From 150a0b0da97a433242cc2f1d371468eee4749ef3 Mon Sep 17 00:00:00 2001
From: blue <blue@macaw.me>
Date: Tue, 4 Apr 2023 19:14:25 +0300
Subject: [PATCH] better transaction tests

---
 test/storagetransaction.cpp | 118 ++++++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)

diff --git a/test/storagetransaction.cpp b/test/storagetransaction.cpp
index e756931..eac7ac2 100644
--- a/test/storagetransaction.cpp
+++ b/test/storagetransaction.cpp
@@ -1,5 +1,7 @@
 #include <gtest/gtest.h>
 
+#include <iostream>
+
 #include "base.h"
 #include "storage.h"
 
@@ -12,6 +14,24 @@ protected:
 
     ~StorageTransactionsTest() {}
 
+    int  waitForChildFork(int pid) {
+        int status;
+        if (0 > waitpid(pid, &status, 0)) {
+            std::cerr << "[----------]  Waitpid error!" << std::endl;
+            return (-1);
+        }
+        if (WIFEXITED(status)) {
+            const int exit_status = WEXITSTATUS(status);
+            if (exit_status != 0) {
+                std::cerr << "[----------]  Non-zero exit status " << exit_status << " from test!" << std::endl;
+            }
+            return exit_status;
+        } else {
+            std::cerr << "[----------]  Non-normal exit from child!" << std::endl;
+            return (-2);
+        }
+    }
+
     static void SetUpTestSuite() {
         if (db == nullptr) {
             db = new LMDBAL::Base("storageTrnansactionsTestBase");
@@ -20,6 +40,7 @@ protected:
         }
 
         db->open();
+        db->drop();
     }
 
     static void TearDownTestSuite() {
@@ -109,3 +130,100 @@ TEST_F(StorageTransactionsTest, Reading) {
 
     db->abortTransaction(txn);
 }
+
+TEST_F(StorageTransactionsTest, ConcurentReading) {
+    EXPECT_EQ(db->ready(), true);
+
+    LMDBAL::SizeType size = t1->count();
+    LMDBAL::TransactionID txn = db->beginTransaction();
+    EXPECT_EQ(t1->getRecord(5, txn), 13);
+    EXPECT_EQ(t1->getRecord(5), 13);
+
+    t1->removeRecord(5, txn);
+
+    EXPECT_FALSE(t1->checkRecord(5, txn));
+    EXPECT_EQ(t1->getRecord(5), 13);
+
+    t1->addRecord(5, 571, txn);
+    EXPECT_EQ(t1->getRecord(5, txn), 571);
+    EXPECT_EQ(t1->getRecord(5), 13);
+
+    t1->forceRecord(5, -472, txn);
+    EXPECT_EQ(t1->getRecord(5, txn), -472);
+    EXPECT_EQ(t1->getRecord(5), 13);
+
+    t1->replaceAll({
+        {1, 75}
+    }, txn);
+    EXPECT_FALSE(t1->checkRecord(5, txn));
+    EXPECT_EQ(t1->getRecord(5), 13);
+    EXPECT_EQ(t1->count(txn), 1);
+    EXPECT_EQ(t1->count(), size);
+
+    db->commitTransaction(txn);
+
+    EXPECT_FALSE(t1->checkRecord(5));
+    EXPECT_EQ(t1->count(), 1);
+}
+
+TEST_F(StorageTransactionsTest, ConcurentModification) {
+    EXPECT_EQ(db->ready(), true);
+
+    //if you start one writable transaction after another
+    //in a single thread like so:
+    //
+    //LMDBAL::TransactionID txn1 = db->beginTransaction();
+    //LMDBAL::TransactionID txn2 = db->beginTransaction();
+    //
+    //the execution should block on the second transaction
+    //so this test should preform in a sequence
+    //first the parent, then the child
+
+    int pid = fork();
+    if (pid == 0) {  // I am the child
+        std::cout << "beggining second transaction" << std::endl;
+        LMDBAL::TransactionID txn2 = db->beginTransaction();        //<--- this is where the execution should pause
+                                                                    //and wait for the first transaction to get finished
+        std::cout << "checking result of the first transaction value" << std::endl;
+        EXPECT_EQ(t1->getRecord(5, txn2), 812);
+
+        std::cout << "forcing second transaction value" << std::endl;
+        t1->forceRecord(5, -46, txn2);
+
+        std::cout << "checking second transaction value" << std::endl;
+        EXPECT_EQ(t1->getRecord(5, txn2), -46);
+
+        std::cout << "checking value independently" << std::endl;
+        EXPECT_EQ(t1->getRecord(5), 812);
+
+        std::cout << "commiting second transaction" << std::endl;
+        db->commitTransaction(txn2);
+
+        std::cout << "quitting child thread" << std::endl;
+        exit(testing::Test::HasFailure());
+    } else {  // I am the parent
+        std::cout << "beggining first transaction" << std::endl;
+        LMDBAL::TransactionID txn1 = db->beginTransaction();
+
+        std::cout << "putting parent thread to sleep for 5 ms" << std::endl;
+        usleep(5);
+
+        std::cout << "adding first transaction value" << std::endl;
+        t1->addRecord(5, 812, txn1);
+
+        std::cout << "checking first transaction value" << std::endl;
+        EXPECT_EQ(t1->getRecord(5, txn1), 812);
+
+        std::cout << "checking value independently" << std::endl;
+        EXPECT_FALSE(t1->checkRecord(5));
+
+        std::cout << "commiting first transaction" << std::endl;
+        db->commitTransaction(txn1);
+
+        std::cout << "waiting for the other thread to finish" << std::endl;
+        ASSERT_EQ(0, waitForChildFork(pid));    //child process should have no problems
+    }
+
+    std::cout << "checking final result" << std::endl;
+    EXPECT_EQ(t1->getRecord(5), -46);
+}