git-gui: Supply progress feedback when running update-index.

The git-update-index process can take a while to process a large
number of files; for example my laptop would probably need almost
an hour to chug through 20,000 modified files.  In these incredibly
large cases the user should be given at least some feedback to let
them know the application is still working on their behalf, even if
it won't them do anything else (as the index is locked).

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

git-gui

@@ -178,9 +178,7 @@ if {$appname == {git-citool}} {
 set single_commit 0
 set status_active 0
 set diff_active 0
-set update_active 0
 set commit_active 0
-set update_index_fd {}
 
 set disable_on_lock [list]
 set index_lock_type none
@@ -1100,55 +1098,73 @@ proc display_all_files {} {
 	$ui_other conf -state disabled
 }
 
-proc with_update_index {body} {
-	global update_index_fd
+proc update_index {pathList} {
+	global update_index_cp ui_status_value
 
-	if {$update_index_fd == {}} {
-		if {![lock_index update]} return
-		set update_index_fd [open \
-			"| git update-index --add --remove -z --stdin" \
-			w]
-		fconfigure $update_index_fd -translation binary
-		uplevel 1 $body
-		close $update_index_fd
-		set update_index_fd {}
-		unlock_index
-	} else {
-		uplevel 1 $body
-	}
+	if {![lock_index update]} return
+
+	set update_index_cp 0
+	set totalCnt [llength $pathList]
+	set batch [expr {int($totalCnt * .01) + 1}]
+	if {$batch > 25} {set batch 25}
+
+	set ui_status_value "Including files ... 0/$totalCnt 0%"
+	set ui_status_value [format \
+		"Including files ... %i/%i files (%.2f%%)" \
+		$update_index_cp \
+		$totalCnt \
+		0.0]
+	set fd [open "| git update-index --add --remove -z --stdin" w]
+	fconfigure $fd -blocking 0 -translation binary
+	fileevent $fd writable [list \
+		write_update_index \
+		$fd \
+		$pathList \
+		$totalCnt \
+		$batch \
+		]
 }
 
-proc update_index {path} {
-	global update_index_fd
-
-	if {$update_index_fd == {}} {
-		error {not in with_update_index}
-	} else {
-		puts -nonewline $update_index_fd "$path\0"
-	}
-}
-
-proc toggle_mode {path} {
+proc write_update_index {fd pathList totalCnt batch} {
+	global update_index_cp ui_status_value
 	global file_states ui_fname_value
 
-	set s $file_states($path)
-	set m [lindex $s 0]
-
-	switch -- $m {
-	AM -
-	_O {set new A*}
-	_M -
-	MM {set new M*}
-	AD -
-	_D {set new D*}
-	default {return}
+	if {$update_index_cp >= $totalCnt} {
+		close $fd
+		unlock_index
+		set ui_status_value {Ready.}
+		return
 	}
 
-	with_update_index {update_index $path}
-	display_file $path $new
-	if {$ui_fname_value == $path} {
-		show_diff $path
+	for {set i $batch} \
+		{$update_index_cp < $totalCnt && $i > 0} \
+		{incr i -1} {
+		set path [lindex $pathList $update_index_cp]
+		incr update_index_cp
+
+		switch -- [lindex $file_states($path) 0] {
+		AM -
+		_O {set new A*}
+		_M -
+		MM {set new M*}
+		AD -
+		_D {set new D*}
+		default {continue}
+		}
+
+		puts -nonewline $fd $path
+		puts -nonewline $fd "\0"
+		display_file $path $new
+		if {$ui_fname_value == $path} {
+			show_diff $path
+		}
 	}
+
+	set ui_status_value [format \
+		"Including files ... %i/%i files (%.2f%%)" \
+		$update_index_cp \
+		$totalCnt \
+		[expr {100.0 * $update_index_cp / $totalCnt}]]
 }
 
 ######################################################################
@@ -1627,27 +1643,25 @@ proc do_rescan {} {
 }
 
 proc do_include_all {} {
-	global update_active ui_status_value
+	global file_states
 
-	if {$update_active || ![lock_index begin-update]} return
+	if {![lock_index begin-update]} return
 
-	set update_active 1
-	set ui_status_value {Including all modified files...}
-	after 1 {
-		with_update_index {
-			foreach path [array names file_states] {
-				set s $file_states($path)
-				set m [lindex $s 0]
-				switch -- $m {
-				AM -
-				MM -
-				_M -
-				_D {toggle_mode $path}
-				}
-			}
+	set pathList [list]
+	foreach path [array names file_states] {
+		set s $file_states($path)
+		set m [lindex $s 0]
+		switch -- $m {
+		AM -
+		MM -
+		_M -
+		_D {lappend pathList $path}
 		}
-		set update_active 0
-		set ui_status_value {Ready.}
+	}
+	if {$pathList == {}} {
+		unlock_index
+	} else {
+		update_index $pathList
 	}
 }
 
@@ -1844,7 +1858,7 @@ proc unclick {w x y} {
 	if {$path == {}} return
 
 	if {$col == 0} {
-		toggle_mode $path
+		update_index [list $path]
 	}
 }
 
@@ -2318,4 +2332,5 @@ load_all_remotes
 populate_remote_menu .mbar.fetch From fetch_from
 populate_remote_menu .mbar.push To push_to
 populate_pull_menu .mbar.pull
+tkwait visibility .
 update_status