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

$3

* ETagCacheLevelDB
* Parameters
* addHeaders
* Parameters
* statistics
* storeResponse
* Parameters
* loadResponse
* Parameters
* rawTagData
* Parameters

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

$3

* db

$3

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

#### Parameters

* url (string | URL)
* headers Object

Returns Promise<boolean> true if etag was found in cache and header has been added

$3

Deliver statisics data.

Returns Object

$3

Stores response in the cache.
Two entries are stored:

* url : etag
* etag : body

#### Parameters

* response Response as produced by fetch

Returns Promise\

$3

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

#### Parameters

* response Response as provided by fetch

Returns Promise<Response>

rawTagData

Strips away etag flags (weak and the like)

$3

* etag` (string | null)

Returns (string | undefined) raw etag