Initial distributor implementation

appengine/cmd/dm/mutate/ack_fwd_dep.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package mutate
 
 import (
         "github.com/luci/gae/service/datastore"
         "github.com/luci/luci-go/appengine/cmd/dm/model"
         "github.com/luci/luci-go/appengine/tumble"
         "github.com/luci/luci-go/common/api/dm/service/v1"
         "golang.org/x/net/context"
 )
 
-// AckFwdDep records the fact that a BackDep was successfully created for this
-// FwdDep. It may also propagate Finished information (e.g. that the depended-on
-// Attempt was actually already completed at the time that the dependency was
-// taken on it).
-//
-// AckFwdDep is also used to propagate the fact that an Attempt (A) completed
-// back to another Attempt (B) that's blocked on A.
+// AckFwdDep records the fact that a dependency was completed.
 type AckFwdDep struct {
-        Dep           *model.FwdEdge
-        DepIsFinished bool
+        Dep *model.FwdEdge
 }
 
 // Root implements tumble.Mutation.
 func (f *AckFwdDep) Root(c context.Context) *datastore.Key {
         return datastore.Get(c).MakeKey("Attempt", f.Dep.From.DMEncoded())
 }
 
 // RollForward implements tumble.Mutation.
 func (f *AckFwdDep) RollForward(c context.Context) (muts []tumble.Mutation, err error) {
         ds := datastore.Get(c)
 
         atmpt, fdep := f.Dep.Fwd(c)
         err = ds.GetMulti([]interface{}{atmpt, fdep})
         if err != nil {
                 return
         }
 
-        // if the attempt and fdep aren't on the same execution, then bail
-        if atmpt.CurExecution != fdep.ForExecution {
+        if atmpt.State != dm.Attempt_WAITING || atmpt.CurExecution != fdep.ForExecution {
                 return
         }
 
-        needPut := false
-
         idx := uint32(fdep.BitIndex)
 
-        if !atmpt.AddingDepsBitmap.IsSet(idx) {
-                atmpt.AddingDepsBitmap.Set(idx)
+        if !atmpt.DepMap.IsSet(idx) {
+                atmpt.DepMap.Set(idx)
 
-                if atmpt.AddingDepsBitmap.All(true) {
-                        atmpt.MustModifyState(c, dm.Attempt_BLOCKED)
+                if atmpt.DepMap.All(true) {
+                        if err = atmpt.ModifyState(c, dm.Attempt_SCHEDULING); err != nil {
+                                return
+                        }
+                        atmpt.DepMap.Reset()
+                        muts = append(muts, &ScheduleExecution{For: f.Dep.From})
                 }
 
-                needPut = true
-        }
-
-        if f.DepIsFinished {
-                if !atmpt.WaitingDepBitmap.IsSet(idx) {
-                        atmpt.WaitingDepBitmap.Set(idx)
-
-                        if atmpt.WaitingDepBitmap.All(true) {
-                                atmpt.MustModifyState(c, dm.Attempt_NEEDS_EXECUTION)
-                                muts = append(muts, &ScheduleExecution{For: f.Dep.From})
-                        }
-
-                        needPut = true
-                }
-        }
-
-        if needPut {
                 err = ds.Put(atmpt)
         }
 
         return
 }
 
 func init() {
         tumble.Register((*AckFwdDep)(nil))
 }