json_socket_translator: convert to gatekeeper protocol

README.md

@@ -88,8 +88,7 @@ $http [
 ### JSON Socket Translator
 
 Communicate with sockets that send and receive lines of JSON using `<send …>` and `<recv …>` messages.
-
-Do not send messages into the dataspace configure with `<json-socket-translator …>` until `<connected @socketPath string>` is asserted.
+Responds to the gatekeeper step `<json-socket-translator { socket: <unix "…"> / <tcp "…" … }> $resolver>`.
 
 ```
 # MPV configuration example
@@ -107,25 +106,11 @@ Do not send messages into the dataspace configure with `<json-socket-translator
   protocol: none
 }>
 
-let ?mpvSpace = dataspace
-
-? <service-state <daemon mpv-server> ready> [
-  <require-service <daemon syndesizer>>
-  ? <service-object <daemon syndesizer> ?cap> [
-    $cap <json-socket-translator {
-      dataspace: $mpvSpace
-      socket: <unix "/run/user/1000/mpv.sock">
-    }>
-  ]
-]
-
-$mpvSpace [
-
+let ?resolver = dataspace
+$resolver ? <accepted ?mpvSpace> $mpvSpace [
   # announce the dataspace when the translator is connected
-  ? <connected $socketPath> [
-    $config <mpv $mpvSpace>
-    $config <bind <ref { oid: "mpv" key: #x"" }> $mpvSpace #f>
-  ]
+  $config <mpv $mpvSpace>
+  $config <bind <ref { oid: "mpv" key: #x"" }> $mpvSpace #f>
 
   # translate <play-file …> to an MPV command
   ?? <play-file ?file> [
@@ -137,6 +122,15 @@ $mpvSpace [
     ! <send { "command": ["playlist-clear"] }>
   ]
 ]
+
+? <service-state <daemon mpv-server> ready> [
+  <require-service <daemon syndesizer>>
+  ? <service-object <daemon syndesizer> ?cap> [
+    $cap <resolve <json-socket-translator {
+        socket: <unix "/run/user/1000/mpv.sock">
+      }> $resolver>
+  ]
+]
 ```
 
 ### JSON Stdio Translator

config.prs

@@ -19,8 +19,6 @@ JsonTranslatorArguments = <json-stdio-translator {
   dataspace: #:any
 }>.
 
-JsonTranslatorConnected = <connected @address SocketAddress>.
-
 TcpAddress = <tcp @host string @port int>.
 UnixAddress = <unix @path string>.
 
@@ -34,8 +32,7 @@ HttpDriverArguments = <http-driver {
   dataspace: #:any
 }>.
 
-JsonSocketTranslatorArguments = <json-socket-translator {
-  dataspace: #:any
+JsonSocketTranslatorStep = <json-socket-translator {
   socket: SocketAddress
 }>.
 

src/schema/config.nim

@@ -40,16 +40,6 @@ type
   Base64DecoderArguments* {.preservesRecord: "base64-decoder".} = object
     `field0`*: Base64DecoderArgumentsField0
 
-  JsonTranslatorConnected* {.preservesRecord: "connected".} = object
-    `address`*: SocketAddress
-
-  JsonSocketTranslatorArgumentsField0* {.preservesDictionary.} = object
-    `dataspace`* {.preservesEmbedded.}: EmbeddedRef
-    `socket`*: SocketAddress
-
-  JsonSocketTranslatorArguments* {.preservesRecord: "json-socket-translator".} = object
-    `field0`*: JsonSocketTranslatorArgumentsField0
-
   XsltArgumentsField0* {.preservesDictionary.} = object
     `dataspace`* {.preservesEmbedded.}: EmbeddedRef
 
@@ -62,6 +52,12 @@ type
   HttpDriverArguments* {.preservesRecord: "http-driver".} = object
     `field0`*: HttpDriverArgumentsField0
 
+  JsonSocketTranslatorStepField0* {.preservesDictionary.} = object
+    `socket`*: SocketAddress
+
+  JsonSocketTranslatorStep* {.preservesRecord: "json-socket-translator".} = object
+    `field0`*: JsonSocketTranslatorStepField0
+
   WebhooksArgumentsField0* {.preservesDictionary.} = object
     `endpoints`*: Table[seq[string], EmbeddedRef]
     `listen`*: Tcp
@@ -131,10 +127,9 @@ type
 proc `$`*(x: WebsocketArguments | HttpClientArguments | JsonTranslatorArguments |
     SocketAddress |
     Base64DecoderArguments |
-    JsonTranslatorConnected |
-    JsonSocketTranslatorArguments |
     XsltArguments |
     HttpDriverArguments |
+    JsonSocketTranslatorStep |
     WebhooksArguments |
     FileSystemUsageArguments |
     SqliteArguments |
@@ -153,10 +148,9 @@ proc encode*(x: WebsocketArguments | HttpClientArguments |
     JsonTranslatorArguments |
     SocketAddress |
     Base64DecoderArguments |
-    JsonTranslatorConnected |
-    JsonSocketTranslatorArguments |
     XsltArguments |
     HttpDriverArguments |
+    JsonSocketTranslatorStep |
     WebhooksArguments |
     FileSystemUsageArguments |
     SqliteArguments |

src/syndesizer/json_socket_translator.nim

@@ -1,11 +1,12 @@
 # SPDX-FileCopyrightText: ☭ Emery Hemingway
 # SPDX-License-Identifier: Unlicense
 
-import std/[json, options]
-import pkg/sys/[ioqueue, sockets]
-import preserves, preserves/jsonhooks, syndicate
-
-import ../schema/[config, json_messages]
+import
+  std/[json, options],
+  pkg/sys/[ioqueue, sockets],
+  pkg/preserves, pkg/preserves/jsonhooks,
+  pkg/syndicate, pkg/syndicate/protocols/[gatekeeper, sturdy],
+   ../schema/[config, json_messages]
 
 template translateSocketBody {.dirty.} =
   # Template workaround for CPS and parameterized types.
@@ -24,7 +25,8 @@ template translateSocketBody {.dirty.} =
           whelp write(socket[], $data & "\n")
       else:
         stderr.writeLine "dropped send of ", data
-    discard publish(turn, ds, initRecord("connected", sa.toPreserves))
+    discard publish(turn, observer, ResolvedAccepted(responderSession: ds))
+      # Resolve the <json-socket-translator { }> step.
   onStop(facet, kill)
   run(facet, setup)
   while alive:
@@ -45,33 +47,36 @@ template translateSocketBody {.dirty.} =
   stderr.writeLine "close socket ", sa
   close(socket[])
 
-proc translateSocket(facet: Facet; ds: Cap; sa: TcpAddress) {.asyncio.} =
+proc translateSocket(facet: Facet; sa: TcpAddress; ds, observer: Cap) {.asyncio.} =
   var
     socket = new AsyncConn[Protocol.Tcp]
     conn = connectTcpAsync(sa.host, Port sa.port)
   socket[] = conn
   translateSocketBody()
 
-proc translateSocket(facet: Facet; ds: Cap; sa: UnixAddress) {.asyncio.} =
+proc translateSocket(facet: Facet; sa: UnixAddress; ds, observer: Cap) {.asyncio.} =
   var
     socket = new AsyncConn[Protocol.Unix]
     conn = connectUnixAsync(sa.path)
   socket[] = conn
   translateSocketBody()
 
-proc spawnJsonSocketTranslator*(turn: Turn; root: Cap): Actor {.discardable.} =
+proc spawnJsonSocketTranslator*(turn: Turn; relay: Cap): Actor {.discardable.} =
+  let pat = Resolve?:{ 0: JsonSocketTranslatorStep.grabTypeFlat, 1: grab() }
   spawnActor(turn, "json-socket-translator") do (turn: Turn):
-    during(turn, root, ?:JsonSocketTranslatorArguments) do (ds: Cap, sa: TcpAddress):
+    during(turn, relay, pat) do (sa: TcpAddress, observer: Cap):
       linkActor(turn, "json-socket-translator") do (turn: Turn):
+        let ds = turn.newDataspace()
         discard trampoline:
-          whelp translateSocket(turn.facet, ds, sa)
-    during(turn, root, ?:JsonSocketTranslatorArguments) do (ds: Cap, sa: UnixAddress):
+          whelp translateSocket(turn.facet, sa, ds, observer)
+    during(turn, relay, pat) do (sa: UnixAddress, observer: Cap):
       linkActor(turn, "json-socket-translator") do (turn: Turn):
+        let ds = turn.newDataspace()
         discard trampoline:
-          whelp translateSocket(turn.facet, ds, sa)
+          whelp translateSocket(turn.facet, sa, ds, observer)
 
 when isMainModule:
   import syndicate/relays
   runActor("main") do (turn: Turn):
-    resolveEnvironment(turn) do (turn: Turn; ds: Cap):
-      spawnJsonSocketTranslator(turn, ds)
+    resolveEnvironment(turn) do (turn: Turn; relay: Cap):
+      spawnJsonSocketTranslator(turn, relay)