Mercurial > jhg

annotate src/com/tmate/hgkit/fs/DataAccessProvider.java @ 23:6f9aca1a97be

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Severe defect in buffer wrap on seek
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Thu, 06 Jan 2011 03:30:43 +0100
parents 382cfe9463db
children 71a9ba42cee8
rev   line source
10
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
1 /*
23
6f9aca1a97be Severe defect in buffer wrap on seek
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 10
diff changeset
2 * Copyright (c) 2010, 2011 Artem Tikhomirov
10
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
3 */
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
4 package com.tmate.hgkit.fs;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
5
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
6 import java.io.File;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
7 import java.io.FileInputStream;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
8 import java.io.IOException;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
9 import java.nio.ByteBuffer;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
10 import java.nio.MappedByteBuffer;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
11 import java.nio.channels.FileChannel;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
12
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
13 /**
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
14 *
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
15 * @author artem
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
16 */
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
17 public class DataAccessProvider {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
18
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
19 private final int mapioMagicBoundary;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
20 private final int bufferSize;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
21
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
22 public DataAccessProvider() {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
23 mapioMagicBoundary = 100 * 1024;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
24 bufferSize = 8 * 1024;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
25 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
26
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
27 public DataAccess create(File f) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
28 if (!f.exists()) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
29 return new DataAccess();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
30 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
31 try {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
32 FileChannel fc = new FileInputStream(f).getChannel();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
33 if (fc.size() > mapioMagicBoundary) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
34 return new MemoryMapFileAccess(fc, fc.size());
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
35 } else {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
36 // XXX once implementation is more or less stable,
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
37 // may want to try ByteBuffer.allocateDirect() to see
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
38 // if there's any performance gain.
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
39 boolean useDirectBuffer = false;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
40 return new FileAccess(fc, fc.size(), bufferSize, useDirectBuffer);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
41 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
42 } catch (IOException ex) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
43 // unlikely to happen, we've made sure file exists.
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
44 ex.printStackTrace(); // FIXME log error
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
45 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
46 return new DataAccess(); // non-null, empty.
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
47 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
48
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
49 // DOESN'T WORK YET
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
50 private static class MemoryMapFileAccess extends DataAccess {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
51 private FileChannel fileChannel;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
52 private final long size;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
53 private long position = 0;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
54
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
55 public MemoryMapFileAccess(FileChannel fc, long channelSize) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
56 fileChannel = fc;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
57 size = channelSize;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
58 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
59
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
60 @Override
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
61 public void seek(long offset) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
62 position = offset;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
63 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
64
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
65 @Override
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
66 public void skip(int bytes) throws IOException {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
67 position += bytes;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
68 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
69
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
70 private boolean fill() throws IOException {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
71 final int BUFFER_SIZE = 8 * 1024;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
72 long left = size - position;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
73 MappedByteBuffer rv = fileChannel.map(FileChannel.MapMode.READ_ONLY, position, left < BUFFER_SIZE ? left : BUFFER_SIZE);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
74 position += rv.capacity();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
75 return rv.hasRemaining();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
76 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
77
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
78 @Override
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
79 public void done() {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
80 if (fileChannel != null) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
81 try {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
82 fileChannel.close();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
83 } catch (IOException ex) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
84 ex.printStackTrace(); // log debug
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
85 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
86 fileChannel = null;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
87 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
88 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
89 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
90
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
91 // (almost) regular file access - FileChannel and buffers.
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
92 private static class FileAccess extends DataAccess {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
93 private FileChannel fileChannel;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
94 private final long size;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
95 private ByteBuffer buffer;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
96 private long bufferStartInFile = 0; // offset of this.buffer in the file.
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
97
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
98 public FileAccess(FileChannel fc, long channelSize, int bufferSizeHint, boolean useDirect) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
99 fileChannel = fc;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
100 size = channelSize;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
101 final int capacity = size < bufferSizeHint ? (int) size : bufferSizeHint;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
102 buffer = useDirect ? ByteBuffer.allocateDirect(capacity) : ByteBuffer.allocate(capacity);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
103 buffer.flip(); // or .limit(0) to indicate it's empty
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
104 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
105
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
106 @Override
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
107 public boolean isEmpty() {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
108 return bufferStartInFile + buffer.position() >= size;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
109 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
110
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
111 @Override
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
112 public void seek(long offset) throws IOException {
23
6f9aca1a97be Severe defect in buffer wrap on seek
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 10
diff changeset
113 if (offset > size) {
6f9aca1a97be Severe defect in buffer wrap on seek
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 10
diff changeset
114 throw new IllegalArgumentException();
6f9aca1a97be Severe defect in buffer wrap on seek
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 10
diff changeset
115 }
10
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
116 if (offset < bufferStartInFile + buffer.limit() && offset >= bufferStartInFile) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
117 buffer.position((int) (offset - bufferStartInFile));
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
118 } else {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
119 // out of current buffer, invalidate it (force re-read)
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
120 // XXX or ever re-read it right away?
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
121 bufferStartInFile = offset;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
122 buffer.clear();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
123 buffer.limit(0); // or .flip() to indicate we switch to reading
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
124 fileChannel.position(offset);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
125 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
126 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
127
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
128 @Override
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
129 public void skip(int bytes) throws IOException {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
130 final int newPos = buffer.position() + bytes;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
131 if (newPos >= 0 && newPos < buffer.limit()) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
132 // no need to move file pointer, just rewind/seek buffer
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
133 buffer.position(newPos);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
134 } else {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
135 //
23
6f9aca1a97be Severe defect in buffer wrap on seek
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents: 10
diff changeset
136 seek(bufferStartInFile + newPos);
10
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
137 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
138 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
139
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
140 private boolean fill() throws IOException {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
141 if (!buffer.hasRemaining()) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
142 bufferStartInFile += buffer.limit();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
143 buffer.clear();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
144 if (bufferStartInFile < size) { // just in case there'd be any exception on EOF, not -1
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
145 fileChannel.read(buffer);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
146 // may return -1 when EOF, but empty will reflect this, hence no explicit support here
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
147 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
148 buffer.flip();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
149 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
150 return buffer.hasRemaining();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
151 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
152
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
153 @Override
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
154 public void readBytes(byte[] buf, int offset, int length) throws IOException {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
155 final int tail = buffer.remaining();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
156 if (tail >= length) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
157 buffer.get(buf, offset, length);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
158 } else {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
159 buffer.get(buf, offset, tail);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
160 if (fill()) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
161 buffer.get(buf, offset + tail, length - tail);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
162 } else {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
163 throw new IOException(); // shall not happen provided stream contains expected data and no attempts to read past nonEmpty() == false are made.
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
164 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
165 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
166 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
167
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
168 @Override
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
169 public byte readByte() throws IOException {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
170 if (buffer.hasRemaining()) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
171 return buffer.get();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
172 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
173 if (fill()) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
174 return buffer.get();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
175 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
176 throw new IOException();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
177 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
178
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
179 @Override
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
180 public void done() {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
181 if (buffer != null) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
182 buffer = null;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
183 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
184 if (fileChannel != null) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
185 try {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
186 fileChannel.close();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
187 } catch (IOException ex) {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
188 ex.printStackTrace(); // log debug
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
189 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
190 fileChannel = null;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
191 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
192 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
193 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
194 }