gitk: Get rid of idrowranges and rowrangelist

Instead make the rowranges procedure compute its result by looking
in the rowidlist entries for the rows around the children of the id
and the id itself.  This turns out not to take too long, and not having
to maintain idrowranges and rowrangelist speeds up the layout.

This also makes optimize_rows not use rowranges, since all it really
needed was a way to work out if one id is the first child of another,
so it can just look at the children list.

Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -1927,7 +1927,7 @@ proc showview {n} {
     global curview viewdata viewfiles
     global displayorder parentlist rowidlist
     global colormap rowtextx commitrow nextcolor canvxmax
-    global numcommits rowrangelist commitlisted idrowranges rowchk
+    global numcommits commitlisted rowchk
     global selectedline currentid canv canvy0
     global treediffs
     global pending_select phase
@@ -1963,13 +1963,13 @@ proc showview {n} {
 	set vcmitlisted($curview) $commitlisted
 	if {$phase ne {}} {
 	    set viewdata($curview) \
-		[list $phase $rowidlist {} $rowrangelist \
-		     [flatten idrowranges] [flatten idinlist] \
+		[list $phase $rowidlist {} {} \
+		     {} [flatten idinlist] \
 		     $rowlaidout $rowoptim $numcommits]
 	} elseif {![info exists viewdata($curview)]
 		  || [lindex $viewdata($curview) 0] ne {}} {
 	    set viewdata($curview) \
-		[list {} $rowidlist {} $rowrangelist]
+		[list {} $rowidlist {} {}]
 	}
     }
     catch {unset treediffs}
@@ -1998,12 +1998,9 @@ proc showview {n} {
     set parentlist $vparentlist($n)
     set commitlisted $vcmitlisted($n)
     set rowidlist [lindex $v 1]
-    set rowrangelist [lindex $v 3]
     if {$phase eq {}} {
 	set numcommits [llength $displayorder]
-	catch {unset idrowranges}
     } else {
-	unflatten idrowranges [lindex $v 4]
 	unflatten idinlist [lindex $v 5]
 	set rowlaidout [lindex $v 6]
 	set rowoptim [lindex $v 7]
@@ -2670,7 +2667,7 @@ proc idcol {idlist id {i 0}} {
 }
 
 proc makeuparrow {oid y x} {
-    global rowidlist uparrowlen idrowranges displayorder
+    global rowidlist uparrowlen displayorder
 
     for {set i 0} {$i < $uparrowlen && $y > 1} {incr i} {
 	incr y -1
@@ -2678,13 +2675,12 @@ proc makeuparrow {oid y x} {
 	set x [idcol $idl $oid $x]
 	lset rowidlist $y [linsert $idl $x $oid]
     }
-    lappend idrowranges($oid) [lindex $displayorder $y]
 }
 
 proc initlayout {} {
     global rowidlist displayorder commitlisted
     global rowlaidout rowoptim
-    global idinlist rowchk rowrangelist idrowranges
+    global idinlist rowchk
     global numcommits canvxmax canv
     global nextcolor
     global parentlist
@@ -2695,7 +2691,6 @@ proc initlayout {} {
     set displayorder {}
     set commitlisted {}
     set parentlist {}
-    set rowrangelist {}
     set nextcolor 0
     set rowidlist {{}}
     catch {unset idinlist}
@@ -2705,7 +2700,6 @@ proc initlayout {} {
     set canvxmax [$canv cget -width]
     catch {unset colormap}
     catch {unset rowtextx}
-    catch {unset idrowranges}
     set selectfirst 1
 }
 
@@ -2952,9 +2946,8 @@ proc layoutrows {row endrow last} {
     global rowidlist displayorder
     global uparrowlen downarrowlen maxwidth mingaplen
     global children parentlist
-    global idrowranges
     global commitidx curview
-    global idinlist rowchk rowrangelist
+    global idinlist rowchk
 
     set idlist [lindex $rowidlist $row]
     while {$row < $endrow} {
@@ -2970,8 +2963,6 @@ proc layoutrows {row endrow last} {
 		    if {$r == 0} {
 			set idlist [lreplace $idlist $x $x]
 			set idinlist($i) 0
-			set rm1 [expr {$row - 1}]
-			lappend idrowranges($i) [lindex $displayorder $rm1]
 			continue
 		    }
 		    set rowchk($i) [expr {$row + $r}]
@@ -3001,20 +2992,12 @@ proc layoutrows {row endrow last} {
 	} else {
 	    unset idinlist($id)
 	}
-	set ranges {}
-	if {[info exists idrowranges($id)]} {
-	    set ranges $idrowranges($id)
-	    lappend ranges $id
-	    unset idrowranges($id)
-	}
-	lappend rowrangelist $ranges
 	incr row
 	set idlist [lreplace $idlist $col $col]
 	set x $col
 	foreach i $newolds {
 	    set x [idcol $idlist $i $x]
 	    set idlist [linsert $idlist $x $i]
-	    set idrowranges($i) $id
 	}
 	foreach oid $oldolds {
 	    set x [idcol $idlist $oid $x]
@@ -3047,7 +3030,6 @@ proc addextraid {id row} {
 
 proc layouttail {} {
     global rowidlist idinlist commitidx curview
-    global idrowranges rowrangelist
 
     set row $commitidx($curview)
     set idlist [lindex $rowidlist $row]
@@ -3056,9 +3038,6 @@ proc layouttail {} {
 	set id [lindex $idlist $col]
 	addextraid $id $row
 	catch {unset idinlist($id)}
-	lappend idrowranges($id) $id
-	lappend rowrangelist $idrowranges($id)
-	unset idrowranges($id)
 	incr row
 	set idlist [lreplace $idlist $col $col]
 	lappend rowidlist $idlist
@@ -3069,9 +3048,6 @@ proc layouttail {} {
 	addextraid $id $row
 	lset rowidlist $row [list $id]
 	makeuparrow $id $row 0
-	lappend idrowranges($id) $id
-	lappend rowrangelist $idrowranges($id)
-	unset idrowranges($id)
 	incr row
 	lappend rowidlist {}
     }
@@ -3092,7 +3068,7 @@ proc insert_pad {row col npad} {
 }
 
 proc optimize_rows {row col endrow} {
-    global rowidlist displayorder
+    global rowidlist displayorder curview children
 
     if {$row < 1} {
 	set row 1
@@ -3131,8 +3107,9 @@ proc optimize_rows {row col endrow} {
 		}
 	    }
 	    if {$z0 eq {}} {
-		set ranges [rowranges $id]
-		if {$ranges ne {} && $y0 > [lindex $ranges 0]} {
+		# if row y0 is the first child of $id then it's not an arrow
+		if {[lindex $children($curview,$id) 0] ne
+		    [lindex $displayorder $y0]} {
 		    set isarrow 1
 		}
 	    }
@@ -3195,11 +3172,10 @@ proc optimize_rows {row col endrow} {
 		set x0 [lsearch -exact $previdlist $id]
 		if {$x0 < 0} {
 		    # check if this is the link to the first child
-		    set ranges [rowranges $id]
-		    if {$ranges ne {} && $row == [lindex $ranges 0]} {
+		    set kid [lindex $displayorder $y0]
+		    if {[lindex $children($curview,$id) 0] eq $kid} {
 			# it is, work out offset to child
-			set id [lindex $displayorder $y0]
-			set x0 [lsearch -exact $previdlist $id]
+			set x0 [lsearch -exact $previdlist $kid]
 		    }
 		}
 		if {$x0 <= $col} break
@@ -3236,24 +3212,59 @@ proc linewidth {id} {
 }
 
 proc rowranges {id} {
-    global phase idrowranges commitrow rowlaidout rowrangelist curview
+    global commitrow curview children uparrowlen downarrowlen
+    global rowidlist
 
-    set ranges {}
-    if {$phase eq {} ||
-	([info exists commitrow($curview,$id)]
-	 && $commitrow($curview,$id) < $rowlaidout)} {
-	set ranges [lindex $rowrangelist $commitrow($curview,$id)]
-    } elseif {[info exists idrowranges($id)]} {
-	set ranges $idrowranges($id)
+    set kids $children($curview,$id)
+    if {$kids eq {}} {
+	return {}
     }
-    set linenos {}
-    foreach rid $ranges {
-	lappend linenos $commitrow($curview,$rid)
+    set ret {}
+    lappend kids $id
+    foreach child $kids {
+	if {![info exists commitrow($curview,$child)]} break
+	set row $commitrow($curview,$child)
+	if {![info exists prev]} {
+	    lappend ret [expr {$row + 1}]
+	} else {
+	    if {$row <= $prevrow} {
+		puts "oops children out of order [shortids $id] $row < [shortids $prev] $prevrow"
+	    }
+	    # see if the line extends the whole way from prevrow to row
+	    if {$row > $prevrow + $uparrowlen + $downarrowlen &&
+		[lsearch -exact [lindex $rowidlist \
+			    [expr {int(($row + $prevrow) / 2)}]] $id] < 0} {
+		# it doesn't, see where it ends
+		set r [expr {$prevrow + $downarrowlen}]
+		if {[lsearch -exact [lindex $rowidlist $r] $id] < 0} {
+		    while {[incr r -1] > $prevrow &&
+			   [lsearch -exact [lindex $rowidlist $r] $id] < 0} {}
+		} else {
+		    while {[incr r] <= $row &&
+			   [lsearch -exact [lindex $rowidlist $r] $id] >= 0} {}
+		    incr r -1
+		}
+		lappend ret $r
+		# see where it starts up again
+		set r [expr {$row - $uparrowlen}]
+		if {[lsearch -exact [lindex $rowidlist $r] $id] < 0} {
+		    while {[incr r] < $row &&
+			   [lsearch -exact [lindex $rowidlist $r] $id] < 0} {}
+		} else {
+		    while {[incr r -1] >= $prevrow &&
+			   [lsearch -exact [lindex $rowidlist $r] $id] >= 0} {}
+		    incr r
+		}
+		lappend ret $r
+	    }
+	}
+	if {$child eq $id} {
+	    lappend ret $row
+	}
+	set prev $id
+	set prevrow $row
     }
-    if {$linenos ne {}} {
-	lset linenos 0 [expr {[lindex $linenos 0] + 1}]
-    }
-    return $linenos
+    return $ret
 }
 
 proc drawlineseg {id row endrow arrowlow} {
@@ -3938,7 +3949,7 @@ proc show_status {msg} {
 proc insertrow {row newcmit} {
     global displayorder parentlist commitlisted children
     global commitrow curview rowidlist numcommits
-    global rowrangelist rowlaidout rowoptim numcommits
+    global rowlaidout rowoptim numcommits
     global selectedline rowchk commitidx
 
     if {$row >= $numcommits} {
@@ -3970,18 +3981,6 @@ proc insertrow {row newcmit} {
     }
     set rowidlist [linsert $rowidlist $row $idlist]
 
-    set rowrangelist [linsert $rowrangelist $row {}]
-    if {[llength $kids] > 1} {
-	set rp1 [expr {$row + 1}]
-	set ranges [lindex $rowrangelist $rp1]
-	if {$ranges eq {}} {
-	    set ranges [list $newcmit $p]
-	} elseif {[lindex $ranges end-1] eq $p} {
-	    lset ranges end-1 $newcmit
-	}
-	lset rowrangelist $rp1 $ranges
-    }
-
     catch {unset rowchk}
 
     incr rowlaidout
@@ -3998,7 +3997,7 @@ proc insertrow {row newcmit} {
 proc removerow {row} {
     global displayorder parentlist commitlisted children
     global commitrow curview rowidlist numcommits
-    global rowrangelist idrowranges rowlaidout rowoptim numcommits
+    global rowlaidout rowoptim numcommits
     global linesegends selectedline rowchk commitidx
 
     if {$row >= $numcommits} {
@@ -4026,15 +4025,6 @@ proc removerow {row} {
 
     set rowidlist [lreplace $rowidlist $row $row]
 
-    set rowrangelist [lreplace $rowrangelist $row $row]
-    if {[llength $kids] > 0} {
-	set ranges [lindex $rowrangelist $row]
-	if {[lindex $ranges end-1] eq $id} {
-	    set ranges [lreplace $ranges end-1 end]
-	    lset rowrangelist $row $ranges
-	}
-    }
-
     catch {unset rowchk}
 
     incr rowlaidout -1