283 lines
6.9 KiB
TypeScript
283 lines
6.9 KiB
TypeScript
"use strict";
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function lpad(s:string, n:number):string { while(s.length<n) s=" "+s; return s; }
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function byte2signed(b:number):number {
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b &= 0xff;
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return (b < 0x80) ? b : -(256-b);
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}
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function getFilenameForPath(s:string):string {
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var toks = s.split('/');
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return toks[toks.length-1];
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}
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function getFilenamePrefix(s:string):string {
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var pos = s.lastIndexOf('.');
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return (pos > 0) ? s.substr(0, pos) : s;
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}
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function hex(v:number, nd?:number) {
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try {
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if (!nd) nd = 2;
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var s = v.toString(16).toUpperCase();
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while (s.length < nd)
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s = "0" + s;
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return s;
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} catch (e) {
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return v+"";
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}
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}
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function arrayCompare(a:any[], b:any[]):boolean {
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if (a == null && b == null) return true;
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if (a == null) return false;
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if (b == null) return false;
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if (a.length != b.length) return false;
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for (var i=0; i<a.length; i++)
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if (a[i] != b[i])
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return false;
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return true;
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}
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function invertMap(m:{}):{} {
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var r = {};
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if (m) {
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for (var k in m) r[m[k]] = k;
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}
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return r;
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}
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function highlightDifferences(s1:string, s2:string):string {
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var split1 = s1.split(/(\S+\s+)/).filter(function(n) {return n});
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var split2 = s2.split(/(\S+\s+)/).filter(function(n) {return n});
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var i = 0;
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var j = 0;
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var result = "";
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while (i < split1.length && j < split2.length) {
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var w1 = split1[i];
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var w2 = split2[j];
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if (w2 && w2.indexOf("\n") >= 0) {
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while (i < s1.length && split1[i].indexOf("\n") < 0)
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i++;
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}
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if (w1 != w2) {
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w2 = '<span class="hilite">' + w2 + '</span>';
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}
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result += w2;
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i++;
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j++;
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}
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while (j < split2.length) {
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result += split2[j++];
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}
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return result;
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}
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function lzgmini() {
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// Constants
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var LZG_HEADER_SIZE = 16;
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var LZG_METHOD_COPY = 0;
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var LZG_METHOD_LZG1 = 1;
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// LUT for decoding the copy length parameter
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var LZG_LENGTH_DECODE_LUT = [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,
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20,21,22,23,24,25,26,27,28,29,35,48,72,128];
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// Decoded data (produced by the decode() method)
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var outdata = null;
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// Calculate the checksum
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var calcChecksum = function(data) {
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var a = 1;
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var b = 0;
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var i = LZG_HEADER_SIZE;
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while (i < data.length)
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{
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a = (a + (data[i] & 0xff)) & 0xffff;
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b = (b + a) & 0xffff;
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i++;
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}
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return (b << 16) | a;
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}
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// Decode LZG coded data. The function returns the size of the decoded data.
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// Use any of the get* methods to retrieve the decoded data.
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this.decode = function(data:number[]):number[] {
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// Start by clearing the decompressed array in this object
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outdata = null;
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// Check magic ID
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if ((data.length < LZG_HEADER_SIZE) || (data[0] != 76) ||
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(data[1] != 90) || (data[2] != 71))
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{
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return null;
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}
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// Calculate & check the checksum
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var checksum = ((data[11] & 0xff) << 24) |
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((data[12] & 0xff) << 16) |
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((data[13] & 0xff) << 8) |
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(data[14] & 0xff);
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if (calcChecksum(data) != checksum)
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{
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return null;
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}
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// Check which method to use
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var method = data[15] & 0xff;
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if (method == LZG_METHOD_LZG1)
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{
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// Get marker symbols
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var m1 = data[16] & 0xff;
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var m2 = data[17] & 0xff;
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var m3 = data[18] & 0xff;
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var m4 = data[19] & 0xff;
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// Main decompression loop
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var symbol, b, b2, b3, len, offset;
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var dst = new Array();
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var dstlen = 0;
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var k = LZG_HEADER_SIZE + 4;
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var datalen = data.length;
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while (k <= datalen)
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{
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symbol = data[k++] & 0xff;
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if ((symbol != m1) && (symbol != m2) && (symbol != m3) && (symbol != m4))
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{
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// Literal copy
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dst[dstlen++] = symbol;
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}
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else
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{
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b = data[k++] & 0xff;
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if (b != 0)
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{
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// Decode offset / length parameters
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if (symbol == m1)
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{
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// marker1 - "Distant copy"
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len = LZG_LENGTH_DECODE_LUT[b & 0x1f];
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b2 = data[k++] & 0xff;
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b3 = data[k++] & 0xff;
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offset = (((b & 0xe0) << 11) | (b2 << 8) | b3) + 2056;
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}
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else if (symbol == m2)
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{
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// marker2 - "Medium copy"
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len = LZG_LENGTH_DECODE_LUT[b & 0x1f];
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b2 = data[k++] & 0xff;
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offset = (((b & 0xe0) << 3) | b2) + 8;
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}
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else if (symbol == m3)
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{
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// marker3 - "Short copy"
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len = (b >> 6) + 3;
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offset = (b & 63) + 8;
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}
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else
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{
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// marker4 - "Near copy (incl. RLE)"
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len = LZG_LENGTH_DECODE_LUT[b & 0x1f];
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offset = (b >> 5) + 1;
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}
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// Copy the corresponding data from the history window
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for (i = 0; i < len; i++)
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{
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dst[dstlen] = dst[dstlen-offset];
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dstlen++;
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}
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}
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else
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{
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// Literal copy (single occurance of a marker symbol)
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dst[dstlen++] = symbol;
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}
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}
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}
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// Store the decompressed data in the lzgmini object for later retrieval
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outdata = dst;
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return outdata;
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}
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else if (method == LZG_METHOD_COPY)
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{
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// Plain copy
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var dst = new Array();
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var dstlen = 0;
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var datalen = data.length;
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for (var i = LZG_HEADER_SIZE; i < datalen; i++)
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{
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dst[dstlen++] = data[i] & 0xff;
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}
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outdata = dst;
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return outdata;
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}
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else
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{
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// Unknown method
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return null;
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}
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}
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// Get the decoded byte array
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this.getByteArray = function():number[]
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{
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return outdata;
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}
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// Get the decoded string from a Latin 1 (or ASCII) encoded array
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this.getStringLatin1 = function():string
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{
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var str = "";
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if (outdata != null)
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{
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var charLUT = new Array();
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for (var i = 0; i < 256; ++i)
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charLUT[i] = String.fromCharCode(i);
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var outlen = outdata.length;
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for (var i = 0; i < outlen; i++)
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str += charLUT[outdata[i]];
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}
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return str;
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}
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// Get the decoded string from an UTF-8 encoded array
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this.getStringUTF8 = function():string
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{
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var str = "";
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if (outdata != null)
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{
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var charLUT = new Array();
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for (var i = 0; i < 128; ++i)
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charLUT[i] = String.fromCharCode(i);
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var c;
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var outlen = outdata.length;
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for (var i = 0; i < outlen;)
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{
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c = outdata[i++];
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if (c < 128)
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{
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str += charLUT[c];
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}
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else
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{
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if ((c > 191) && (c < 224))
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{
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c = ((c & 31) << 6) | (outdata[i++] & 63);
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}
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else
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{
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c = ((c & 15) << 12) | ((outdata[i] & 63) << 6) | (outdata[i+1] & 63);
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i += 2;
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}
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str += String.fromCharCode(c);
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}
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}
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}
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return str;
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}
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}
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