Add opts.onwait to constructor (#115)

Author: kasperisager

README.md

@@ -66,7 +66,8 @@ Note that `tree`, `data`, and `bitfield` are normally heavily sparse files.
   valueEncoding: 'json' | 'utf-8' | 'binary', // defaults to binary
   encodeBatch: batch => { ... }, // optionally apply an encoding to complete batches
   keyPair: kp, // optionally pass the public key and secret key as a key pair
-  encryptionKey: k // optionally pass an encryption key to enable block encryption
+  encryptionKey: k, // optionally pass an encryption key to enable block encryption
+  onwait: () => {} // hook that is called if gets are waiting for download
 }
 ```
 

index.js

@@ -70,6 +70,7 @@ module.exports = class Hypercore extends EventEmitter {
     this.sessions = opts._sessions || [this]
     this.auth = opts.auth || null
     this.autoClose = !!opts.autoClose
+    this.onwait = opts.onwait || null
 
     this.closing = null
     this.opening = this._openSession(key, storage, opts)
@@ -662,6 +663,7 @@ module.exports = class Hypercore extends EventEmitter {
     } else {
       if (opts && opts.wait === false) return null
       if (opts && opts.onwait) opts.onwait(index)
+      else if (this.onwait) this.onwait(index)
 
       const activeRequests = (opts && opts.activeRequests) || this.activeRequests