feat: be possible to set staleTtl from data

Author: Kikobeats

package.json

@@ -55,7 +55,7 @@
   ],
   "dependencies": {
     "@keyvhq/core": "~1.1.1",
-    "@keyvhq/memoize": "~1.2.0",
+    "@keyvhq/memoize": "~1.2.2",
     "compress-brotli": "~1.3.0",
     "debug-logfmt": "~1.0.4",
     "etag": "~1.8.1",

src/index.js

@@ -7,7 +7,7 @@ const Keyv = require('@keyvhq/core')
 const assert = require('assert')
 const getEtag = require('etag')
 
-const { hasQueryParameter, createSetHeaders } = require('./util')
+const { hasQueryParameter, setHeaders } = require('./util')
 
 const cacheableResponse = ({
   bypassQueryParameter = 'force',
@@ -17,29 +17,36 @@ const cacheableResponse = ({
   getKey = require('./util').getKey,
   send,
   staleTtl: rawStaleTtl = 3600000,
-  ttl: defaultTtl = 86400000,
+  ttl: rawTtl = 86400000,
   ...compressOpts
 } = {}) => {
   assert(get, '.get required')
   assert(send, '.send required')
 
-  const staleTtl = typeof rawStaleTtl === 'number' ? rawStaleTtl : undefined
+  const isStaleEnabled = rawStaleTtl !== false
+
+  const staleTtl = isStaleEnabled
+    ? typeof rawStaleTtl === 'function'
+        ? rawStaleTtl
+        : ({ staleTtl = rawStaleTtl } = {}) => staleTtl
+    : undefined
+
+  const ttl =
+    typeof rawTtl === 'function' ? rawTtl : ({ ttl = rawTtl } = {}) => ttl
 
   const { serialize, compress, decompress } = createCompress({
     enable: enableCompression,
     ...compressOpts
   })
 
   const memoGet = memoize(get, cache, {
-    ttl: ({ ttl = defaultTtl } = {}) => ttl,
+    ttl,
     staleTtl,
     objectMode: true,
     key: opts => getKey(opts, { bypassQueryParameter }),
     value: compress
   })
 
-  const setHeaders = createSetHeaders({ staleTtl })
-
   return async opts => {
     const { req, res } = opts
     const hasForce = hasQueryParameter(req, bypassQueryParameter)
@@ -50,10 +57,11 @@ const cacheableResponse = ({
     const isHit = !hasForce && !isExpired && hasValue
 
     const {
-      etag: cachedEtag,
-      ttl = defaultTtl,
       createdAt = Date.now(),
       data = null,
+      etag: cachedEtag,
+      staleTtl = isStaleEnabled ? memoGet.staleTtl(result) : undefined,
+      ttl = memoGet.ttl(result),
       ...props
     } = result
 
@@ -79,6 +87,7 @@ const cacheableResponse = ({
       isHit,
       isStale,
       ttl,
+      staleTtl,
       hasForce
     })
 

src/util.js

@@ -28,29 +28,36 @@ const toSeconds = ms => Math.floor(ms / 1000)
 const getStatus = ({ isHit, isStale, hasForce }) =>
   isHit ? (isStale ? 'STALE' : 'HIT') : hasForce ? 'BYPASS' : 'MISS'
 
-const createSetHeaders = ({ staleTtl }) => {
-  return ({ res, createdAt, isHit, isStale, ttl, hasForce, etag }) => {
-    // Specifies the maximum amount of time a resource
-    // will be considered fresh in seconds
-    const diff = hasForce ? 0 : createdAt + ttl - Date.now()
-    const maxAge = toSeconds(diff)
-    const revalidation = staleTtl ? toSeconds(staleTtl) : 0
-
-    let cacheControl = `public, must-revalidate, max-age=${maxAge}`
-
-    if (revalidation) {
-      cacheControl = `${cacheControl}, stale-while-revalidate=${revalidation}, stale-if-error=${revalidation}`
-    }
-
-    res.setHeader('Cache-Control', cacheControl)
-    res.setHeader('X-Cache-Status', getStatus({ isHit, isStale, hasForce }))
-    res.setHeader('X-Cache-Expired-At', prettyMs(diff))
-    res.setHeader('ETag', etag)
+const setHeaders = ({
+  createdAt,
+  etag,
+  hasForce,
+  isHit,
+  isStale,
+  res,
+  staleTtl,
+  ttl
+}) => {
+  // Specifies the maximum amount of time a resource
+  // will be considered fresh in seconds
+  const diff = hasForce ? 0 : createdAt + ttl - Date.now()
+  const maxAge = toSeconds(diff)
+  const revalidation = staleTtl ? toSeconds(staleTtl) : 0
+
+  let cacheControl = `public, must-revalidate, max-age=${maxAge}`
+
+  if (revalidation) {
+    cacheControl = `${cacheControl}, stale-while-revalidate=${revalidation}, stale-if-error=${revalidation}`
   }
+
+  res.setHeader('Cache-Control', cacheControl)
+  res.setHeader('X-Cache-Status', getStatus({ isHit, isStale, hasForce }))
+  res.setHeader('X-Cache-Expired-At', prettyMs(diff))
+  res.setHeader('ETag', etag)
 }
 
 module.exports = {
-  hasQueryParameter,
   getKey,
-  createSetHeaders
+  hasQueryParameter,
+  setHeaders
 }