Mercurial > jhg

annotate src/com/tmate/hgkit/fs/DataAccess.java @ 48:e34f90b9ded1

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Limit option for history/log
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Fri, 14 Jan 2011 23:22:20 +0100
parents 382cfe9463db
children 9429c7bd1920
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 /*
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
2 * Copyright (c) 2010 Artem Tikhomirov
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.IOException;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
7
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
8 /**
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
9 * relevant parts of DataInput, non-stream nature (seek operation), explicit check for end of data.
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
10 * convenient skip (+/- bytes)
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
11 * Primary goal - effective file read, so that clients don't need to care whether to call few
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
12 * distinct getInt() or readBytes(totalForFewInts) and parse themselves instead in an attempt to optimize.
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 public class DataAccess {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
15 public boolean isEmpty() {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
16 return true;
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
17 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
18 // absolute positioning
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
19 public void seek(long offset) throws IOException {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
20 throw new UnsupportedOperationException();
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 // relative positioning
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
23 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
24 throw new UnsupportedOperationException();
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 // shall be called once this object no longer needed
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
27 public void done() {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
28 // no-op in this empty implementation
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
29 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
30 public int readInt() throws IOException {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
31 byte[] b = new byte[4];
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
32 readBytes(b, 0, 4);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
33 return b[0] << 24 | (b[1] & 0xFF) << 16 | (b[2] & 0xFF) << 8 | (b[3] & 0xFF);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
34 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
35 public long readLong() throws IOException {
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
36 byte[] b = new byte[8];
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
37 readBytes(b, 0, 8);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
38 int i1 = b[0] << 24 | (b[1] & 0xFF) << 16 | (b[2] & 0xFF) << 8 | (b[3] & 0xFF);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
39 int i2 = b[4] << 24 | (b[5] & 0xFF) << 16 | (b[6] & 0xFF) << 8 | (b[7] & 0xFF);
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
40 return ((long) i1) << 32 | ((long) i2 & 0xFFFFFFFF);
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 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
43 throw new UnsupportedOperationException();
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
44 }
382cfe9463db Dirstate parsing. DataAccess refactored to allow reuse and control over constants
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
45 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
46 throw new UnsupportedOperationException();
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 }