Add Task DB implementation using a local BoltDB.

build_scheduler/go/db/modified_tasks.go

 package db
 
 import (
         "sort"
         "sync"
         "time"
 
         "github.com/satori/go.uuid"
 )
 
@@ skipping 43 matching lines @@
                 m.mtx.Unlock()
                 if !anyLeft {
                         break
                 }
         }
 }
 
 // TrackModifiedTask indicates the given Task should be returned from the next
 // call to GetModifiedTasks from each subscriber.
 func (m *ModifiedTasks) TrackModifiedTask(t *Task) {
+        m.TrackModifiedTasks([]*Task{t})
+}
+
+// TrackModifiedTasks calls TrackModifiedTask on each item.
+func (m *ModifiedTasks) TrackModifiedTasks(tasks []*Task) {
         m.mtx.Lock()
         defer m.mtx.Unlock()
-        // Make a single copy, since GetModifiedTasks also copies.
-        t = t.Copy()
-        for _, modTasks := range m.tasks {
-                modTasks[t.Id] = t
+        for _, t := range tasks {
+                // Make a single copy, since GetModifiedTasks also copies.
+                t = t.Copy()
+                for _, modTasks := range m.tasks {
+                        modTasks[t.Id] = t
+                }
         }
 }
 
 // See docs for DB interface.
 func (m *ModifiedTasks) StartTrackingModifiedTasks() (string, error) {
         m.mtx.Lock()
         defer m.mtx.Unlock()
         if len(m.tasks) == 0 {
                 // Initialize the data structure and start expiration goroutine.
                 m.tasks = map[string]map[string]*Task{}
                 m.expiration = map[string]time.Time{}
                 go m.clearExpiredSubscribers()
         } else if len(m.tasks) >= MAX_MODIFIED_BUILDS_USERS {
                 return "", ErrTooManyUsers
         }
         id := uuid.NewV5(uuid.NewV1(), uuid.NewV4().String()).String()
         m.tasks[id] = map[string]*Task{}
         m.expiration[id] = time.Now().Add(MODIFIED_BUILDS_TIMEOUT)
         return id, nil
 }