test-results: package model: Add full_result.go and tests

go/src/infra/appengine/test-results/model/test_file.go

 package model
 
 import (
         "bytes"
         "fmt"
         "io"
         "io/ioutil"
         "math"
         "time"
 
         "golang.org/x/net/context"
 
         "github.com/luci/gae/service/datastore"
         "github.com/luci/luci-go/common/errors"
         "github.com/luci/luci-go/common/logging"
 )
 
 // IsAggregateTestFile returns whether filename is that of an aggregate test file.
 func IsAggregateTestFile(filename string) bool {
         switch filename {
         case "results.json", "results-small.json":
                 return true
         default:
                 return false
         }
 }
 
 // BuildNum is int64 that is used to handle TestFile datastore records
-// with null build_number.
+// with null build_number. The value is >= 0 if the datastore value
+// was not null.
 type BuildNum int64
 
 var _ datastore.PropertyConverter = (*BuildNum)(nil)
 
+// IsNil returns whether b had null value in datastore.
 func (b *BuildNum) IsNil() bool { return *b == -1 }
 
+// ToProperty is for implementing datastore.PropertyConverter.
 func (b *BuildNum) ToProperty() (p datastore.Property, err error) {
         if b.IsNil() {
                 return
         }
         p = datastore.MkProperty(*b)
         return
 }
 
+// FromProperty is for implementing datastore.PropertyConverter.
 func (b *BuildNum) FromProperty(p datastore.Property) error {
         switch p.Type() {
         case datastore.PTNull:
                 *b = -1
         case datastore.PTInt:
                 *b = BuildNum(p.Value().(int64))
         default:
                 return fmt.Errorf("wrong type for property: %s", p.Type())
         }
         return nil
@@ skipping 258 matching lines @@
         q = q.Order("-date")
 
         if p.Limit < 0 || p.Limit > defaultLimit {
                 q = q.Limit(defaultLimit)
         } else {
                 q = q.Limit(p.Limit)
         }
 
         return q
 }