main/classes/charset/src/com/ibm/icu/charset/CharsetASCII.java - external/github.com/unicode-org/icu - Git at Google

 // © 2016 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html#License
 /**
  *******************************************************************************
  * Copyright (C) 2006-2011, International Business Machines Corporation and    *
  * others. All Rights Reserved.                                                *
  *******************************************************************************
  *
  *******************************************************************************
  */
 package com.ibm.icu.charset;

 import java.nio.ByteBuffer;
 import java.nio.CharBuffer;
 import java.nio.IntBuffer;
 import java.nio.charset.CharsetDecoder;
 import java.nio.charset.CharsetEncoder;
 import java.nio.charset.CoderResult;

 import com.ibm.icu.text.UTF16;
 import com.ibm.icu.text.UnicodeSet;

 class CharsetASCII extends CharsetICU {
     protected byte[] fromUSubstitution = new byte[] { (byte) 0x1a };

     public CharsetASCII(String icuCanonicalName, String javaCanonicalName, String[] aliases) {
         super(icuCanonicalName, javaCanonicalName, aliases);
         maxBytesPerChar = 1;
         minBytesPerChar = 1;
         maxCharsPerByte = 1;
     }

     class CharsetDecoderASCII extends CharsetDecoderICU {

         public CharsetDecoderASCII(CharsetICU cs) {
             super(cs);
         }

         @Override
         protected CoderResult decodeLoop(ByteBuffer source, CharBuffer target, IntBuffer offsets,
                 boolean flush) {
             if (!source.hasRemaining()) {
                 /* no input, nothing to do */
                 return CoderResult.UNDERFLOW;
             }
             if (!target.hasRemaining()) {
                 /* no output available, can't do anything */
                 return CoderResult.OVERFLOW;
             }

             CoderResult cr;
             int oldSource = source.position();
             int oldTarget = target.position();

             if (source.hasArray() && target.hasArray()) {
                 /* optimized loop */

                 /*
                  * extract arrays from the buffers and obtain various constant values that will be
                  * necessary in the core loop
                  */
                 byte[] sourceArray = source.array();
                 int sourceOffset = source.arrayOffset();
                 int sourceIndex = oldSource + sourceOffset;
                 int sourceLength = source.limit() - oldSource;

                 char[] targetArray = target.array();
                 int targetOffset = target.arrayOffset();
                 int targetIndex = oldTarget + targetOffset;
                 int targetLength = target.limit() - oldTarget;

                 int limit = ((sourceLength < targetLength) ? sourceLength : targetLength)
                         + sourceIndex;
                 int offset = targetIndex - sourceIndex;

                 /*
                  * perform the core loop... if it returns null, it must be due to an overflow or
                  * underflow
                  */
                 cr = decodeLoopCoreOptimized(source, target, sourceArray, targetArray, sourceIndex, offset, limit);
                 if (cr == null) {
                     if (sourceLength <= targetLength) {
                         source.position(oldSource + sourceLength);
                         target.position(oldTarget + sourceLength);
                         cr = CoderResult.UNDERFLOW;
                     } else {
                         source.position(oldSource + targetLength);
                         target.position(oldTarget + targetLength);
                         cr = CoderResult.OVERFLOW;
                     }
                 }
             } else {
                 /* unoptimized loop */
                 cr = decodeLoopCoreUnoptimized(source, target);
                 if (cr == CoderResult.OVERFLOW) {
                     /* the target is full */
                     source.position(source.position() - 1); /* rewind by 1 */
                 }
             }

             /* set offsets since the start */
             if (offsets != null) {
                 int count = target.position() - oldTarget;
                 int sourceIndex = -1;
                 while (--count >= 0) offsets.put(++sourceIndex);
             }

             return cr;
         }

         protected CoderResult decodeLoopCoreOptimized(ByteBuffer source, CharBuffer target,
                 byte[] sourceArray, char[] targetArray, int oldSource, int offset, int limit) {
             int i, ch = 0;

             /*
              * perform ascii conversion from the source array to the target array, making sure each
              * byte in the source is within the correct range
              */
             for (i = oldSource; i < limit && (((ch = (sourceArray[i] & 0xff)) & 0x80) == 0); i++)
                 targetArray[i + offset] = (char) ch;

             /*
              * if some byte was not in the correct range, we need to deal with this byte by calling
              * decodeMalformedOrUnmappable and move the source and target positions to reflect the
              * early termination of the loop
              */
             if ((ch & 0x80) != 0) {
                 source.position(i + 1);
                 target.position(i + offset);
                 return decodeMalformedOrUnmappable(ch);
             } else
                 return null;
         }

         protected CoderResult decodeLoopCoreUnoptimized(ByteBuffer source, CharBuffer target) {
             int ch = 0;

             /*
              * perform ascii conversion from the source buffer to the target buffer, making sure
              * each byte in the source is within the correct range
              */
             while (source.hasRemaining()) {
                 ch = source.get() & 0xff;

                 if ((ch & 0x80) == 0) {
                     if (target.hasRemaining()) {
                         target.put((char)ch);
                     } else {
                         return CoderResult.OVERFLOW;
                     }
                 } else {
                     /*
                      * if we reach here, it's because a character was not in the correct range, and we need
                      * to deak with this by calling decodeMalformedOrUnmappable
                      */
                     return decodeMalformedOrUnmappable(ch);
                 }
             }

             return CoderResult.UNDERFLOW;
         }

         protected CoderResult decodeMalformedOrUnmappable(int ch) {
             /*
              * put the guilty character into toUBytesArray and return a message saying that the
              * character was malformed and of length 1.
              */
             toUBytesArray[0] = (byte) ch;
             toULength = 1;
             return CoderResult.malformedForLength(1);
         }
     }

     class CharsetEncoderASCII extends CharsetEncoderICU {

         public CharsetEncoderASCII(CharsetICU cs) {
             super(cs, fromUSubstitution);
             implReset();
         }

         private final static int NEED_TO_WRITE_BOM = 1;

         @Override
         protected void implReset() {
             super.implReset();
             fromUnicodeStatus = NEED_TO_WRITE_BOM;
         }

         @Override
         protected CoderResult encodeLoop(CharBuffer source, ByteBuffer target, IntBuffer offsets,
                 boolean flush) {
             if (!source.hasRemaining()) {
                 /* no input, nothing to do */
                 return CoderResult.UNDERFLOW;
             }
             if (!target.hasRemaining()) {
                 /* no output available, can't do anything */
                 return CoderResult.OVERFLOW;
             }

             CoderResult cr;
             int oldSource = source.position();
             int oldTarget = target.position();

             if (fromUChar32 != 0) {
                 /*
                  * if we have a leading character in fromUChar32 that needs to be dealt with, we
                  * need to check for a matching trail character and taking the appropriate action as
                  * dictated by encodeTrail.
                  */
                 cr = encodeTrail(source, (char) fromUChar32, flush);
             } else {
                 if (source.hasArray() && target.hasArray()) {
                     /* optimized loop */

                     /*
                      * extract arrays from the buffers and obtain various constant values that will
                      * be necessary in the core loop
                      */
                     char[] sourceArray = source.array();
                     int sourceOffset = source.arrayOffset();
                     int sourceIndex = oldSource + sourceOffset;
                     int sourceLength = source.limit() - oldSource;

                     byte[] targetArray = target.array();
                     int targetOffset = target.arrayOffset();
                     int targetIndex = oldTarget + targetOffset;
                     int targetLength = target.limit() - oldTarget;

                     int limit = ((sourceLength < targetLength) ? sourceLength : targetLength)
                             + sourceIndex;
                     int offset = targetIndex - sourceIndex;

                     /*
                      * perform the core loop... if it returns null, it must be due to an overflow or
                      * underflow
                      */
                     cr = encodeLoopCoreOptimized(source, target, sourceArray, targetArray, sourceIndex, offset, limit, flush);
                     if (cr == null) {
                         if (sourceLength <= targetLength) {
                             source.position(oldSource + sourceLength);
                             target.position(oldTarget + sourceLength);
                             cr = CoderResult.UNDERFLOW;
                         } else {
                             source.position(oldSource + targetLength);
                             target.position(oldTarget + targetLength);
                             cr = CoderResult.OVERFLOW;
                         }
                     }
                 } else {
                     /* unoptimized loop */

                     cr = encodeLoopCoreUnoptimized(source, target, flush);

                     if (cr == CoderResult.OVERFLOW) {
                         source.position(source.position() - 1); /* rewind by 1 */
                     }
                 }
             }

             /* set offsets since the start */
             if (offsets != null) {
                 int count = target.position() - oldTarget;
                 int sourceIndex = -1;
                 while (--count >= 0) offsets.put(++sourceIndex);
             }

             return cr;
         }

         protected CoderResult encodeLoopCoreOptimized(CharBuffer source, ByteBuffer target,
                 char[] sourceArray, byte[] targetArray, int oldSource, int offset, int limit,
                 boolean flush) {
             int i, ch = 0;

             /*
              * perform ascii conversion from the source array to the target array, making sure each
              * char in the source is within the correct range
              */
             for (i = oldSource; i < limit && (((ch = sourceArray[i]) & 0xff80) == 0); i++)
                 targetArray[i + offset] = (byte) ch;

             /*
              * if some byte was not in the correct range, we need to deal with this byte by calling
              * encodeMalformedOrUnmappable and move the source and target positions to reflect the
              * early termination of the loop
              */
             if ((ch & 0xff80) != 0) {
                 source.position((i + 1) - source.arrayOffset());
                 target.position(i + offset);
                 return encodeMalformedOrUnmappable(source, ch, flush);
             } else
                 return null;
         }

         protected CoderResult encodeLoopCoreUnoptimized(CharBuffer source, ByteBuffer target, boolean flush) {
             int ch;

             /*
              * perform ascii conversion from the source buffer to the target buffer, making sure
              * each char in the source is within the correct range
              */
             while (source.hasRemaining()) {
                 ch = source.get();

                 if ((ch & 0xff80) == 0) {
                     if (target.hasRemaining()) {
                         target.put((byte) ch);
                     } else {
                         return CoderResult.OVERFLOW;
                     }
                 } else {
                     /*
                      * if we reach here, it's because a character was not in the correct range, and we need
                      * to deak with this by calling encodeMalformedOrUnmappable.
                      */
                     return encodeMalformedOrUnmappable(source, ch, flush);
                 }
             }

             return CoderResult.UNDERFLOW;
         }

         protected final CoderResult encodeMalformedOrUnmappable(CharBuffer source, int ch, boolean flush) {
             /*
              * if the character is a lead surrogate, we need to call encodeTrail to attempt to match
              * it up with a trail surrogate. if not, the character is unmappable.
              */
             return (UTF16.isSurrogate((char) ch))
                     ? encodeTrail(source, (char) ch, flush)
                     : CoderResult.unmappableForLength(1);
         }

         private final CoderResult encodeTrail(CharBuffer source, char lead, boolean flush) {
             /*
              * ASCII doesn't support characters in the BMP, so if handleSurrogates returns null,
              * we leave fromUChar32 alone (it should store a new codepoint) and call it unmappable.
              */
             CoderResult cr = handleSurrogates(source, lead);
             if (cr != null) {
                 return cr;
             } else {
                 //source.position(source.position() - 2);
                 return CoderResult.unmappableForLength(2);
             }
         }

     }

     @Override
     public CharsetDecoder newDecoder() {
         return new CharsetDecoderASCII(this);
     }

     @Override
     public CharsetEncoder newEncoder() {
         return new CharsetEncoderASCII(this);
     }

     @Override
     void getUnicodeSetImpl( UnicodeSet setFillIn, int which){
         setFillIn.add(0,0x7f);
      }
 }
	// © 2016 and later: Unicode, Inc. and others.
	// License & terms of use: http://www.unicode.org/copyright.html#License
	/**
	*******************************************************************************
	* Copyright (C) 2006-2011, International Business Machines Corporation and *
	* others. All Rights Reserved. *
	*******************************************************************************
	*
	*******************************************************************************
	*/
	package com.ibm.icu.charset;

	import java.nio.ByteBuffer;
	import java.nio.CharBuffer;
	import java.nio.IntBuffer;
	import java.nio.charset.CharsetDecoder;
	import java.nio.charset.CharsetEncoder;
	import java.nio.charset.CoderResult;

	import com.ibm.icu.text.UTF16;
	import com.ibm.icu.text.UnicodeSet;

	class CharsetASCII extends CharsetICU {
	protected byte[] fromUSubstitution = new byte[] { (byte) 0x1a };

	public CharsetASCII(String icuCanonicalName, String javaCanonicalName, String[] aliases) {
	super(icuCanonicalName, javaCanonicalName, aliases);
	maxBytesPerChar = 1;
	minBytesPerChar = 1;
	maxCharsPerByte = 1;
	}

	class CharsetDecoderASCII extends CharsetDecoderICU {

	public CharsetDecoderASCII(CharsetICU cs) {
	super(cs);
	}

	@Override
	protected CoderResult decodeLoop(ByteBuffer source, CharBuffer target, IntBuffer offsets,
	boolean flush) {
	if (!source.hasRemaining()) {
	/* no input, nothing to do */
	return CoderResult.UNDERFLOW;
	}
	if (!target.hasRemaining()) {
	/* no output available, can't do anything */
	return CoderResult.OVERFLOW;
	}

	CoderResult cr;
	int oldSource = source.position();
	int oldTarget = target.position();

	if (source.hasArray() && target.hasArray()) {
	/* optimized loop */

	/*
	* extract arrays from the buffers and obtain various constant values that will be
	* necessary in the core loop
	*/
	byte[] sourceArray = source.array();
	int sourceOffset = source.arrayOffset();
	int sourceIndex = oldSource + sourceOffset;
	int sourceLength = source.limit() - oldSource;

	char[] targetArray = target.array();
	int targetOffset = target.arrayOffset();
	int targetIndex = oldTarget + targetOffset;
	int targetLength = target.limit() - oldTarget;

	int limit = ((sourceLength < targetLength) ? sourceLength : targetLength)
	+ sourceIndex;
	int offset = targetIndex - sourceIndex;

	/*
	* perform the core loop... if it returns null, it must be due to an overflow or
	* underflow
	*/
	cr = decodeLoopCoreOptimized(source, target, sourceArray, targetArray, sourceIndex, offset, limit);
	if (cr == null) {
	if (sourceLength <= targetLength) {
	source.position(oldSource + sourceLength);
	target.position(oldTarget + sourceLength);
	cr = CoderResult.UNDERFLOW;
	} else {
	source.position(oldSource + targetLength);
	target.position(oldTarget + targetLength);
	cr = CoderResult.OVERFLOW;
	}
	}
	} else {
	/* unoptimized loop */
	cr = decodeLoopCoreUnoptimized(source, target);
	if (cr == CoderResult.OVERFLOW) {
	/* the target is full */
	source.position(source.position() - 1); /* rewind by 1 */
	}
	}

	/* set offsets since the start */
	if (offsets != null) {
	int count = target.position() - oldTarget;
	int sourceIndex = -1;
	while (--count >= 0) offsets.put(++sourceIndex);
	}

	return cr;
	}

	protected CoderResult decodeLoopCoreOptimized(ByteBuffer source, CharBuffer target,
	byte[] sourceArray, char[] targetArray, int oldSource, int offset, int limit) {
	int i, ch = 0;

	/*
	* perform ascii conversion from the source array to the target array, making sure each
	* byte in the source is within the correct range
	*/
	for (i = oldSource; i < limit && (((ch = (sourceArray[i] & 0xff)) & 0x80) == 0); i++)
	targetArray[i + offset] = (char) ch;

	/*
	* if some byte was not in the correct range, we need to deal with this byte by calling
	* decodeMalformedOrUnmappable and move the source and target positions to reflect the
	* early termination of the loop
	*/
	if ((ch & 0x80) != 0) {
	source.position(i + 1);
	target.position(i + offset);
	return decodeMalformedOrUnmappable(ch);
	} else
	return null;
	}

	protected CoderResult decodeLoopCoreUnoptimized(ByteBuffer source, CharBuffer target) {
	int ch = 0;

	/*
	* perform ascii conversion from the source buffer to the target buffer, making sure
	* each byte in the source is within the correct range
	*/
	while (source.hasRemaining()) {
	ch = source.get() & 0xff;

	if ((ch & 0x80) == 0) {
	if (target.hasRemaining()) {
	target.put((char)ch);
	} else {
	return CoderResult.OVERFLOW;
	}
	} else {
	/*
	* if we reach here, it's because a character was not in the correct range, and we need
	* to deak with this by calling decodeMalformedOrUnmappable
	*/
	return decodeMalformedOrUnmappable(ch);
	}
	}

	return CoderResult.UNDERFLOW;
	}

	protected CoderResult decodeMalformedOrUnmappable(int ch) {
	/*
	* put the guilty character into toUBytesArray and return a message saying that the
	* character was malformed and of length 1.
	*/
	toUBytesArray[0] = (byte) ch;
	toULength = 1;
	return CoderResult.malformedForLength(1);
	}
	}

	class CharsetEncoderASCII extends CharsetEncoderICU {

	public CharsetEncoderASCII(CharsetICU cs) {
	super(cs, fromUSubstitution);
	implReset();
	}

	private final static int NEED_TO_WRITE_BOM = 1;

	@Override
	protected void implReset() {
	super.implReset();
	fromUnicodeStatus = NEED_TO_WRITE_BOM;
	}

	@Override
	protected CoderResult encodeLoop(CharBuffer source, ByteBuffer target, IntBuffer offsets,
	boolean flush) {
	if (!source.hasRemaining()) {
	/* no input, nothing to do */
	return CoderResult.UNDERFLOW;
	}
	if (!target.hasRemaining()) {
	/* no output available, can't do anything */
	return CoderResult.OVERFLOW;
	}

	CoderResult cr;
	int oldSource = source.position();
	int oldTarget = target.position();

	if (fromUChar32 != 0) {
	/*
	* if we have a leading character in fromUChar32 that needs to be dealt with, we
	* need to check for a matching trail character and taking the appropriate action as
	* dictated by encodeTrail.
	*/
	cr = encodeTrail(source, (char) fromUChar32, flush);
	} else {
	if (source.hasArray() && target.hasArray()) {
	/* optimized loop */

	/*
	* extract arrays from the buffers and obtain various constant values that will
	* be necessary in the core loop
	*/
	char[] sourceArray = source.array();
	int sourceOffset = source.arrayOffset();
	int sourceIndex = oldSource + sourceOffset;
	int sourceLength = source.limit() - oldSource;

	byte[] targetArray = target.array();
	int targetOffset = target.arrayOffset();
	int targetIndex = oldTarget + targetOffset;
	int targetLength = target.limit() - oldTarget;

	int limit = ((sourceLength < targetLength) ? sourceLength : targetLength)
	+ sourceIndex;
	int offset = targetIndex - sourceIndex;

	/*
	* perform the core loop... if it returns null, it must be due to an overflow or
	* underflow
	*/
	cr = encodeLoopCoreOptimized(source, target, sourceArray, targetArray, sourceIndex, offset, limit, flush);
	if (cr == null) {
	if (sourceLength <= targetLength) {
	source.position(oldSource + sourceLength);
	target.position(oldTarget + sourceLength);
	cr = CoderResult.UNDERFLOW;
	} else {
	source.position(oldSource + targetLength);
	target.position(oldTarget + targetLength);
	cr = CoderResult.OVERFLOW;
	}
	}
	} else {
	/* unoptimized loop */

	cr = encodeLoopCoreUnoptimized(source, target, flush);

	if (cr == CoderResult.OVERFLOW) {
	source.position(source.position() - 1); /* rewind by 1 */
	}
	}
	}

	/* set offsets since the start */
	if (offsets != null) {
	int count = target.position() - oldTarget;
	int sourceIndex = -1;
	while (--count >= 0) offsets.put(++sourceIndex);
	}

	return cr;
	}

	protected CoderResult encodeLoopCoreOptimized(CharBuffer source, ByteBuffer target,
	char[] sourceArray, byte[] targetArray, int oldSource, int offset, int limit,
	boolean flush) {
	int i, ch = 0;

	/*
	* perform ascii conversion from the source array to the target array, making sure each
	* char in the source is within the correct range
	*/
	for (i = oldSource; i < limit && (((ch = sourceArray[i]) & 0xff80) == 0); i++)
	targetArray[i + offset] = (byte) ch;

	/*
	* if some byte was not in the correct range, we need to deal with this byte by calling
	* encodeMalformedOrUnmappable and move the source and target positions to reflect the
	* early termination of the loop
	*/
	if ((ch & 0xff80) != 0) {
	source.position((i + 1) - source.arrayOffset());
	target.position(i + offset);
	return encodeMalformedOrUnmappable(source, ch, flush);
	} else
	return null;
	}

	protected CoderResult encodeLoopCoreUnoptimized(CharBuffer source, ByteBuffer target, boolean flush) {
	int ch;

	/*
	* perform ascii conversion from the source buffer to the target buffer, making sure
	* each char in the source is within the correct range
	*/
	while (source.hasRemaining()) {
	ch = source.get();

	if ((ch & 0xff80) == 0) {
	if (target.hasRemaining()) {
	target.put((byte) ch);
	} else {
	return CoderResult.OVERFLOW;
	}
	} else {
	/*
	* if we reach here, it's because a character was not in the correct range, and we need
	* to deak with this by calling encodeMalformedOrUnmappable.
	*/
	return encodeMalformedOrUnmappable(source, ch, flush);
	}
	}

	return CoderResult.UNDERFLOW;
	}

	protected final CoderResult encodeMalformedOrUnmappable(CharBuffer source, int ch, boolean flush) {
	/*
	* if the character is a lead surrogate, we need to call encodeTrail to attempt to match
	* it up with a trail surrogate. if not, the character is unmappable.
	*/
	return (UTF16.isSurrogate((char) ch))
	? encodeTrail(source, (char) ch, flush)
	: CoderResult.unmappableForLength(1);
	}

	private final CoderResult encodeTrail(CharBuffer source, char lead, boolean flush) {
	/*
	* ASCII doesn't support characters in the BMP, so if handleSurrogates returns null,
	* we leave fromUChar32 alone (it should store a new codepoint) and call it unmappable.
	*/
	CoderResult cr = handleSurrogates(source, lead);
	if (cr != null) {
	return cr;
	} else {
	//source.position(source.position() - 2);
	return CoderResult.unmappableForLength(2);
	}
	}

	}

	@Override
	public CharsetDecoder newDecoder() {
	return new CharsetDecoderASCII(this);
	}

	@Override
	public CharsetEncoder newEncoder() {
	return new CharsetEncoderASCII(this);
	}

	@Override
	void getUnicodeSetImpl( UnicodeSet setFillIn, int which){
	setFillIn.add(0,0x7f);
	}
	}