*make message encoding/decoding async for use with the kernel

*need to make createChannel async

index.js

@@ -51,10 +51,9 @@ class Channel {
   }
 
   async open(handshake) {
-    if (this._slave) {
-      await this._mux.pullLocal();
-      await this._mux.pullFree();
-    }
+    await this._mux.pullLocal();
+    await this._mux.pullFree();
+
     const freeLen = this._mux._free.length;
     const id =
       this._mux._free.length > 0
@@ -65,16 +64,15 @@ class Channel {
     this._localId = id + 1;
     this._mux._local[id] = this;
 
-    if (this._slave) {
-      if (freeLen > 0) {
-        await this._mux.popFree(id);
-      } else {
-        await this._mux.pushLocal(id);
-      }
+    if (freeLen > 0) {
+      await this._mux.popFree(id);
+    } else {
+      await this._mux.pushLocal(id);
     }
 
     if (this._remoteId === 0) {
       this._info.outgoing.push(this._localId);
+      await this._mux.pushInfos();
     }
 
     const state = { buffer: null, start: 2, end: 2 };
@@ -148,27 +146,27 @@ class Channel {
     if (this.closed === true) return;
     this.closed = true;
 
+    await this._mux.pullInfos();
+
     this._info.opened--;
 
+    await this._mux.pushInfos();
+
     if (this._remoteId > 0) {
       this._mux._remote[this._remoteId - 1] = null;
       this._remoteId = 0;
-      if (this._slave) {
-        await this._mux.pullFree();
-      }
+      await this._mux.pullFree();
       // If remote has acked, we can reuse the local id now
       // otherwise, we need to wait for the "ack" to arrive
       this._mux._free.push(this._localId - 1);
 
-      if (this._slave) {
-        await this._mux.pushFree(this._localId - 1);
-      }
+      await this._mux.pushFree(this._localId - 1);
     }
 
     this._mux._local[this._localId - 1] = null;
     this._localId = 0;
 
-    this._mux._gc(this._info);
+    await this._mux._gc(this._info);
     this._track(this.onclose(isRemote, this));
 
     if (this._active === 0) this._destroy();
@@ -225,34 +223,34 @@ class Channel {
       type,
       encoding,
       onmessage,
-      recv(state, session) {
-        session._track(m.onmessage(encoding.decode(state), session));
+      async recv(state, session) {
+        session._track(m.onmessage(await encoding.decode(state), session));
       },
-      send(m, session = s) {
+      async send(m, session = s) {
         if (session.closed === true) return false;
 
         const mux = session._mux;
         const state = { buffer: null, start: 0, end: typeLen };
 
         if (mux._batch !== null) {
-          encoding.preencode(state, m);
+          await encoding.preencode(state, m);
           state.buffer = mux._alloc(state.end);
 
           c.uint.encode(state, type);
-          encoding.encode(state, m);
+          await encoding.encode(state, m);
 
           mux._pushBatch(session._localId, state.buffer);
           return true;
         }
 
         c.uint.preencode(state, session._localId);
-        encoding.preencode(state, m);
+        await encoding.preencode(state, m);
 
         state.buffer = mux._alloc(state.end);
 
         c.uint.encode(state, session._localId);
         c.uint.encode(state, type);
-        encoding.encode(state, m);
+        await encoding.encode(state, m);
 
         return mux.stream.write(state.buffer);
       },
@@ -280,7 +278,11 @@ class Channel {
 
 module.exports = class Protomux {
   constructor(stream, { alloc, slave = false } = {}) {
-    if (stream.userData === null) stream.userData = this;
+    if (stream.userData) {
+      throw new Error("Mux already set for this stream");
+    }
+
+    stream.userData = this;
 
     this.isProtomux = true;
     this.stream = stream;
@@ -304,7 +306,6 @@ module.exports = class Protomux {
 
     this._infos = new Map();
     this._notify = new Map();
-    this._slave = slave;
 
     this.stream.on("data", this._ondata.bind(this));
     this.stream.on("end", this._onend.bind(this));
@@ -356,8 +357,7 @@ module.exports = class Protomux {
     const info = this._infos.get(key);
     return info ? info.opened > 0 : false;
   }
-
-  createChannel({
+  async createChannel({
     userData = null,
     protocol,
     aliases = [],
@@ -371,7 +371,7 @@ module.exports = class Protomux {
   }) {
     if (this.stream.destroyed) return null;
 
-    const info = this._get(protocol, id, aliases);
+    const info = await this._get(protocol, id, aliases);
     if (unique && info.opened > 0) return null;
 
     if (info.incoming.length === 0) {
@@ -392,7 +392,12 @@ module.exports = class Protomux {
 
     this._remoteBacklog--;
 
+    await this.pullInfos();
+
     const remoteId = info.incoming.shift();
+
+    await this.pushInfos();
+
     const r = this._remote[remoteId - 1];
     if (r === null) return null;
 
@@ -457,9 +462,11 @@ module.exports = class Protomux {
     this.stream.write(state.buffer);
   }
 
-  _get(protocol, id, aliases = []) {
+  async _get(protocol, id, aliases = []) {
     const key = toKey(protocol, id);
 
+    await this.pullInfos();
+
     let info = this._infos.get(key);
     if (info) return info;
 
@@ -482,18 +489,22 @@ module.exports = class Protomux {
       this._infos.set(key, info);
     }
 
+    await this.pushInfos();
+
     return info;
   }
 
-  _gc(info) {
+  async _gc(info) {
     if (
       info.opened === 0 &&
       info.outgoing.length === 0 &&
       info.incoming.length === 0
     ) {
+      await this.pullInfos();
       this._infos.delete(info.key);
 
       for (const alias of info.aliases) this._infos.delete(alias);
+      await this.pullInfos();
     }
   }
 
@@ -602,18 +613,15 @@ module.exports = class Protomux {
     }
 
     const rid = remoteId - 1;
-    const info = this._get(protocol, id);
+    const info = await this._get(protocol, id);
 
-    if (this._slave) {
-      await this.pullRemote();
-    }
+    await this.pullRemote();
 
     // allow the remote to grow the ids by one
     if (this._remote.length === rid) {
       this._remote.push(null);
-      if (this._slave) {
-        await this.pushRemote(this._remote.length - 1);
-      }
+
+      await this.pushRemote(this._remote.length - 1);
     }
 
     if (rid >= this._remote.length || this._remote[rid] !== null) {
@@ -621,26 +629,25 @@ module.exports = class Protomux {
     }
 
     if (info.outgoing.length > 0) {
+      await this.pullInfos();
       const localId = info.outgoing.shift();
       const session = this._local[localId - 1];
 
+      await this.pushInfos();
+
       if (session === null) {
-        if (this._slave) {
-          await this.pullFree();
-        }
+        await this.pullFree();
         // we already closed the channel - ignore
         this._free.push(localId - 1);
-        if (this._slave) {
-          await this.pushFree(localId - 1);
-        }
+
+        await this.pushFree(localId - 1);
+
         return;
       }
 
       this._remote[rid] = { state, pending: null, session: null };
 
-      if (this._slave) {
-        await this.pushRemote(remoteId);
-      }
+      await this.pushRemote(remoteId);
 
       session._remoteId = remoteId;
       session._fullyOpen();
@@ -658,12 +665,13 @@ module.exports = class Protomux {
       throw new Error("Remote exceeded backlog");
     }
 
+    await this.pullInfos();
+
     info.pairing++;
     info.incoming.push(remoteId);
 
-    if (this._slave) {
-      await this.pushRemote(remoteId);
-    }
+    await this.pushInfos();
+    await this.pushRemote(remoteId);
 
     this._requestSession(protocol, id, info).catch(this._safeDestroyBound);
   }
@@ -676,22 +684,23 @@ module.exports = class Protomux {
       const i = info.outgoing.indexOf(localId);
       if (i === -1) continue;
 
+      await this.pullInfos();
+
       info.outgoing.splice(i, 1);
 
+      await this.pushInfos();
+
       const session = this._local[localId - 1];
 
-      if (this._slave) {
-        await this.pullFree(localId - 1);
-      }
+      await this.pullFree(localId - 1);
 
       this._free.push(localId - 1);
-      if (this._slave) {
-        await this.pushFree(localId - 1);
-      }
+
+      await this.pushFree(localId - 1);
 
       if (session !== null) session._close(true);
 
-      this._gc(info);
+      await this._gc(info);
       return;
     }
 
@@ -718,13 +727,25 @@ module.exports = class Protomux {
 
     if (notify) await notify(id);
 
-    if (--info.pairing > 0) return;
+    await this.pullInfos();
+
+    let p = --info.pairing;
+
+    await this.pushInfos();
+
+    if (p > 0) return;
 
     while (info.incoming.length > 0) {
-      this._rejectSession(info, info.incoming.shift());
+      await this.pullInfos();
+
+      const id = info.incoming.shift();
+
+      await this.pushInfos();
+
+      this._rejectSession(info, id);
     }
 
-    this._gc(info);
+    await this._gc(info);
   }
 
   _rejectSession(info, remoteId) {
@@ -790,6 +811,12 @@ module.exports = class Protomux {
   async pushRemote(id) {
     await this.stream.syncProtomux("pushRemote", id);
   }
+  async pushInfos() {
+    await this.stream.syncProtomux(
+      "pushInfos",
+      Array.from(this._infos.entries())
+    );
+  }
 
   async pullLocal() {
     const ids = await this.stream.syncProtomux("pullLocal");
@@ -817,6 +844,14 @@ module.exports = class Protomux {
       }
     });
   }
+  async pullInfos() {
+    const info = await this.stream.syncProtomux(
+      "pullInfos",
+      Array.from(this._infos.entries())
+    );
+
+    this._infos = new Map(info);
+  }
 };
 
 function noop() {}