Avoid the creation of large numbers of small LDB files.

src/cpp/ripple/Application.cpp

@@ -180,6 +180,7 @@ void Application::setup()
 			options.filter_policy = leveldb::NewBloomFilterPolicy(10);
 		if (theConfig.LDB_IMPORT)
 			options.write_buffer_size = 32 << 20;
+		options.write_buffer_size = std::max(options.write_buffer_size, theConfig.getSize(siLDBWriteSize) << 20);
 		leveldb::Status status = leveldb::DB::Open(options, (theConfig.DATA_DIR / "hashnode").string(), &mHashNodeLDB);
 		if (!status.ok() || !mHashNodeLDB)
 		{

src/cpp/ripple/Config.cpp

@@ -515,7 +515,8 @@ int Config::getSize(SizedItemName item)
 		{ siLineCacheAge,		{	500,	600,	1800,	3600,		7200	} },
 		{ siHashNodeDBCache,	{	24,		48,		64,		128,		256		} },
 		{ siTxnDBCache,			{	4,		12,		48,		96,			192		} },
-		{ siLgrDBCache,			{	4,		8,		32,		64,			128		} }
+		{ siLgrDBCache,			{	4,		8,		32,		64,			128		} },
+		{ siLDBWriteSize,		{	8,		16,		32,		64,			128		} }
 	};
 
 	for (int i = 0; i < (sizeof(sizeTable) / sizeof(SizedItem)); ++i)

src/cpp/ripple/Config.h

@@ -67,7 +67,8 @@ enum SizedItemName
 	siLineCacheAge,
 	siHashNodeDBCache,
 	siTxnDBCache,
-	siLgrDBCache
+	siLgrDBCache,
+	siLDBWriteSize
 };
 
 struct SizedItem