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qwen/nodejs/node_modules/@hapi/topo/lib/index.js

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+'use strict';
+
+const Assert = require('@hapi/hoek/lib/assert');
+
+
+const internals = {};
+
+
+exports.Sorter = class {
+
+    constructor() {
+
+        this._items = [];
+        this.nodes = [];
+    }
+
+    add(nodes, options) {
+
+        options = options || {};
+
+        // Validate rules
+
+        const before = [].concat(options.before || []);
+        const after = [].concat(options.after || []);
+        const group = options.group || '?';
+        const sort = options.sort || 0;                   // Used for merging only
+
+        Assert(!before.includes(group), `Item cannot come before itself: ${group}`);
+        Assert(!before.includes('?'), 'Item cannot come before unassociated items');
+        Assert(!after.includes(group), `Item cannot come after itself: ${group}`);
+        Assert(!after.includes('?'), 'Item cannot come after unassociated items');
+
+        if (!Array.isArray(nodes)) {
+            nodes = [nodes];
+        }
+
+        for (const node of nodes) {
+            const item = {
+                seq: this._items.length,
+                sort,
+                before,
+                after,
+                group,
+                node
+            };
+
+            this._items.push(item);
+        }
+
+        // Insert event
+
+        if (!options.manual) {
+            const valid = this._sort();
+            Assert(valid, 'item', group !== '?' ? `added into group ${group}` : '', 'created a dependencies error');
+        }
+
+        return this.nodes;
+    }
+
+    merge(others) {
+
+        if (!Array.isArray(others)) {
+            others = [others];
+        }
+
+        for (const other of others) {
+            if (other) {
+                for (const item of other._items) {
+                    this._items.push(Object.assign({}, item));      // Shallow cloned
+                }
+            }
+        }
+
+        // Sort items
+
+        this._items.sort(internals.mergeSort);
+        for (let i = 0; i < this._items.length; ++i) {
+            this._items[i].seq = i;
+        }
+
+        const valid = this._sort();
+        Assert(valid, 'merge created a dependencies error');
+
+        return this.nodes;
+    }
+
+    sort() {
+
+        const valid = this._sort();
+        Assert(valid, 'sort created a dependencies error');
+
+        return this.nodes;
+    }
+
+    _sort() {
+
+        // Construct graph
+
+        const graph = {};
+        const graphAfters = Object.create(null);            // A prototype can bungle lookups w/ false positives
+        const groups = Object.create(null);
+
+        for (const item of this._items) {
+            const seq = item.seq;                           // Unique across all items
+            const group = item.group;
+
+            // Determine Groups
+
+            groups[group] = groups[group] || [];
+            groups[group].push(seq);
+
+            // Build intermediary graph using 'before'
+
+            graph[seq] = item.before;
+
+            // Build second intermediary graph with 'after'
+
+            for (const after of item.after) {
+                graphAfters[after] = graphAfters[after] || [];
+                graphAfters[after].push(seq);
+            }
+        }
+
+        // Expand intermediary graph
+
+        for (const node in graph) {
+            const expandedGroups = [];
+
+            for (const graphNodeItem in graph[node]) {
+                const group = graph[node][graphNodeItem];
+                groups[group] = groups[group] || [];
+                expandedGroups.push(...groups[group]);
+            }
+
+            graph[node] = expandedGroups;
+        }
+
+        // Merge intermediary graph using graphAfters into final graph
+
+        for (const group in graphAfters) {
+            if (groups[group]) {
+                for (const node of groups[group]) {
+                    graph[node].push(...graphAfters[group]);
+                }
+            }
+        }
+
+        // Compile ancestors
+
+        const ancestors = {};
+        for (const node in graph) {
+            const children = graph[node];
+            for (const child of children) {
+                ancestors[child] = ancestors[child] || [];
+                ancestors[child].push(node);
+            }
+        }
+
+        // Topo sort
+
+        const visited = {};
+        const sorted = [];
+
+        for (let i = 0; i < this._items.length; ++i) {          // Looping through item.seq values out of order
+            let next = i;
+
+            if (ancestors[i]) {
+                next = null;
+                for (let j = 0; j < this._items.length; ++j) {  // As above, these are item.seq values
+                    if (visited[j] === true) {
+                        continue;
+                    }
+
+                    if (!ancestors[j]) {
+                        ancestors[j] = [];
+                    }
+
+                    const shouldSeeCount = ancestors[j].length;
+                    let seenCount = 0;
+                    for (let k = 0; k < shouldSeeCount; ++k) {
+                        if (visited[ancestors[j][k]]) {
+                            ++seenCount;
+                        }
+                    }
+
+                    if (seenCount === shouldSeeCount) {
+                        next = j;
+                        break;
+                    }
+                }
+            }
+
+            if (next !== null) {
+                visited[next] = true;
+                sorted.push(next);
+            }
+        }
+
+        if (sorted.length !== this._items.length) {
+            return false;
+        }
+
+        const seqIndex = {};
+        for (const item of this._items) {
+            seqIndex[item.seq] = item;
+        }
+
+        this._items = [];
+        this.nodes = [];
+
+        for (const value of sorted) {
+            const sortedItem = seqIndex[value];
+            this.nodes.push(sortedItem.node);
+            this._items.push(sortedItem);
+        }
+
+        return true;
+    }
+};
+
+
+internals.mergeSort = (a, b) => {
+
+    return a.sort === b.sort ? 0 : (a.sort < b.sort ? -1 : 1);
+};