source: trip-planner-front/node_modules/webpack/lib/optimize/InnerGraph.js@ 571e0df

/*
        MIT License http://www.opensource.org/licenses/mit-license.php
        Author Sergey Melyukov @smelukov
*/

"use strict";

const { UsageState } = require("../ExportsInfo");

/** @typedef {import("estree").Node} AnyNode */
/** @typedef {import("../Dependency")} Dependency */
/** @typedef {import("../ModuleGraph")} ModuleGraph */
/** @typedef {import("../ModuleGraphConnection")} ModuleGraphConnection */
/** @typedef {import("../ModuleGraphConnection").ConnectionState} ConnectionState */
/** @typedef {import("../Parser").ParserState} ParserState */
/** @typedef {import("../javascript/JavascriptParser")} JavascriptParser */
/** @typedef {import("../util/runtime").RuntimeSpec} RuntimeSpec */

/** @typedef {Map<TopLevelSymbol, Set<string | TopLevelSymbol> | true>} InnerGraph */
/** @typedef {function(boolean | Set<string> | undefined): void} UsageCallback */

/**
 * @typedef {Object} StateObject
 * @property {InnerGraph} innerGraph
 * @property {TopLevelSymbol=} currentTopLevelSymbol
 * @property {Map<TopLevelSymbol, Set<UsageCallback>>} usageCallbackMap
 */

/** @typedef {false|StateObject} State */

/** @type {WeakMap<ParserState, State>} */
const parserStateMap = new WeakMap();
const topLevelSymbolTag = Symbol("top level symbol");

/**
 * @param {ParserState} parserState parser state
 * @returns {State} state
 */
function getState(parserState) {
        return parserStateMap.get(parserState);
}

/**
 * @param {ParserState} parserState parser state
 * @returns {void}
 */
exports.bailout = parserState => {
        parserStateMap.set(parserState, false);
};

/**
 * @param {ParserState} parserState parser state
 * @returns {void}
 */
exports.enable = parserState => {
        const state = parserStateMap.get(parserState);
        if (state === false) {
                return;
        }
        parserStateMap.set(parserState, {
                innerGraph: new Map(),
                currentTopLevelSymbol: undefined,
                usageCallbackMap: new Map()
        });
};

/**
 * @param {ParserState} parserState parser state
 * @returns {boolean} true, when enabled
 */
exports.isEnabled = parserState => {
        const state = parserStateMap.get(parserState);
        return !!state;
};

/**
 * @param {ParserState} state parser state
 * @param {TopLevelSymbol} symbol the symbol
 * @param {string | TopLevelSymbol | true} usage usage data
 * @returns {void}
 */
exports.addUsage = (state, symbol, usage) => {
        const innerGraphState = getState(state);

        if (innerGraphState) {
                const { innerGraph } = innerGraphState;
                const info = innerGraph.get(symbol);
                if (usage === true) {
                        innerGraph.set(symbol, true);
                } else if (info === undefined) {
                        innerGraph.set(symbol, new Set([usage]));
                } else if (info !== true) {
                        info.add(usage);
                }
        }
};

/**
 * @param {JavascriptParser} parser the parser
 * @param {string} name name of variable
 * @param {string | TopLevelSymbol | true} usage usage data
 * @returns {void}
 */
exports.addVariableUsage = (parser, name, usage) => {
        const symbol =
                /** @type {TopLevelSymbol} */ (
                        parser.getTagData(name, topLevelSymbolTag)
                ) || exports.tagTopLevelSymbol(parser, name);
        if (symbol) {
                exports.addUsage(parser.state, symbol, usage);
        }
};

/**
 * @param {ParserState} state parser state
 * @returns {void}
 */
exports.inferDependencyUsage = state => {
        const innerGraphState = getState(state);

        if (!innerGraphState) {
                return;
        }

        const { innerGraph, usageCallbackMap } = innerGraphState;
        const processed = new Map();
        // flatten graph to terminal nodes (string, undefined or true)
        const nonTerminal = new Set(innerGraph.keys());
        while (nonTerminal.size > 0) {
                for (const key of nonTerminal) {
                        /** @type {Set<string|TopLevelSymbol> | true} */
                        let newSet = new Set();
                        let isTerminal = true;
                        const value = innerGraph.get(key);
                        let alreadyProcessed = processed.get(key);
                        if (alreadyProcessed === undefined) {
                                alreadyProcessed = new Set();
                                processed.set(key, alreadyProcessed);
                        }
                        if (value !== true && value !== undefined) {
                                for (const item of value) {
                                        alreadyProcessed.add(item);
                                }
                                for (const item of value) {
                                        if (typeof item === "string") {
                                                newSet.add(item);
                                        } else {
                                                const itemValue = innerGraph.get(item);
                                                if (itemValue === true) {
                                                        newSet = true;
                                                        break;
                                                }
                                                if (itemValue !== undefined) {
                                                        for (const i of itemValue) {
                                                                if (i === key) continue;
                                                                if (alreadyProcessed.has(i)) continue;
                                                                newSet.add(i);
                                                                if (typeof i !== "string") {
                                                                        isTerminal = false;
                                                                }
                                                        }
                                                }
                                        }
                                }
                                if (newSet === true) {
                                        innerGraph.set(key, true);
                                } else if (newSet.size === 0) {
                                        innerGraph.set(key, undefined);
                                } else {
                                        innerGraph.set(key, newSet);
                                }
                        }
                        if (isTerminal) {
                                nonTerminal.delete(key);
                        }
                }
        }

        /** @type {Map<Dependency, true | Set<string>>} */
        for (const [symbol, callbacks] of usageCallbackMap) {
                const usage = /** @type {true | Set<string> | undefined} */ (
                        innerGraph.get(symbol)
                );
                for (const callback of callbacks) {
                        callback(usage === undefined ? false : usage);
                }
        }
};

/**
 * @param {ParserState} state parser state
 * @param {UsageCallback} onUsageCallback on usage callback
 */
exports.onUsage = (state, onUsageCallback) => {
        const innerGraphState = getState(state);

        if (innerGraphState) {
                const { usageCallbackMap, currentTopLevelSymbol } = innerGraphState;
                if (currentTopLevelSymbol) {
                        let callbacks = usageCallbackMap.get(currentTopLevelSymbol);

                        if (callbacks === undefined) {
                                callbacks = new Set();
                                usageCallbackMap.set(currentTopLevelSymbol, callbacks);
                        }

                        callbacks.add(onUsageCallback);
                } else {
                        onUsageCallback(true);
                }
        } else {
                onUsageCallback(undefined);
        }
};

/**
 * @param {ParserState} state parser state
 * @param {TopLevelSymbol} symbol the symbol
 */
exports.setTopLevelSymbol = (state, symbol) => {
        const innerGraphState = getState(state);

        if (innerGraphState) {
                innerGraphState.currentTopLevelSymbol = symbol;
        }
};

/**
 * @param {ParserState} state parser state
 * @returns {TopLevelSymbol|void} usage data
 */
exports.getTopLevelSymbol = state => {
        const innerGraphState = getState(state);

        if (innerGraphState) {
                return innerGraphState.currentTopLevelSymbol;
        }
};

/**
 * @param {JavascriptParser} parser parser
 * @param {string} name name of variable
 * @returns {TopLevelSymbol} symbol
 */
exports.tagTopLevelSymbol = (parser, name) => {
        const innerGraphState = getState(parser.state);
        if (!innerGraphState) return;

        parser.defineVariable(name);

        const existingTag = /** @type {TopLevelSymbol} */ (
                parser.getTagData(name, topLevelSymbolTag)
        );
        if (existingTag) {
                return existingTag;
        }

        const fn = new TopLevelSymbol(name);
        parser.tagVariable(name, topLevelSymbolTag, fn);
        return fn;
};

/**
 * @param {Dependency} dependency the dependency
 * @param {Set<string> | boolean} usedByExports usedByExports info
 * @param {ModuleGraph} moduleGraph moduleGraph
 * @param {RuntimeSpec} runtime runtime
 * @returns {boolean} false, when unused. Otherwise true
 */
exports.isDependencyUsedByExports = (
        dependency,
        usedByExports,
        moduleGraph,
        runtime
) => {
        if (usedByExports === false) return false;
        if (usedByExports !== true && usedByExports !== undefined) {
                const selfModule = moduleGraph.getParentModule(dependency);
                const exportsInfo = moduleGraph.getExportsInfo(selfModule);
                let used = false;
                for (const exportName of usedByExports) {
                        if (exportsInfo.getUsed(exportName, runtime) !== UsageState.Unused)
                                used = true;
                }
                if (!used) return false;
        }
        return true;
};

/**
 * @param {Dependency} dependency the dependency
 * @param {Set<string> | boolean} usedByExports usedByExports info
 * @param {ModuleGraph} moduleGraph moduleGraph
 * @returns {null | false | function(ModuleGraphConnection, RuntimeSpec): ConnectionState} function to determine if the connection is active
 */
exports.getDependencyUsedByExportsCondition = (
        dependency,
        usedByExports,
        moduleGraph
) => {
        if (usedByExports === false) return false;
        if (usedByExports !== true && usedByExports !== undefined) {
                const selfModule = moduleGraph.getParentModule(dependency);
                const exportsInfo = moduleGraph.getExportsInfo(selfModule);
                return (connections, runtime) => {
                        for (const exportName of usedByExports) {
                                if (exportsInfo.getUsed(exportName, runtime) !== UsageState.Unused)
                                        return true;
                        }
                        return false;
                };
        }
        return null;
};

class TopLevelSymbol {
        /**
         * @param {string} name name of the variable
         */
        constructor(name) {
                this.name = name;
        }
}

exports.TopLevelSymbol = TopLevelSymbol;
exports.topLevelSymbolTag = topLevelSymbolTag;