debug: support max Age

wellwelwel · Sep 20, 2024 · 1d8d76e · 1d8d76e
1 parent 700ac33
commit 1d8d76e
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Showing 5 changed files with 156 additions and 47 deletions.
diff --git a/benchmark/worker.cjs b/benchmark/worker.cjs
@@ -1,5 +1,4 @@
 const process = require('node:process');
-const { cpuUsage } = require('node:process');
 const { performance } = require('node:perf_hooks');
 const { LRUCache } = require('lru-cache');
 const { createLRU } = require('../lib/index.js');
@@ -8,26 +7,32 @@ const benchmarkName = process.argv[2];
 
 const measurePerformance = (fn) => {
   const startTime = performance.now();
-  const startCpu = cpuUsage();
+  const startCpu = process.cpuUsage();
 
   fn();
 
   const endTime = performance.now();
-  const endCpu = cpuUsage(startCpu);
+  const endCpu = process.cpuUsage(startCpu);
 
   return {
     time: endTime - startTime,
     cpu: endCpu.user + endCpu.system,
   };
 };
 
-const times = 10;
+const times = 100;
 const max = 100000;
 const brute = 1000000;
 
 const benchmarks = {
-  'lru-cache': () => new LRUCache({ max }),
-  'lru.min': () => createLRU({ max }),
+  'lru-cache': () => {
+    let event = 0;
+    return new LRUCache({ max, ttl: 1000, dispose: () => event++ });
+  },
+  'lru.min': () => {
+    let event = 0;
+    return createLRU({ max, maxAge: 1000, onEviction: () => event++ });
+  },
 };
 
 const benchmark = (createCache) => {

diff --git a/benchmark/worker.mjs b/benchmark/worker.mjs
@@ -21,14 +21,27 @@ const measurePerformance = (fn) => {
   };
 };
 
-const times = 10;
+const times = 100;
 const max = 100000;
 const brute = 1000000;
 
 const benchmarks = {
-  'lru-cache': () => new LRUCache({ max }),
-  'quick-lru': () => new QuickLRU({ maxSize: max }),
-  'lru.min': () => createLRU({ max }),
+  'lru-cache': () => {
+    let event = 0;
+    return new LRUCache({ max, ttl: 1000, dispose: () => event++ });
+  },
+  'quick-lru': () => {
+    let event = 0;
+    return new QuickLRU({
+      maxSize: max,
+      maxAge: 1000,
+      onEviction: () => event++,
+    });
+  },
+  'lru.min': () => {
+    let event = 0;
+    return createLRU({ max, maxAge: 1000, onEviction: () => event++ });
+  },
 };
 
 const benchmark = (createCache) => {
@@ -57,7 +70,7 @@ const benchmark = (createCache) => {
     results.time += result.time;
     results.cpu += result.cpu;
 
-    cache.clear();
+    // cache.clear(); // quick-lru doesn't evict on `clear`
   }
 
   return {

diff --git a/src/index.ts b/src/index.ts
@@ -1,16 +1,24 @@
+import { performance } from 'node:perf_hooks';
+
 export type CacheOptions<Key = unknown, Value = unknown> = {
   /** Maximum number of items the cache can hold. */
   max: number;
+  maxAge?: number;
   /** Function called when an item is evicted from the cache. */
   onEviction?: (key: Key, value: Value) => unknown;
 };
 
 export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
-  let { max, onEviction } = options;
+  let { max, onEviction, maxAge = undefined } = options;
 
   if (!(Number.isInteger(max) && max > 0))
     throw new TypeError('`max` must be a positive integer');
 
+  if (typeof maxAge === 'number' && maxAge <= 0)
+    throw new TypeError('`maxAge` must be a positive number');
+
+  const Age = typeof performance?.now === 'object' ? performance : Date;
+
   let size = 0;
   let head = 0;
   let tail = 0;
@@ -19,6 +27,8 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
   const keyMap: Map<Key, number> = new Map();
   const keyList: (Key | undefined)[] = new Array(max).fill(undefined);
   const valList: (Value | undefined)[] = new Array(max).fill(undefined);
+  const expList: number[] = new Array(max).fill(0);
+  const ageList: number[] = new Array(max).fill(0);
   const next: number[] = new Array(max).fill(0);
   const prev: number[] = new Array(max).fill(0);
 
@@ -48,6 +58,8 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
 
     keyList[evictHead] = undefined;
     valList[evictHead] = undefined;
+    expList[evictHead] = 0;
+    ageList[evictHead] = 0;
     head = next[evictHead];
 
     if (head !== 0) prev[head] = 0;
@@ -61,9 +73,52 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
     return evictHead;
   };
 
+  const _delete = (key: Key): boolean => {
+    const index = keyMap.get(key);
+
+    if (index === undefined) return false;
+
+    onEviction?.(key, valList[index]!);
+    keyMap.delete(key);
+    free.push(index);
+
+    keyList[index] = undefined;
+    valList[index] = undefined;
+    expList[index] = 0;
+    ageList[index] = 0;
+
+    const prevIndex = prev[index];
+    const nextIndex = next[index];
+
+    if (prevIndex !== 0) next[prevIndex] = nextIndex;
+    if (nextIndex !== 0) prev[nextIndex] = prevIndex;
+
+    if (index === head) head = nextIndex;
+    if (index === tail) tail = prevIndex;
+
+    size--;
+
+    return true;
+  };
+
+  const _checkAge = (key: Key): boolean => {
+    const index = keyMap.get(key);
+
+    if (index !== undefined) {
+      const expiresAt = expList[index];
+
+      if (expiresAt !== 0 && Age.now() > expiresAt) {
+        _delete(key);
+        return false;
+      }
+    }
+
+    return true;
+  };
+
   return {
     /** Adds a key-value pair to the cache. Updates the value if the key already exists. */
-    set(key: Key, value: Value): undefined {
+    set(key: Key, value: Value, options?: { maxAge?: number }): undefined {
       if (key === undefined) return;
 
       let index = keyMap.get(key);
@@ -77,6 +132,19 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
 
       valList[index] = value;
 
+      const keyMaxAge = options?.maxAge !== undefined ? options.maxAge : maxAge;
+
+      if (keyMaxAge !== undefined) {
+        if (typeof keyMaxAge !== 'number' || keyMaxAge <= 0)
+          throw new TypeError('`maxAge` must be a positive number');
+
+        expList[index] = Age.now() + keyMaxAge;
+        ageList[index] = keyMaxAge;
+      } else {
+        expList[index] = 0;
+        ageList[index] = 0;
+      }
+
       if (size === 1) head = tail = index;
       else setTail(index, 'set');
     },
@@ -86,20 +154,40 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
       const index = keyMap.get(key);
 
       if (index === undefined) return;
+      if (!_checkAge(key)) return;
+
       if (index !== tail) setTail(index, 'get');
 
+      const itemMaxAge = ageList[index];
+      if (itemMaxAge !== 0) {
+        expList[index] = Age.now() + itemMaxAge;
+      }
+
       return valList[index];
     },
 
     /** Retrieves the value for a given key without changing its position. */
     peek: (key: Key): Value | undefined => {
       const index = keyMap.get(key);
 
+      if (!_checkAge(key)) return;
       return index !== undefined ? valList[index] : undefined;
     },
 
     /** Checks if a key exists in the cache. */
-    has: (key: Key): boolean => keyMap.has(key),
+    has: (key: Key): boolean => {
+      const index = keyMap.get(key);
+
+      if (index === undefined) return false;
+      if (!_checkAge(key)) return false;
+
+      const itemMaxAge = ageList[index];
+      if (itemMaxAge !== 0) {
+        expList[index] = Age.now() + itemMaxAge;
+      }
+
+      return true;
+    },
 
     /** Iterates over all keys in the cache, from most recent to least recent. */
     *keys(): IterableIterator<Key> {
@@ -146,31 +234,7 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
     },
 
     /** Deletes a key-value pair from the cache. */
-    delete(key: Key): boolean {
-      const index = keyMap.get(key);
-
-      if (index === undefined) return false;
-
-      onEviction?.(key, valList[index]!);
-      keyMap.delete(key);
-      free.push(index);
-
-      keyList[index] = undefined;
-      valList[index] = undefined;
-
-      const prevIndex = prev[index];
-      const nextIndex = next[index];
-
-      if (prevIndex !== 0) next[prevIndex] = nextIndex;
-      if (nextIndex !== 0) prev[nextIndex] = prevIndex;
-
-      if (index === head) head = nextIndex;
-      if (index === tail) tail = prevIndex;
-
-      size--;
-
-      return true;
-    },
+    delete: _delete,
 
     /** Evicts the oldest item or the specified number of the oldest items from the cache. */
     evict: (number: number): undefined => {
@@ -198,6 +262,8 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
       keyMap.clear();
       keyList.fill(undefined);
       valList.fill(undefined);
+      expList.fill(0);
+      ageList.fill(0);
 
       free = [];
       size = 0;
@@ -216,17 +282,25 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
 
         const preserve = Math.min(size, newMax);
         const remove = size - preserve;
-        const newKeyList: (Key | undefined)[] = new Array(newMax);
-        const newValList: (Value | undefined)[] = new Array(newMax);
-        const newNext: number[] = new Array(newMax);
-        const newPrev: number[] = new Array(newMax);
+        const newKeyList: (Key | undefined)[] = new Array(newMax).fill(
+          undefined
+        );
+        const newValList: (Value | undefined)[] = new Array(newMax).fill(
+          undefined
+        );
+        const newExpList: number[] = new Array(newMax).fill(0);
+        const newAgeList: number[] = new Array(newMax).fill(0);
+        const newNext: number[] = new Array(newMax).fill(0);
+        const newPrev: number[] = new Array(newMax).fill(0);
 
         for (let i = 1; i <= remove; i++)
           onEviction?.(keyList[i]!, valList[i]!);
 
         for (let i = preserve - 1; i >= 0; i--) {
           newKeyList[i] = keyList[current];
           newValList[i] = valList[current];
+          newExpList[i] = expList[current];
+          newAgeList[i] = ageList[current];
           newNext[i] = i + 1;
           newPrev[i] = i - 1;
           keyMap.set(newKeyList[i]!, i);
@@ -239,12 +313,16 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
 
         keyList.length = newMax;
         valList.length = newMax;
+        expList.length = newMax;
+        ageList.length = newMax;
         next.length = newMax;
         prev.length = newMax;
 
         for (let i = 0; i < preserve; i++) {
           keyList[i] = newKeyList[i];
           valList[i] = newValList[i];
+          expList[i] = newExpList[i];
+          ageList[i] = newAgeList[i];
           next[i] = newNext[i];
           prev[i] = newPrev[i];
         }
@@ -257,6 +335,8 @@ export const createLRU = <Key, Value>(options: CacheOptions<Key, Value>) => {
 
         keyList.push(...new Array(fill).fill(undefined));
         valList.push(...new Array(fill).fill(undefined));
+        expList.push(...new Array(fill).fill(0));
+        ageList.push(...new Array(fill).fill(0));
         next.push(...new Array(fill).fill(0));
         prev.push(...new Array(fill).fill(0));
       }

diff --git a/t.ts b/t.ts
@@ -0,0 +1,12 @@
+import { createLRU } from './src/index.js';
+
+const LRU = createLRU({
+  max: 100,
+  maxAge: 1000,
+});
+
+LRU.set('A', 'Value');
+
+setTimeout(() => {
+  console.log(LRU.get('A'));
+}, 2000);
diff --git a/tools/browserfy.ts b/tools/browserfy.ts
@@ -4,10 +4,9 @@ import { transformAsync } from '@babel/core';
 import { minify } from 'terser';
 
 (async () => {
-  const contents = (await readFile('src/index.ts', 'utf8')).replace(
-    /export const /gim,
-    'window.'
-  );
+  const contents = (await readFile('src/index.ts', 'utf8'))
+    .replace(/export const/gim, 'window.')
+    .replace(/import { performance } from 'node:perf_hooks';/gim, '');
 
   const result = await esbuild.build({
     stdin: {