state: add allWatcher

state/megawatcher.go

 package state
 
 import (
         "container/list"
         "labix.org/v2/mgo"
         "launchpad.net/juju-core/state/api/params"
         "launchpad.net/tomb"
         "reflect"
 )
 
@@ skipping 185 matching lines @@
         if reflect.DeepEqual(info, entry.info) {
                 return
         }
         // We already know about the entity; update its doc.
         a.latestRevno++
         entry.revno = a.latestRevno
         entry.info = info
         a.list.MoveToFront(elem)
 }
 
-// Delta holds details of a change to the environment.
-type Delta struct {
-        // If Remove is true, the entity has been removed;
-        // otherwise it has been created or changed.
-        Remove bool
-        // Entity holds data about the entity that has changed.
-        Entity params.EntityInfo
-}
-
 // changesSince returns any changes that have occurred since
 // the given revno, oldest first.
-func (a *allInfo) changesSince(revno int64) []Delta {
+func (a *allInfo) changesSince(revno int64) []params.Delta {
         e := a.list.Front()
         n := 0
         for ; e != nil; e = e.Next() {
                 entry := e.Value.(*entityEntry)
                 if entry.revno <= revno {
                         break
                 }
                 n++
         }
         if e != nil {
                 // We've found an element that we've already seen.
                 e = e.Prev()
         } else {
                 // We haven't seen any elements, so we want all of them.
                 e = a.list.Back()
                 n++
         }
-        changes := make([]Delta, 0, n)
+        changes := make([]params.Delta, 0, n)
         for ; e != nil; e = e.Prev() {
                 entry := e.Value.(*entityEntry)
-                changes = append(changes, Delta{
-                        Remove: entry.removed,
-                        Entity: entry.info,
+                changes = append(changes, params.Delta{
+                        Removed: entry.removed,
+                        Entity:  entry.info,
                 })
         }
         return changes
 }