Merge pull request #12846 from aabadie/pr/pkg/flatbuffers

pkg: add support for FlatBuffers serialization library

dist/tools/flatc/.gitignore

@@ -0,0 +1,2 @@
+flatc
+bin

dist/tools/flatc/Makefile

@@ -0,0 +1,28 @@
+PKG_NAME=flatc
+PKG_URL=https://github.com/google/flatbuffers
+PKG_VERSION=9e7e8cbe9f675123dd41b7c62868acad39188cae
+PKG_LICENSE=Apache2.0
+
+PKG_BUILDDIR=$(CURDIR)/bin
+
+# manually set some RIOT env vars, so this Makefile can be called stand-alone
+RIOTBASE ?= $(CURDIR)/../../..
+RIOTTOOLS ?= $(CURDIR)/..
+GITCACHE ?= $(RIOTTOOLS)/git/git-cache
+
+CMAKE_OPTIONS = \
+    -DCMAKE_BUILD_TYPE=Release       \
+    -DFLATBUFFERS_BUILD_TESTS=OFF    \
+    -DFLATBUFFERS_BUILD_FLATHASH=OFF \
+    -DFLATBUFFERS_BUILD_FLATLIB=OFF  \
+    #
+
+include $(RIOTBASE)/pkg/pkg.mk
+
+all:
+	@cd "$(PKG_BUILDDIR)" && env -i PATH="$(PATH)" cmake -G "Unix Makefiles" $(CMAKE_OPTIONS) .
+	"$(MAKE)" -C "$(PKG_BUILDDIR)"
+	@mv "$(PKG_BUILDDIR)"/flatc $(CURDIR)/flatc
+
+distclean::
+	@rm -f $(CURDIR)/flatc

makefiles/tools/targets.inc.mk

@@ -34,3 +34,8 @@ $(RIOTTOOLS)/setsid/setsid: $(RIOTTOOLS)/setsid/Makefile
 	@echo "[INFO] setsid binary not found - building it from source now"
 	@make -C $(RIOTTOOLS)/setsid
 	@echo "[INFO] setsid binary successfully built!"
+
+$(RIOTTOOLS)/flatc/flatc: $(RIOTTOOLS)/flatc/Makefile
+	@echo "[INFO] flatc binary not found - building it from source now"
+	make -C $(RIOTTOOLS)/flatc
+	@echo "[INFO] flatc binary successfully built!"

pkg/flatbuffers/Makefile

@@ -0,0 +1,9 @@
+PKG_NAME=flatbuffers
+PKG_URL=https://github.com/google/flatbuffers
+PKG_VERSION=v1.11.0
+PKG_LICENSE=Apache2.0
+
+include $(RIOTBASE)/pkg/pkg.mk
+
+all:
+	"$(MAKE)" -C $(PKG_BUILDDIR)/src -f $(CURDIR)/Makefile.$(PKG_NAME)

pkg/flatbuffers/Makefile.dep

@@ -0,0 +1 @@
+USEMODULE += cpp11-compat

pkg/flatbuffers/Makefile.flatbuffers

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+MODULE = flatbuffers
+
+NO_AUTO_SRC := 1
+
+include $(RIOTBASE)/Makefile.base

pkg/flatbuffers/Makefile.include

@@ -0,0 +1,11 @@
+INCLUDES += -I$(PKGDIRBASE)/flatbuffers/include
+
+FLATC ?= flatc
+
+ifneq (0,$(shell which flatc 2>&1 > /dev/null ; echo $$?))
+  FLATC = $(RIOTTOOLS)/flatc/flatc
+  $(call target-export-variables,all,FLATC)
+endif
+
+# This module requires cpp11 support
+CXXEXFLAGS += -std=c++11

pkg/flatbuffers/doc.txt

@@ -0,0 +1,8 @@
+/**
+ * @defgroup pkg_flatbuffers FlatBuffers
+ * @ingroup  pkg
+ * @ingroup  sys_serialization
+ * @brief    FlatBuffers: Memory Efficient Serialization Library
+ *
+ * @see      http://google.github.io/flatbuffers/
+ */

tests/pkg_flatbuffers/.gitignore

@@ -0,0 +1 @@
+monster_generated.h

tests/pkg_flatbuffers/Makefile

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+include ../Makefile.tests_common
+
+USEPKG += flatbuffers
+
+# Skip warning raised when building monster_generated.h
+CXXEXFLAGS += -Wno-type-limits
+
+BUILDDEPS += monster_generated.h
+
+include $(RIOTBASE)/Makefile.include
+
+monster_generated.h: $(FLATC)
+	$(Q)$(FLATC) --cpp $(CURDIR)/monster.fbs

tests/pkg_flatbuffers/Makefile.ci

@@ -0,0 +1,3 @@
+BOARD_INSUFFICIENT_MEMORY := \
+    stm32f030f4-demo \
+    #

tests/pkg_flatbuffers/README.md

@@ -0,0 +1,26 @@
+FlatBuffer sample application
+=============================
+
+This application shows how to use the FlatBuffer library from Google for
+serializing/deserializing a runtime C++ object to/from a binary buffer.
+
+The application is
+[taken as is from the upstream repository](https://github.com/google/flatbuffers/blob/master/samples/sample_binary.cpp).
+
+More details are available on
+[the FlatBuffers website](http://google.github.io/flatbuffers/).
+
+Usage
+-----
+
+Simply flash and run the application on the board of your choice using:
+
+    make BOARD=<board of your choice> -C tests/pkg_flatbuffers flash term
+
+Expected result
+---------------
+
+The application creates an object, serialize it in a FlatBuffer and after
+reloading the serialized object it displays:
+
+    "The FlatBuffer was successfully created and verified!"

tests/pkg_flatbuffers/main.cpp

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2015 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include "monster_generated.h"  // Already includes "flatbuffers/flatbuffers.h".
+
+using namespace MyGame::Sample;
+
+// Example how to use FlatBuffers to create and read binary buffers.
+
+int main(int /*argc*/, const char * /*argv*/[]) {
+  // Build up a serialized buffer algorithmically:
+  flatbuffers::FlatBufferBuilder builder;
+
+  // First, lets serialize some weapons for the Monster: A 'sword' and an 'axe'.
+  auto weapon_one_name = builder.CreateString("Sword");
+  short weapon_one_damage = 3;
+
+  auto weapon_two_name = builder.CreateString("Axe");
+  short weapon_two_damage = 5;
+
+  // Use the `CreateWeapon` shortcut to create Weapons with all fields set.
+  auto sword = CreateWeapon(builder, weapon_one_name, weapon_one_damage);
+  auto axe = CreateWeapon(builder, weapon_two_name, weapon_two_damage);
+
+  // Create a FlatBuffer's `vector` from the `std::vector`.
+  std::vector<flatbuffers::Offset<Weapon>> weapons_vector;
+  weapons_vector.push_back(sword);
+  weapons_vector.push_back(axe);
+  auto weapons = builder.CreateVector(weapons_vector);
+
+  // Second, serialize the rest of the objects needed by the Monster.
+  auto position = Vec3(1.0f, 2.0f, 3.0f);
+
+  auto name = builder.CreateString("MyMonster");
+
+  unsigned char inv_data[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
+  auto inventory = builder.CreateVector(inv_data, 10);
+
+  // Shortcut for creating monster with all fields set:
+  auto orc = CreateMonster(builder, &position, 150, 80, name, inventory,
+                           Color_Red, weapons, Equipment_Weapon, axe.Union());
+
+  builder.Finish(orc);  // Serialize the root of the object.
+
+  // We now have a FlatBuffer we can store on disk or send over a network.
+
+  // ** file/network code goes here :) **
+  // access builder.GetBufferPointer() for builder.GetSize() bytes
+
+  // Instead, we're going to access it right away (as if we just received it).
+
+  // Get access to the root:
+  auto monster = GetMonster(builder.GetBufferPointer());
+
+  // Get and test some scalar types from the FlatBuffer.
+  assert(monster->hp() == 80);
+  assert(monster->mana() == 150);  // default
+  assert(monster->name()->str() == "MyMonster");
+
+  // Get and test a field of the FlatBuffer's `struct`.
+  auto pos = monster->pos();
+  assert(pos);
+  assert(pos->z() == 3.0f);
+  (void)pos;
+
+  // Get a test an element from the `inventory` FlatBuffer's `vector`.
+  auto inv = monster->inventory();
+  assert(inv);
+  assert(inv->Get(9) == 9);
+  (void)inv;
+
+  // Get and test the `weapons` FlatBuffers's `vector`.
+  std::string expected_weapon_names[] = { "Sword", "Axe" };
+  short expected_weapon_damages[] = { 3, 5 };
+  auto weps = monster->weapons();
+  for (unsigned int i = 0; i < weps->size(); i++) {
+    assert(weps->Get(i)->name()->str() == expected_weapon_names[i]);
+    assert(weps->Get(i)->damage() == expected_weapon_damages[i]);
+  }
+  (void)expected_weapon_names;
+  (void)expected_weapon_damages;
+
+  // Get and test the `Equipment` union (`equipped` field).
+  assert(monster->equipped_type() == Equipment_Weapon);
+  auto equipped = static_cast<const Weapon *>(monster->equipped());
+  assert(equipped->name()->str() == "Axe");
+  assert(equipped->damage() == 5);
+  (void)equipped;
+
+  printf("The FlatBuffer was successfully created and verified!\n");
+}

tests/pkg_flatbuffers/monster.fbs

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+// Example IDL file for our monster's schema.
+
+namespace MyGame.Sample;
+
+enum Color:byte { Red = 0, Green, Blue = 2 }
+
+union Equipment { Weapon } // Optionally add more tables.
+
+struct Vec3 {
+  x:float;
+  y:float;
+  z:float;
+}
+
+table Monster {
+  pos:Vec3;
+  mana:short = 150;
+  hp:short = 100;
+  name:string;
+  friendly:bool = false (deprecated);
+  inventory:[ubyte];
+  color:Color = Blue;
+  weapons:[Weapon];
+  equipped:Equipment;
+  path:[Vec3];
+}
+
+table Weapon {
+  name:string;
+  damage:short;
+}
+
+root_type Monster;

tests/pkg_flatbuffers/tests/01-run.py

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+#!/usr/bin/env python3
+
+import sys
+from testrunner import run
+
+
+def testfunc(child):
+    child.expect_exact('The FlatBuffer was successfully created and verified!')
+
+
+if __name__ == "__main__":
+    sys.exit(run(testfunc))