feat: batching sending of authors

Author: anatolystansler

src/main/kotlin/app/hashers/RepoHasher.kt

@@ -16,6 +16,7 @@ import app.utils.EmptyRepoException
 import app.utils.FileHelper.toPath
 import app.utils.HashingException
 import app.utils.RepoHelper
+import app.utils.batch
 import org.eclipse.jgit.api.Git
 import java.io.File
 import java.io.IOException
@@ -145,7 +146,9 @@ class RepoHasher(private val api: Api,
     private fun postAuthorsToServer(authors: HashSet<Author>,
                                     serverRepo: Repo) {
         authors.forEach { author -> author.repo = serverRepo }
-        api.postAuthors(authors.toList()).onErrorThrow()
+        for (authorsBatch in authors.asSequence().batch(1000)) {
+            api.postAuthors(authorsBatch).onErrorThrow()
+        }
     }
 
     private fun initServerRepo(localRepo: LocalRepo,

src/main/kotlin/app/utils/Misc.kt

@@ -0,0 +1,24 @@
+// Copyright 2018 Sourcerer Inc. All Rights Reserved.
+// Author: Anatoly Kislov ([email protected])
+
+package app.utils
+
+// TODO(anatoly): Replace with chunked from new Kotlin version.
+// SO #34498368 @ Jayson Minard.
+fun <T> Sequence<T>.batch(n: Int): Sequence<List<T>> {
+    return BatchingSequence(this, n)
+}
+
+class BatchingSequence<T>(val source: Sequence<T>,
+                                  val batchSize: Int) : Sequence<List<T>> {
+    override fun iterator(): Iterator<List<T>> = object :
+            AbstractIterator<List<T>>() {
+        val iterate = if (batchSize > 0) source.iterator() else
+            emptyList<T>().iterator()
+        override fun computeNext() {
+            if (iterate.hasNext()) setNext(iterate.asSequence()
+                    .take(batchSize).toList())
+            else done()
+        }
+    }
+}