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Diffstat (limited to 'XMPCore/src/com/adobe/xmp/impl/FixASCIIControlsReader.java')
| -rw-r--r-- | XMPCore/src/com/adobe/xmp/impl/FixASCIIControlsReader.java | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/XMPCore/src/com/adobe/xmp/impl/FixASCIIControlsReader.java b/XMPCore/src/com/adobe/xmp/impl/FixASCIIControlsReader.java new file mode 100644 index 0000000..c6ac7d4 --- /dev/null +++ b/XMPCore/src/com/adobe/xmp/impl/FixASCIIControlsReader.java @@ -0,0 +1,214 @@ +// ================================================================================================= +// ADOBE SYSTEMS INCORPORATED +// Copyright 2006 Adobe Systems Incorporated +// All Rights Reserved +// +// NOTICE: Adobe permits you to use, modify, and distribute this file in accordance with the terms +// of the Adobe license agreement accompanying it. +// ================================================================================================= + +package com.adobe.xmp.impl; + +import java.io.IOException; +import java.io.PushbackReader; +import java.io.Reader; + + +/** + * @since 22.08.2006 + */ +public class FixASCIIControlsReader extends PushbackReader +{ + /** */ + private static final int STATE_START = 0; + /** */ + private static final int STATE_AMP = 1; + /** */ + private static final int STATE_HASH = 2; + /** */ + private static final int STATE_HEX = 3; + /** */ + private static final int STATE_DIG1 = 4; + /** */ + private static final int STATE_ERROR = 5; + /** */ + private static final int BUFFER_SIZE = 8; + /** the state of the automaton */ + private int state = STATE_START; + /** the result of the escaping sequence */ + private int control = 0; + /** count the digits of the sequence */ + private int digits = 0; + + /** + * The look-ahead size is 6 at maximum (&#xAB;) + * @see PushbackReader#PushbackReader(Reader, int) + * @param in a Reader + */ + public FixASCIIControlsReader(Reader in) + { + super(in, BUFFER_SIZE); + } + + + /** + * @see Reader#read(char[], int, int) + */ + public int read(char[] cbuf, int off, int len) throws IOException + { + int readAhead = 0; + int read = 0; + int pos = off; + char[] readAheadBuffer = new char[BUFFER_SIZE]; + + boolean available = true; + while (available && read < len) + { + available = super.read(readAheadBuffer, readAhead, 1) == 1; + if (available) + { + char c = processChar(readAheadBuffer[readAhead]); + if (state == STATE_START) + { + // replace control chars with space + if (Utils.isControlChar(c)) + { + c = ' '; + } + cbuf[pos++] = c; + readAhead = 0; + read++; + } + else if (state == STATE_ERROR) + { + unread(readAheadBuffer, 0, readAhead + 1); + readAhead = 0; + } + else + { + readAhead++; + } + } + else if (readAhead > 0) + { + // handles case when file ends within excaped sequence + unread(readAheadBuffer, 0, readAhead); + state = STATE_ERROR; + readAhead = 0; + available = true; + } + } + + + return read > 0 || available ? read : -1; + } + + + /** + * Processes numeric escaped chars to find out if they are a control character. + * @param ch a char + * @return Returns the char directly or as replacement for the escaped sequence. + */ + private char processChar(char ch) + { + switch (state) + { + case STATE_START: + if (ch == '&') + { + state = STATE_AMP; + } + return ch; + + case STATE_AMP: + if (ch == '#') + { + state = STATE_HASH; + } + else + { + state = STATE_ERROR; + } + return ch; + + case STATE_HASH: + if (ch == 'x') + { + control = 0; + digits = 0; + state = STATE_HEX; + } + else if ('0' <= ch && ch <= '9') + { + control = Character.digit(ch, 10); + digits = 1; + state = STATE_DIG1; + } + else + { + state = STATE_ERROR; + } + return ch; + + case STATE_DIG1: + if ('0' <= ch && ch <= '9') + { + control = control * 10 + Character.digit(ch, 10); + digits++; + if (digits <= 5) + { + state = STATE_DIG1; + } + else + { + state = STATE_ERROR; // sequence too long + } + } + else if (ch == ';' && Utils.isControlChar((char) control)) + { + state = STATE_START; + return (char) control; + } + else + { + state = STATE_ERROR; + } + return ch; + + case STATE_HEX: + if (('0' <= ch && ch <= '9') || + ('a' <= ch && ch <= 'f') || + ('A' <= ch && ch <= 'F')) + { + control = control * 16 + Character.digit(ch, 16); + digits++; + if (digits <= 4) + { + state = STATE_HEX; + } + else + { + state = STATE_ERROR; // sequence too long + } + } + else if (ch == ';' && Utils.isControlChar((char) control)) + { + state = STATE_START; + return (char) control; + } + else + { + state = STATE_ERROR; + } + return ch; + + case STATE_ERROR: + state = STATE_START; + return ch; + + default: + // not reachable + return ch; + } + } +} |