com.jtransc.charset.charsets.JTranscCharsetUTF8 Maven / Gradle / Ivy

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JVM AOT compiler currently generating JavaScript, C++, Haxe, with initial focus on Kotlin and games.

There is a newer version: 0.6.8

package com.jtransc.charset.charsets;

import java.io.ByteArrayOutputStream;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;

import com.jtransc.charset.JTranscCharset;

public class JTranscCharsetUTF8 extends JTranscCharset {
	public JTranscCharsetUTF8() {
		super(new String[] { "UTF-8", "UTF8" }, 1, 1.2f, 4);
	}

	@Override
	public void encode(char[] in, int offset, int len, ByteArrayOutputStream out) {
		for (int n = 0; n < len; n++) {
			int codePoint = in[offset + n];

			if ((codePoint & ~0x7F) == 0) { // 1-byte sequence
				out.write(codePoint);
			} else {
				if ((codePoint & ~0x7FF) == 0) { // 2-byte sequence
					out.write(((codePoint >> 6) & 0x1F) | 0xC0);
				} else if ((codePoint & ~0xFFFF) == 0) { // 3-byte sequence
					out.write(((codePoint >> 12) & 0x0F) | 0xE0);
					out.write(createByte(codePoint, 6));
				} else if ((codePoint & 0xFFE00000) == 0) { // 4-byte sequence
					out.write(((codePoint >> 18) & 0x07) | 0xF0);
					out.write(createByte(codePoint, 12));
					out.write(createByte(codePoint, 6));
				}
				out.write((codePoint & 0x3F) | 0x80);
			}
		}
	}

	static private int createByte(int codePoint, int shift) {
		return ((codePoint >> shift) & 0x3F) | 0x80;
	}

	@Override
	public void decode(byte[] in, int offset, int len, StringBuilder out) {
		int i = offset;
		int end = offset + len;
		while (i < end) {
			int c = in[i++] & 0xFF;
			switch (c >> 4) {
				case 0:
				case 1:
				case 2:
				case 3:
				case 4:
				case 5:
				case 6:
				case 7: {
					// 0xxxxxxx
					out.append((char) (c));
					break;
				}
				case 12:
				case 13: {
					// 110x xxxx   10xx xxxx
					out.append((char) (((c & 0x1F) << 6) | (in[i++] & 0x3F)));
					break;
				}
				case 14: {
					// 1110 xxxx  10xx xxxx  10xx xxxx
					out.append((char) (((c & 0x0F) << 12) | ((in[i++] & 0x3F) << 6) | ((in[i++] & 0x3F) << 0)));
					break;
				}
			}
		}
	}

	@Override
	public void decode(ByteBuffer in, CharBuffer out) {
		while (in.hasRemaining() && out.hasRemaining()) {
			int c = in.get() & 0xFF;

			switch (c >> 4) {
				case 0:
				case 1:
				case 2:
				case 3:
				case 4:
				case 5:
				case 6:
				case 7: {
					// 0xxxxxxx
					out.append((char) (c));
					break;
				}
				case 12:
				case 13: {
					// 110x xxxx   10xx xxxx
					if(in.hasRemaining()) {
						out.append((char) (((c & 0x1F) << 6) | (in.get() & 0x3F)));
					}
					break;
				}
				case 14: {
					// 1110 xxxx  10xx xxxx  10xx xxxx
					if(in.hasRemaining()) {
						out.append((char) (((c & 0x0F) << 12) | ((in.get() & 0x3F) << 6) | ((in.get() & 0x3F) << 0)));
					}
					break;
				}
			}
		}
	}
}