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Source Map encode with TypedArrays #jsbench #jsperf (https://jsbench.github.io/#9cf1800a21b25e7cc0af56649178b174) #jsbench #jsperf
Raw
index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
<title>Source Map encode with TypedArrays #jsbench #jsperf</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
<script src="./suite.js"></script>
</head>
<body>
<h1>Open the console to view the results</h1>
<h2><code>cmd + alt + j</code> or <code>ctrl + alt + j</code></h2>
</body>
</html>
Raw
suite.js
"use strict";
(function (factory) {
if (typeof Benchmark !== "undefined") {
factory(Benchmark);
} else {
factory(require("benchmark"));
}
})(function (Benchmark) {
var suite = new Benchmark.Suite;
Benchmark.prototype.setup = function () {
const comma = ','.charCodeAt(0);
const semicolon = ';'.charCodeAt(0);
const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
const intToChar = new Uint8Array(64); // 64 possible chars.
const charToInt = new Uint8Array(128); // z is 122 in ASCII
for (let i = 0; i < chars.length; i++) {
const c = chars.charCodeAt(i);
intToChar[i] = c;
charToInt[c] = i;
}
// Provide a fallback for older environments.
const td = typeof TextDecoder !== 'undefined'
? /* #__PURE__ */ new TextDecoder()
: typeof Buffer !== 'undefined'
? {
decode(buf) {
const out = Buffer.from(buf.buffer, buf.byteOffset, buf.byteLength);
return out.toString();
},
}
: {
decode(buf) {
let out = '';
for (let i = 0; i < buf.length; i++) {
out += String.fromCharCode(buf[i]);
}
return out;
},
};
function decode(mappings) {
const state = new Int32Array(5);
const decoded = [];
let index = 0;
do {
const semi = indexOf(mappings, index);
const line = [];
let sorted = true;
let lastCol = 0;
state[0] = 0;
for (let i = index; i < semi; i++) {
let seg;
i = decodeInteger(mappings, i, state, 0); // genColumn
const col = state[0];
if (col < lastCol)
sorted = false;
lastCol = col;
if (hasMoreVlq(mappings, i, semi)) {
i = decodeInteger(mappings, i, state, 1); // sourcesIndex
i = decodeInteger(mappings, i, state, 2); // sourceLine
i = decodeInteger(mappings, i, state, 3); // sourceColumn
if (hasMoreVlq(mappings, i, semi)) {
i = decodeInteger(mappings, i, state, 4); // namesIndex
seg = [col, state[1], state[2], state[3], state[4]];
}
else {
seg = [col, state[1], state[2], state[3]];
}
}
else {
seg = [col];
}
line.push(seg);
}
if (!sorted)
sort(line);
decoded.push(line);
index = semi + 1;
} while (index <= mappings.length);
return decoded;
}
function indexOf(mappings, index) {
const idx = mappings.indexOf(';', index);
return idx === -1 ? mappings.length : idx;
}
function decodeInteger(mappings, pos, state, j) {
let value = 0;
let shift = 0;
let integer = 0;
do {
const c = mappings.charCodeAt(pos++);
integer = charToInt[c];
value |= (integer & 31) << shift;
shift += 5;
} while (integer & 32);
const shouldNegate = value & 1;
value >>>= 1;
if (shouldNegate) {
value = -0x80000000 | -value;
}
state[j] += value;
return pos;
}
function hasMoreVlq(mappings, i, length) {
if (i >= length)
return false;
return mappings.charCodeAt(i) !== comma;
}
function sort(line) {
line.sort(sortComparator);
}
function sortComparator(a, b) {
return a[0] - b[0];
}
function encodeInteger(buf, pos, state, segment, j) {
const next = segment[j];
let num = next - state[j];
state[j] = next;
num = num < 0 ? (-num << 1) | 1 : num << 1;
do {
let clamped = num & 0b011111;
num >>>= 5;
if (num > 0)
clamped |= 0b100000;
buf[pos++] = intToChar[clamped];
} while (num > 0);
return pos;
}
function encodeSingle(decoded) {
const state = new Int32Array(5);
const bufLength = 1024 * 16;
const subLength = bufLength - 36;
const buf = new Uint8Array(bufLength);
const sub = buf.subarray(0, subLength);
let pos = 0;
let out = '';
for (let i = 0; i < decoded.length; i++) {
const line = decoded[i];
if (i > 0) {
if (pos === bufLength) {
out += td.decode(buf);
pos = 0;
}
buf[pos++] = semicolon;
}
if (line.length === 0)
continue;
state[0] = 0;
for (let j = 0; j < line.length; j++) {
const segment = line[j];
// We can push up to 5 ints, each int can take at most 7 chars, and we
// may push a comma.
if (pos > subLength) {
out += td.decode(sub);
buf.copyWithin(0, subLength, pos);
pos -= subLength;
}
if (j > 0)
buf[pos++] = comma;
pos = encodeInteger(buf, pos, state, segment, 0); // genColumn
if (segment.length === 1)
continue;
pos = encodeInteger(buf, pos, state, segment, 1); // sourcesIndex
pos = encodeInteger(buf, pos, state, segment, 2); // sourceLine
pos = encodeInteger(buf, pos, state, segment, 3); // sourceColumn
if (segment.length === 4)
continue;
pos = encodeInteger(buf, pos, state, segment, 4); // namesIndex
}
}
return out + td.decode(buf.subarray(0, pos));
}
function encodeMultiple(decoded) {
const state = new Int32Array(5);
const bufLength = 1024 * 16;
const subLength = bufLength - 36;
const buf = new Uint8Array(bufLength);
let pos = 0;
let out = '';
for (let i = 0; i < decoded.length; i++) {
const line = decoded[i];
if (i > 0) {
if (pos === bufLength) {
out += td.decode(buf);
pos = 0;
}
buf[pos++] = semicolon;
}
if (line.length === 0)
continue;
state[0] = 0;
for (let j = 0; j < line.length; j++) {
const segment = line[j];
// We can push up to 5 ints, each int can take at most 7 chars, and we
// may push a comma.
if (pos > subLength) {
out += td.decode(buf.subarray(0, pos));
pos = 0;
}
if (j > 0)
buf[pos++] = comma;
pos = encodeInteger(buf, pos, state, segment, 0); // genColumn
if (segment.length === 1)
continue;
pos = encodeInteger(buf, pos, state, segment, 1); // sourcesIndex
pos = encodeInteger(buf, pos, state, segment, 2); // sourceLine
pos = encodeInteger(buf, pos, state, segment, 3); // sourceColumn
if (segment.length === 4)
continue;
pos = encodeInteger(buf, pos, state, segment, 4); // namesIndex
}
}
return out + td.decode(buf.subarray(0, pos));
}
const mappings = decode("")
};
suite.add("Encoding using a single subarray", function () {
// Encoding using a single subarray
encodeSingle(mappings);
});
suite.add("Encoding using a throwaway subarrays", function () {
// Encoding using a throwaway subarrays
encodeMultiple(mappings);
});
suite.on("cycle", function (evt) {
console.log(" - " + evt.target);
});
suite.on("complete", function (evt) {
console.log(new Array(30).join("-"));
var results = evt.currentTarget.sort(function (a, b) {
return b.hz - a.hz;
});
results.forEach(function (item) {
console.log((idx + 1) + ". " + item);
});
});
console.log("Source Map encode with TypedArrays #jsbench #jsperf");
console.log(new Array(30).join("-"));
suite.run();
});
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