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comparison src/org/tmatesoft/hg/internal/InflaterDataAccess.java @ 158:b413b16d10a5

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Integer offsets and file length explictly, rather than casts throughout code. Inflater may benefit from total length hint, but shall calculate it by its own if needed
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Wed, 09 Mar 2011 13:16:37 +0100
parents d5268ca7715b
children 31f67be94e71
comparison
equal deleted inserted replaced
157:d5268ca7715b 158:b413b16d10a5
20 import java.io.IOException; 20 import java.io.IOException;
21 import java.util.zip.DataFormatException; 21 import java.util.zip.DataFormatException;
22 import java.util.zip.Inflater; 22 import java.util.zip.Inflater;
23 import java.util.zip.ZipException; 23 import java.util.zip.ZipException;
24 24
25 import org.tmatesoft.hg.core.HgBadStateException;
26
25 27
26 /** 28 /**
27 * DataAccess counterpart for InflaterInputStream. 29 * DataAccess counterpart for InflaterInputStream.
28 * XXX is it really needed to be subclass of FilterDataAccess? 30 * XXX is it really needed to be subclass of FilterDataAccess?
29 * 31 *
34 36
35 private final Inflater inflater; 37 private final Inflater inflater;
36 private final byte[] buffer; 38 private final byte[] buffer;
37 private final byte[] singleByte = new byte[1]; 39 private final byte[] singleByte = new byte[1];
38 private int decompressedPos = 0; 40 private int decompressedPos = 0;
39 private int decompressedLength = -1; 41 private int decompressedLength;
40 42
41 public InflaterDataAccess(DataAccess dataAccess, long offset, int length) { 43 public InflaterDataAccess(DataAccess dataAccess, int offset, int compressedLength) {
42 this(dataAccess, offset, length, new Inflater(), 512); 44 this(dataAccess, offset, compressedLength, -1, new Inflater(), 512);
43 } 45 }
44 46
45 public InflaterDataAccess(DataAccess dataAccess, long offset, int length, Inflater inflater, int bufSize) { 47 public InflaterDataAccess(DataAccess dataAccess, int offset, int compressedLength, int actualLength) {
46 super(dataAccess, offset, length); 48 this(dataAccess, offset, compressedLength, actualLength, new Inflater(), 512);
49 }
50
51 public InflaterDataAccess(DataAccess dataAccess, int offset, int compressedLength, int actualLength, Inflater inflater, int bufSize) {
52 super(dataAccess, offset, compressedLength);
47 this.inflater = inflater; 53 this.inflater = inflater;
54 this.decompressedLength = actualLength;
48 buffer = new byte[bufSize]; 55 buffer = new byte[bufSize];
49 } 56 }
50 57
51 @Override 58 @Override
52 public InflaterDataAccess reset() throws IOException { 59 public InflaterDataAccess reset() throws IOException {
56 return this; 63 return this;
57 } 64 }
58 65
59 @Override 66 @Override
60 protected int available() { 67 protected int available() {
61 throw new IllegalStateException("Can't tell how much uncompressed data left"); 68 return length() - decompressedPos;
62 } 69 }
63 70
64 @Override 71 @Override
65 public boolean isEmpty() { 72 public boolean isEmpty() {
66 return super.available() <= 0 && inflater.finished(); // and/or inflater.getRemaining() <= 0 ? 73 // can't use super.available() <= 0 because even when 0 < super.count < 6(?)
74 // decompressedPos might be already == length()
75 return available() <= 0;
67 } 76 }
68 77
69 @Override 78 @Override
70 public long length() { 79 public int length() {
71 if (decompressedLength != -1) { 80 if (decompressedLength != -1) {
72 return decompressedLength; 81 return decompressedLength;
73 } 82 }
83 decompressedLength = 0; // guard to avoid endless loop in case length() would get invoked from below.
74 int c = 0; 84 int c = 0;
75 try { 85 try {
76 int oldPos = decompressedPos; 86 int oldPos = decompressedPos;
77 while (!isEmpty()) { 87 byte[] dummy = new byte[buffer.length];
78 readByte(); 88 int toRead;
79 c++; 89 while ((toRead = super.available()) > 0) {
90 if (toRead > buffer.length) {
91 toRead = buffer.length;
92 }
93 super.readBytes(buffer, 0, toRead);
94 inflater.setInput(buffer, 0, toRead);
95 try {
96 while (!inflater.needsInput()) {
97 c += inflater.inflate(dummy, 0, dummy.length);
98 }
99 } catch (DataFormatException ex) {
100 throw new HgBadStateException(ex);
101 }
80 } 102 }
81 decompressedLength = c + oldPos; 103 decompressedLength = c + oldPos;
82 reset(); 104 reset();
83 seek(oldPos); 105 seek(oldPos);
84 return decompressedLength; 106 return decompressedLength;
85 } catch (IOException ex) { 107 } catch (IOException ex) {
86 ex.printStackTrace(); // FIXME log error
87 decompressedLength = -1; // better luck next time? 108 decompressedLength = -1; // better luck next time?
88 return 0; 109 throw new HgBadStateException(ex); // XXX perhaps, checked exception
89 } 110 }
90 } 111 }
91 112
92 @Override 113 @Override
93 public void seek(long localOffset) throws IOException { 114 public void seek(int localOffset) throws IOException {
94 if (localOffset < 0 /* || localOffset >= length() */) { 115 if (localOffset < 0 /* || localOffset >= length() */) {
95 throw new IllegalArgumentException(); 116 throw new IllegalArgumentException();
96 } 117 }
97 if (localOffset >= decompressedPos) { 118 if (localOffset >= decompressedPos) {
98 skip((int) (localOffset - decompressedPos)); 119 skip((int) (localOffset - decompressedPos));