https://github.com/arlac77/etag-cache-leveldb

etag cache based on leveldb
https://github.com/arlac77/etag-cache-leveldb

Last synced: about 1 year ago
JSON representation

etag cache based on leveldb

• Host: GitHub
• URL: https://github.com/arlac77/etag-cache-leveldb
• Owner: arlac77
• License: 0bsd
• Created: 2022-05-22T11:39:16.000Z (about 4 years ago)
• Default Branch: master
• Last Pushed: 2025-05-08T18:06:48.000Z (about 1 year ago)
• Last Synced: 2025-05-08T19:53:58.989Z (about 1 year ago)
• Language: JavaScript
• Size: 1.67 MB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

          
[![npm](https://img.shields.io/npm/v/etag-cache-leveldb.svg)](https://www.npmjs.com/package/etag-cache-leveldb)

[![License](https://img.shields.io/badge/License-0BSD-blue.svg)](https://spdx.org/licenses/0BSD.html)

[![Typed with TypeScript](https://flat.badgen.net/badge/icon/Typed?icon=typescript\&label\&labelColor=blue\&color=555555)](https://typescriptlang.org)

[![bundlejs](https://deno.bundlejs.com/?q=etag-cache-leveldb\&badge=detailed)](https://bundlejs.com/?q=etag-cache-leveldb)

[![downloads](http://img.shields.io/npm/dm/etag-cache-leveldb.svg?style=flat-square)](https://npmjs.org/package/etag-cache-leveldb)

[![GitHub Issues](https://img.shields.io/github/issues/arlac77/etag-cache-leveldb.svg?style=flat-square)](https://github.com/arlac77/etag-cache-leveldb/issues)

[![Build Status](https://img.shields.io/endpoint.svg?url=https%3A%2F%2Factions-badge.atrox.dev%2Farlac77%2Fetag-cache-leveldb%2Fbadge\&style=flat)](https://actions-badge.atrox.dev/arlac77/etag-cache-leveldb/goto)

[![Styled with prettier](https://img.shields.io/badge/styled_with-prettier-ff69b4.svg)](https://github.com/prettier/prettier)

[![Commitizen friendly](https://img.shields.io/badge/commitizen-friendly-brightgreen.svg)](http://commitizen.github.io/cz-cli/)

[![Known Vulnerabilities](https://snyk.io/test/github/arlac77/etag-cache-leveldb/badge.svg)](https://snyk.io/test/github/arlac77/etag-cache-leveldb)

[![Coverage Status](https://coveralls.io/repos/arlac77/etag-cache-leveldb/badge.svg)](https://coveralls.io/github/arlac77/etag-cache-leveldb)

# etag-cache-leveldb

etag cache based on leveldb

# example

```js

import levelup from "levelup";

import leveldown from "leveldown";

import { ETagCacheLevelDB } from "etag-cache-leveldb";

const someDirectory = "/tmp";

const db = await levelup(leveldown(someDirectory));

const cache = new ETagCacheLevelDB(db);

const url = "https://api.github.com/";

const response = await fetch(url);

await cache.storeResponse(response);

// later

const headers = {};

await cache.addHeaders(url, headers); // fill in etag header

const responseWithETag = await fetch(url, { headers });

const cachedResponse = await cache.loadResponse(responseWithETag);

```

# API

### Table of Contents

*   [ETagCacheLevelDB](#etagcacheleveldb)

    *   [Parameters](#parameters)

    *   [addHeaders](#addheaders)

        *   [Parameters](#parameters-1)

    *   [statistics](#statistics)

    *   [storeResponse](#storeresponse)

        *   [Parameters](#parameters-2)

    *   [loadResponse](#loadresponse)

        *   [Parameters](#parameters-3)

*   [rawTagData](#rawtagdata)

    *   [Parameters](#parameters-4)

## ETagCacheLevelDB

Stores etags and bodies into leveldb.

Reconstructs response with body if etag or url matches.

Will store in the cache:

url : etag

etag : body

### Parameters

*   `db`  

### addHeaders

Adds the "If-None-Match" header if etag is found for the url.

#### Parameters

*   `url` **([string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String) | [URL](https://developer.mozilla.org/docs/Web/API/URL/URL))** 

*   `headers` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** 

Returns **[Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)<[boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)>** true if etag was found in cache and header has been added

### statistics

Deliver statisics data.

Returns **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** 

### storeResponse

Stores response in the cache.

Two entries are stored:

*   url : etag

*   etag : body

#### Parameters

*   `response` **[Response](https://developer.mozilla.org/docs/Web/Guide/HTML/HTML5)** as produced by fetch

Returns **[Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)\** 

### loadResponse

Constructs a new Response feed from the cache if a matching etag is found in the cache.

#### Parameters

*   `response` **[Response](https://developer.mozilla.org/docs/Web/Guide/HTML/HTML5)** as provided by fetch

Returns **[Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)<[Response](https://developer.mozilla.org/docs/Web/Guide/HTML/HTML5)>** 

## rawTagData

Strips away etag flags (weak and the like)

### Parameters

*   `etag` **([string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String) | null)** 

Returns **([string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String) | [undefined](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/undefined))** raw etag