From 8321a45f46d6317108177e092ca6740ee47f2076 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Thu, 7 Sep 2017 13:19:44 +0200
Subject: [PATCH] ethdb: improve docs and add IdealBatchSize

---
 ethdb/interface.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/ethdb/interface.go b/ethdb/interface.go
index 7dd07135ca..6a61289bff 100644
--- a/ethdb/interface.go
+++ b/ethdb/interface.go
@@ -16,10 +16,16 @@
 
 package ethdb
 
+// Code using batches should try to add this much data to the batch.
+// The value was determined empirically.
+const IdealBatchSize = 100 * 1024
+
+// Putter wraps the database write operation supported by both batches and regular databases.
 type Putter interface {
 	Put(key []byte, value []byte) error
 }
 
+// Database wraps all database operations. All methods are safe for concurrent use.
 type Database interface {
 	Putter
 	Get(key []byte) ([]byte, error)
@@ -29,6 +35,8 @@ type Database interface {
 	NewBatch() Batch
 }
 
+// Batch is a write-only database that commits changes to its host database
+// when Write is called. Batch cannot be used concurrently.
 type Batch interface {
 	Putter
 	Write() error