Refactor: replace BFS w/ DFS [skip ci]

Build/lib/trie.test.ts

@@ -125,12 +125,12 @@ describe('Trie', () => {
     trie.add('cdn.example.com');
     trie.add('example.org');
 
-    expect(trie.find('example.com')).toStrictEqual(['example.com', 'blog.example.com', 'cdn.example.com']);
-    expect(trie.find('com')).toStrictEqual(['example.com', 'blog.example.com', 'cdn.example.com']);
-    expect(trie.find('.example.com')).toStrictEqual(['blog.example.com', 'cdn.example.com']);
+    expect(trie.find('example.com')).toStrictEqual(['example.com', 'cdn.example.com', 'blog.example.com']);
+    expect(trie.find('com')).toStrictEqual(['example.com', 'cdn.example.com', 'blog.example.com']);
+    expect(trie.find('.example.com')).toStrictEqual(['cdn.example.com', 'blog.example.com']);
     expect(trie.find('org')).toStrictEqual(['example.org']);
     expect(trie.find('example.net')).toStrictEqual([]);
-    expect(trie.dump()).toStrictEqual(['example.com', 'example.org', 'blog.example.com', 'cdn.example.com']);
+    expect(trie.dump()).toStrictEqual(['example.org', 'example.com', 'cdn.example.com', 'blog.example.com']);
   });
 
   it('should be possible to retrieve items matching the given prefix even with a smol trie', () => {
@@ -147,7 +147,7 @@ describe('Trie', () => {
     expect(trie.find('.example.com')).toStrictEqual(['.example.com']);
     expect(trie.find('org')).toStrictEqual(['example.org']);
     expect(trie.find('example.net')).toStrictEqual([]);
-    expect(trie.dump()).toStrictEqual(['.example.com', 'example.org']);
+    expect(trie.dump()).toStrictEqual(['example.org', '.example.com']);
   });
 
   it('should be possible to create a trie from an arbitrary iterable.', () => {
@@ -173,14 +173,14 @@ describe('surge domainset dedupe', () => {
   it('should match subdomain - 1', () => {
     const trie = createTrie(['www.noc.one', 'www.sukkaw.com', 'blog.skk.moe', 'image.cdn.skk.moe', 'cdn.sukkaw.net'], false);
 
-    expect(trie.find('.skk.moe')).toStrictEqual(['blog.skk.moe', 'image.cdn.skk.moe']);
+    expect(trie.find('.skk.moe')).toStrictEqual(['image.cdn.skk.moe', 'blog.skk.moe']);
     expect(trie.find('.sukkaw.com')).toStrictEqual(['www.sukkaw.com']);
   });
 
   it('should match subdomain - 2', () => {
     const trie = createTrie(['www.noc.one', 'www.sukkaw.com', '.skk.moe', 'blog.skk.moe', 'image.cdn.skk.moe', 'cdn.sukkaw.net'], false);
 
-    expect(trie.find('.skk.moe')).toStrictEqual(['.skk.moe', 'blog.skk.moe', 'image.cdn.skk.moe']);
+    expect(trie.find('.skk.moe')).toStrictEqual(['.skk.moe', 'image.cdn.skk.moe', 'blog.skk.moe']);
     expect(trie.find('.sukkaw.com')).toStrictEqual(['www.sukkaw.com']);
   });
 
@@ -203,13 +203,13 @@ describe('smol tree', () => {
     ], true);
 
     expect(trie.dump()).toStrictEqual([
-      'skk.moe',
-      'anotherskk.moe',
+      'img.skk.local',
+      'blog.img.skk.local',
       '.cdn.local',
-      'blog.skk.moe',
+      'anotherskk.moe',
       'blog.anotherskk.moe',
-      'img.skk.local',
-      'blog.img.skk.local'
+      'skk.moe',
+      'blog.skk.moe'
     ]);
   });
 
@@ -221,10 +221,10 @@ describe('smol tree', () => {
     ], true);
 
     expect(trie.dump()).toStrictEqual([
-      '.skk.moe',
-      'www.noc.one',
+      '.sub.example.com',
       'cdn.noc.one',
-      '.sub.example.com'
+      'www.noc.one',
+      '.skk.moe'
     ]);
   });
 
@@ -262,10 +262,10 @@ describe('smol tree', () => {
     ], true);
 
     expect(trie.dump()).toStrictEqual([
-      'commercial.shouji.360.cn',
       'cdn.creative.medialytics.com',
-      'act.commercial.shouji.360.cn',
-      'px.cdn.creative.medialytics.com'
+      'px.cdn.creative.medialytics.com',
+      'commercial.shouji.360.cn',
+      'act.commercial.shouji.360.cn'
     ]);
   });
 
@@ -278,10 +278,10 @@ describe('smol tree', () => {
     ], true);
 
     expect(trie.dump()).toStrictEqual([
-      'skk.moe',
       'anotherskk.moe',
-      'blog.skk.moe',
-      'blog.anotherskk.moe'
+      'blog.anotherskk.moe',
+      'skk.moe',
+      'blog.skk.moe'
     ]);
   });
 
@@ -299,34 +299,34 @@ describe('smol tree', () => {
     trie.whitelist('.skk.moe');
 
     expect(trie.dump()).toStrictEqual([
-      'anotherskk.moe',
-      '.cdn.local',
-      'blog.anotherskk.moe',
       'img.skk.local',
-      'blog.img.skk.local'
+      'blog.img.skk.local',
+      '.cdn.local',
+      'anotherskk.moe',
+      'blog.anotherskk.moe'
     ]);
 
     trie.whitelist('anotherskk.moe');
     expect(trie.dump()).toStrictEqual([
-      '.cdn.local',
-      'blog.anotherskk.moe',
       'img.skk.local',
-      'blog.img.skk.local'
+      'blog.img.skk.local',
+      '.cdn.local',
+      'blog.anotherskk.moe'
     ]);
 
     trie.add('anotherskk.moe');
     trie.whitelist('.anotherskk.moe');
 
     expect(trie.dump()).toStrictEqual([
-      '.cdn.local',
       'img.skk.local',
-      'blog.img.skk.local'
+      'blog.img.skk.local',
+      '.cdn.local'
     ]);
 
     trie.whitelist('img.skk.local');
     expect(trie.dump()).toStrictEqual([
-      '.cdn.local',
-      'blog.img.skk.local'
+      'blog.img.skk.local',
+      '.cdn.local'
     ]);
 
     trie.whitelist('cdn.local');
@@ -349,15 +349,14 @@ describe('smol tree', () => {
     ], true);
 
     expect(trie.dump()).toStrictEqual([
-      '.t.co',
+      'cdn.example.com', 'blog.cdn.example.com',
       '.skk.moe',
-      'cdn.example.com', 'blog.cdn.example.com'
+      '.t.co'
     ]);
 
     trie.whitelist('.t.co');
     expect(trie.dump()).toStrictEqual([
-      '.skk.moe',
-      'cdn.example.com', 'blog.cdn.example.com'
+      'cdn.example.com', 'blog.cdn.example.com', '.skk.moe'
     ]);
 
     trie.whitelist('skk.moe');

Build/lib/trie.ts

@@ -6,7 +6,6 @@ import { fastStringCompare } from './misc';
 import util from 'node:util';
 import { noop } from 'foxts/noop';
 import { fastStringArrayJoin } from 'foxts/fast-string-array-join';
-import FIFO from 'fast-fifo';
 
 import { deleteBit, getBit, missingBit, setBit } from 'foxts/bitwise';
 
@@ -193,9 +192,9 @@ abstract class Triebase<Meta = unknown> {
 
   private static bfsResults: [node: TrieNode | null, suffix: string[]] = [null, []];
 
-  private static bfs<Meta>(this: void, nodeStack: FIFO<TrieNode<Meta>>, suffixStack: FIFO<string[]>) {
-    const node = nodeStack.shift()!;
-    const suffix = suffixStack.shift()!;
+  private static dfs<Meta>(this: void, nodeStack: Array<TrieNode<Meta>>, suffixStack: string[][]) {
+    const node = nodeStack.pop()!;
+    const suffix = suffixStack.pop()!;
 
     node[2].forEach((childNode, k) => {
       // Pushing the child node to the stack for next iteration of DFS
@@ -210,9 +209,9 @@ abstract class Triebase<Meta = unknown> {
     return Triebase.bfsResults;
   }
 
-  private static bfsWithSort<Meta>(this: void, nodeStack: FIFO<TrieNode<Meta>>, suffixStack: FIFO<string[]>) {
-    const node = nodeStack.shift()!;
-    const suffix = suffixStack.shift()!;
+  private static dfsWithSort<Meta>(this: void, nodeStack: Array<TrieNode<Meta>>, suffixStack: string[][]) {
+    const node = nodeStack.pop()!;
+    const suffix = suffixStack.pop()!;
 
     const child = node[2];
 
@@ -241,13 +240,13 @@ abstract class Triebase<Meta = unknown> {
     initialSuffix: string[] = [],
     withSort = false
   ) {
-    const bfsImpl = withSort ? Triebase.bfsWithSort : Triebase.bfs;
+    const bfsImpl = withSort ? Triebase.dfsWithSort : Triebase.dfs;
 
-    const nodeStack = new FIFO<TrieNode<Meta>>();
+    const nodeStack: Array<TrieNode<Meta>> = [];
     nodeStack.push(initialNode);
 
     // Resolving initial string (begin the start of the stack)
-    const suffixStack = new FIFO<string[]>();
+    const suffixStack: string[][] = [];
     suffixStack.push(initialSuffix);
 
     let node: TrieNode<Meta> = initialNode;
@@ -275,19 +274,19 @@ abstract class Triebase<Meta = unknown> {
     initialNode = this.$root,
     initialSuffix: string[] = []
   ) {
-    const nodeStack = new FIFO<TrieNode<Meta>>();
+    const nodeStack: Array<TrieNode<Meta>> = [];
     nodeStack.push(initialNode);
 
     // Resolving initial string (begin the start of the stack)
-    const suffixStack = new FIFO<string[]>();
+    const suffixStack: string[][] = [];
     suffixStack.push(initialSuffix);
 
     let node: TrieNode<Meta> = initialNode;
     let child: Map<string, TrieNode<Meta>> = node[2];
 
     do {
-      node = nodeStack.shift()!;
-      const suffix = suffixStack.shift()!;
+      node = nodeStack.pop()!;
+      const suffix = suffixStack.pop()!;
       child = node[2];
       if (child.size) {
         const keys = Array.from(child.keys()).sort(Triebase.compare);