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+# 2008 Feb 19
+#
+# The author disclaims copyright to this source code. In place of
+# a legal notice, here is a blessing:
+#
+# May you do good and not evil.
+# May you find forgiveness for yourself and forgive others.
+# May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# This file contains Tcl code that may be useful for testing or
+# analyzing r-tree structures created with this module. It is
+# used by both test procedures and the r-tree viewer application.
+#
+
+
+#--------------------------------------------------------------------------
+# PUBLIC API:
+#
+# rtree_depth
+# rtree_ndim
+# rtree_node
+# rtree_mincells
+# rtree_check
+# rtree_dump
+# rtree_treedump
+#
+
+proc rtree_depth {db zTab} {
+ $db one "SELECT rtreedepth(data) FROM ${zTab}_node WHERE nodeno=1"
+}
+
+proc rtree_nodedepth {db zTab iNode} {
+ set iDepth [rtree_depth $db $zTab]
+
+ set ii $iNode
+ while {$ii != 1} {
+ set sql "SELECT parentnode FROM ${zTab}_parent WHERE nodeno = $ii"
+ set ii [db one $sql]
+ incr iDepth -1
+ }
+
+ return $iDepth
+}
+
+# Return the number of dimensions of the rtree.
+#
+proc rtree_ndim {db zTab} {
+ set nDim [expr {(([llength [$db eval "pragma table_info($zTab)"]]/6)-1)/2}]
+}
+
+# Return the contents of rtree node $iNode.
+#
+proc rtree_node {db zTab iNode {iPrec 6}} {
+ set nDim [rtree_ndim $db $zTab]
+ set sql "
+ SELECT rtreenode($nDim, data) FROM ${zTab}_node WHERE nodeno = $iNode
+ "
+ set node [db one $sql]
+
+ set nCell [llength $node]
+ set nCoord [expr $nDim*2]
+ for {set ii 0} {$ii < $nCell} {incr ii} {
+ for {set jj 1} {$jj <= $nCoord} {incr jj} {
+ set newval [format "%.${iPrec}f" [lindex $node $ii $jj]]
+ lset node $ii $jj $newval
+ }
+ }
+ set node
+}
+
+proc rtree_mincells {db zTab} {
+ set n [$db one "select length(data) FROM ${zTab}_node LIMIT 1"]
+ set nMax [expr {int(($n-4)/(8+[rtree_ndim $db $zTab]*2*4))}]
+ return [expr {int($nMax/3)}]
+}
+
+# An integrity check for the rtree $zTab accessible via database
+# connection $db.
+#
+proc rtree_check {db zTab} {
+ array unset ::checked
+
+ # Check each r-tree node.
+ set rc [catch {
+ rtree_node_check $db $zTab 1 [rtree_depth $db $zTab]
+ } msg]
+ if {$rc && $msg ne ""} { error $msg }
+
+ # Check that the _rowid and _parent tables have the right
+ # number of entries.
+ set nNode [$db one "SELECT count(*) FROM ${zTab}_node"]
+ set nRow [$db one "SELECT count(*) FROM ${zTab}"]
+ set nRowid [$db one "SELECT count(*) FROM ${zTab}_rowid"]
+ set nParent [$db one "SELECT count(*) FROM ${zTab}_parent"]
+
+ if {$nNode != ($nParent+1)} {
+ error "Wrong number of entries in ${zTab}_parent"
+ }
+ if {$nRow != $nRowid} {
+ error "Wrong number of entries in ${zTab}_rowid"
+ }
+
+ return $rc
+}
+
+proc rtree_node_check {db zTab iNode iDepth} {
+ if {[info exists ::checked($iNode)]} { error "Second ref to $iNode" }
+ set ::checked($iNode) 1
+
+ set node [rtree_node $db $zTab $iNode]
+ if {$iNode!=1 && [llength $node]==0} { error "No such node: $iNode" }
+
+ if {$iNode != 1 && [llength $node]<[rtree_mincells $db $zTab]} {
+ puts "Node $iNode: Has only [llength $node] cells"
+ error ""
+ }
+ if {$iNode == 1 && [llength $node]==1 && [rtree_depth $db $zTab]>0} {
+ set depth [rtree_depth $db $zTab]
+ puts "Node $iNode: Has only 1 child (tree depth is $depth)"
+ error ""
+ }
+
+ set nDim [expr {([llength [lindex $node 0]]-1)/2}]
+
+ if {$iDepth > 0} {
+ set d [expr $iDepth-1]
+ foreach cell $node {
+ set shouldbe [rtree_node_check $db $zTab [lindex $cell 0] $d]
+ if {$cell ne $shouldbe} {
+ puts "Node $iNode: Cell is: {$cell}, should be {$shouldbe}"
+ error ""
+ }
+ }
+ }
+
+ set mapping_table "${zTab}_parent"
+ set mapping_sql "SELECT parentnode FROM $mapping_table WHERE rowid = \$rowid"
+ if {$iDepth==0} {
+ set mapping_table "${zTab}_rowid"
+ set mapping_sql "SELECT nodeno FROM $mapping_table WHERE rowid = \$rowid"
+ }
+ foreach cell $node {
+ set rowid [lindex $cell 0]
+ set mapping [db one $mapping_sql]
+ if {$mapping != $iNode} {
+ puts "Node $iNode: $mapping_table entry for cell $rowid is $mapping"
+ error ""
+ }
+ }
+
+ set ret [list $iNode]
+ for {set ii 1} {$ii <= $nDim*2} {incr ii} {
+ set f [lindex $node 0 $ii]
+ foreach cell $node {
+ set f2 [lindex $cell $ii]
+ if {($ii%2)==1 && $f2<$f} {set f $f2}
+ if {($ii%2)==0 && $f2>$f} {set f $f2}
+ }
+ lappend ret $f
+ }
+ return $ret
+}
+
+proc rtree_dump {db zTab} {
+ set zRet ""
+ set nDim [expr {(([llength [$db eval "pragma table_info($zTab)"]]/6)-1)/2}]
+ set sql "SELECT nodeno, rtreenode($nDim, data) AS node FROM ${zTab}_node"
+ $db eval $sql {
+ append zRet [format "% -10s %s\n" $nodeno $node]
+ }
+ set zRet
+}
+
+proc rtree_nodetreedump {db zTab zIndent iDepth iNode} {
+ set ret ""
+ set node [rtree_node $db $zTab $iNode 1]
+ append ret [format "%-3d %s%s\n" $iNode $zIndent $node]
+ if {$iDepth>0} {
+ foreach cell $node {
+ set i [lindex $cell 0]
+ append ret [rtree_nodetreedump $db $zTab "$zIndent " [expr $iDepth-1] $i]
+ }
+ }
+ set ret
+}
+
+proc rtree_treedump {db zTab} {
+ set d [rtree_depth $db $zTab]
+ rtree_nodetreedump $db $zTab "" $d 1
+}