Implemented readline and password input functionality (#452)

R/execution.r

@@ -62,6 +62,7 @@ Executor <- setRefClass(
     Class = 'Executor',
     fields = list(
         send_response         = 'function',
+        handle_stdin          = 'function',
         abort_queued_messages = 'function',
         execution_count       = 'integer',
         payload               = 'list',
@@ -120,6 +121,25 @@ quit = function(save = 'default', status = 0, runLast = TRUE) {
     payload <<- c(.self$payload, list(list(source = 'ask_exit', keepkernel = FALSE)))
 },
 
+# noninteractive
+readline = function(prompt = '') {
+    log_debug('entering custom readline')
+    send_response('input_request', current_request, 'stdin',
+        list(prompt = prompt, password = FALSE))
+    # wait for 'input_reply' response message
+    input <- handle_stdin()
+},
+
+# noninteractive 5.0 protocol:
+readpass = function(prompt = '') {
+    log_debug('entering custom readpass')
+    send_response('input_request', current_request, 'stdin',
+        list(prompt = prompt, password = TRUE))
+    # wait for 'input_reply' response message
+    log_debug('exiting custom readpass')
+    input = handle_stdin()
+},
+
 handle_error = function(e) tryCatch({
     log_debug('Error output: %s', toString(e))
     calls <- head(sys.calls()[-seq_len(nframe + 1L)], -3)
@@ -223,6 +243,12 @@ execute = function(request) {
     payload <<- list()
     err <<- list()
 
+    # shade base::readline
+    add_to_user_searchpath('readline', .self$readline)
+
+    # shade 'readpass' if it appears in other packages
+    add_to_user_searchpath('readpass', .self$readpass)
+
     # shade base::quit
     add_to_user_searchpath('quit', .self$quit)
     add_to_user_searchpath('q', .self$quit)

R/kernel.r

@@ -123,7 +123,7 @@ handle_shell = function() {
         is_complete_request = is_complete(msg),
         inspect_request     = inspect(msg),
         shutdown_request    = shutdown(msg),
-        print(c('Got unhandled msg_type:', msg$header$msg_type)))
+        log_debug(c('Got unhandled msg_type:', msg$header$msg_type)))
 
     send_response('status', msg, 'iopub', list(
         execution_state = 'idle'))
@@ -166,6 +166,27 @@ abort_queued_messages = function() {
 
 },
 
+handle_stdin = function() {
+    "React to a stdin message coming in"
+
+    # wait for 'input_reply' response message
+    while (TRUE) {
+        log_debug('stdin loop: beginning')
+        zmq.poll(c(sockets$stdin),          # only stdin channel
+                 c(.pbd_env$ZMQ.PO$POLLIN)) # type
+
+        if (bitwAnd(zmq.poll.get.revents(1), .pbd_env$ZMQ.PO$POLLIN)) {
+            log_debug('stdin loop: found msg')
+            parts <- zmq.recv.multipart(sockets$stdin, unserialize = FALSE)
+            msg <- wire_to_msg(parts)
+            return(msg$content$value)
+        } else {
+            # else shouldn't be possible
+            log_error('stdin loop: zmq.poll returned but no message found?')
+        }
+    }
+},
+
 is_complete = function(request) {
     "Checks whether the code in the rest is complete"
 
@@ -336,7 +357,7 @@ handle_control = function() {
         log_debug('Control: shutdown...')
         shutdown(msg)
     } else {
-        print(paste('Unhandled control message, msg_type:', msg$header$msg_type))
+        log_debug(paste('Unhandled control message, msg_type:', msg$header$msg_type))
     }
 },
 
@@ -371,8 +392,11 @@ initialize = function(connection_file) {
     zmq.bind(sockets$stdin,   url_with_port('stdin_port'))
     zmq.bind(sockets$shell,   url_with_port('shell_port'))
 
-    executor <<- Executor$new(send_response = .self$send_response,
+    executor <<- Executor$new(
+        send_response         = .self$send_response,
+        handle_stdin          = .self$handle_stdin,
         abort_queued_messages = .self$abort_queued_messages)
+
     comm_manager <<- CommManager$new(send_response = .self$send_response)
     runtime_env$comm_manager <- comm_manager
 },
@@ -386,7 +410,7 @@ run = function() {
             rep(.pbd_env$ZMQ.PO$POLLIN, 3))
         log_debug('main loop: after poll')
 
-        # It's important that these messages are handler one  by one in each
+        # It's important that these messages are handled one by one in each
         # look. The problem is that during the handler, a new zmq.poll could be
         # done (and is done in case of errors in a execution request) and this
         # invalidates the zmq.poll.get.revents call leading to "funny" results