Extracted strategy from batch uuids provider implementation.

Reimplemented Periodic strategy.
Implemented FullBus strategy (#24).
Started working on tests.

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased] - xxxx-xx-xx
+### Added
+- [#24](https://github.com/elyby/chrly/issues/24): Added a new batch Mojang UUIDs provider strategy `full-bus` and
+  corresponding configuration param `QUEUE_STRATEGY` with the default value `periodic`.
 
 ## [4.4.1] - 2020-04-24
 ### Added

README.md

@@ -97,6 +97,14 @@ docker-compose up -d app
         <td>Sentry can be used to collect app errors</td>
         <td><code>https://public:private@your.sentry.io/1</code></td>
     </tr>
+    <tr>
+        <td>QUEUE_STRATEGY</td>
+        <td>
+            Sets the strategy for batch Mojang UUIDs provider queue. Allowed values are <code>periodic</code> and
+            <code>full-bus</code> (see <a href="https://github.com/elyby/chrly/issues/24">#24</a>).
+        </td>
+        <td><code>periodic</code></td>
+    </tr>
     <tr>
         <td>QUEUE_LOOP_DELAY</td>
         <td>

di/mojang_textures.go

@@ -1,6 +1,7 @@
 package di
 
 import (
+	"context"
 	"fmt"
 	"net/url"
 	"time"
@@ -18,6 +19,9 @@ var mojangTextures = di.Options(
 	di.Provide(newMojangTexturesProvider),
 	di.Provide(newMojangTexturesUuidsProviderFactory),
 	di.Provide(newMojangTexturesBatchUUIDsProvider),
+	di.Provide(newMojangTexturesBatchUUIDsProviderStrategyFactory),
+	di.Provide(newMojangTexturesBatchUUIDsProviderDelayedStrategy),
+	di.Provide(newMojangTexturesBatchUUIDsProviderFullBusStrategy),
 	di.Provide(newMojangTexturesRemoteUUIDsProvider),
 	di.Provide(newMojangSignedTexturesProvider),
 	di.Provide(newMojangTexturesStorageFactory),
@@ -75,7 +79,7 @@ func newMojangTexturesUuidsProviderFactory(
 
 func newMojangTexturesBatchUUIDsProvider(
 	container *di.Container,
-	config *viper.Viper,
+	strategy mojangtextures.BatchUuidsProviderStrategy,
 	emitter mojangtextures.Emitter,
 ) (*mojangtextures.BatchUuidsProvider, error) {
 	if err := container.Provide(func(emitter es.Subscriber, config *viper.Viper) *namedHealthChecker {
@@ -106,14 +110,56 @@ func newMojangTexturesBatchUUIDsProvider(
 		return nil, err
 	}
 
+	return mojangtextures.NewBatchUuidsProvider(context.Background(), strategy, emitter), nil
+}
+
+func newMojangTexturesBatchUUIDsProviderStrategyFactory(
+	container *di.Container,
+	config *viper.Viper,
+) (mojangtextures.BatchUuidsProviderStrategy, error) {
+	config.SetDefault("queue.strategy", "periodic")
+
+	strategyName := config.GetString("queue.strategy")
+	switch strategyName {
+	case "periodic":
+		var strategy *mojangtextures.PeriodicStrategy
+		err := container.Resolve(&strategy)
+		if err != nil {
+			return nil, err
+		}
+
+		return strategy, nil
+	case "full-bus":
+		var strategy *mojangtextures.FullBusStrategy
+		err := container.Resolve(&strategy)
+		if err != nil {
+			return nil, err
+		}
+
+		return strategy, nil
+	default:
+		return nil, fmt.Errorf("unknown queue strategy \"%s\"", strategyName)
+	}
+}
+
+func newMojangTexturesBatchUUIDsProviderDelayedStrategy(config *viper.Viper) *mojangtextures.PeriodicStrategy {
 	config.SetDefault("queue.loop_delay", 2*time.Second+500*time.Millisecond)
 	config.SetDefault("queue.batch_size", 10)
 
-	return &mojangtextures.BatchUuidsProvider{
-		Emitter:        emitter,
-		IterationDelay: config.GetDuration("queue.loop_delay"),
-		IterationSize:  config.GetInt("queue.batch_size"),
-	}, nil
+	return mojangtextures.NewPeriodicStrategy(
+		config.GetDuration("queue.loop_delay"),
+		config.GetInt("queue.batch_size"),
+	)
+}
+
+func newMojangTexturesBatchUUIDsProviderFullBusStrategy(config *viper.Viper) *mojangtextures.FullBusStrategy {
+	config.SetDefault("queue.loop_delay", 2*time.Second+500*time.Millisecond)
+	config.SetDefault("queue.batch_size", 10)
+
+	return mojangtextures.NewFullBusStrategy(
+		config.GetDuration("queue.loop_delay"),
+		config.GetInt("queue.batch_size"),
+	)
 }
 
 func newMojangTexturesRemoteUUIDsProvider(