make zcopy work when node exists but is empty

zookeeper.tcl

@@ -43,19 +43,29 @@ namespace eval ::zookeeper {
  # copy_data - copy data
  #
  proc copy_data {zk data zpath} {
- # get the node
+ if {![$zk exists $zpath]} {
+ # the node doesn't exist, create it
+ $zk create $zpath -value $data
+ return
+ }
+
+ # node exists, but it may not have any data in it.
+ # if it has data, compare that and if it's the
+ # same, do nothing.
+ #
+ # otherwise, set the data
+
  if {[$zk get $zpath -data zdata -version zversion]} {
- # the node exists
  # if it matches the file, leave it alone
  if {$data == $zdata} {
  return
  }
- # file is different set the znode to contain it
- $zk set $zpath $data $zversion
  } else {
- # the node doesn't exist, create it
- $zk create $zpath -value $data
+ set zversion 0
  }
+
+ # file is different set the znode to contain it
+ $zk set $zpath $data $zversion
  }
 
  #
@@ -75,6 +85,23 @@ namespace eval ::zookeeper {
  zsync $zk $dir $zpath$tailDir $pattern
  }
  }
+
+ #
+ # zcopy - copy a znode tree to a filesystem
+ #
+ # zpath is prepended to the destination path
+ #
+ proc zcopy {zk zpath path {pattern *}} {
+ file mkdir $path
+ set regexp "^${path}(.*)"
+ set children [$zk children $zpath]
+ foreach znode $children {
+ regexp $regexp $file dummy tail
+ copy_file $zk $file $zpath$tail
+ regexp $regexp $dir dummy tailDir
+ zcopy $zk $dir $zpath$tailDir $pattern
+ }
+ }
 } ;# namespace ::zookeeper
 
 # vim: set ts=4 sw=4 sts=4 noet :