prepare 4.5.0 release (#131)

.circleci/config.yml

@@ -41,7 +41,8 @@ defaults:
             if [ -z "$DISABLE_COVERAGE" ]; then
               go_cover_args="-covermode=atomic -coverprofile /tmp/circle-artifacts/coverage.txt"
             fi
-            go test -race $go_cover_args -v . ./redis | tee >(richgo testfilter) > $CIRCLE_ARTIFACTS/report.txt
+            # Note, we need to specify all these packages individually for go test in order to remain 1.8-compatible
+            go test -race $go_cover_args -v . ./redis ./ldconsul ./lddynamodb ./ldfiledata ./ldfilewatch ./utils | tee >(richgo testfilter) > $CIRCLE_ARTIFACTS/report.txt
             if [ -z "$DISABLE_COVERAGE" ]; then
               ./cc-test-reporter format-coverage $CIRCLE_ARTIFACTS/coverage.txt -t gocov --output $CIRCLE_ARTIFACTS/coverage.json
               ./cc-test-reporter upload-coverage --input $CIRCLE_ARTIFACTS/coverage.json
@@ -70,6 +71,8 @@ jobs:
         environment:
           <<: *environment
       - image: redis
+      - image: consul
+      - image: amazon/dynamodb-local
 
     <<: *build_steps
 
@@ -82,6 +85,8 @@ jobs:
           <<: *environment
           DISABLE_COVERAGE: 1
       - image: redis
+      - image: consul
+      - image: amazon/dynamodb-local
 
     <<: *build_steps
 
@@ -94,6 +99,8 @@ jobs:
           <<: *environment
           DISABLE_COVERAGE: 1
       - image: redis
+      - image: consul
+      - image: amazon/dynamodb-local
 
     <<: *build_steps
 

CODEOWNERS

@@ -1 +1 @@
-* @ashanbrown
+

README.md

@@ -78,6 +78,11 @@ if showFeature {
 }
 ```
 
+Database integrations
+---------------------
+
+Feature flag data can be kept in a persistent store using Redis, Consul, or DynamoDB. These adapters are implemented in the subpackages `redis`, `ldconsul`, and `lddynamodb`; to use them, call the `New...FeatureStore` function provided by the subpackage, and put the returned object in the `FeatureStore` field of your client configuration. See the subpackages and the [SDK reference guide](https://docs.launchdarkly.com/v2.0/docs/using-a-persistent-feature-store) for more information.
+
 Learn more
 -----------
 

feature_store.go

@@ -6,18 +6,44 @@ import (
 	"sync"
 )
 
-// FeatureStore is an interface describing a structure that maintains the live collection of features and related objects.
-// It is used by LaunchDarkly when streaming mode is enabled, and stores data returned
-// by the streaming API. Custom FeatureStore implementations can be passed to the
-// LaunchDarkly client via a custom Config object. LaunchDarkly provides two FeatureStore
-// implementations: one backed by an in-memory map, and one backed by Redis.
-// Implementations must be thread-safe.
+// FeatureStore is an interface describing a structure that maintains the live collection of features
+// and related objects. Whenever the SDK retrieves feature flag data from LaunchDarkly, via streaming
+// or polling, it puts the data into the FeatureStore; then it queries the store whenever a flag needs
+// to be evaluated. Therefore, implementations must be thread-safe.
+//
+// The SDK provides a default in-memory implementation (NewInMemoryFeatureStore), as well as database
+// integrations in the "redis", "ldconsul", and "lddynamodb" packages. To use an implementation other
+// than the default, put an instance of it in the FeatureStore property of your client configuration.
+//
+// If you want to create a custom implementation, it may be helpful to use the FeatureStoreWrapper
+// type in the utils package; this provides commonly desired behaviors such as caching. Custom
+// implementations must be able to handle any objects that implement the VersionedData interface,
+// so if they need to marshal objects, the marshaling must be reflection-based. The VersionedDataKind
+// type provides the necessary metadata to support this.
 type FeatureStore interface {
+	// Get attempts to retrieve an item of the specified kind from the data store using its unique key.
+	// If no such item exists, it returns nil. If the item exists but has a Deleted property that is true,
+	// it returns nil.
 	Get(kind VersionedDataKind, key string) (VersionedData, error)
+	// All retrieves all items of the specified kind from the data store, returning a map of keys to
+	// items. Any items whose Deleted property is true must be omitted. If the store is empty, it
+	// returns an empty map.
 	All(kind VersionedDataKind) (map[string]VersionedData, error)
+	// Init performs an update of the entire data store, replacing any existing data.
 	Init(map[VersionedDataKind]map[string]VersionedData) error
+	// Delete removes the specified item from the data store, unless its Version property is greater
+	// than or equal to the specified version, in which case nothing happens. Removal should be done
+	// by storing an item whose Deleted property is true (use VersionedDataKind.MakeDeleteItem()).
 	Delete(kind VersionedDataKind, key string, version int) error
+	// Upsert adds or updates the specified item, unless the existing item in the store has a Version
+	// property greater than or equal to the new item's Version, in which case nothing happens.
 	Upsert(kind VersionedDataKind, item VersionedData) error
+	// Initialized returns true if the data store contains a data set, meaning that Init has been
+	// called at least once. In a shared data store, it should be able to detect this even if Init
+	// was called in a different process, i.e. the test should be based on looking at what is in
+	// the data store. Once this has been determined to be true, it can continue to return true
+	// without having to check the store again; this method should be as fast as possible since it
+	// may be called during feature flag evaluations.
 	Initialized() bool
 }
 

feature_store_test.go

@@ -7,10 +7,10 @@ import (
 	ldtest "gopkg.in/launchdarkly/go-client.v4/shared_test"
 )
 
-func makeInMemoryStore() ld.FeatureStore {
-	return ld.NewInMemoryFeatureStore(nil)
+func makeInMemoryStore() (ld.FeatureStore, error) {
+	return ld.NewInMemoryFeatureStore(nil), nil
 }
 
 func TestInMemoryFeatureStore(t *testing.T) {
-	ldtest.RunFeatureStoreTests(t, makeInMemoryStore)
+	ldtest.RunFeatureStoreTests(t, makeInMemoryStore, nil, false)
 }