storage stores first opened discovery key as default

index.js

@@ -32,7 +32,8 @@ const TL = {
   LOCAL_SEED: 1,
   DKEYS: 2,
   CORE: 3,
-  DATA: 4
+  DATA: 4,
+  DEFAULT_KEY: 5
 }
 
 // core prefixes
@@ -276,6 +277,7 @@ class HypercoreStorage {
   constructor (db, mutex, discoveryKey) {
     this.db = db
     this.mutex = mutex
+
     this.discoveryKey = discoveryKey
 
     // pointers
@@ -284,15 +286,22 @@ class HypercoreStorage {
   }
 
   async open () {
+    if (!this.discoveryKey) {
+      const discoveryKey = await getDefaultKey(this.db)
+      if (!discoveryKey) throw new Error('No discovery key was provided')
+
+      this.discoveryKey = discoveryKey
+    }
+
     const val = await this.db.get(encodeDiscoveryKey(this.discoveryKey))
-    if (val === null) return false
+    if (val === null) return null
 
     const { core, data } = c.decode(m.CorePointer, val)
 
     this.corePointer = core
     this.dataPointer = data
 
-    return true
+    return this.getCoreInfo()
   }
 
   async create ({ key, manifest, keyPair, encryptionKey }) {
@@ -306,8 +315,16 @@ class HypercoreStorage {
         return false
       }
 
+      if (!key) throw new Error('No key was provided')
+
+      let info = await getStorageInfo(this.db)
+
       const write = this.db.write()
-      const info = (await getStorageInfo(this.db)) || { free: 0, total: 0 }
+
+      if (!info) {
+        write.tryPut(Buffer.from([TL.DEFAULT_KEY]), this.discoveryKey)
+        info = { free: 0, total: 0 }
+      }
 
       const core = info.total++
       const data = info.free++
@@ -430,6 +447,24 @@ class HypercoreStorage {
     return p
   }
 
+  async getCoreInfo () {
+    const r = this.createReadBatch()
+
+    const auth = r.getCoreAuth()
+    const localKeyPair = r.getLocalKeyPair()
+    const encryptionKey = r.getEncryptionKey()
+    const head = r.getCoreHead()
+
+    await r.flush()
+
+    return {
+      auth: await auth,
+      localKeyPair: await localKeyPair,
+      encryptionKey: await encryptionKey,
+      head: await head
+    }
+  }
+
   getBitfieldPage (index) {
     const b = this.createReadBatch()
     const p = b.getBitfieldPage(index)
@@ -486,6 +521,10 @@ function mapOnlyDiscoveryKey (data) {
   return data.key.subarray(1)
 }
 
+async function getDefaultKey (db) {
+  return db.get(Buffer.from([TL.DEFAULT_KEY]))
+}
+
 async function getStorageInfo (db) {
   const value = await db.get(Buffer.from([TL.STORAGE_INFO]))
   if (value === null) return null

test/basic.js

@@ -596,6 +596,38 @@ test('user data', async function (t) {
   t.alike(await c.getUserData('hej'), Buffer.from('verden'))
 })
 
+test('reopen default core', async function (t) {
+  const dir = await tmp(t)
+
+  const manifest = Buffer.from('manifest')
+  const keyPair = {
+    publicKey: Buffer.alloc(32, 2),
+    secretKey: Buffer.alloc(32, 3)
+  }
+  const encryptionKey = Buffer.alloc(32, 4)
+
+  const s1 = await getStorage(t, dir)
+  const c1 = s1.get(DK_0)
+  if (!(await c1.open())) await c1.create({ key: DK_1, manifest, keyPair, encryptionKey })
+
+  await s1.close()
+
+  const s2 = await getStorage(t, dir)
+  const c2 = s2.get()
+
+  t.alike(await c2.open(), {
+    auth: {
+      key: DK_1,
+      manifest
+    },
+    localKeyPair: keyPair,
+    encryptionKey,
+    head: null
+  })
+
+  t.alike(c2.discoveryKey, DK_0)
+})
+
 async function getStorage (t, dir) {
   if (!dir) dir = await tmp(t)
   const s = new CoreStorage(dir)
@@ -609,7 +641,7 @@ async function getCore (t) {
   const s = await getStorage(t)
   const c = s.get(DK_0)
 
-  t.is(await c.open(), false)
+  t.is(await c.open(), null)
   await c.create({ key: DK_0 })
 
   return c