data-structure-typed/test/utils/big-o.js

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'use strict';
Object.defineProperty(exports, '__esModule', {value: true});
exports.logBigOMetrics = exports.logBigOMetricsWrap = exports.bigO = exports.magnitude = void 0;
var config_1 = require('../config');
var isDebug = config_1.isDebugTest;
var orderReducedBy = 2; // reduction of bigO's order compared to the baseline bigO
exports.magnitude = {
CONSTANT: Math.floor(Number.MAX_SAFE_INTEGER / Math.pow(10, orderReducedBy)),
LOG_N: Math.pow(10, 9 - orderReducedBy),
LINEAR: Math.pow(10, 6 - orderReducedBy),
N_LOG_N: Math.pow(10, 5 - orderReducedBy),
SQUARED: Math.pow(10, 4 - orderReducedBy),
CUBED: Math.pow(10, 3 - orderReducedBy),
FACTORIAL: 20 - orderReducedBy
};
exports.bigO = {
CONSTANT: exports.magnitude.CONSTANT / 100000,
LOG_N: Math.log2(exports.magnitude.LOG_N) / 1000,
LINEAR: exports.magnitude.LINEAR / 1000,
N_LOG_N: (exports.magnitude.N_LOG_N * Math.log2(exports.magnitude.LOG_N)) / 1000,
SQUARED: Math.pow(exports.magnitude.SQUARED, 2) / 1000,
CUBED: Math.pow(exports.magnitude.SQUARED, 3) / 1000,
FACTORIAL: 10000
};
function findPotentialN(input) {
var longestArray = [];
var mostProperties = {};
function recurse(obj) {
if (Array.isArray(obj)) {
if (obj.length > longestArray.length) {
longestArray = obj;
}
} else if (typeof obj === 'object' && obj !== null) {
var keys = Object.keys(obj);
if (keys.length > Object.keys(mostProperties).length) {
mostProperties = obj;
}
keys.forEach(function (key) {
recurse(obj[key]);
});
}
}
if (Array.isArray(input)) {
input.forEach(function (item) {
recurse(item);
});
} else {
recurse(input);
}
// return [longestArray, mostProperties] : [any[], { [key: string]: any }];
return Math.max(longestArray.length, Object.keys(mostProperties).length);
}
function linearRegression(x, y) {
var n = x.length;
var sumX = x.reduce(function (acc, val) {
return acc + val;
}, 0);
var sumY = y.reduce(function (acc, val) {
return acc + val;
}, 0);
var sumXSquared = x.reduce(function (acc, val) {
return acc + Math.pow(val, 2);
}, 0);
var sumXY = x.reduce(function (acc, val, i) {
return acc + val * y[i];
}, 0);
var slope = (n * sumXY - sumX * sumY) / (n * sumXSquared - Math.pow(sumX, 2));
var intercept = (sumY - slope * sumX) / n;
var yHat = x.map(function (val) {
return slope * val + intercept;
});
var totalVariation = y
.map(function (val, i) {
return Math.pow(val - yHat[i], 2);
})
.reduce(function (acc, val) {
return acc + val;
}, 0);
var explainedVariation = y
.map(function (val) {
return Math.pow(val - sumY / n, 2);
})
.reduce(function (acc, val) {
return acc + val;
}, 0);
var rSquared = 1 - totalVariation / explainedVariation;
return {slope: slope, intercept: intercept, rSquared: rSquared};
}
function estimateBigO(runtimes, dataSizes) {
// Make sure the input runtimes and data sizes have the same length
if (runtimes.length !== dataSizes.length) {
return 'Lengths of input arrays do not match';
}
// Create an array to store the computational complexity of each data point
var complexities = [];
// Traverse different possible complexities
var complexitiesToCheck = [
'O(1)',
'O(log n)',
'O(n)',
'O(n log n)',
'O(n^2)' // squared time complexity
];
var _loop_1 = function (complexity) {
// Calculate data points for fitting
var fittedData = dataSizes.map(function (size) {
if (complexity === 'O(1)') {
return 1; // constant time complexity
} else if (complexity === 'O(log n)') {
return Math.log(size);
} else if (complexity === 'O(n)') {
return size;
} else if (complexity === 'O(n log n)') {
return size * Math.log(size);
} else if (complexity === 'O(n^2)') {
return Math.pow(size, 2);
} else {
return Math.pow(size, 10);
}
});
// Fit the data points using linear regression analysis
var regressionResult = linearRegression(fittedData, runtimes);
// Check the R-squared value of the fit. It is usually considered a valid fit if it is greater than 0.9.
if (regressionResult.rSquared >= 0.9) {
complexities.push(complexity);
}
};
for (var _i = 0, complexitiesToCheck_1 = complexitiesToCheck; _i < complexitiesToCheck_1.length; _i++) {
var complexity = complexitiesToCheck_1[_i];
_loop_1(complexity);
}
// If there is no valid fitting result, return "cannot estimate", otherwise return the estimated time complexity
if (complexities.length === 0) {
return 'Unable to estimate';
} else {
return complexities.join(' or ');
}
}
var methodLogs = new Map();
function logBigOMetricsWrap(fn, args, fnName) {
var startTime = performance.now();
var result = fn(args);
var endTime = performance.now();
var runTime = endTime - startTime;
var methodName = ''.concat(fnName);
if (!methodLogs.has(methodName)) {
methodLogs.set(methodName, []);
}
var methodLog = methodLogs.get(methodName);
var maxDataSize = args.length === 1 && typeof args[0] === 'number' ? args[0] : findPotentialN(args);
if (methodLog) {
methodLog.push([runTime, maxDataSize]);
if (methodLog.length >= 20) {
isDebug && console.log('triggered', methodName, methodLog);
var bigO_1 = estimateBigO(
methodLog.map(function (_a) {
var runTime = _a[0];
return runTime;
}),
methodLog.map(function (_a) {
var runTime = _a[0];
return runTime;
})
);
isDebug && console.log('Estimated Big O: '.concat(bigO_1));
methodLogs.delete(methodName);
}
}
return result;
}
exports.logBigOMetricsWrap = logBigOMetricsWrap;
function logBigOMetrics(target, propertyKey, descriptor) {
var originalMethod = descriptor.value;
descriptor.value = function () {
var args = [];
for (var _i = 0; _i < arguments.length; _i++) {
args[_i] = arguments[_i];
}
var startTime = performance.now();
var result = originalMethod.apply(this, args);
var endTime = performance.now();
var runTime = endTime - startTime;
var methodName = ''.concat(target.constructor.name, '.').concat(propertyKey);
if (!methodLogs.has(methodName)) {
methodLogs.set(methodName, []);
}
var methodLog = methodLogs.get(methodName);
var maxDataSize = args.length === 1 && typeof args[0] === 'number' ? args[0] : findPotentialN(args);
if (methodLog) {
methodLog.push([runTime, maxDataSize]);
if (methodLog.length >= 20) {
isDebug && console.log('triggered', methodName, methodLog);
var bigO_2 = estimateBigO(
methodLog.map(function (_a) {
var runTime = _a[0];
return runTime;
}),
methodLog.map(function (_a) {
var runTime = _a[0];
return runTime;
})
);
isDebug && console.log('Estimated Big O: '.concat(bigO_2));
methodLogs.delete(methodName);
}
}
return result;
};
return descriptor;
}
exports.logBigOMetrics = logBigOMetrics;