From 88dcf22abff266fd86b50838a41a0233dfd560af Mon Sep 17 00:00:00 2001
From: glozow <gloriajzhao@gmail.com>
Date: Thu, 7 Sep 2023 08:40:34 +0100
Subject: [PATCH] [test] DisconnectedBlockTransactions::DynamicMemoryUsage

---
 src/Makefile.test.include              |  1 +
 src/test/disconnected_transactions.cpp | 94 ++++++++++++++++++++++++++
 2 files changed, 95 insertions(+)
 create mode 100644 src/test/disconnected_transactions.cpp

diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index 5dc20d4fab9fa0..578101022be629 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -92,6 +92,7 @@ BITCOIN_TESTS =\
   test/dbwrapper_tests.cpp \
   test/denialofservice_tests.cpp \
   test/descriptor_tests.cpp \
+  test/disconnected_transactions.cpp \
   test/flatfile_tests.cpp \
   test/fs_tests.cpp \
   test/getarg_tests.cpp \
diff --git a/src/test/disconnected_transactions.cpp b/src/test/disconnected_transactions.cpp
new file mode 100644
index 00000000000000..71c9c40386b99b
--- /dev/null
+++ b/src/test/disconnected_transactions.cpp
@@ -0,0 +1,94 @@
+// Copyright (c) 2023 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+//
+#include <test/util/setup_common.h>
+#include <kernel/disconnected_transactions.h>
+
+#include <boost/test/unit_test.hpp>
+
+BOOST_FIXTURE_TEST_SUITE(disconnected_transactions, TestChain100Setup)
+
+//! Tests that DisconnectedBlockTransactions limits its own memory properly
+BOOST_AUTO_TEST_CASE(disconnectpool_memory_limits)
+{
+    // Use the coinbase transactions from TestChain100Setup. It doesn't matter whether these
+    // transactions would realistically be in a block together, they just need distinct txids for
+    // this test to work.
+    std::vector<CTransactionRef> block_vtx(m_coinbase_txns);
+
+    size_t usage_full{0};
+    // DisconnectedBlockTransactions with a comfortable maximum memory usage s.t. nothing is evicted.
+    {
+        DisconnectedBlockTransactions disconnectpool{MAX_DISCONNECTED_TX_POOL_SIZE * 1000};
+        auto evicted_txns = disconnectpool.AddTransactionsFromBlock(block_vtx);
+        BOOST_CHECK_EQUAL(evicted_txns.size(), 0);
+        BOOST_CHECK(disconnectpool.DynamicMemoryUsage() <= MAX_DISCONNECTED_TX_POOL_SIZE * 1000);
+
+        usage_full = disconnectpool.DynamicMemoryUsage();
+
+        disconnectpool.clear();
+    }
+
+    // DisconnectedBlockTransactions that's just a little too small for all of the transactions.
+    {
+        const size_t MAX_MEMUSAGE_99{usage_full - sizeof(void*)};
+        DisconnectedBlockTransactions disconnectpool{MAX_MEMUSAGE_99};
+        auto evicted_txns = disconnectpool.AddTransactionsFromBlock(block_vtx);
+        BOOST_CHECK(disconnectpool.DynamicMemoryUsage() <= MAX_MEMUSAGE_99);
+
+        // Only 1 transaction needed to be evicted
+        BOOST_CHECK_EQUAL(1, evicted_txns.size());
+
+        // Transactions are added from back to front and eviction is FIFO.
+        // The last transaction of block_vtx should be the first to be evicted.
+        BOOST_CHECK_EQUAL(block_vtx.back(), evicted_txns.front());
+
+        disconnectpool.clear();
+    }
+}
+
+//! Sanity checks for DisconnectedBlockTransactions::DynamicMemoryUsage.
+BOOST_AUTO_TEST_CASE(disconnectpool_memusage)
+{
+    if (sizeof(void*) != 8) {
+        BOOST_TEST_MESSAGE("Exiting DisconnectedBlockTransactions memusage tests early due to unsupported arch");
+    }
+
+    // Use the coinbase transactions from TestChain100Setup as they all have the same size and it
+    // doesn't matter whether these transactions would realistically be in a block together. They
+    // just need distinct txids for this test to work.
+    std::vector<CTransactionRef> block_vtx(m_coinbase_txns);
+
+    // Sanity check the sizes are as expected. If setup_common changes the size of coinbase
+    // transactions, update COINBASE_TX_USAGE.
+    const size_t COINBASE_TX_USAGE{640};
+    BOOST_CHECK_EQUAL(block_vtx.size(), 100);
+    for (const auto& tx : block_vtx) {
+        BOOST_CHECK_EQUAL(RecursiveDynamicUsage(tx), COINBASE_TX_USAGE);
+    }
+
+    // Test DisconnectedBlockTransactions::DynamicMemoryUsage() for 100 transactions
+    const size_t EXPECTED_USAGE_100{77648};
+    {
+        const size_t MAX_MEMUSAGE_100{EXPECTED_USAGE_100};
+        DisconnectedBlockTransactions disconnectpool{MAX_MEMUSAGE_100};
+        auto evicted_txns = disconnectpool.AddTransactionsFromBlock(block_vtx);
+        BOOST_CHECK_EQUAL(evicted_txns.size(), 0);
+        BOOST_CHECK_EQUAL(disconnectpool.DynamicMemoryUsage(), EXPECTED_USAGE_100);
+        disconnectpool.clear();
+    }
+
+    // Test DisconnectedBlockTransactions::DynamicMemoryUsage() for 1 transaction
+    const size_t EXPECTED_USAGE_1{800};
+    {
+        const size_t MAX_MEMUSAGE_100{EXPECTED_USAGE_100};
+        DisconnectedBlockTransactions disconnectpool{MAX_MEMUSAGE_100};
+        auto evicted_txns = disconnectpool.AddTransactionsFromBlock({block_vtx.front()});
+        BOOST_CHECK_EQUAL(evicted_txns.size(), 0);
+        BOOST_CHECK_EQUAL(disconnectpool.DynamicMemoryUsage(), EXPECTED_USAGE_1);
+        disconnectpool.clear();
+    }
+}
+
+BOOST_AUTO_TEST_SUITE_END()