cache: more efficient pruning

Reduce transaction lock times.

Refs: #4124

Author: ronag

lib/cache/sqlite-cache-store.js

@@ -62,16 +62,13 @@ module.exports = class SqliteCacheStore {
    */
   #deleteByUrlQuery
 
-  /**
-   * @type {import('node:sqlite').StatementSync}
-   */
-  #countEntriesQuery
-
   /**
    * @type {import('node:sqlite').StatementSync | null}
    */
   #deleteOldValuesQuery
 
+  #pruneInterval
+
   /**
    * @param {import('../../types/cache-interceptor.d.ts').default.SqliteCacheStoreOpts | undefined} opts
    */
@@ -196,10 +193,6 @@ module.exports = class SqliteCacheStore {
       `DELETE FROM cacheInterceptorV${VERSION} WHERE url = ?`
     )
 
-    this.#countEntriesQuery = this.#db.prepare(
-      `SELECT COUNT(*) AS total FROM cacheInterceptorV${VERSION}`
-    )
-
     this.#deleteExpiredValuesQuery = this.#db.prepare(
       `DELETE FROM cacheInterceptorV${VERSION} WHERE deleteAt <= ?`
     )
@@ -212,13 +205,18 @@ module.exports = class SqliteCacheStore {
           SELECT
             id
           FROM cacheInterceptorV${VERSION}
-          ORDER BY cachedAt DESC
-          LIMIT ?
+          ORDER BY deleteAt DESC
+          OFFSET ${this.#maxCount}
         )
       `)
+
+    this.#pruneInterval = setInterval(() => {
+      this.#prune()
+    }, 10e3)
   }
 
   close () {
+    clearInterval(this.#pruneInterval)
     this.#db.close()
   }
 
@@ -232,7 +230,7 @@ module.exports = class SqliteCacheStore {
     const value = this.#findValue(key)
     return value
       ? {
-          body: value.body ? Buffer.from(value.body.buffer, value.body.byteOffset, value.body.byteLength) : undefined,
+          body: value.body ? Buffer.from(value.body.buffer) : undefined,
           statusCode: value.statusCode,
           statusMessage: value.statusMessage,
           headers: value.headers ? JSON.parse(value.headers) : undefined,
@@ -243,7 +241,7 @@ module.exports = class SqliteCacheStore {
             : undefined,
           cachedAt: value.cachedAt,
           staleAt: value.staleAt,
-          deleteAt: value.deleteAt
+          deleteAt: value.deleteAt || value.staleAt || value.cachedAt
         }
       : undefined
   }
@@ -279,7 +277,6 @@ module.exports = class SqliteCacheStore {
         existingValue.id
       )
     } else {
-      this.#prune()
       // New response, let's insert it
       this.#insertValueQuery.run(
         url,
@@ -346,36 +343,15 @@ module.exports = class SqliteCacheStore {
   }
 
   #prune () {
-    if (this.size <= this.#maxCount) {
-      return 0
-    }
-
-    {
-      const removed = this.#deleteExpiredValuesQuery.run(Date.now()).changes
-      if (removed) {
-        return removed
-      }
-    }
-
-    {
-      const removed = this.#deleteOldValuesQuery?.run(Math.max(Math.floor(this.#maxCount * 0.1), 1)).changes
-      if (removed) {
-        return removed
-      }
+    if (this.#deleteOldValuesQuery) {
+      this.#deleteOldValuesQuery?.run()
+    } else {
+      this.#deleteExpiredValuesQuery.run(Date.now())
     }
 
     return 0
   }
 
-  /**
-   * Counts the number of rows in the cache
-   * @returns {Number}
-   */
-  get size () {
-    const { total } = this.#countEntriesQuery.get()
-    return total
-  }
-
   /**
    * @param {import('../../types/cache-interceptor.d.ts').default.CacheKey} key
    * @returns {string}
@@ -411,6 +387,10 @@ module.exports = class SqliteCacheStore {
       let matches = true
 
       if (value.vary) {
+        if (!headers) {
+          return undefined
+        }
+
         const vary = JSON.parse(value.vary)
 
         for (const header in vary) {
@@ -436,21 +416,18 @@ module.exports = class SqliteCacheStore {
  * @returns {boolean}
  */
 function headerValueEquals (lhs, rhs) {
-  if (lhs == null && rhs == null) {
-    return true
-  }
-
-  if ((lhs == null && rhs != null) ||
-      (lhs != null && rhs == null)) {
-    return false
-  }
-
   if (Array.isArray(lhs) && Array.isArray(rhs)) {
     if (lhs.length !== rhs.length) {
       return false
     }
 
-    return lhs.every((x, i) => x === rhs[i])
+    for (let i = 0; i < lhs.length; i++) {
+      if (rhs.includes(lhs[i])) {
+        return false
+      }
+    }
+
+    return true
   }
 
   return lhs === rhs