From a13b388243247a423a8c8476e35a4ebe6c9bde5b Mon Sep 17 00:00:00 2001 From: Austin Clements Date: Fri, 31 May 2013 20:40:04 -0400 Subject: [PATCH] emacs: Utilities to manage asynchronous notmuch processes This provides a new notmuch-lib utility to start an asynchronous notmuch process that handles redirecting of stderr and checking of the exit status. This is similar to `notmuch-call-notmuch-json', but for asynchronous processes (and it leaves output processing to the caller). --- emacs/notmuch-lib.el | 77 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 73 insertions(+), 4 deletions(-) diff --git a/emacs/notmuch-lib.el b/emacs/notmuch-lib.el index 7c6cf61a..28f78e0f 100644 --- a/emacs/notmuch-lib.el +++ b/emacs/notmuch-lib.el @@ -395,18 +395,21 @@ signaled error. This function does not return." (error "%s" (concat msg (when extra " (see *Notmuch errors* for more details)")))) -(defun notmuch-check-async-exit-status (proc msg) +(defun notmuch-check-async-exit-status (proc msg &optional command err-file) "If PROC exited abnormally, pop up an error buffer and signal an error. This is a wrapper around `notmuch-check-exit-status' for asynchronous process sentinels. PROC and MSG must be the -arguments passed to the sentinel." +arguments passed to the sentinel. COMMAND and ERR-FILE, if +provided, are passed to `notmuch-check-exit-status'. If COMMAND +is not provided, it is taken from `process-command'." (let ((exit-status (case (process-status proc) ((exit) (process-exit-status proc)) ((signal) msg)))) (when exit-status - (notmuch-check-exit-status exit-status (process-command proc))))) + (notmuch-check-exit-status exit-status (or command (process-command proc)) + nil err-file)))) (defun notmuch-check-exit-status (exit-status command &optional output err-file) "If EXIT-STATUS is non-zero, pop up an error buffer and signal an error. @@ -460,7 +463,7 @@ You may need to restart Emacs or upgrade your notmuch package.")) )))) (defun notmuch-call-notmuch-json (&rest args) - "Invoke `notmuch-command' with `args' and return the parsed JSON output. + "Invoke `notmuch-command' with ARGS and return the parsed JSON output. The returned output will represent objects using property lists and arrays as lists. If notmuch exits with a non-zero status, @@ -481,6 +484,72 @@ an error." (json-read))) (delete-file err-file))))) +(defun notmuch-start-notmuch (name buffer sentinel &rest args) + "Start and return an asynchronous notmuch command. + +This starts and returns an asynchronous process running +`notmuch-command' with ARGS. The exit status is checked via +`notmuch-check-async-exit-status'. Output written to stderr is +redirected and displayed when the process exits (even if the +process exits successfully). NAME and BUFFER are the same as in +`start-process'. SENTINEL is a process sentinel function to call +when the process exits, or nil for none. The caller must *not* +invoke `set-process-sentinel' directly on the returned process, +as that will interfere with the handling of stderr and the exit +status." + + ;; There is no way (as of Emacs 24.3) to capture stdout and stderr + ;; separately for asynchronous processes, or even to redirect stderr + ;; to a file, so we use a trivial shell wrapper to send stderr to a + ;; temporary file and clean things up in the sentinel. + (let* ((err-file (make-temp-file "nmerr")) + ;; Use a pipe + (process-connection-type nil) + ;; Find notmuch using Emacs' `exec-path' + (command (or (executable-find notmuch-command) + (error "command not found: %s" notmuch-command))) + (proc (apply #'start-process name buffer + "/bin/sh" "-c" + "exec 2>\"$1\"; shift; exec \"$0\" \"$@\"" + command err-file args))) + (process-put proc 'err-file err-file) + (process-put proc 'sub-sentinel sentinel) + (process-put proc 'real-command (cons notmuch-command args)) + (set-process-sentinel proc #'notmuch-start-notmuch-sentinel) + proc)) + +(defun notmuch-start-notmuch-sentinel (proc event) + (let ((err-file (process-get proc 'err-file)) + (sub-sentinel (process-get proc 'sub-sentinel)) + (real-command (process-get proc 'real-command))) + (condition-case err + (progn + ;; Invoke the sub-sentinel, if any + (when sub-sentinel + (funcall sub-sentinel proc event)) + ;; Check the exit status. This will signal an error if the + ;; exit status is non-zero. + (notmuch-check-async-exit-status proc event real-command err-file) + ;; If that didn't signal an error, then any error output was + ;; really warning output. Show warnings, if any. + (let ((warnings + (with-temp-buffer + (unless (= (second (insert-file-contents err-file)) 0) + (end-of-line) + ;; Show first line; stuff remaining lines in the + ;; errors buffer. + (let ((l1 (buffer-substring (point-min) (point)))) + (skip-chars-forward "\n") + (cons l1 (unless (eobp) + (buffer-substring (point) (point-max))))))))) + (when warnings + (notmuch-logged-error (car warnings) (cdr warnings))))) + (error + ;; Emacs behaves strangely if an error escapes from a sentinel, + ;; so turn errors into messages. + (message "%s" (error-message-string err)))) + (ignore-errors (delete-file err-file)))) + ;; This variable is used only buffer local, but it needs to be ;; declared globally first to avoid compiler warnings. (defvar notmuch-show-process-crypto nil) -- 2.43.0