* first action! (#1)

node_modules/make-fetch-happen/cache.js

@@ -0,0 +1,245 @@
+'use strict'
+
+const cacache = require('cacache')
+const fetch = require('node-fetch-npm')
+const pipe = require('mississippi').pipe
+const ssri = require('ssri')
+const through = require('mississippi').through
+const to = require('mississippi').to
+const url = require('url')
+const stream = require('stream')
+
+const MAX_MEM_SIZE = 5 * 1024 * 1024 // 5MB
+
+function cacheKey (req) {
+  const parsed = url.parse(req.url)
+  return `make-fetch-happen:request-cache:${
+    url.format({
+      protocol: parsed.protocol,
+      slashes: parsed.slashes,
+      host: parsed.host,
+      hostname: parsed.hostname,
+      pathname: parsed.pathname
+    })
+  }`
+}
+
+// This is a cacache-based implementation of the Cache standard,
+// using node-fetch.
+// docs: https://developer.mozilla.org/en-US/docs/Web/API/Cache
+//
+module.exports = class Cache {
+  constructor (path, opts) {
+    this._path = path
+    this.Promise = (opts && opts.Promise) || Promise
+  }
+
+  // Returns a Promise that resolves to the response associated with the first
+  // matching request in the Cache object.
+  match (req, opts) {
+    opts = opts || {}
+    const key = cacheKey(req)
+    return cacache.get.info(this._path, key).then(info => {
+      return info && cacache.get.hasContent(
+        this._path, info.integrity, opts
+      ).then(exists => exists && info)
+    }).then(info => {
+      if (info && info.metadata && matchDetails(req, {
+        url: info.metadata.url,
+        reqHeaders: new fetch.Headers(info.metadata.reqHeaders),
+        resHeaders: new fetch.Headers(info.metadata.resHeaders),
+        cacheIntegrity: info.integrity,
+        integrity: opts && opts.integrity
+      })) {
+        const resHeaders = new fetch.Headers(info.metadata.resHeaders)
+        addCacheHeaders(resHeaders, this._path, key, info.integrity, info.time)
+        if (req.method === 'HEAD') {
+          return new fetch.Response(null, {
+            url: req.url,
+            headers: resHeaders,
+            status: 200
+          })
+        }
+        let body
+        const cachePath = this._path
+        // avoid opening cache file handles until a user actually tries to
+        // read from it.
+        if (opts.memoize !== false && info.size > MAX_MEM_SIZE) {
+          body = new stream.PassThrough()
+          const realRead = body._read
+          body._read = function (size) {
+            body._read = realRead
+            pipe(
+              cacache.get.stream.byDigest(cachePath, info.integrity, {
+                memoize: opts.memoize
+              }),
+              body,
+              err => body.emit(err))
+            return realRead.call(this, size)
+          }
+        } else {
+          let readOnce = false
+          // cacache is much faster at bulk reads
+          body = new stream.Readable({
+            read () {
+              if (readOnce) return this.push(null)
+              readOnce = true
+              cacache.get.byDigest(cachePath, info.integrity, {
+                memoize: opts.memoize
+              }).then(data => {
+                this.push(data)
+                this.push(null)
+              }, err => this.emit('error', err))
+            }
+          })
+        }
+        return this.Promise.resolve(new fetch.Response(body, {
+          url: req.url,
+          headers: resHeaders,
+          status: 200,
+          size: info.size
+        }))
+      }
+    })
+  }
+
+  // Takes both a request and its response and adds it to the given cache.
+  put (req, response, opts) {
+    opts = opts || {}
+    const size = response.headers.get('content-length')
+    const fitInMemory = !!size && opts.memoize !== false && size < MAX_MEM_SIZE
+    const ckey = cacheKey(req)
+    const cacheOpts = {
+      algorithms: opts.algorithms,
+      metadata: {
+        url: req.url,
+        reqHeaders: req.headers.raw(),
+        resHeaders: response.headers.raw()
+      },
+      size,
+      memoize: fitInMemory && opts.memoize
+    }
+    if (req.method === 'HEAD' || response.status === 304) {
+      // Update metadata without writing
+      return cacache.get.info(this._path, ckey).then(info => {
+        // Providing these will bypass content write
+        cacheOpts.integrity = info.integrity
+        addCacheHeaders(
+          response.headers, this._path, ckey, info.integrity, info.time
+        )
+        return new this.Promise((resolve, reject) => {
+          pipe(
+            cacache.get.stream.byDigest(this._path, info.integrity, cacheOpts),
+            cacache.put.stream(this._path, cacheKey(req), cacheOpts),
+            err => err ? reject(err) : resolve(response)
+          )
+        })
+      }).then(() => response)
+    }
+    let buf = []
+    let bufSize = 0
+    let cacheTargetStream = false
+    const cachePath = this._path
+    let cacheStream = to((chunk, enc, cb) => {
+      if (!cacheTargetStream) {
+        if (fitInMemory) {
+          cacheTargetStream =
+          to({highWaterMark: MAX_MEM_SIZE}, (chunk, enc, cb) => {
+            buf.push(chunk)
+            bufSize += chunk.length
+            cb()
+          }, done => {
+            cacache.put(
+              cachePath,
+              cacheKey(req),
+              Buffer.concat(buf, bufSize),
+              cacheOpts
+            ).then(
+              () => done(),
+              done
+            )
+          })
+        } else {
+          cacheTargetStream =
+          cacache.put.stream(cachePath, cacheKey(req), cacheOpts)
+        }
+      }
+      cacheTargetStream.write(chunk, enc, cb)
+    }, done => {
+      cacheTargetStream ? cacheTargetStream.end(done) : done()
+    })
+    const oldBody = response.body
+    const newBody = through({highWaterMark: fitInMemory && MAX_MEM_SIZE})
+    response.body = newBody
+    oldBody.once('error', err => newBody.emit('error', err))
+    newBody.once('error', err => oldBody.emit('error', err))
+    cacheStream.once('error', err => newBody.emit('error', err))
+    pipe(oldBody, to((chunk, enc, cb) => {
+      cacheStream.write(chunk, enc, () => {
+        newBody.write(chunk, enc, cb)
+      })
+    }, done => {
+      cacheStream.end(() => {
+        newBody.end(() => {
+          done()
+        })
+      })
+    }), err => err && newBody.emit('error', err))
+    return response
+  }
+
+  // Finds the Cache entry whose key is the request, and if found, deletes the
+  // Cache entry and returns a Promise that resolves to true. If no Cache entry
+  // is found, it returns false.
+  'delete' (req, opts) {
+    opts = opts || {}
+    if (typeof opts.memoize === 'object') {
+      if (opts.memoize.reset) {
+        opts.memoize.reset()
+      } else if (opts.memoize.clear) {
+        opts.memoize.clear()
+      } else {
+        Object.keys(opts.memoize).forEach(k => {
+          opts.memoize[k] = null
+        })
+      }
+    }
+    return cacache.rm.entry(
+      this._path,
+      cacheKey(req)
+    // TODO - true/false
+    ).then(() => false)
+  }
+}
+
+function matchDetails (req, cached) {
+  const reqUrl = url.parse(req.url)
+  const cacheUrl = url.parse(cached.url)
+  const vary = cached.resHeaders.get('Vary')
+  // https://tools.ietf.org/html/rfc7234#section-4.1
+  if (vary) {
+    if (vary.match(/\*/)) {
+      return false
+    } else {
+      const fieldsMatch = vary.split(/\s*,\s*/).every(field => {
+        return cached.reqHeaders.get(field) === req.headers.get(field)
+      })
+      if (!fieldsMatch) {
+        return false
+      }
+    }
+  }
+  if (cached.integrity) {
+    return ssri.parse(cached.integrity).match(cached.cacheIntegrity)
+  }
+  reqUrl.hash = null
+  cacheUrl.hash = null
+  return url.format(reqUrl) === url.format(cacheUrl)
+}
+
+function addCacheHeaders (resHeaders, path, key, hash, time) {
+  resHeaders.set('X-Local-Cache', encodeURIComponent(path))
+  resHeaders.set('X-Local-Cache-Key', encodeURIComponent(key))
+  resHeaders.set('X-Local-Cache-Hash', encodeURIComponent(hash))
+  resHeaders.set('X-Local-Cache-Time', new Date(time).toUTCString())
+}