string-cache-map

library1.2.0jsnpmunverified

StringCacheMap (v1.2.0) is a high-performance, LRU-based Map implementation specifically optimized for string keys, designed as a drop-in replacement for WeakMap when keys are strings. It provides a WeakMap-compatible API (set, get, has, delete) with configurable capacity limits and a victim cache for fast LRU eviction. Unlike plain objects or Map, it avoids collisions with built-in properties like 'constructor' and ensures predictable memory usage. Released on npm with a stable API, it is suitable for caching scenarios where string keys are used and memory constraints exist. It offers a 'hard' mode (default) that strictly evicts oldest entries, and a 'soft' mode that preserves recently set values.

storage

npm install string-cache-map

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · STRING-CACHE-MAP

string-cache-map

storagejavascriptv1.2.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import StringCacheMap from 'string-cache-map'

✗ const { StringCacheMap } = require('string-cache-map')

Package exports a single default class; named import will fail. CommonJS users must use const StringCacheMap = require('string-cache-map').default or use the default export pattern.

StringCacheMap (type in TypeScript)

✓ import type StringCacheMap from 'string-cache-map'

For TypeScript type imports, use this syntax to import only the type. The package does not ship types natively; install @types/string-cache-map if available.

Creates a StringCacheMap with a capacity limit of 2, adds three entries, and demonstrates LRU eviction behavior.

import StringCacheMap from 'string-cache-map'; const cache = new StringCacheMap(2); // limit to 2 entries cache.set('user1', { name: 'Alice' }); cache.set('user2', { name: 'Bob' }); console.log(cache.get('user1')); // { name: 'Alice' } console.log(cache.has('user3')); // false cache.set('user3', { name: 'Charlie' }); // evicts oldest (user2) console.log(cache.has('user2')); // false (evicted) console.log(cache.get('user3')); // { name: 'Charlie' }

Debug

Known issues

gotchaConstructor limit does not guarantee exactly N entries; the cache may temporarily hold up to 2*limit entries before eviction.

fix

Set limit to expected maximum capacity; for strict limits, use hard mode (default) and be aware of the double-buffer behavior.

affects: >=1.0.0

gotchaString type keys only; non-string keys will cause unexpected behavior (coercion to string or errors).

fix

Always pass strings as keys; manually convert keys with String(key) if needed.

affects: >=1.0.0

gotchaThe 'hard' mode (default) evicts last set values; soft mode (hard=false) retains newer values. Mode must be chosen at construction; cannot be changed later.

fix

Select appropriate mode when instantiating: new StringCacheMap(limit, hard).

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: Class extends value undefined is not a constructor or null

Trying to import the default export incorrectly with named import syntax.

fix

Use import StringCacheMap from 'string-cache-map' (default import) instead of import { StringCacheMap } from ...

Uncaught TypeError: StringCacheMap is not a constructor

Using require incorrectly: const { StringCacheMap } = require(...) returns undefined because there is no named export.

fix

Use const StringCacheMap = require('string-cache-map').default or const StringCacheMap = require('string-cache-map') if the package sets module.exports = default.

ReferenceError: StringCacheMap is not defined

Forgot to import the module.

fix

Add import StringCacheMap from 'string-cache-map' at the top of the file.

Upgrade

Version history

1.2.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

22 hits · last 30 days

node

Resources

githubhttps://github.com/drpicox/string-cache-map ↗

packagestring-cache-map ↗

homepagehttps://github.com/drpicox/string-cache-map#readme ↗