| // Copyright 2014 Google LLC |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| // This file provides error functions for common API failure modes. |
| |
| package datastore |
| |
| import ( |
| "fmt" |
| ) |
| |
| // MultiError is returned by batch operations when there are errors with |
| // particular elements. Errors will be in a one-to-one correspondence with |
| // the input elements; successful elements will have a nil entry. |
| type MultiError []error |
| |
| func (m MultiError) Error() string { |
| s, n := "", 0 |
| for _, e := range m { |
| if e != nil { |
| if n == 0 { |
| s = e.Error() |
| } |
| n++ |
| } |
| } |
| switch n { |
| case 0: |
| return "(0 errors)" |
| case 1: |
| return s |
| case 2: |
| return s + " (and 1 other error)" |
| } |
| return fmt.Sprintf("%s (and %d other errors)", s, n-1) |
| } |