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author | Minteck <nekostarfan@gmail.com> | 2021-08-24 14:41:48 +0200 |
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committer | Minteck <nekostarfan@gmail.com> | 2021-08-24 14:41:48 +0200 |
commit | d25e11bee6ca5ca523884da132d18e1400e077b9 (patch) | |
tree | 8af39fde19f7ed640a60fb397c7edd647dff1c4c /node_modules/cacheable-request/src | |
download | kartik-iridium-d25e11bee6ca5ca523884da132d18e1400e077b9.tar.gz kartik-iridium-d25e11bee6ca5ca523884da132d18e1400e077b9.tar.bz2 kartik-iridium-d25e11bee6ca5ca523884da132d18e1400e077b9.zip |
Initial commit
Diffstat (limited to 'node_modules/cacheable-request/src')
-rw-r--r-- | node_modules/cacheable-request/src/index.js | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/node_modules/cacheable-request/src/index.js b/node_modules/cacheable-request/src/index.js new file mode 100644 index 0000000..3fcea3f --- /dev/null +++ b/node_modules/cacheable-request/src/index.js @@ -0,0 +1,251 @@ +'use strict'; + +const EventEmitter = require('events'); +const urlLib = require('url'); +const normalizeUrl = require('normalize-url'); +const getStream = require('get-stream'); +const CachePolicy = require('http-cache-semantics'); +const Response = require('responselike'); +const lowercaseKeys = require('lowercase-keys'); +const cloneResponse = require('clone-response'); +const Keyv = require('keyv'); + +class CacheableRequest { + constructor(request, cacheAdapter) { + if (typeof request !== 'function') { + throw new TypeError('Parameter `request` must be a function'); + } + + this.cache = new Keyv({ + uri: typeof cacheAdapter === 'string' && cacheAdapter, + store: typeof cacheAdapter !== 'string' && cacheAdapter, + namespace: 'cacheable-request' + }); + + return this.createCacheableRequest(request); + } + + createCacheableRequest(request) { + return (opts, cb) => { + let url; + if (typeof opts === 'string') { + url = normalizeUrlObject(urlLib.parse(opts)); + opts = {}; + } else if (opts instanceof urlLib.URL) { + url = normalizeUrlObject(urlLib.parse(opts.toString())); + opts = {}; + } else { + const [pathname, ...searchParts] = (opts.path || '').split('?'); + const search = searchParts.length > 0 ? + `?${searchParts.join('?')}` : + ''; + url = normalizeUrlObject({ ...opts, pathname, search }); + } + + opts = { + headers: {}, + method: 'GET', + cache: true, + strictTtl: false, + automaticFailover: false, + ...opts, + ...urlObjectToRequestOptions(url) + }; + opts.headers = lowercaseKeys(opts.headers); + + const ee = new EventEmitter(); + const normalizedUrlString = normalizeUrl( + urlLib.format(url), + { + stripWWW: false, + removeTrailingSlash: false, + stripAuthentication: false + } + ); + const key = `${opts.method}:${normalizedUrlString}`; + let revalidate = false; + let madeRequest = false; + + const makeRequest = opts => { + madeRequest = true; + let requestErrored = false; + let requestErrorCallback; + + const requestErrorPromise = new Promise(resolve => { + requestErrorCallback = () => { + if (!requestErrored) { + requestErrored = true; + resolve(); + } + }; + }); + + const handler = response => { + if (revalidate && !opts.forceRefresh) { + response.status = response.statusCode; + const revalidatedPolicy = CachePolicy.fromObject(revalidate.cachePolicy).revalidatedPolicy(opts, response); + if (!revalidatedPolicy.modified) { + const headers = revalidatedPolicy.policy.responseHeaders(); + response = new Response(revalidate.statusCode, headers, revalidate.body, revalidate.url); + response.cachePolicy = revalidatedPolicy.policy; + response.fromCache = true; + } + } + + if (!response.fromCache) { + response.cachePolicy = new CachePolicy(opts, response, opts); + response.fromCache = false; + } + + let clonedResponse; + if (opts.cache && response.cachePolicy.storable()) { + clonedResponse = cloneResponse(response); + + (async () => { + try { + const bodyPromise = getStream.buffer(response); + + await Promise.race([ + requestErrorPromise, + new Promise(resolve => response.once('end', resolve)) + ]); + + if (requestErrored) { + return; + } + + const body = await bodyPromise; + + const value = { + cachePolicy: response.cachePolicy.toObject(), + url: response.url, + statusCode: response.fromCache ? revalidate.statusCode : response.statusCode, + body + }; + + let ttl = opts.strictTtl ? response.cachePolicy.timeToLive() : undefined; + if (opts.maxTtl) { + ttl = ttl ? Math.min(ttl, opts.maxTtl) : opts.maxTtl; + } + + await this.cache.set(key, value, ttl); + } catch (error) { + ee.emit('error', new CacheableRequest.CacheError(error)); + } + })(); + } else if (opts.cache && revalidate) { + (async () => { + try { + await this.cache.delete(key); + } catch (error) { + ee.emit('error', new CacheableRequest.CacheError(error)); + } + })(); + } + + ee.emit('response', clonedResponse || response); + if (typeof cb === 'function') { + cb(clonedResponse || response); + } + }; + + try { + const req = request(opts, handler); + req.once('error', requestErrorCallback); + req.once('abort', requestErrorCallback); + ee.emit('request', req); + } catch (error) { + ee.emit('error', new CacheableRequest.RequestError(error)); + } + }; + + (async () => { + const get = async opts => { + await Promise.resolve(); + + const cacheEntry = opts.cache ? await this.cache.get(key) : undefined; + if (typeof cacheEntry === 'undefined') { + return makeRequest(opts); + } + + const policy = CachePolicy.fromObject(cacheEntry.cachePolicy); + if (policy.satisfiesWithoutRevalidation(opts) && !opts.forceRefresh) { + const headers = policy.responseHeaders(); + const response = new Response(cacheEntry.statusCode, headers, cacheEntry.body, cacheEntry.url); + response.cachePolicy = policy; + response.fromCache = true; + + ee.emit('response', response); + if (typeof cb === 'function') { + cb(response); + } + } else { + revalidate = cacheEntry; + opts.headers = policy.revalidationHeaders(opts); + makeRequest(opts); + } + }; + + const errorHandler = error => ee.emit('error', new CacheableRequest.CacheError(error)); + this.cache.once('error', errorHandler); + ee.on('response', () => this.cache.removeListener('error', errorHandler)); + + try { + await get(opts); + } catch (error) { + if (opts.automaticFailover && !madeRequest) { + makeRequest(opts); + } + + ee.emit('error', new CacheableRequest.CacheError(error)); + } + })(); + + return ee; + }; + } +} + +function urlObjectToRequestOptions(url) { + const options = { ...url }; + options.path = `${url.pathname || '/'}${url.search || ''}`; + delete options.pathname; + delete options.search; + return options; +} + +function normalizeUrlObject(url) { + // If url was parsed by url.parse or new URL: + // - hostname will be set + // - host will be hostname[:port] + // - port will be set if it was explicit in the parsed string + // Otherwise, url was from request options: + // - hostname or host may be set + // - host shall not have port encoded + return { + protocol: url.protocol, + auth: url.auth, + hostname: url.hostname || url.host || 'localhost', + port: url.port, + pathname: url.pathname, + search: url.search + }; +} + +CacheableRequest.RequestError = class extends Error { + constructor(error) { + super(error.message); + this.name = 'RequestError'; + Object.assign(this, error); + } +}; + +CacheableRequest.CacheError = class extends Error { + constructor(error) { + super(error.message); + this.name = 'CacheError'; + Object.assign(this, error); + } +}; + +module.exports = CacheableRequest; |