vim: refactor database handling

To minimize memory usage we need to destroy the queries and the
databases, so we should keep track of them.

Each buffer gets a database connection that is destroyed when the buffer
is destroyed, and all the queries along with it.

Ideally notmuch should destroy the queries when the database is
destroyed, but it's not doing that at the moment.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>

diff --git a/vim/notmuch.vim b/vim/notmuch.vim
index 11a7c26d65ec917a9563017ca3aff6ed1908c6d9..72bf73b312e9a30ab661849f94a12eb2cd7008f9 100644 (file)
--- a/vim/notmuch.vim
+++ b/vim/notmuch.vim
@@ -80,6 +80,7 @@ function! s:new_file_buffer(type, fname)
        exec printf('edit %s', a:fname)
        execute printf('set filetype=notmuch-%s', a:type)
        execute printf('set syntax=notmuch-%s', a:type)
+       ruby $curbuf.init(VIM::evaluate('a:type'))
        ruby $buf_queue.push($curbuf.number)
 endfunction
 
@@ -195,6 +196,7 @@ function! s:search_search_prompt()
        setlocal modifiable
 ruby << EOF
        $cur_search = VIM::evaluate('text')
+       $curbuf.reopen
        search_render($cur_search)
 EOF
        setlocal nomodifiable
@@ -206,6 +208,7 @@ endfunction
 
 function! s:search_refresh()
        setlocal modifiable
+       ruby $curbuf.reopen
        ruby search_render($cur_search)
        setlocal nomodifiable
 endfunction
@@ -227,6 +230,7 @@ endfunction
 
 function! s:folders_refresh()
        setlocal modifiable
+       ruby $curbuf.reopen
        ruby folders_render()
        setlocal nomodifiable
 endfunction
@@ -254,6 +258,7 @@ function! s:show_next_thread()
 endfunction
 
 function! s:kill_this_buffer()
+       ruby $curbuf.close
        bdelete!
 ruby << EOF
        $buf_queue.pop
@@ -276,6 +281,7 @@ function! s:new_buffer(type)
        keepjumps 0d
        execute printf('set filetype=notmuch-%s', a:type)
        execute printf('set syntax=notmuch-%s', a:type)
+       ruby $curbuf.init(VIM::evaluate('a:type'))
        ruby $buf_queue.push($curbuf.number)
 endfunction
 
@@ -295,33 +301,31 @@ ruby << EOF
        $cur_thread = thread_id
        $messages.clear
        $curbuf.render do |b|
-               do_read do |db|
-                       q = db.query(get_cur_view)
-                       q.sort = 0
-                       msgs = q.search_messages
-                       msgs.each do |msg|
-                               m = Mail.read(msg.filename)
-                               part = m.find_first_text
-                               nm_m = Message.new(msg, m)
-                               $messages << nm_m
-                               date_fmt = VIM::evaluate('g:notmuch_rb_datetime_format')
-                               date = Time.at(msg.date).strftime(date_fmt)
-                               nm_m.start = b.count
-                               b << "%s %s (%s)" % [msg['from'], date, msg.tags]
-                               b << "Subject: %s" % [msg['subject']]
-                               b << "To: %s" % msg['to']
-                               b << "Cc: %s" % msg['cc']
-                               b << "Date: %s" % msg['date']
-                               nm_m.body_start = b.count
-                               b << "--- %s ---" % part.mime_type
-                               part.convert.each_line do |l|
-                                       b << l.chomp
-                               end
-                               b << ""
-                               nm_m.end = b.count
+               q = $curbuf.query(get_cur_view)
+               q.sort = 0
+               msgs = q.search_messages
+               msgs.each do |msg|
+                       m = Mail.read(msg.filename)
+                       part = m.find_first_text
+                       nm_m = Message.new(msg, m)
+                       $messages << nm_m
+                       date_fmt = VIM::evaluate('g:notmuch_rb_datetime_format')
+                       date = Time.at(msg.date).strftime(date_fmt)
+                       nm_m.start = b.count
+                       b << "%s %s (%s)" % [msg['from'], date, msg.tags]
+                       b << "Subject: %s" % [msg['subject']]
+                       b << "To: %s" % msg['to']
+                       b << "Cc: %s" % msg['cc']
+                       b << "Date: %s" % msg['date']
+                       nm_m.body_start = b.count
+                       b << "--- %s ---" % part.mime_type
+                       part.convert.each_line do |l|
+                               b << l.chomp
                        end
-                       b.delete(b.count)
+                       b << ""
+                       nm_m.end = b.count
                end
+               b.delete(b.count)
        end
        $messages.each_with_index do |msg, i|
                VIM::command("syntax region nmShowMsg#{i}Desc start='\\%%%il' end='\\%%%il' contains=@nmShowMsgDesc" % [msg.start, msg.start + 1])
@@ -469,24 +473,6 @@ ruby << EOF
                end
        end
 
-       def do_write
-               db = Notmuch::Database.new($db_name, :mode => Notmuch::MODE_READ_WRITE)
-               begin
-                       yield db
-               ensure
-                       db.close
-               end
-       end
-
-       def do_read
-               db = Notmuch::Database.new($db_name)
-               begin
-                       yield db
-               ensure
-                       db.close
-               end
-       end
-
        def open_reply(orig)
                help_lines = [
                        'Notmuch-Help: Type in your message here; to help you use these bindings:',
@@ -559,21 +545,18 @@ ruby << EOF
                        folders = VIM::evaluate('g:notmuch_rb_folders')
                        count_threads = VIM::evaluate('g:notmuch_rb_folders_count_threads')
                        $searches.clear
-                       do_read do |db|
-                               folders.each do |name, search|
-                                       q = db.query(search)
-                                       $searches << search
-                                       count = count_threads ? q.search_threads.count : q.search_messages.count
-                                       b << "%9d %-20s (%s)" % [count, name, search]
-                               end
+                       folders.each do |name, search|
+                               q = $curbuf.query(search)
+                               $searches << search
+                               count = count_threads ? q.search_threads.count : q.search_messages.count
+                               b << "%9d %-20s (%s)" % [count, name, search]
                        end
                end
        end
 
        def search_render(search)
                date_fmt = VIM::evaluate('g:notmuch_rb_date_format')
-               db = Notmuch::Database.new($db_name)
-               q = db.query(search)
+               q = $curbuf.query(search)
                $threads.clear
                t = q.search_threads
 
@@ -593,7 +576,7 @@ ruby << EOF
        end
 
        def do_tag(filter, tags)
-               do_write do |db|
+               $curbuf.do_write do |db|
                        q = db.query(filter)
                        q.search_messages.each do |e|
                                e.freeze
@@ -610,6 +593,40 @@ ruby << EOF
                                e.thaw
                                e.tags_to_maildir_flags
                        end
+                       q.destroy!
+               end
+       end
+
+       module DbHelper
+               def init(name)
+                       @name = name
+                       @db = Notmuch::Database.new($db_name)
+                       @queries = []
+               end
+
+               def query(*args)
+                       q = @db.query(*args)
+                       @queries << q
+                       q
+               end
+
+               def close
+                       @queries.delete_if { |q| ! q.destroy! }
+                       @db.close
+               end
+
+               def reopen
+                       close if @db
+                       @db = Notmuch::Database.new($db_name)
+               end
+
+               def do_write
+                       db = Notmuch::Database.new($db_name, :mode => Notmuch::MODE_READ_WRITE)
+                       begin
+                               yield db
+                       ensure
+                               db.close
+                       end
                end
        end
 
@@ -658,6 +675,8 @@ ruby << EOF
        end
 
        class VIM::Buffer
+               include DbHelper
+
                def <<(a)
                        append(count(), a)
                end