| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.store.raw.log.LogAccessFileBuffer |
| 4 | |
| 5 | Copyright 2003, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.store.raw.log; |
| 22 | |
| 23 | |
| 24 | /** |
| 25 | |
| 26 | A single buffer of data. |
| 27 | |
| 28 | **/ |
| 29 | |
| 30 | final class LogAccessFileBuffer |
| 31 | { |
| 32 | |
| 33 | |
| 34 | /************************************************************************** |
| 35 | * Fields of the class |
| 36 | ************************************************************************** |
| 37 | */ |
| 38 | protected byte[] buffer; |
| 39 | protected int bytes_free; |
| 40 | protected int position; |
| 41 | protected int length; |
| 42 | |
| 43 | LogAccessFileBuffer next; |
| 44 | LogAccessFileBuffer prev; |
| 45 | |
| 46 | /************************************************************************** |
| 47 | * Constructors for This class: |
| 48 | ************************************************************************** |
| 49 | */ |
| 50 | public LogAccessFileBuffer( |
| 51 | int size) |
| 52 | { |
| 53 | buffer = new byte[size]; |
| 54 | prev = null; |
| 55 | next = null; |
| 56 | |
| 57 | init(0); |
| 58 | } |
| 59 | |
| 60 | /************************************************************************** |
| 61 | * Private/Protected methods of This class: |
| 62 | ************************************************************************** |
| 63 | */ |
| 64 | public void init(int reserve) |
| 65 | { |
| 66 | length = buffer.length - reserve; |
| 67 | bytes_free = length; |
| 68 | position = reserve; |
| 69 | } |
| 70 | |
| 71 | /************************************************************************** |
| 72 | * Public Methods of This class: |
| 73 | ************************************************************************** |
| 74 | */ |
| 75 | |
| 76 | /************************************************************************** |
| 77 | * Public Methods of XXXX class: |
| 78 | ************************************************************************** |
| 79 | */ |
| 80 | } |