Coroutines!

CMakeLists.txt

@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: MIT
 
 cmake_minimum_required(VERSION 3.16)
-project(libasql VERSION 0.91.0 LANGUAGES CXX)
+project(libasql VERSION 0.92.0 LANGUAGES CXX)
 
 include(GNUInstallDirs)
 
@@ -22,7 +22,7 @@ set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules)
 # to always look for includes there:
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
-set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD 23)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 

demos/async1/CMakeLists.txt

@@ -8,6 +8,13 @@ target_link_libraries(async1
     Qt::Core
 )
 
+add_executable(coroutines coroutines.cpp)
+target_link_libraries(coroutines
+    ASql::Core
+    ASql::Pg
+    Qt::Core
+)
+
 add_executable(transactions transactions.cpp)
 target_link_libraries(transactions
     ASql::Core

demos/async1/coroutines.cpp

@@ -0,0 +1,290 @@
+/*
+ * SPDX-FileCopyrightText: (C) 2020 Daniel Nicoletti <[email protected]>
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "../../src/acache.h"
+#include "../../src/acoroexpected.h"
+#include "../../src/adatabase.h"
+#include "../../src/amigrations.h"
+#include "../../src/apg.h"
+#include "../../src/apool.h"
+#include "../../src/aresult.h"
+#include "../../src/atransaction.h"
+
+#include <thread>
+
+#include <QCoreApplication>
+#include <QDateTime>
+#include <QElapsedTimer>
+#include <QJsonArray>
+#include <QJsonObject>
+#include <QLoggingCategory>
+#include <QScopeGuard>
+#include <QTimer>
+
+using namespace ASql;
+using namespace Qt::StringLiterals;
+
+int main(int argc, char *argv[])
+{
+    QCoreApplication app(argc, argv);
+
+    APool::create(APg::factory(u"postgres:///?target_session_attrs=read-write"_s));
+    APool::setMaxIdleConnections(10);
+
+    auto db = APool::database();
+
+    auto counter = std::make_shared<int>(0);
+    QElapsedTimer t;
+    if (false) {
+        t.start();
+        for (int i = 0; i < 100'000; ++i) {
+            db.exec(u"SELECT 1", nullptr, [counter, &t](AResult &result) {
+                if (*counter == 999) {
+                    qDebug() << "lambda" << t.elapsed();
+                }
+                *counter = *counter + 1;
+            });
+        }
+
+        *counter = 0;
+        t.start();
+        auto bench = [&t, counter, &db]() -> ACoroTerminator {
+            auto counter = std::make_shared<int>();
+            for (int i = 0; i < 100'000; ++i) {
+                auto result = co_await db.coExec(u"SELECT 1", nullptr);
+                // qDebug() << "coroutine" << *counter << t.elapsed();
+                if (*counter == 999) {
+                    qDebug() << "coroutine" << *counter << t.elapsed();
+                }
+                *counter = *counter + 1;
+            }
+        };
+        bench();
+    }
+
+    if (false) {
+        auto callEx = []() -> ACoroTerminator {
+            qDebug() << "coro started";
+
+            auto db = APool::database();
+            db.exec(u"SELECT 2", nullptr, [](AResult &result) {
+                if (result.error()) {
+                    qDebug() << "Error" << result.errorString();
+                } else {
+                    qDebug() << "1s loop" << result.toHash();
+                }
+            });
+
+            auto obj = new QObject;
+            QTimer::singleShot(500, obj, [obj] {
+                qDebug() << "Delete Obj";
+                delete obj;
+            });
+
+            {
+                auto result = co_await db.coExec(u8"SELECT now(), pg_sleep(3)", obj);
+                if (result.has_value()) {
+                    qDebug() << "coro result has value" << result->toJsonObject();
+                } else {
+                    qDebug() << "coro result error" << result.error();
+                }
+                obj->setProperty("crash", true);
+            }
+
+            {
+                auto result = co_await db.coExec(u8"SELECT now(), pg_sleep(1)", nullptr);
+                if (result.has_value()) {
+                    qDebug() << "coro result has value" << result->toJsonObject();
+                } else {
+                    qDebug() << "coro result error" << result.error();
+                }
+                obj->setProperty("crash", true);
+            }
+        };
+
+        callEx();
+    }
+
+    if (false) {
+        auto callTransaction = []() -> ACoroTerminator {
+            auto _ = qScopeGuard([] { qDebug() << "coro exited"; });
+            qDebug() << "coro started";
+
+            auto db = co_await APool::coDatabase();
+
+            auto transaction = co_await db->coBegin();
+            qDebug() << "transaction started";
+
+            auto result = co_await db->coExec(u8"SELECT now()");
+            if (result.has_value()) {
+                qDebug() << "coro result has value" << result->toJsonObject();
+            } else {
+                qDebug() << "coro result error" << result.error();
+            }
+
+            auto result2 = co_await db->coExec(u8"SELECT now()");
+            if (result2.has_value()) {
+                qDebug() << "coro result2 has value" << result2->toJsonObject();
+            } else {
+                qDebug() << "coro result2 error" << result2.error();
+            }
+
+            auto commit = co_await transaction->coCommit();
+            if (commit.has_value()) {
+                qDebug() << "coro commit has value" << commit->toJsonObject();
+            } else {
+                qDebug() << "coro commit error" << commit.error();
+            }
+        };
+
+        callTransaction();
+    }
+
+    if (false) {
+        auto cache = new ACache;
+        cache->setDatabase(db);
+
+        auto callCache = [cache]() -> ACoroTerminator {
+            auto _ = qScopeGuard([] { qDebug() << "coro cache exited"; });
+            qDebug() << "coro cache started";
+
+            auto result = co_await cache->coExec(u"SELECT now(), pg_sleep(1)"_s, nullptr);
+            if (result.has_value()) {
+                qDebug() << "coro result has value" << result->toJsonObject();
+            } else {
+                qDebug() << "coro result error" << result.error();
+            }
+
+            auto resultCached = co_await cache->coExec(u"SELECT now(), pg_sleep(1)"_s, nullptr);
+            if (resultCached.has_value()) {
+                qDebug() << "coro resultCached has value" << resultCached->toJsonObject();
+            } else {
+                qDebug() << "coro resultCached error" << resultCached.error();
+            }
+        };
+
+        callCache();
+    }
+
+    if (false) {
+        auto callInvalid = []() -> ACoroTerminator {
+            auto _ = qScopeGuard([] { qDebug() << "coro db invalid exited"; });
+            qDebug() << "coro db invalid started";
+
+            ADatabase db;
+            auto result = co_await db.coExec(u"SELECT now()"_s, nullptr);
+            if (result.has_value()) {
+                qDebug() << "coro result has value" << result->toJsonObject();
+            } else {
+                qDebug() << "coro result error" << result.error();
+            }
+        };
+
+        callInvalid();
+    }
+
+    if (true) {
+        auto callOuter = []() -> ACoroTerminator {
+            auto _ = qScopeGuard([] { qDebug() << "coro outer exited"; });
+            qDebug() << "coro outer started";
+
+            auto callInner = []() -> ACoroTerminator {
+                auto _ = qScopeGuard([] { qDebug() << "coro inner exited"; });
+                qDebug() << "coro inner started";
+
+                auto db = co_await APool::coDatabase();
+                if (!db) {
+                    qDebug() << "coro db error" << db.error();
+                    co_return;
+                }
+
+                auto result = co_await db->coExec(u"SELECT now()"_s, nullptr);
+                if (result.has_value()) {
+                    qDebug() << "coro result has value" << result->toJsonObject();
+                } else {
+                    qDebug() << "coro result error" << result.error();
+                }
+            };
+
+            // Cannot be awaited :)
+            callInner();
+            co_return;
+        };
+
+        callOuter();
+    }
+
+    if (false) {
+        auto callPool = []() -> ACoroTerminator {
+            auto _ = qScopeGuard([] { qDebug() << "coro pool exited"; });
+            qDebug() << "coro pool started";
+
+            auto db = co_await APool::coDatabase();
+            if (db.has_value()) {
+                qDebug() << "coro pool has value" << db->isOpen();
+            } else {
+                qDebug() << "coro pool error" << db.error();
+            }
+
+            auto result = co_await db->coExec(u"SELECT now(), pg_sleep(1)"_s, nullptr);
+            if (result.has_value()) {
+                qDebug() << "coro result has value" << result->toJsonObject();
+            } else {
+                qDebug() << "coro result error" << result.error();
+            }
+        };
+
+        callPool();
+    }
+
+    if (false) {
+        auto callTerminatorEarly = []() -> ACoroTerminator {
+            auto _ = qScopeGuard([] { qDebug() << "coro exited"; });
+            qDebug() << "coro started";
+
+            auto obj = new QObject;
+            QTimer::singleShot(500, obj, [obj] {
+                qDebug() << "Delete Obj";
+                delete obj;
+            });
+            co_yield obj; // so that this promise is destroyed if this object is destroyed
+
+            auto db = co_await APool::coDatabase();
+
+            auto result = co_await db->coExec(u8"SELECT now(), pg_sleep(2)", obj);
+            if (result.has_value()) {
+                qDebug() << "coro result has value" << result->toJsonObject();
+            } else {
+                qDebug() << "coro result error" << result.error();
+            }
+        };
+        callTerminatorEarly();
+
+        auto callTerminatorLater = []() -> ACoroTerminator {
+            auto _ = qScopeGuard([] { qDebug() << "coro exited"; });
+            qDebug() << "coro started";
+
+            auto obj = new QObject;
+            QTimer::singleShot(2000, obj, [obj] {
+                qDebug() << "Delete Obj later";
+                delete obj;
+            });
+            co_yield obj; // so that this promise is destroyed if this object is destroyed
+
+            auto db = co_await APool::coDatabase();
+
+            auto result = co_await db->coExec(u8"SELECT now()", obj);
+            if (result.has_value()) {
+                qDebug() << "coro result has value" << result->toJsonObject();
+            } else {
+                qDebug() << "coro result error" << result.error();
+            }
+        };
+
+        callTerminatorLater();
+    }
+
+    app.exec();
+}

src/CMakeLists.txt

@@ -14,14 +14,15 @@ set(asql_SRC
     acache.cpp
     apreparedquery.cpp
     apreparedquery.h
+    acoroexpected.cpp
 )
 
 set(asql_HEADERS
     adatabase.h
     apreparedquery.h
     apool.h
     atransaction.h
-
+    acoroexpected.h
     aresult.h
     adriver.h
     adriverfactory.h

src/acache.cpp

@@ -5,6 +5,7 @@
 
 #include "acache.h"
 
+#include "acoroexpected.h"
 #include "adatabase.h"
 #include "apool.h"
 #include "aresult.h"
@@ -249,6 +250,38 @@ int ACache::size() const
     return d->cache.size();
 }
 
+AExpectedResult ACache::coExec(QStringView query, QObject *receiver)
+{
+    AExpectedResult coro(receiver);
+    execExpiring(query, -1ms, {}, receiver, coro.callback);
+    return coro;
+}
+
+AExpectedResult ACache::coExec(QStringView query, const QVariantList &args, QObject *receiver)
+{
+    AExpectedResult coro(receiver);
+    execExpiring(query, -1ms, args, receiver, coro.callback);
+    return coro;
+}
+
+AExpectedResult
+    ACache::coExecExpiring(QStringView query, std::chrono::milliseconds maxAge, QObject *receiver)
+{
+    AExpectedResult coro(receiver);
+    execExpiring(query, maxAge, {}, receiver, coro.callback);
+    return coro;
+}
+
+AExpectedResult ACache::coExecExpiring(QStringView query,
+                                       std::chrono::milliseconds maxAge,
+                                       const QVariantList &args,
+                                       QObject *receiver)
+{
+    AExpectedResult coro(receiver);
+    execExpiring(query, maxAge, args, receiver, coro.callback);
+    return coro;
+}
+
 void ACache::exec(QStringView query, QObject *receiver, AResultFn cb)
 {
     execExpiring(query, -1ms, {}, receiver, cb);