Initial distributor implementation

common/api/dm/service/v1/execution_state_evolve.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 dm
 
 import (
         "fmt"
 )
 
 // validExecutionStateEvolution defines all valid {From -> []To} state
 // transitions. The identity transition (X -> X) is implied, as long as X has an
 // entry in this mapping.
 var validExecutionStateEvolution = map[Execution_State][]Execution_State{
-        Execution_SCHEDULED: {Execution_RUNNING, Execution_FINISHED, Execution_MISSING, Execution_CANCELLED, Execution_TIMED_OUT},
-        Execution_RUNNING:   {Execution_FINISHED, Execution_FAILED, Execution_MISSING, Execution_CANCELLED},
+        Execution_SCHEDULING: {
+                Execution_RUNNING,           // ActivateExecution
+                Execution_ABNORMAL_FINISHED, // cancel/timeout/err/etc.
+        },
+        Execution_RUNNING: {
+                Execution_STOPPING,          // FinishAttempt/EnsureGraphData
+                Execution_ABNORMAL_FINISHED, // cancel/timeout/err/etc.
+        },
+        Execution_STOPPING: {
+                Execution_FINISHED,          // got persistent state from distributor
+                Execution_ABNORMAL_FINISHED, // cancel/timeout/err/etc.
+        },
 
-        Execution_CANCELLED: {},
-        Execution_FINISHED:  {},
-        Execution_FAILED:    {},
-        Execution_MISSING:   {},
-        Execution_REJECTED:  {},
-        Execution_TIMED_OUT: {},
+        Execution_FINISHED:          {},
+        Execution_ABNORMAL_FINISHED: {},
 }
 
 // Evolve attempts to evolve the state of this Attempt. If the state
 // evolution is not allowed (e.g. invalid state transition), this returns an
 // error.
 func (s *Execution_State) Evolve(newState Execution_State) error {
         nextStates := validExecutionStateEvolution[*s]
         if nextStates == nil {
                 return fmt.Errorf("invalid state transition: no transitions defined for %s", *s)
         }
@@ skipping 18 matching lines @@
         if err != nil {
                 panic(err)
         }
 }
 
 // Terminal returns true iff there are no valid evolutions from the current
 // state.
 func (s Execution_State) Terminal() bool {
         return len(validExecutionStateEvolution[s]) == 0
 }