GitHub #8: Seed indexes from index.yml

service/datastore/testable.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package datastore
 
+import "io"

[iannucci, 2016/01/13 19:12:20]

always use

import (
  "io"
)

style. It's easier to add stuff later.

[nishanths (utexas), 2016/01/14 21:12:56]

Done.

+
 // TestingSnapshot is an opaque implementation-defined snapshot type.
 type TestingSnapshot interface {
         ImATestingSnapshot()
 }
 
 // Testable is the testable interface for fake datastore implementations.
 type Testable interface {
         // AddIndex adds the provided index.
         // Blocks all datastore access while the index is built.
         // Panics if any of the IndexDefinition objects are not Compound()
@@ skipping 49 matching lines @@
         //   - AllocateIDs returns an error.
         //   - Put'ing incomplete Keys returns an error.
         //   - Transactions are disabled and will return an error.
         //
         // This is mainly only useful when using an embedded in-memory datastore as
         // a fully-consistent 'datastore-lite'. In particular, this is useful for the
         // txnBuf filter which uses it to fulfil queries in a buffered transaction,
         // but never wants the in-memory versions of these entities to bleed through
         // to the user code.
         DisableSpecialEntities(bool)
+
+        // ParseIndexYAML parses the contents of a index YAML file into
+        // a list of datastore.IndexDefinitions.
+        //
+        // ParseIndexYAML panics if there was an error during parsing.
+        ParseIndexYAML(content io.Reader) []*IndexDefinition
+
+        // FindAndAddIndexYAML walks up from the directory of the source file
+        // until it finds a `index.yaml` or `index.yml` file.
+        // If an index YAML file is found, it opens and parses the file,
+        // and adds all the indexes found.
+        //
+        // FindAndAddIndexYAML panics if the root of the drive is reached without
+        // finding an index YAML file. FindAndAddIndexYAML also panics if there is
+        // an error reading the found index YAML file.
+        FindAndAddIndexYAML()

[dnj, 2016/01/13 16:16:40]

I don't think this capability needs to be added to the "Testable" interface.
Maybe top-level methods in "impl/memory"?

Also, both of these should return errors rather than panic on failure. They are
explicitly called by the user, so it's reasonable to task the user with handling
their failure.

[iannucci, 2016/01/13 19:12:20]

If anything they should be top level methods in service/datastore; there's
nothing impl/memory-specific about them.

To that end, moving them to be toplevel functions in this package:

  func ParseIndexYAML(io.Reader) ([]*IndexDefinition, error)
  func FindAndParseIndexYAML() ([]*IndexDefinition, error)

would be fine.
If they're in Testable, I disagree. 100% of the usecases would be to call them
and then assert no error. If they're top level functions and not testing
functions, then yes they should return errors.

[nishanths (utexas), 2016/01/14 21:12:56]

Done. Moved to service/datastore with the method signatures that @iannucci
posted.

 }