Add batching to writes (#1076)

Fixes #1077

unittests/util/BatchingTests.cpp

@@ -0,0 +1,76 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "util/Batching.h"
+
+#include <gtest/gtest.h>
+
+#include <algorithm>
+
+TEST(BatchingTests, simpleBatch)
+{
+    std::vector<int> const input{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    std::vector<int> output;
+
+    util::forEachBatch(input, 3, [&](auto begin, auto end) {
+        std::copy(begin, end, std::back_inserter(output));
+        EXPECT_LE(std::distance(begin, end), 3);
+    });
+
+    EXPECT_EQ(input, output);
+}
+
+TEST(BatchingTests, simpleBatchEven)
+{
+    std::vector<int> const input{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    std::vector<int> output;
+
+    util::forEachBatch(input, 2, [&](auto begin, auto end) {
+        std::copy(begin, end, std::back_inserter(output));
+        EXPECT_LE(std::distance(begin, end), 2);
+    });
+
+    EXPECT_EQ(input, output);
+}
+
+TEST(BatchingTests, batchSizeBiggerThanInput)
+{
+    std::vector<int> const input{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    std::vector<int> output;
+
+    util::forEachBatch(input, 20, [&](auto begin, auto end) {
+        std::copy(begin, end, std::back_inserter(output));
+        EXPECT_LE(std::distance(begin, end), 20);
+    });
+
+    EXPECT_EQ(input, output);
+}
+
+TEST(BatchingTests, emptyInput)
+{
+    std::vector<int> const input{};
+    std::vector<int> output;
+
+    util::forEachBatch(input, 20, [&](auto begin, auto end) {
+        std::copy(begin, end, std::back_inserter(output));
+        ASSERT_FALSE(true) << "Should not be called";
+    });
+
+    EXPECT_EQ(input, output);
+}