Mercurial > jhg
annotate src/com/tmate/hgkit/fs/ByteArrayDataAccess.java @ 53:a6f39e595b2b wrap-data-access
Merged changes from default branch
author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
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date | Sun, 16 Jan 2011 01:40:38 +0100 |
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1 /* |
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2 * Copyright (c) 2011 Artem Tikhomirov |
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3 */ |
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4 package com.tmate.hgkit.fs; |
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5 |
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6 import java.io.IOException; |
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7 |
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8 /** |
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9 * |
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10 * @author artem |
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11 */ |
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12 public class ByteArrayDataAccess extends DataAccess { |
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13 |
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14 private final byte[] data; |
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15 private final int offset; |
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16 private final int length; |
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17 private int pos; |
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18 |
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19 public ByteArrayDataAccess(byte[] data) { |
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20 this(data, 0, data.length); |
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21 } |
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22 |
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23 public ByteArrayDataAccess(byte[] data, int offset, int length) { |
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24 this.data = data; |
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25 this.offset = offset; |
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26 this.length = length; |
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27 pos = 0; |
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28 } |
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29 |
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30 @Override |
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31 public byte readByte() throws IOException { |
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32 if (pos >= length) { |
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33 throw new IOException(); |
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34 } |
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35 return data[offset + pos++]; |
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36 } |
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37 @Override |
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38 public void readBytes(byte[] buf, int off, int len) throws IOException { |
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39 if (len > (this.length - pos)) { |
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40 throw new IOException(); |
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41 } |
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42 System.arraycopy(data, pos, buf, off, len); |
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43 pos += len; |
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44 } |
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45 |
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46 @Override |
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47 public void reset() { |
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48 pos = 0; |
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49 } |
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50 @Override |
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51 public long length() { |
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52 return length; |
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53 } |
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54 @Override |
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55 public void seek(long offset) { |
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56 pos = (int) offset; |
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57 } |
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58 @Override |
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59 public void skip(int bytes) throws IOException { |
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60 seek(pos + bytes); |
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61 } |
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62 @Override |
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63 public boolean isEmpty() { |
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64 return pos >= length; |
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65 } |
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66 |
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67 // |
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68 |
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69 // when byte[] needed from DA, we may save few cycles and some memory giving this (otherwise unsafe) access to underlying data |
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70 @Override |
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71 public byte[] byteArray() { |
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72 return data; |
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73 } |
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74 } |