notmuch-test: Eliminate sleeps to speed up test suite run

We were sleeping merely to ensure that our updates to the mail store
would result in the mtime of the appropriate directories being
updated. We make the test suite run faster by not sleeping, but
instead explicitly updating the mtime of the directory to a future
time with touch.

We're careful to ensure that the time is not merely in the future
compared to the current time, but also later than any previous update
to the same directory mtime.

test/notmuch-test

@@ -20,6 +20,15 @@ find_notmuch_binary ()
     echo notmuch
 }
 
+increment_mtime_amount=0
+increment_mtime ()
+{
+    dir=$1
+
+    increment_mtime_amount=$((increment_mtime_amount + 1))
+    touch -d "+${increment_mtime_amount} seconds" $dir
+}
+
 # Generate a new message in the mail directory, with
 # a unique message ID and subject.
 #
@@ -108,9 +117,8 @@ ${template[body]}
 EOF
 }
 
-do_sleep ()
+    # Ensure that the mtime of the containing directory is updated
-{
+    increment_mtime $(dirname ${gen_msg_filename})
-    sleep 1
 }
 
 NOTMUCH_IGNORED_OUTPUT_REGEXP='^Processed [0-9]*( total)? file|Found [0-9]* total file'
@@ -155,12 +163,10 @@ printf " No new messages...\t\t"
 execute_expecting new "No new mail."
 
 printf " Single new message...\t\t"
-do_sleep
 generate_message
 execute_expecting new "Added 1 new message to the database."
 
 printf " Multiple new messages...\t"
-do_sleep
 generate_message
 generate_message
 execute_expecting new "Added 2 new messages to the database."
@@ -191,51 +197,48 @@ generate_message
 tmp_msg_filename=tmp/$gen_msg_filename
 mkdir -p $(dirname $tmp_msg_filename)
 mv $gen_msg_filename $tmp_msg_filename
-do_sleep
+increment_mtime ${MAIL_DIR}
 $NOTMUCH new > /dev/null
-do_sleep
 mv $tmp_msg_filename $gen_msg_filename
+increment_mtime ${MAIL_DIR}
 execute_expecting new "Added 1 new message to the database."
 
 printf " Renamed message...\t\t"
 
-do_sleep
 generate_message
 $NOTMUCH new > /dev/null
-do_sleep
 mv $gen_msg_filename ${gen_msg_filename}-renamed
+increment_mtime ${MAIL_DIR}
 execute_expecting new "No new mail. Detected 1 file rename."
 
 printf " Deleted message...\t\t"
 
-do_sleep
 rm ${gen_msg_filename}-renamed
+increment_mtime ${MAIL_DIR}
 execute_expecting new "No new mail. Removed 1 message."
 
 printf " Renamed directory...\t\t"
 
-do_sleep
 generate_message [dir]=dir
 generate_message [dir]=dir
 generate_message [dir]=dir
 
 $NOTMUCH new > /dev/null
 
-do_sleep
 mv ${MAIL_DIR}/dir ${MAIL_DIR}/dir-renamed
+increment_mtime ${MAIL_DIR}
 
 execute_expecting new "No new mail. Detected 3 file renames."
 
 printf " Deleted directory...\t\t"
 
-do_sleep
 rm -rf ${MAIL_DIR}/dir-renamed
+increment_mtime ${MAIL_DIR}
 
 execute_expecting new "No new mail. Removed 3 messages."
 
 printf " New directory (at end of list)... "
 
-do_sleep
 generate_message [dir]=zzz
 generate_message [dir]=zzz
 generate_message [dir]=zzz
@@ -244,8 +247,8 @@ execute_expecting new "Added 3 new messages to the database."
 
 printf " Deleted directory (end of list)... "
 
-do_sleep
 rm -rf ${MAIL_DIR}/zzz
+increment_mtime ${MAIL_DIR}
 
 execute_expecting new "No new mail. Removed 3 messages."
 
@@ -260,18 +263,16 @@ ln -s ${TEST_DIR}/actual_maildir ${MAIL_DIR}/symlink
 execute_expecting new "Added 1 new message to the database."
 
 printf " New symlink to a file...\t"
-do_sleep
 generate_message
 external_msg_filename=${TEST_DIR}/external/$(basename $gen_msg_filename)
 mkdir -p $(dirname $external_msg_filename)
 mv $gen_msg_filename $external_msg_filename
 ln -s $external_msg_filename $gen_msg_filename
-
+increment_mtime ${MAIL_DIR}
 execute_expecting new "Added 1 new message to the database."
 
 printf " New two-level directory...\t"
 
-do_sleep
 generate_message [dir]=two/levels
 generate_message [dir]=two/levels
 generate_message [dir]=two/levels
@@ -280,8 +281,8 @@ execute_expecting new "Added 3 new messages to the database."
 
 printf " Deleted two-level directory... "
 
-do_sleep
 rm -rf ${MAIL_DIR}/two
+increment_mtime ${MAIL_DIR}
 
 execute_expecting new "No new mail. Removed 3 messages."