write(byte[] b, int off, int len) throws IOException {}
192
193 public void writeInt(int i) throws IOException {}
194
195 public void writeLong(long i) throws IOException {}
196
197 public void close() throws IOException {
198 file.close();
199 }
200
201 public boolean isReadOnly() {
202 return true;
203 }
204
205 public boolean wasNio() {
206 return false;
207 }
208
209 private void resetStream() throws IOException {
210
211 if (file != null) {
212 file.close();
213 }
214
215 InputStream fis = getClass().getResourceAsStream(fileName);
216
217 file = new DataInputStream (fis);
218 }
219
220 private void fileSeek(long position) throws IOException {
221
222 long skipPosition = realPosition;
223
224 if (position < skipPosition) {
225 resetStream();
226
227 skipPosition = 0;
228 }
229
230 while (position > skipPosition) {
231 skipPosition += file.skip(position - skipPosition);
232 }
233 }
234
235 public boolean canAccess(int length) {
236 return false;
237 }
238
239 public boolean canSeek(long position) {
240 return false;
241 }
242
243 public Database getDatabase() {
244 return null;
245 }
246 }
247 |
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