001package ball.io; 002/*- 003 * ########################################################################## 004 * Utilities 005 * $Id: CharSequenceReader.java 5856 2020-04-27 20:21:05Z ball $ 006 * $HeadURL: svn+ssh://svn.hcf.dev/var/spool/scm/repository.svn/ball-util/trunk/src/main/java/ball/io/CharSequenceReader.java $ 007 * %% 008 * Copyright (C) 2008 - 2020 Allen D. Ball 009 * %% 010 * Licensed under the Apache License, Version 2.0 (the "License"); 011 * you may not use this file except in compliance with the License. 012 * You may obtain a copy of the License at 013 * 014 * http://www.apache.org/licenses/LICENSE-2.0 015 * 016 * Unless required by applicable law or agreed to in writing, software 017 * distributed under the License is distributed on an "AS IS" BASIS, 018 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 019 * See the License for the specific language governing permissions and 020 * limitations under the License. 021 * ########################################################################## 022 */ 023import java.io.IOException; 024import java.io.LineNumberReader; 025import java.io.Reader; 026import java.util.Objects; 027import lombok.ToString; 028 029/** 030 * {@link CharSequence} {@link Reader} implementation. 031 * 032 * @author {@link.uri mailto:ball@hcf.dev Allen D. Ball} 033 * @version $Revision: 5856 $ 034 */ 035@ToString 036public class CharSequenceReader extends LineNumberReader { 037 038 /** 039 * Sole constructor. 040 * 041 * @param sequence The {@link CharSequence}. 042 */ 043 public CharSequenceReader(CharSequence sequence) { 044 super(new ReaderImpl(sequence), 1024); 045 } 046 047 @ToString 048 private static class ReaderImpl extends Reader { 049 private CharSequence sequence = null; 050 private volatile int length = 0; 051 private volatile int pos = 0; 052 private volatile int mark = 0; 053 054 public ReaderImpl(CharSequence sequence) { 055 super(new Object()); 056 057 this.sequence = Objects.requireNonNull(sequence); 058 this.length = sequence.length(); 059 } 060 061 @Override 062 public int read() throws IOException { 063 int character = -1; 064 065 synchronized (lock) { 066 if (pos < length) { 067 character = sequence.charAt(pos++); 068 } 069 } 070 071 return character; 072 } 073 074 @Override 075 public int read(char chars[], int off, int len) throws IOException { 076 int count = -1; 077 078 synchronized (lock) { 079 if (pos < length) { 080 count = Math.min(length - pos, len); 081 082 for (int i = 0; i < count; i += 1) { 083 chars[off + i] = sequence.charAt(pos + i); 084 } 085 086 pos += count; 087 } 088 } 089 090 return count; 091 } 092 093 @Override 094 public long skip(long count) throws IOException { 095 if (count < 0) { 096 throw new IllegalArgumentException("skip value is negative"); 097 } 098 099 synchronized (lock) { 100 count = Math.min(count, length - pos); 101 pos += count; 102 } 103 104 return count; 105 } 106 107 @Override 108 public boolean ready() throws IOException { return true; } 109 110 @Override 111 public boolean markSupported() { return true; } 112 113 @Override 114 public void mark(int readAheadLimit) throws IOException { 115 if (readAheadLimit < 0){ 116 throw new IllegalArgumentException("Read-ahead limit < 0"); 117 } 118 119 synchronized (lock) { 120 mark = pos; 121 } 122 } 123 124 @Override 125 public void reset() throws IOException { 126 synchronized (lock) { 127 pos = mark; 128 } 129 } 130 131 @Override 132 public void close() throws IOException { sequence = null; } 133 } 134}