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const charmap =
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"!#%&'()*+,-./:;<=>?@[]^_`{|}~¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿABCDEFGHIJKLMNOPQRSTUVWXYZ";
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let compressionCache = {};
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let decompressionCache = {};
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/**
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* Compresses an integer into a tight string representation
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* @param {number} i
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* @returns {string}
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*/
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function compressInt(i) {
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// Zero value breaks
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i += 1;
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// save `i` as the cache key
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// to avoid it being modified by the
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// rest of the function.
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const cache_key = i;
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if (compressionCache[cache_key]) {
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return compressionCache[cache_key];
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}
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let result = "";
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do {
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result += charmap[i % charmap.length];
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i = Math.floor(i / charmap.length);
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} while (i > 0);
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return (compressionCache[cache_key] = result);
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}
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/**
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* Decompresses an integer from its tight string representation
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* @param {string} s
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* @returns {number}
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*/
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function decompressInt(s) {
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if (decompressionCache[s]) {
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return decompressionCache[s];
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}
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s = "" + s;
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let result = 0;
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for (let i = s.length - 1; i >= 0; --i) {
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result = result * charmap.length + charmap.indexOf(s.charAt(i));
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}
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// Fixes zero value break fix from above
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result -= 1;
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return (decompressionCache[s] = result);
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}
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|
// Sanity
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if (G_IS_DEV) {
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for (let i = 0; i < 10000; ++i) {
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if (decompressInt(compressInt(i)) !== i) {
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|
throw new Error(
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|
"Bad compression for: " +
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i +
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|
" compressed: " +
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|
|
compressInt(i) +
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|
" decompressed: " +
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decompressInt(compressInt(i))
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|
);
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}
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}
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}
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|
/**
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|
* @param {any} obj
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|
|
* @param {Map} keys
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|
* @param {Map} values
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|
|
* @returns {any[]|object|number|string}
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|
*/
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|
function compressObjectInternal(obj, keys, values) {
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|
if (Array.isArray(obj)) {
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|
let result = [];
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for (let i = 0; i < obj.length; ++i) {
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|
result.push(compressObjectInternal(obj[i], keys, values));
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|
}
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|
return result;
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|
} else if (typeof obj === "object" && obj !== null) {
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|
let result = {};
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|
|
for (const key in obj) {
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|
let index = keys.get(key);
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|
|
if (index === undefined) {
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|
|
index = keys.size;
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|
|
keys.set(key, index);
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|
|
}
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|
|
const value = obj[key];
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|
|
result[compressInt(index)] = compressObjectInternal(value, keys, values);
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|
|
}
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|
return result;
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|
|
} else if (typeof obj === "string") {
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|
|
let index = values.get(obj);
|
|
|
if (index === undefined) {
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|
|
index = values.size;
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|
|
values.set(obj, index);
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|
|
}
|
|
|
return compressInt(index);
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|
|
}
|
|
|
return obj;
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
* @param {Map} hashMap
|
|
|
* @returns {Array}
|
|
|
*/
|
|
|
function indexMapToArray(hashMap) {
|
|
|
const result = new Array(hashMap.size);
|
|
|
hashMap.forEach((index, key) => {
|
|
|
result[index] = key;
|
|
|
});
|
|
|
return result;
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
* @param {object} obj
|
|
|
*/
|
|
|
export function compressObject(obj) {
|
|
|
const keys = new Map();
|
|
|
const values = new Map();
|
|
|
const data = compressObjectInternal(obj, keys, values);
|
|
|
return {
|
|
|
keys: indexMapToArray(keys),
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|
|
values: indexMapToArray(values),
|
|
|
data,
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|
|
};
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
* @param {object} obj
|
|
|
* @param {string[]} keys
|
|
|
* @param {any[]} values
|
|
|
* @returns {object}
|
|
|
*/
|
|
|
function decompressObjectInternal(obj, keys = [], values = []) {
|
|
|
if (Array.isArray(obj)) {
|
|
|
let result = [];
|
|
|
for (let i = 0; i < obj.length; ++i) {
|
|
|
result.push(decompressObjectInternal(obj[i], keys, values));
|
|
|
}
|
|
|
return result;
|
|
|
} else if (typeof obj === "object" && obj !== null) {
|
|
|
let result = {};
|
|
|
for (const key in obj) {
|
|
|
const realIndex = decompressInt(key);
|
|
|
const value = obj[key];
|
|
|
result[keys[realIndex]] = decompressObjectInternal(value, keys, values);
|
|
|
}
|
|
|
return result;
|
|
|
} else if (typeof obj === "string") {
|
|
|
const realIndex = decompressInt(obj);
|
|
|
return values[realIndex];
|
|
|
}
|
|
|
return obj;
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
* @param {object} obj
|
|
|
*/
|
|
|
export function decompressObject(obj) {
|
|
|
if (obj.keys && obj.values && obj.data) {
|
|
|
const keys = obj.keys;
|
|
|
const values = obj.values;
|
|
|
const result = decompressObjectInternal(obj.data, keys, values);
|
|
|
return result;
|
|
|
}
|
|
|
return obj;
|
|
|
}
|