73 lines
2.8 KiB
JavaScript
73 lines
2.8 KiB
JavaScript
function readIEEE754(buf, idx, isLE, nl, ml) {
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if(isLE === undefined) isLE = true;
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if(!nl) nl = 8;
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if(!ml && nl === 8) ml = 52;
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var e, m, el = nl * 8 - ml - 1, eMax = (1 << el) - 1, eBias = eMax >> 1;
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var bits = -7, d = isLE ? -1 : 1, i = isLE ? (nl - 1) : 0, s = buf[idx + i];
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i += d;
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e = s & ((1 << (-bits)) - 1); s >>>= (-bits); bits += el;
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for (; bits > 0; e = e * 256 + buf[idx + i], i += d, bits -= 8);
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m = e & ((1 << (-bits)) - 1); e >>>= (-bits); bits += ml;
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for (; bits > 0; m = m * 256 + buf[idx + i], i += d, bits -= 8);
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if (e === eMax) return m ? NaN : ((s ? -1 : 1) * Infinity);
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else if (e === 0) e = 1 - eBias;
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else { m = m + Math.pow(2, ml); e = e - eBias; }
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return (s ? -1 : 1) * m * Math.pow(2, e - ml);
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}
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var __toBuffer;
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if(typeof Buffer !== "undefined") {
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Buffer.prototype.hexlify= function() { return this.toString('hex'); };
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__toBuffer = function(bufs) { return Buffer.concat(bufs[0]); };
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} else {
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__toBuffer = function(bufs) {
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var x = [];
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for(var i = 0; i != bufs[0].length; ++i) { x = x.concat(bufs[0][i]); }
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return x;
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};
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}
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var __readUInt8 = function(b, idx) { return b.readUInt8 ? b.readUInt8(idx) : b[idx]; };
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var __readUInt16LE = function(b, idx) { return b.readUInt16LE ? b.readUInt16LE(idx) : b[idx+1]*(1<<8)+b[idx]; };
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var __readInt16LE = function(b, idx) { var u = __readUInt16LE(b,idx); if(!(u & 0x8000)) return u; return (0xffff - u + 1) * -1; };
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var __readUInt32LE = function(b, idx) { return b.readUInt32LE ? b.readUInt32LE(idx) : b[idx+3]*(1<<24)+b[idx+2]*(1<<16)+b[idx+1]*(1<<8)+b[idx]; };
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var __readInt32LE = function(b, idx) { if(b.readInt32LE) return b.readInt32LE(idx); var u = __readUInt32LE(b,idx); if(!(u & 0x80000000)) return u; return (0xffffffff - u + 1) * -1; };
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var __readDoubleLE = function(b, idx) { return b.readDoubleLE ? b.readDoubleLE(idx) : readIEEE754(b, idx||0);};
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function ReadShift(size, t) {
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var o = "", oo = [], w, vv, i, loc; t = t || 'u';
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if(size === 'ieee754') { size = 8; t = 'f'; }
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switch(size) {
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case 1: o = __readUInt8(this, this.l); break;
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case 2: o=(t==='u' ? __readUInt16LE : __readInt16LE)(this, this.l); break;
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case 4: o = __readUInt32LE(this, this.l); break;
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case 8: if(t === 'f') { o = __readDoubleLE(this, this.l); break; }
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/* falls through */
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case 16: o = this.toString('hex', this.l,this.l+size); break;
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case 'dbcs': size = 2*t; loc = this.l;
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for(i = 0; i != t; ++i) {
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oo.push(_getchar(__readUInt16LE(this, loc)));
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loc+=2;
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} o = oo.join(""); break;
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case 'sbcs': size = t; o = ""; loc = this.l;
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for(i = 0; i != t; ++i) {
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o += _getchar(__readUInt8(this, loc));
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loc+=1;
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} break;
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}
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this.l+=size; return o;
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}
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function prep_blob(blob, pos) {
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blob.read_shift = ReadShift.bind(blob);
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blob.l = pos || 0;
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var read = ReadShift.bind(blob);
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return [read];
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}
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function parsenoop(blob, length) { blob.l += length; }
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