cpp-common/bt2: add C++ graph bindings

Add C++ bindings to create and manipulate graphs.

Create `bt2::Graph` objects with the `bt2::Graph::create()` static
method.

Add components to graphs with the `bt2::Graph::addComponent()`
methods.  There are overloads of this methods for sources, filters and
sinks, and with and without initialization data.

Connect ports with the `bt2::Graph::connectPorts()` method.  The method
does not (yet) provide access to the connection object returned by the
lib.

Run a graph with `bt2::Graph::run()` or `bt2::Graph::run_once()`.

Change-Id: I92719f9dd6e8c77ded20d1bb4a5ddd2a03e8cf0d
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/11806
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>

diff --git a/src/Makefile.am b/src/Makefile.am
index b226abee6b56a36821d2d56a8a160d4693fe4eac..01ae18b5f64040cfe233bc53747314f114b58972 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -120,6 +120,7 @@ cpp_common_libcpp_common_la_SOURCES = \
        cpp-common/bt2/component-class-dev.hpp \
        cpp-common/bt2/component-class.hpp \
        cpp-common/bt2/component-port.hpp \
+       cpp-common/bt2/graph.hpp \
        cpp-common/bt2/exc.hpp \
        cpp-common/bt2/field-class.hpp \
        cpp-common/bt2/field-path.hpp \

diff --git a/src/cpp-common/bt2/graph.hpp b/src/cpp-common/bt2/graph.hpp
new file mode 100644 (file)
index 0000000..787888a
--- /dev/null
+++ b/src/cpp-common/bt2/graph.hpp
@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2024 EfficiOS, Inc.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef BABELTRACE_CPP_COMMON_BT2_GRAPH_HPP
+#define BABELTRACE_CPP_COMMON_BT2_GRAPH_HPP
+
+#include <cstdint>
+
+#include <babeltrace2/babeltrace.h>
+
+#include "borrowed-object.hpp"
+#include "component-class.hpp"
+#include "exc.hpp"
+#include "shared-object.hpp"
+
+namespace bt2 {
+namespace internal {
+
+struct GraphRefFuncs final
+{
+    static void get(const bt_graph * const libObjPtr) noexcept
+    {
+        bt_graph_get_ref(libObjPtr);
+    }
+
+    static void put(const bt_graph * const libObjPtr) noexcept
+    {
+        bt_graph_put_ref(libObjPtr);
+    }
+};
+
+} /* namespace internal */
+
+class Graph final : public BorrowedObject<bt_graph>
+{
+public:
+    using Shared = SharedObject<Graph, bt_graph, internal::GraphRefFuncs>;
+
+    explicit Graph(const LibObjPtr libObjPtr) noexcept : _ThisBorrowedObject {libObjPtr}
+    {
+    }
+
+    static Shared create(const std::uint64_t mipVersion)
+    {
+        const auto libObjPtr = bt_graph_create(mipVersion);
+
+        if (!libObjPtr) {
+            throw MemoryError {};
+        }
+
+        return Shared::createWithoutRef(libObjPtr);
+    }
+
+    ConstSourceComponent addComponent(const ConstSourceComponentClass componentClass,
+                                      const bt2c::CStringView name,
+                                      const OptionalBorrowedObject<ConstMapValue> params = {},
+                                      const LoggingLevel loggingLevel = LoggingLevel::NONE) const
+    {
+        return this->_addComponent<ConstSourceComponent>(
+            componentClass, name, params, static_cast<void *>(nullptr), loggingLevel,
+            bt_graph_add_source_component_with_initialize_method_data);
+    }
+
+    template <typename InitDataT>
+    ConstSourceComponent addComponent(const ConstSourceComponentClass componentClass,
+                                      const bt2c::CStringView name, InitDataT& initData,
+                                      const OptionalBorrowedObject<ConstMapValue> params = {},
+                                      const LoggingLevel loggingLevel = LoggingLevel::NONE) const
+    {
+        return this->_addComponent<ConstSourceComponent>(
+            componentClass, name, params, &initData, loggingLevel,
+            bt_graph_add_source_component_with_initialize_method_data);
+    }
+
+    ConstFilterComponent addComponent(const ConstFilterComponentClass componentClass,
+                                      const bt2c::CStringView name,
+                                      const OptionalBorrowedObject<ConstMapValue> params = {},
+                                      const LoggingLevel loggingLevel = LoggingLevel::NONE) const
+    {
+        return this->_addComponent<ConstFilterComponent>(
+            componentClass, name, params, static_cast<void *>(nullptr), loggingLevel,
+            bt_graph_add_filter_component_with_initialize_method_data);
+    }
+
+    template <typename InitDataT>
+    ConstFilterComponent addComponent(const ConstFilterComponentClass componentClass,
+                                      const bt2c::CStringView name, InitDataT& initData,
+                                      const OptionalBorrowedObject<ConstMapValue> params = {},
+                                      const LoggingLevel loggingLevel = LoggingLevel::NONE) const
+    {
+        return this->_addComponent<ConstFilterComponent>(
+            componentClass, name, params, &initData, loggingLevel,
+            bt_graph_add_filter_component_with_initialize_method_data);
+    }
+
+    ConstSinkComponent addComponent(const ConstSinkComponentClass componentClass,
+                                    const bt2c::CStringView name,
+                                    const OptionalBorrowedObject<ConstMapValue> params = {},
+                                    const LoggingLevel loggingLevel = LoggingLevel::NONE) const
+    {
+        return this->_addComponent<ConstSinkComponent>(
+            componentClass, name, params, static_cast<void *>(nullptr), loggingLevel,
+            bt_graph_add_sink_component_with_initialize_method_data);
+    }
+
+    template <typename InitDataT>
+    ConstSinkComponent addComponent(const ConstSinkComponentClass componentClass,
+                                    const bt2c::CStringView name, InitDataT& initData,
+                                    const OptionalBorrowedObject<ConstMapValue> params = {},
+                                    const LoggingLevel loggingLevel = LoggingLevel::NONE) const
+    {
+        return this->_addComponent<ConstSinkComponent>(
+            componentClass, name, params, &initData, loggingLevel,
+            bt_graph_add_sink_component_with_initialize_method_data);
+    }
+
+    void connectPorts(const ConstOutputPort outputPort, const ConstInputPort inputPort) const
+    {
+        const auto status = bt_graph_connect_ports(this->libObjPtr(), outputPort.libObjPtr(),
+                                                   inputPort.libObjPtr(), nullptr);
+
+        if (status == BT_GRAPH_CONNECT_PORTS_STATUS_ERROR) {
+            throw Error {};
+        } else if (status == BT_GRAPH_CONNECT_PORTS_STATUS_MEMORY_ERROR) {
+            throw MemoryError {};
+        }
+    }
+
+    void runOnce() const
+    {
+        const auto status = bt_graph_run_once(this->libObjPtr());
+
+        if (status == BT_GRAPH_RUN_ONCE_STATUS_ERROR) {
+            throw Error {};
+        } else if (status == BT_GRAPH_RUN_ONCE_STATUS_MEMORY_ERROR) {
+            throw MemoryError {};
+        } else if (status == BT_GRAPH_RUN_ONCE_STATUS_AGAIN) {
+            throw TryAgain {};
+        }
+    }
+
+    void run() const
+    {
+        const auto status = bt_graph_run(this->libObjPtr());
+
+        if (status == BT_GRAPH_RUN_STATUS_ERROR) {
+            throw Error {};
+        } else if (status == BT_GRAPH_RUN_STATUS_MEMORY_ERROR) {
+            throw MemoryError {};
+        } else if (status == BT_GRAPH_RUN_STATUS_AGAIN) {
+            throw TryAgain {};
+        }
+    }
+
+private:
+    template <typename ConstComponentT, typename ConstComponentClassT, typename InitDataT,
+              typename AddFuncT>
+    ConstComponentT
+    _addComponent(const ConstComponentClassT componentClass, const bt2c::CStringView name,
+                  const OptionalBorrowedObject<ConstMapValue> params, InitDataT * const initData,
+                  const LoggingLevel loggingLevel, AddFuncT&& addFunc) const
+    {
+        typename ConstComponentT::LibObjPtr libObjPtr = nullptr;
+
+        const auto status = addFunc(this->libObjPtr(), componentClass.libObjPtr(), name,
+                                    params ? params->libObjPtr() : nullptr,
+                                    const_cast<void *>(static_cast<const void *>(initData)),
+                                    static_cast<bt_logging_level>(loggingLevel), &libObjPtr);
+
+        if (status == BT_GRAPH_ADD_COMPONENT_STATUS_ERROR) {
+            throw Error {};
+        } else if (status == BT_GRAPH_ADD_COMPONENT_STATUS_MEMORY_ERROR) {
+            throw MemoryError {};
+        }
+
+        return wrap(libObjPtr);
+    }
+};
+
+} /* namespace bt2 */
+
+#endif /* BABELTRACE_CPP_COMMON_BT2_GRAPH_HPP */