[Refactor] extract implementations to side-channel-weakmap, `side-c…

…hannel-map`, `side-channel-list`
ljharb · Dec 11, 2024 · ada5955 · ada5955
1 parent c01d2d3
commit ada5955
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Showing 6 changed files with 106 additions and 239 deletions.
diff --git a/.eslintrc b/.eslintrc
@@ -4,6 +4,7 @@
 	"extends": "@ljharb",
 
 	"rules": {
+		"id-length": 0,
 		"max-lines-per-function": 0,
 		"multiline-comment-style": 1,
 		"new-cap": [2, { "capIsNewExceptions": ["GetIntrinsic"] }],

diff --git a/index.d.ts b/index.d.ts
@@ -1,13 +1,14 @@
+import getSideChannelList from 'side-channel-list';
+import getSideChannelMap from 'side-channel-map';
+import getSideChannelWeakMap from 'side-channel-weakmap';
+
 declare namespace getSideChannel {
-	type Channel<V, K> = {
-		assert: (key: K) => void;
-		has: (key: K) => boolean;
-		get: (key: K) => V | undefined;
-		set: (key: K, value: V) => void;
-		delete: (key: K) => boolean;
-	}
+	type Channel<K, V> =
+		| getSideChannelList.Channel<K, V>
+		| ReturnType<Exclude<typeof getSideChannelMap<K, V>, false>>
+		| ReturnType<Exclude<typeof getSideChannelWeakMap<K, V>, false>>;
 }
 
-declare function getSideChannel<V, K>(): getSideChannel.Channel<V, K>;
+declare function getSideChannel<K, V>(): getSideChannel.Channel<K, V>;
 
 export = getSideChannel;
diff --git a/index.js b/index.js
@@ -1,107 +1,18 @@
 'use strict';
 
-var GetIntrinsic = require('get-intrinsic');
-var callBound = require('call-bind/callBound');
-var inspect = require('object-inspect');
-
 var $TypeError = require('es-errors/type');
-var $WeakMap = GetIntrinsic('%WeakMap%', true);
-var $Map = GetIntrinsic('%Map%', true);
-
-/** @template T @typedef {<T extends (this: any, ...args: any[]) => any>(this: ThisParameterType<T>, ...args: Parameters<T>) => ReturnType<T>} CallBind */
-
-/** @type {CallBind<<K extends object, V>(this: WeakMap<K, V>, key: K) => V>} */
-var $weakMapGet = callBound('WeakMap.prototype.get', true);
-/** @type {CallBind<typeof WeakMap.prototype.set>} */
-var $weakMapSet = callBound('WeakMap.prototype.set', true);
-/** @type {CallBind<typeof WeakMap.prototype.has>} */
-var $weakMapHas = callBound('WeakMap.prototype.has', true);
-/** @type {CallBind<typeof WeakMap.prototype.delete>} */
-var $weakMapDelete = callBound('WeakMap.prototype.delete', true);
-/** @type {CallBind<typeof Map.prototype.get>} */
-var $mapGet = callBound('Map.prototype.get', true);
-/** @type {CallBind<typeof Map.prototype.set>} */
-var $mapSet = callBound('Map.prototype.set', true);
-/** @type {CallBind<typeof Map.prototype.has>} */
-var $mapHas = callBound('Map.prototype.has', true);
-/** @type {CallBind<typeof Map.prototype.delete>} */
-var $mapDelete = callBound('Map.prototype.delete', true);
-
-/*
-* This function traverses the list returning the node corresponding to the given key.
-*
-* That node is also moved to the head of the list, so that if it's accessed again we don't need to traverse the whole list.
-* By doing so, all the recently used nodes can be accessed relatively quickly.
-*/
-/** @type {import('./list.d.ts').listGetNode} */
-// eslint-disable-next-line consistent-return
-var listGetNode = function (list, key, isDelete) {
-	/** @type {typeof list | NonNullable<(typeof list)['next']>} */
-	var prev = list;
-	/** @type {(typeof list)['next']} */
-	var curr;
-	// eslint-disable-next-line eqeqeq
-	for (; (curr = prev.next) != null; prev = curr) {
-		if (curr.key === key) {
-			prev.next = curr.next;
-			if (!isDelete) {
-				// eslint-disable-next-line no-extra-parens
-				curr.next = /** @type {NonNullable<typeof list.next>} */ (list.next);
-				list.next = curr; // eslint-disable-line no-param-reassign
-			}
-			return curr;
-		}
-	}
-};
+var inspect = require('object-inspect');
+var getSideChannelList = require('side-channel-list');
+var getSideChannelMap = require('side-channel-map');
+var getSideChannelWeakMap = require('side-channel-weakmap');
 
-/** @type {import('./list.d.ts').listGet} */
-// eslint-disable-next-line consistent-return
-var listGet = function (objects, key) {
-	if (objects) {
-		var node = listGetNode(objects, key);
-		return node && node.value;
-	}
-};
-/** @type {import('./list.d.ts').listSet} */
-var listSet = function (objects, key, value) {
-	if (objects) {
-		var node = listGetNode(objects, key);
-		if (node) {
-			node.value = value;
-		} else {
-		// Prepend the new node to the beginning of the list
-			objects.next = /** @type {import('./list.d.ts').ListNode<typeof value, typeof key>} */ ({ // eslint-disable-line no-param-reassign, no-extra-parens
-				key: key,
-				next: objects.next,
-				value: value
-			});
-		}
-	}
-};
-/** @type {import('./list.d.ts').listHas} */
-var listHas = function (objects, key) {
-	if (!objects) {
-		return false;
-	}
-	return !!listGetNode(objects, key);
-};
-/** @type {import('./list.d.ts').listDelete} */
-// eslint-disable-next-line consistent-return
-var listDelete = function (objects, key) {
-	if (objects) {
-		return listGetNode(objects, key, true);
-	}
-};
+var makeChannel = getSideChannelWeakMap || getSideChannelMap || getSideChannelList;
 
 /** @type {import('.')} */
 module.exports = function getSideChannel() {
 	/** @typedef {ReturnType<typeof getSideChannel>} Channel */
-	/** @typedef {Parameters<Channel['get']>[0]} K */
-	/** @typedef {Parameters<Channel['set']>[1]} V */
 
-	/** @type {WeakMap<K & object, V> | undefined} */ var $wm;
-	/** @type {Map<K, V> | undefined} */ var $m;
-	/** @type {import('./list.d.ts').RootNode<V, K> | undefined} */ var $o;
+	/** @type {Channel | undefined} */ var $channelData;
 
 	/** @type {Channel} */
 	var channel = {
@@ -111,72 +22,20 @@ module.exports = function getSideChannel() {
 			}
 		},
 		'delete': function (key) {
-			if ($WeakMap && key && (typeof key === 'object' || typeof key === 'function')) {
-				if ($wm) {
-					return $weakMapDelete($wm, key);
-				}
-			} else if ($Map) {
-				if ($m) {
-					return $mapDelete($m, key);
-				}
-			} else {
-				if ($o) { // eslint-disable-line no-lonely-if
-					var root = $o && $o.next;
-					var deletedNode = listDelete($o, key);
-					if (deletedNode && root && root === deletedNode) {
-						$o = void undefined;
-					}
-					return !!deletedNode;
-				}
-			}
-			return false;
+			return !!$channelData && $channelData['delete'](key);
 		},
-		get: function (key) { // eslint-disable-line consistent-return
-			if ($WeakMap && key && (typeof key === 'object' || typeof key === 'function')) {
-				if ($wm) {
-					return $weakMapGet($wm, key);
-				}
-			} else if ($Map) {
-				if ($m) {
-					return $mapGet($m, key);
-				}
-			} else {
-				return listGet($o, key);
-			}
+		get: function (key) {
+			return $channelData && $channelData.get(key);
 		},
 		has: function (key) {
-			if ($WeakMap && key && (typeof key === 'object' || typeof key === 'function')) {
-				if ($wm) {
-					return $weakMapHas($wm, key);
-				}
-			} else if ($Map) {
-				if ($m) {
-					return $mapHas($m, key);
-				}
-			} else {
-				return listHas($o, key);
-			}
-			return false;
+			return !!$channelData && $channelData.has(key);
 		},
 		set: function (key, value) {
-			if ($WeakMap && key && (typeof key === 'object' || typeof key === 'function')) {
-				if (!$wm) {
-					$wm = new $WeakMap();
-				}
-				$weakMapSet($wm, key, value);
-			} else if ($Map) {
-				if (!$m) {
-					$m = new $Map();
-				}
-				$mapSet($m, key, value);
-			} else {
-				if (!$o) {
-					// Initialize the linked list as an empty node, so that we don't have to special-case handling of the first node: we can always refer to it as (previous node).next, instead of something like (list).head
-					$o = { next: void undefined };
-				}
-				// eslint-disable-next-line no-extra-parens
-				listSet(/** @type {NonNullable<typeof $o>} */ ($o), key, value);
+			if (!$channelData) {
+				$channelData = makeChannel();
 			}
+
+			$channelData.set(key, value);
 		}
 	};
 	// @ts-expect-error TODO: figure out why this is erroring

diff --git a/list.d.ts b/list.d.ts
diff --git a/package.json b/package.json
@@ -4,8 +4,8 @@
 	"description": "Store information about any JS value in a side channel. Uses WeakMap if available.",
 	"main": "index.js",
 	"exports": {
-		"./package.json": "./package.json",
-		".": "./index.js"
+		".": "./index.js",
+		"./package.json": "./package.json"
 	},
 	"types": "./index.d.ts",
 	"scripts": {
@@ -43,17 +43,16 @@
 	},
 	"homepage": "https://github.com/ljharb/side-channel#readme",
 	"dependencies": {
-		"call-bind": "^1.0.8",
 		"es-errors": "^1.3.0",
-		"get-intrinsic": "^1.2.5",
-		"object-inspect": "^1.13.3"
+		"object-inspect": "^1.13.3",
+		"side-channel-list": "^1.0.0",
+		"side-channel-map": "^1.0.1",
+		"side-channel-weakmap": "^1.0.2"
 	},
 	"devDependencies": {
 		"@arethetypeswrong/cli": "^0.17.1",
 		"@ljharb/eslint-config": "^21.1.1",
 		"@ljharb/tsconfig": "^0.2.2",
-		"@types/call-bind": "^1.0.5",
-		"@types/get-intrinsic": "^1.2.3",
 		"@types/object-inspect": "^1.13.0",
 		"@types/tape": "^5.6.5",
 		"auto-changelog": "^2.5.0",