[PATCH v3] Emacs: Add address completion mechanism implemented in elisp

[Mark Walters]

On Mon, 08 Sep 2014, David Edmondson <dme at dme.org> wrote:
> On Mon, Aug 11 2014, Michal Sojka wrote:
>> Currently, notmuch has an address completion mechanism that requires
>> external command to provide completion candidates. This patch adds a
>> completion mechanism inspired by https://github.com/tjim/nevermore,
>> which is implemented in Emacs lisp only.
>>
>> The core of the new mechanism is the function notmuch-address-harvest
>> that collects the completion candidates from the notmuch database and
>> stores them in notmuch-address-completions variable.
>> notmuch-address-harvest is called on the first entry to message-mode
>> and runs asychnornously so that the user doesn't have to wait for it
>> to complete while composing the message. The
>> notmuch-address-completions variable is used in message-mode as a
>> source of completion candidates. Currently, there are two ways how the
>> notmuch-address-completions variable is used.
>>
>> First, preexisting address completion mechanism is extended to use
>> notmuch-address-completions in addition to the external command. This
>> new behavior is configured by setting notmuch-address-command to nil,
>> which is the new default. Note that this may *BREAK EXISTING SETUPS*
>> when the user used external command named "notmuch-addresses", i.e.
>> the previous default. The result will be that the user will use the
>> new mechanism instead of the his command. I believe that many users
>> may not even recognize this because the new mechanism works the same
>> as http://commonmeasure.org/~jkr/git/notmuch_addresses.git and perhaps
>> also as other commands suggested at
>> http://notmuchmail.org/emacstips/#address_completion.
>>
>> Second way of using notmuch-address-completions is notmuch-company.el.
>> This presents the possible completions in a nice popup box after a
>> short typing delay but requires company-mode to be installed.
>
> This looks great, thanks for doing it. It seems like a better approach
> than id:1409921969-65129-1-git-send-email-dme at dme.org. Some comments:
>
> - Adding the address collection to `message-mode-hook' means that it
>   runs every time I start to compose a message. If the address
>   collection is disk intensive, this might be bad for battery life. The
>   set of potential recipients doesn't change _that_ much over time for a
>   typical person, I'd wager. Maybe the hook should only run once a day?
>   (Tunable, of course.)

Just a meta comment really: Austin is very close to posting a patch
adding a timestamp to messages in the database (I think roughly last
modify time). Once that is in an address-harvest query of the form all
messages with any changes since the last harvest should be simple and
fast.

A second more general comment: if something like Jani's patch
id:1410021689-15901-1-git-send-email-jani at nikula.org goes in the
harvesting from addresses is hugely faster (circa 20 times, see
id:8761h0fxow.fsf at qmul.ac.uk ) than harvesting to,cc addresses so some
people might want to tweak/customize that.

Best wishes

Mark

>
> - The addition of company mode support (which I haven't tried) should be
>   a separate patch in the series.
>
>> ---
>> Changes from v1:
>> - Use of notmuch-parser.el instead of the custom parser in the
>>   original code. The notmuch parser is slightly faster.
>> - Use of functions in notmuch-query.el instead of functions in the
>>   original code with almost the same functionality.
>> - Integrated with existing completion mechanism in notmuch.
>> - notmuch-company.el was moved from emacs/contrib to emacs and
>>   no-byte-compile directive was added to it.
>> - Aligned with notmuch naming conventions.
>> - Documented bugs found in notmuch-company.el
>>
>> Changes from v2:
>> - Updated Makefile.local to not conflict with current master
>> ---
>>  emacs/Makefile.local     |  6 ++-
>>  emacs/notmuch-address.el | 95 +++++++++++++++++++++++++++++++++++++++++++-----
>>  emacs/notmuch-company.el | 69 +++++++++++++++++++++++++++++++++++
>>  emacs/notmuch-lib.el     |  3 ++
>>  4 files changed, 163 insertions(+), 10 deletions(-)
>>  create mode 100644 emacs/notmuch-company.el
>>
>> diff --git a/emacs/Makefile.local b/emacs/Makefile.local
>> index 1109cfa..6c93e73 100644
>> --- a/emacs/Makefile.local
>> +++ b/emacs/Makefile.local
>> @@ -20,6 +20,7 @@ emacs_sources := \
>>  	$(dir)/notmuch-print.el \
>>  	$(dir)/notmuch-version.el \
>>  	$(dir)/notmuch-jump.el \
>> +	$(dir)/notmuch-company.el
>>  
>>  $(dir)/notmuch-version.el: $(dir)/Makefile.local version.stamp
>>  $(dir)/notmuch-version.el: $(srcdir)/$(dir)/notmuch-version.el.tmpl
>> @@ -30,7 +31,10 @@ $(dir)/notmuch-version.el: $(srcdir)/$(dir)/notmuch-version.el.tmpl
>>  emacs_images := \
>>  	$(srcdir)/$(dir)/notmuch-logo.png
>>  
>> -emacs_bytecode = $(emacs_sources:.el=.elc)
>> +# Do not try to install files that are not byte-compiled.
>> +emacs_no_byte_compile := $(dir)/notmuch-company.el
>> +
>> +emacs_bytecode = $(patsubst %.el,%.elc,$(filter-out $(emacs_no_byte_compile),$(emacs_sources)))
>>  
>>  # Because of defmacro's and defsubst's, we have to account for load
>>  # dependencies between Elisp files when byte compiling.  Otherwise,
>> diff --git a/emacs/notmuch-address.el b/emacs/notmuch-address.el
>> index fa65cd5..a50f4f4 100644
>> --- a/emacs/notmuch-address.el
>> +++ b/emacs/notmuch-address.el
>> @@ -20,14 +20,18 @@
>>  ;; Authors: David Edmondson <dme at dme.org>
>>  
>>  (require 'message)
>> +(require 'notmuch-query)
>> +(require 'notmuch-parser)
>>  
>>  ;;
>>  
>> -(defcustom notmuch-address-command "notmuch-addresses"
>> -  "The command which generates possible addresses. It must take a
>> -single argument and output a list of possible matches, one per
>> -line."
>> -  :type 'string
>> +(defcustom notmuch-address-command nil
>> +  "The command which generates possible addresses for completion.
>> +It must take a single argument and output a list of possible
>> +matches, one per line. If set to nil, addresses are generated by
>> +a built-in completion mechanism."
>> +  :type '(radio (const :tag "No command: Use built-in completion" nil)
>> +		 (string :tag "Custom command" :value "notmuch-addresses"))
>>    :group 'notmuch-send
>>    :group 'notmuch-external)
>>  
>> @@ -42,6 +46,10 @@ to know how address selection is made by default."
>>    :group 'notmuch-send
>>    :group 'notmuch-external)
>>  
>> +(defvar notmuch-address-completions nil
>> +  "Hash of email addresses for completion during email composition.
>> +  This variable is set by calling `notmuch-address-harvest'.")
>> +
>>  (defun notmuch-address-selection-function (prompt collection initial-input)
>>    "Call (`completing-read'
>>        PROMPT COLLECTION nil nil INITIAL-INPUT 'notmuch-address-history)"
>> @@ -60,7 +68,16 @@ to know how address selection is made by default."
>>  	  (push notmuch-address-message-alist-member message-completion-alist))))
>>  
>>  (defun notmuch-address-options (original)
>> -  (process-lines notmuch-address-command original))
>> +  (cond
>> +   ((eq notmuch-address-command nil)
>> +    (let ((candidates))
>> +      (maphash (lambda (key val)
>> +		 (let ((re (concat "\\<" (regexp-quote original))))
>> +		   (when (string-match re key)
>> +		     (push key candidates))))
>> +	       notmuch-address-completions)
>> +      candidates))
>> +   (t (process-lines notmuch-address-command original))))
>>  
>>  (defun notmuch-address-expand-name ()
>>    (let* ((end (point))
>> @@ -108,11 +125,71 @@ to know how address selection is made by default."
>>  			   (not (file-directory-p bin))))
>>  	      (throw 'found-command bin))))))))
>>  
>> -;; If we can find the program specified by `notmuch-address-command',
>> -;; insinuate ourselves into `message-mode'.
>> -(when (notmuch-address-locate-command notmuch-address-command)
>> +(defun notmuch-address-harvest-msg (msg)
>> +  (let* ((headers (plist-get msg :headers))
>> +	 (to (ignore-errors (mail-extract-address-components (plist-get headers :To) t)))
>> +	 (cc (ignore-errors (mail-extract-address-components (plist-get headers :Cc) t)))
>> +	 (bcc (ignore-errors (mail-extract-address-components (plist-get headers :Bcc) t))))
>> +    (mapc (lambda (parts)
>> +	    (let* ((name (car parts))
>> +		   (email (cadr parts))
>> +		   (entry (if name (format "%s <%s>" name email) email)))
>> +	      (puthash entry t notmuch-address-completions)))
>> +	  (append to cc bcc))
>> +    nil))
>> +
>> +(defun notmuch-address-harvest-handle-result (obj)
>> +  (notmuch-query-map-threads 'notmuch-address-harvest-msg (list obj)))
>> +
>> +(defun notmuch-address-harvest-filter (proc string)
>> +  (when (buffer-live-p (process-buffer proc))
>> +    (with-current-buffer (process-buffer proc)
>> +      (save-excursion
>> +	(goto-char (point-max))
>> +	(insert string))
>> +      (notmuch-sexp-parse-partial-list
>> +       'notmuch-address-harvest-handle-result (process-buffer proc)))))
>> +
>> +(defvar notmuch-address-harvest-proc nil)   ; the process of a harvest underway
>> +
>> +(defun notmuch-address-harvest ()
>> +  "Collect possible addresses for completion. It queries the
>> +notmuch database for all emails sent by the user and collects the
>> +destination addresses from them in
>> +`notmuch-address-completions'. This takes some time so the
>> +address collection runs asynchronously."
>> +  (when notmuch-address-harvest-proc
>> +    (kill-buffer (process-buffer notmuch-address-harvest-proc)) ; this also kills the process
>> +    (setq notmuch-address-harvest-proc nil))
>> +  (setq notmuch-address-completions (make-hash-table :test 'equal))
>> +  (setq notmuch-address-harvest-proc
>> +        (notmuch-start-notmuch
>> +         "notmuch-address-harvest"	; process name
>> +         " *notmuch-address-harvest*"	; process buffer
>> +         nil				; process sentinel
>> +         "show"				; notmuch command
>> +         "--format=sexp"
>> +         "--format-version=2"
>> +         "--body=false"
>> +         "--entire-thread=false"
>> +	 (mapconcat (lambda (x) (concat "from:" x)) (notmuch-user-emails) " or ")))
>> +  (set-process-filter notmuch-address-harvest-proc 'notmuch-address-harvest-filter)
>> +  (set-process-query-on-exit-flag notmuch-address-harvest-proc nil)
>> +  ;; return value
>> +  nil)
>> +
>> +;; If we can find the program specified by `notmuch-address-command'
>> +;; or if it is nil, insinuate ourselves into `message-mode'.
>> +(when (or (eq notmuch-address-command nil)
>> +	  (notmuch-address-locate-command notmuch-address-command))
>>    (notmuch-address-message-insinuate))
>>  
>> +(defun notmuch-address-harvest-start ()
>> +  (when (not notmuch-address-completions) (notmuch-address-harvest)))
>> +
>> +(when (eq notmuch-address-command nil)
>> +  (add-hook 'message-mode-hook 'notmuch-address-harvest-start))
>> +
>>  ;;
>>  
>>  (provide 'notmuch-address)
>> diff --git a/emacs/notmuch-company.el b/emacs/notmuch-company.el
>> new file mode 100644
>> index 0000000..748fcee
>> --- /dev/null
>> +++ b/emacs/notmuch-company.el
>> @@ -0,0 +1,69 @@
>> +;; -*-no-byte-compile: t; -*-
>> +
>> +;; notmuch-company.el --- Mail address completion for notmuch via company-mode
>> +
>> +;; Author: Trevor Jim <tjim at mac.com>
>> +;; Keywords: mail, completion
>> +
>> +;; This program is free software; you can redistribute it and/or modify
>> +;; it under the terms of the GNU General Public License as published by
>> +;; the Free Software Foundation, either version 3 of the License, or
>> +;; (at your option) any later version.
>> +
>> +;; This program is distributed in the hope that it will be useful,
>> +;; but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> +;; GNU General Public License for more details.
>> +
>> +;; You should have received a copy of the GNU General Public License
>> +;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
>> +
>> +;;; Commentary:
>> +
>> +;; To enable this, install company mode (https://company-mode.github.io/)
>> +;; and add
>> +;;
>> +;;     (require 'notmuch-company)
>> +;;
>> +;; to your .emacs.
>> +;;
>> +;; NB company-minimum-prefix-length defaults to 3 so you don't get
>> +;; completion unless you type 3 characters
>> +
>> +;;; Bugs:
>> +;;
>> +;; - matching is case sensitive
>> +;; - matching of non-ascii characters doesn't work well
>> +
>> +;;; Code:
>> +
>> +(require 'company)
>> +(require 'message)
>> +(require 'notmuch-address)
>> +
>> +(defvar-local notmuch-company-last-prefix nil)
>> +;;;###autoload
>> +(defun notmuch-company (command &optional arg &rest ignore)
>> +  "`company-mode' completion back-end for `notmuch'."
>> +  (interactive (list 'interactive))
>> +  (let ((case-fold-search t))
>> +    (pcase command
>> +      (`interactive (company-begin-backend 'notmuch-company))
>> +      (`prefix (and (eq major-mode 'message-mode)
>> +                    (looking-back "^\\(To\\|Cc\\|Bcc\\):.*"
>> +                                  (line-beginning-position))
>> +                    (setq notmuch-company-last-prefix (company-grab-symbol))))
>> +      (`candidates (let ((results (completion-substring--all-completions arg notmuch-address-completions nil 0)))
>> +                     (when results (car results))))
>> +      (`match (if (string-match notmuch-company-last-prefix arg)
>> +                  (match-end 0)
>> +                0))
>> +      (`no-cache t))))
>> +
>> +(add-hook 'message-mode-hook '(lambda ()
>> +                                (company-mode)
>> +                                (make-local-variable 'company-backends)
>> +                                (setq company-backends '(notmuch-company))
>> +				(notmuch-address-harvest-start)))
>> +
>> +(provide 'notmuch-company)
>> diff --git a/emacs/notmuch-lib.el b/emacs/notmuch-lib.el
>> index 19269e3..00e8554 100644
>> --- a/emacs/notmuch-lib.el
>> +++ b/emacs/notmuch-lib.el
>> @@ -228,6 +228,9 @@ on the command line, and then retry your notmuch command")))
>>    "Return the user.other_email value (as a list) from the notmuch configuration."
>>    (split-string (notmuch-config-get "user.other_email") "\n" t))
>>  
>> +(defun notmuch-user-emails ()
>> +  (cons (notmuch-user-primary-email) (notmuch-user-other-email)))
>> +
>>  (defun notmuch-poll ()
>>    "Run \"notmuch new\" or an external script to import mail.
>>  
>> -- 
>> 2.0.1
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