feat: add storage interface + implement indexedDb

package.json

@@ -28,6 +28,7 @@
     "@ipld/dag-pb": "^2.1.18",
     "@multiformats/blake2": "^1.0.11",
     "browser-readablestream-to-it": "^2.0.4",
+    "idb": "^7.1.1",
     "ipfs-unixfs-exporter": "https://gitpkg.now.sh/filecoin-saturn/js-ipfs-unixfs/packages/ipfs-unixfs-exporter?build",
     "multiformats": "^12.1.1"
   },

src/index.js

@@ -3,6 +3,7 @@ import { CID } from 'multiformats'
 import { extractVerifiedContent } from './utils/car.js'
 import { asAsyncIterable, asyncIteratorToBuffer } from './utils/itr.js'
 import { randomUUID } from './utils/uuid.js'
+import { memoryStorage } from './utils/storage.js'
 
 class Saturn {
   /**
@@ -12,6 +13,7 @@ class Saturn {
    * @param {string} [opts.cdnURL=saturn.ms]
    * @param {number} [opts.connectTimeout=5000]
    * @param {number} [opts.downloadTimeout=0]
+   * @param {import('./utils/storage.js').Storage} [opts.storage]
    */
   constructor (opts = {}) {
     this.opts = Object.assign({}, {
@@ -20,9 +22,11 @@ class Saturn {
       logURL: 'https://twb3qukm2i654i3tnvx36char40aymqq.lambda-url.us-west-2.on.aws/',
       connectTimeout: 5_000,
       downloadTimeout: 0
+
     }, opts)
 
     this.logs = []
+    this.storage = this.opts.storage || memoryStorage()
     this.reportingLogs = process?.env?.NODE_ENV !== 'development'
     this.hasPerformanceAPI = typeof window !== 'undefined' && window?.performance
     if (this.reportingLogs && this.hasPerformanceAPI) {

src/utils/storage.js

@@ -0,0 +1,59 @@
+// @ts-check
+
+import { openDB } from 'idb'
+
+const DEFAULT_IDB_VERSION = 1
+const DEFAULT_IDB_STORAGE_NAME = 'saturn-db'
+const DEFAULT_SATURN_STORAGE_NAME = 'saturn-client'
+
+/**
+ * @typedef {object} Storage
+ * @property {function():boolean} check - Checks if the provided Storage is accessible
+ * @property {function(string):Promise<any>} get - Retrieves the value associated with the key.
+ * @property {function(string,any):Promise<void>} set - Sets a new value for the key.
+ * @property {function(string):Promise<any>} delete - Deletes the value associated with the key.
+ */
+
+/**
+ * @function indexedDbStorage
+ * @returns {Storage}
+ */
+export function indexedDbStorage () {
+  const indexedDbExists = (typeof window !== 'undefined') && window?.indexedDB
+  let dbPromise
+  if (indexedDbExists) {
+    dbPromise = openDB(DEFAULT_IDB_STORAGE_NAME, DEFAULT_IDB_VERSION, {
+      upgrade (db) {
+        db.createObjectStore(DEFAULT_SATURN_STORAGE_NAME)
+      }
+    })
+  }
+
+  return {
+    check: () => Boolean(indexedDbExists),
+    get: async (key) => indexedDbExists && (await dbPromise).get(DEFAULT_SATURN_STORAGE_NAME, key),
+    set: async (key, value) => indexedDbExists && (await dbPromise).put(DEFAULT_SATURN_STORAGE_NAME, value, key),
+    delete: async (key) => indexedDbExists && (await dbPromise).delete(DEFAULT_SATURN_STORAGE_NAME, key)
+  }
+}
+
+/**
+ * @function memoryStorage
+ * @returns {Storage}
+ */
+export function memoryStorage () {
+  const storageObject = {}
+
+  return {
+    check: () => true, // Memory storage is always accessible
+    get: (key) => Promise.resolve(storageObject[key]),
+    set: (key, value) => {
+      storageObject[key] = value
+      return Promise.resolve()
+    },
+    delete: (key) => {
+      delete storageObject[key]
+      return Promise.resolve()
+    }
+  }
+}