bmckwm/lmdbal
1
0
Fork 0
forked from blue/lmdbal
Code Pull Requests Activity

tests for transaction RAII behaviour, transaction documentation, minor doc fixes

Browse Source
This commit is contained in:
Blue 2023-10-18 12:44:53 -03:00
parent de741eda21
commit 6b348023bb
Signed by untrusted user: blue
GPG Key ID: 9B203B252A63EE38
8 changed files with 215 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
doc/mainpage.dox
View File

@ -1,12 +1,12 @@
/*! \mainpage Getting Started
*
* Everything begins with a data nase represented by the class LMDBAL::Base.
* Everything begins with a data base represented by the class LMDBAL::Base.
* It repesents a collection of key-value storages that are going to be stored in a sigle data base directory.
* To create a LMDBAL::Base you need to pick up a name of a directory that is going to be created on your machine.
*
* LMDBAL::Base creates or opens existing directory with the given name in the location acquired with
* <a class="el" href="https://doc.qt.io/qt-6/qstandardpaths.html">QStandardPaths</a>::<a class="el" href="https://doc.qt.io/qt-6/qstandardpaths.html#writableLocation">writableLocation</a>(<a class="el" href="https://doc.qt.io/qt-6/qstandardpaths.html">QStandardPaths</a>::<a class="el" href="https://doc.qt.io/qt-6/qstandardpaths.html#StandardLocation-enum">CacheLocation</a>)
* so, the file system destination of your data would depend on the
* so, the file system destination of your data depends on the
* <a class="el" href="https://doc.qt.io/qt-6/qcoreapplication.html">QCoreApplication</a> configuration of your app.
*
* After you have created a LMDBAL::Base you probably want to obtain storage handlers.
@ -15,10 +15,10 @@
* <a class="el" href="https://en.cppreference.com/w/cpp/container/map">std::map</a>
* to speed up the access.
*
* You can obtain handlers by calling LMDBAL::Base::addStorage(const std::string&, bool) or LMDBAL::Base::addCache(const std::string& name).
* You can obtain handlers by calling LMDBAL::Base::addStorage() or LMDBAL::Base::addCache().
* Note that the handlers still belong to the LMDBAL::Base and it's his responsibility to destroy them.
* You are not obliged to save those handlers,
* you can obtain them at any time later using methods LMDBAL::Base::getStorage(const std::string&) or LMDBAL::Base::getCache(const std::string&)
* you can obtain them at any time later using methods LMDBAL::Base::getStorage() or LMDBAL::Base::getCache()
* calling them with the same template types and names.
*
* After you have added all the storages you wanted it's time to open the data base with LMDBAL::Base::open().

18
src/base.cpp
View File

@ -216,6 +216,14 @@ void LMDBAL::Base::drop() {
/**
* \brief Begins read-only transaction
*
* This is the legitimate way to retrieve LMDBAL::Transaction.
* LMDBAL::Transaction is considered runnig right after creation by this method.
* You can terminate transaction manually calling LMDBAL::Transaction::terminate
* but it's not required, because transaction will be terminated automatically
* (if it was not terminated manually) upon the call of the destructor.
*
* You can not use termitated transaction any more.
*
* \returns read-only transaction
*
* \exception LMDBAL::Closed - thrown if the database is closed
@ -229,6 +237,16 @@ LMDBAL::Transaction LMDBAL::Base::beginReadOnlyTransaction() const {
/**
* \brief Begins writable transaction
*
* This is the legitimate way to retrieve LMDBAL::WriteTransaction.
* LMDBAL::WriteTransaction is considered runnig right after creation by this method.
* You can commit all the changes made by this transaction calling LMDBAL::WriteTransaction::commit.
* You can cancel any changes made bu this transaction calling LMDBAL::WriteTransaction::abort
* (or LMDBAL::Transaction::terminate which LMDBAL::WriteTransaction inherits),
* but it's not required, because transaction will be aborted automatically
* (if it was not terminated (committed <b>OR</b> aborted) manually) upon the call of the destructor.
*
* You can not use termitated transaction any more.
*
* \returns writable transaction
*
* \exception LMDBAL::Closed - thrown if the database is closed

2
src/cursor.hpp
View File

@ -186,7 +186,7 @@ void LMDBAL::Cursor<K, V>::renew () const {
*
* This function does nothing if the cursor is closed
*
* \param[in] txn a transaction you wish this cursor to be bound to
* \param[in] transaction - a transaction you wish this cursor to be bound to
*
* \exception LMDBAL::Closed thrown if you try to renew the cursor on a closed database
* \exception LMDBAL::Unknown thrown if there was a problem renewing the cursor by lmdb

6
src/storage.cpp
View File

@ -439,4 +439,10 @@ void LMDBAL::iStorage::transactionCommited(LMDBAL::TransactionID txn) {
void LMDBAL::iStorage::transactionAborted(LMDBAL::TransactionID txn) const {
UNUSED(txn);}
/**
* \brief A method where database additionally handles drop
*
* It's a protected method that is called to optimise drop process
* after the transaction is commited. Used just for optimisations.
*/
void LMDBAL::iStorage::handleDrop() {}

83
src/transaction.cpp
View File

@ -1,17 +1,42 @@
#include "transaction.h"
/**
* \class LMDBAL::Transaction
* \brief Public read only transaction
*
* This class provides read only transactions you can use
* to speed to your queries keeping them thread safe.
* LMDBAL::Transaction is <b>NOT COPYABLE</b> but <b>MOVABLE</b>.
* Transaction can be in one of two states: active or terminated.
* The way to receive an active LMDBAL::Transaction is to call LMDBAL::Base::beginReadOnlyTransaction.
*
* Active transactions become terminated upon the call of LMDBAL::Transaction::terminate.
* Active transactions automaticaly terminate themselves upon destruction.
*
* You <b>CAN NOT</b> use inactive transactions for any query.
*/
/**
* \brief Constructs inactive transaction
*/
LMDBAL::Transaction::Transaction():
txn(nullptr),
active(false),
parent(nullptr)
{}
/**
* \brief Constructs an active transaction
*/
LMDBAL::Transaction::Transaction(TransactionID txn, const Base* parent) :
txn(txn),
active(true),
parent(parent)
{}
/**
* \brief Moves transaction to a new object
*/
LMDBAL::Transaction::Transaction(Transaction&& other):
txn(other.txn),
active(other.active),
@ -20,10 +45,16 @@ LMDBAL::Transaction::Transaction(Transaction&& other):
other.active = false;
}
/**
* \brief Destroys transaction
*/
LMDBAL::Transaction::~Transaction() {
terminate();
}
/**
* \brief Move-assigns transaction to the new object
*/
LMDBAL::Transaction& LMDBAL::Transaction::operator=(Transaction&& other) {
terminate();
@ -36,6 +67,11 @@ LMDBAL::Transaction& LMDBAL::Transaction::operator=(Transaction&& other) {
return *this;
}
/**
* \brief Terminates transaction if it was active
*
* Transaction becomes terminated after calling this method
*/
void LMDBAL::Transaction::terminate() {
if (active) {
parent->abortTransaction(txn);
@ -43,26 +79,73 @@ void LMDBAL::Transaction::terminate() {
}
}
/**
* \brief Returns transaction states
*
* \returns true if the transaction is active, false otherwise
*/
bool LMDBAL::Transaction::isActive() const {
return active; //todo may be it's better if I query it from DB?
}
/**
* \class LMDBAL::WriteTransaction
* \brief Public writable transaction
*
* This class provides writable transactions you can use
* to speed to your queries and modifications keeping them thread safe.
* LMDBAL::WriteTransaction is <b>NOT COPYABLE</b> but <b>MOVABLE</b>.
* Transaction can be in one of two states: active or terminated.
* The way to receive an active LMDBAL::WriteTransaction is to call LMDBAL::Base::beginTransaction.
* You can use LMDBAL::WriteTransaction for everything instead of LMDBAL::Transaction
*
* Active transactions become terminated upon the call of
* LMDBAL::WriteTransaction::abort or LMDBAL::WriteTransaction::commit.
* Calling LMDBAL::Transaction::terminate on LMDBAL::WriteTransaction
* is exactly the same as calling LMDBAL::WriteTransaction::abort.
*
* Active transactions automaticaly terminate themselves upon destruction.
* <b>For LMDBAL::WriteTransaction default behaviour upon destruction is to abort.</b>
*
* You <b>CAN NOT</b> use inactive transactions for any query.
*/
/**
* \brief Constructs active write transaction
*/
LMDBAL::WriteTransaction::WriteTransaction(TransactionID txn, Base* parent):
Transaction(txn, parent)
{}
/**
* \brief Constructs inactive write transaction
*/
LMDBAL::WriteTransaction::WriteTransaction():
Transaction()
{}
/**
* \brief Moves transaction to the new object
*/
LMDBAL::WriteTransaction::WriteTransaction(WriteTransaction&& other):
Transaction(std::move(other))
{}
/**
* \brief Aborts transaction cancelling all changes
*
* Transaction becomes terminated after calling this method
*/
void LMDBAL::WriteTransaction::abort() {
terminate();
}
/**
* \brief Commits transaction submitting all changes
*
* Transaction becomes terminated after calling this method
*/
void LMDBAL::WriteTransaction::commit() {
if (active) {
const_cast<Base*>(parent)->commitTransaction(txn);

6
src/transaction.h
View File

@ -23,9 +23,9 @@ protected:
Transaction(TransactionID txn, const Base* parent);
protected:
TransactionID txn;
bool active;
const Base* parent;
TransactionID txn; /**<\brief Transaction inner handler*/
bool active; /**<\brief Transaction state*/
const Base* parent; /**<\brief Pointer to the database this transaction belongs to*/
};
class WriteTransaction : public Transaction {

48
test/cachetransaction.cpp
View File

@ -229,3 +229,51 @@ TEST_F(CacheTransactionsTest, ConcurentModification) {
EXPECT_EQ(c1->getRecord(5), -46);
}
TEST_F(CacheTransactionsTest, RAIIResourceFree) {
EXPECT_EQ(db->ready(), true);
int pid = fork();
if (pid == 0) { // I am the child
std::cout << "beggining child transaction" << std::endl;
LMDBAL::WriteTransaction 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 parent transaction value" << std::endl;
EXPECT_FALSE(c1->checkRecord(221, txn2));
std::cout << "performing modification from the child thread" << std::endl;
c1->addRecord(221, 14, txn2);
std::cout << "commiting child transaction" << std::endl;
txn2.commit();
std::cout << "quitting child thread, letting child transaction be destroyed after commit" << std::endl;
exit(testing::Test::HasFailure());
} else { // I am the parent
std::cout << "beggining parent transaction" << std::endl;
{
LMDBAL::WriteTransaction txn1 = db->beginTransaction();
std::cout << "putting parent thread to sleep for 5 ms" << std::endl;
usleep(5);
std::cout << "parent thread woke up" << std::endl;
std::cout << "adding value from parent thread" << std::endl;
c1->addRecord(221, 320, txn1);
std::cout << "checking value from parent thread using transaction" << std::endl;
EXPECT_EQ(c1->getRecord(221, txn1), 320);
std::cout << "checking value independently from parent thread" << std::endl;
EXPECT_FALSE(c1->checkRecord(221));
std::cout << "implicitly aborting transaction by leaving the scope" << std::endl;
}
std::cout << "child thread should resume after this line" << std::endl;
ASSERT_EQ(0, waitForChildFork(pid)); //child process should have no problems
}
std::cout << "checking the final result" << std::endl;
EXPECT_EQ(c1->getRecord(221), 14);
}

56
test/storagetransaction.cpp
View File

@ -14,7 +14,7 @@ protected:
~StorageTransactionsTest() {}
int waitForChildFork(int pid) {
int waitForChildFork(int pid) {
int status;
if (0 > waitpid(pid, &status, 0)) {
std::cerr << "[----------] Waitpid error!" << std::endl;
@ -22,9 +22,9 @@ protected:
}
if (WIFEXITED(status)) {
const int exit_status = WEXITSTATUS(status);
if (exit_status != 0) {
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;
@ -224,6 +224,54 @@ TEST_F(StorageTransactionsTest, ConcurentModification) {
ASSERT_EQ(0, waitForChildFork(pid)); //child process should have no problems
}
std::cout << "checking final result" << std::endl;
std::cout << "checking the final result" << std::endl;
EXPECT_EQ(t1->getRecord(5), -46);
}
TEST_F(StorageTransactionsTest, RAIIResourceFree) {
EXPECT_EQ(db->ready(), true);
int pid = fork();
if (pid == 0) { // I am the child
std::cout << "beggining child transaction" << std::endl;
LMDBAL::WriteTransaction 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 parent transaction value" << std::endl;
EXPECT_FALSE(t1->checkRecord(221, txn2));
std::cout << "performing modification from the child thread" << std::endl;
t1->addRecord(221, 14, txn2);
std::cout << "commiting child transaction" << std::endl;
txn2.commit();
std::cout << "quitting child thread, letting child transaction be destroyed after commit" << std::endl;
exit(testing::Test::HasFailure());
} else { // I am the parent
std::cout << "beggining parent transaction" << std::endl;
{
LMDBAL::WriteTransaction txn1 = db->beginTransaction();
std::cout << "putting parent thread to sleep for 5 ms" << std::endl;
usleep(5);
std::cout << "parent thread woke up" << std::endl;
std::cout << "adding value from parent thread" << std::endl;
t1->addRecord(221, 320, txn1);
std::cout << "checking value from parent thread using transaction" << std::endl;
EXPECT_EQ(t1->getRecord(221, txn1), 320);
std::cout << "checking value independently from parent thread" << std::endl;
EXPECT_FALSE(t1->checkRecord(221));
std::cout << "implicitly aborting transaction by leaving the scope" << std::endl;
}
std::cout << "child thread should resume after this line" << std::endl;
ASSERT_EQ(0, waitForChildFork(pid)); //child process should have no problems
}
std::cout << "checking the final result" << std::endl;
EXPECT_EQ(t1->getRecord(221), 14);
}