Merge pull request #283 from wravery/boost-beast-sample

Add an HTTP client/server sample with Boost.Beast

Author: wravery

CMakeLists.txt

@@ -52,9 +52,16 @@ if(GRAPHQL_BUILD_SCHEMAGEN AND GRAPHQL_BUILD_CLIENTGEN)
 
   if(GRAPHQL_UPDATE_SAMPLES)
     list(APPEND VCPKG_MANIFEST_FEATURES "update-samples")
+
+    option(GRAPHQL_BUILD_HTTP_SAMPLE "Build the HTTP client sample using C++20 coroutines with Boost.Beast/Boost.Asio." ON)
+
+    if(GRAPHQL_BUILD_HTTP_SAMPLE)
+      list(APPEND VCPKG_MANIFEST_FEATURES "http-sample")
+    endif()
   endif()
 else()
   set(GRAPHQL_UPDATE_SAMPLES OFF CACHE BOOL "Disable regenerating samples." FORCE)
+  set(GRAPHQL_BUILD_HTTP_SAMPLE OFF CACHE BOOL "Disable regenerating samples." FORCE)
 endif()
 
 project(cppgraphqlgen VERSION ${LATEST_VERSION})

README.md

@@ -127,9 +127,9 @@ do that.
 
 ### schemagen
 
-I'm using [Boost](https://www.boost.org/doc/libs/1_69_0/more/getting_started/index.html) for `schemagen`:
+I'm using [Boost](https://www.boost.org/doc/libs/1_82_0/more/getting_started/index.html) for `schemagen`:
 
-- Command line handling: [Boost.Program_options](https://www.boost.org/doc/libs/1_69_0/doc/html/program_options.html).
+- Command line handling: [Boost.Program_options](https://www.boost.org/doc/libs/1_82_0/doc/html/program_options.html).
 Run `schemagen -?` to get a list of options. Many of the files in the [samples](samples/) directory were generated
 with `schemagen`, you can look at [samples/CMakeLists.txt](samples/CMakeLists.txt) for a few examples of how to call it:
 ```
@@ -144,8 +144,8 @@ Command line options:
   -n [ --namespace ] arg C++ sub-namespace for the generated types
   --source-dir arg       Target path for the <prefix>Schema.cpp source file
   --header-dir arg       Target path for the <prefix>Schema.h header file
-  --no-stubs             Generate abstract classes without stub implementations
-  --separate-files       Generate separate files for each of the types
+  --stubs                Unimplemented fields throw runtime exceptions instead
+                         of compiler errors
   --no-introspection     Do not generate support for Introspection
 ```
 
@@ -161,8 +161,7 @@ Windows and UWP shared library targets (the platform triplets which don't end in
 ### clientgen
 
 The `clientgen` utility is based on `schemagen` and shares the same external dependencies. The command line arguments
-are almost the same, except it takes an extra file for the request document and there is no equivalent to `--no-stubs` or
-`--separate-files`:
+are almost the same, except it takes an extra file for the request document and there is no equivalent to `--stubs`:
 ```
 Usage:  clientgen [options] <schema file> <request file> <output filename prefix> <output namespace>
 Command line options:
@@ -259,6 +258,12 @@ is no implementation of this schema, it relies entirely generated stubs (created
 successfully without defining more than placeholder objects fo the Query, Mutation, and Subscription operations in
 [samples/validation/ValidationMock.h](samples/validation/ValidationMock.h). It is used to test the validation logic
 with every example or counter-example in the spec in [test/ValidationTests.cpp](test/ValidationTests.cpp).
+- [samples/proxy](samples/proxy/) (`GRAPHQL_BUILD_HTTP_SAMPLE=ON`): Generates a `client` and `server` pair of
+executables which proxy requests from the `client` to the `server` over HTTP (on port 8080 for localhost). The HTTP
+support in both samples comes from [Boost.Beast](https://www.boost.org/doc/libs/1_82_0/libs/beast/doc/html/index.html),
+which must be included in your `Boost` installation to build this directory. If you are using `vcpkg`, it will install
+the necessary `Boost` components on demand. _Note: This directory uses the Boost Software License because the samples
+borrow heavily from examples in the `Boost.Beast` documentation._
 
 # Build and Test
 

samples/CMakeLists.txt

@@ -7,3 +7,19 @@ add_subdirectory(client)
 add_subdirectory(learn)
 add_subdirectory(today)
 add_subdirectory(validation)
+
+if(GRAPHQL_BUILD_HTTP_SAMPLE)
+  find_package(Boost QUIET)
+  if(Boost_FOUND)
+    if(Boost_VERSION VERSION_GREATER_EQUAL "1.81.0")
+      if(EXISTS "${Boost_INCLUDE_DIR}/boost/beast.hpp")
+        message(STATUS "Using Boost.Beast ${Boost_VERSION}")
+        add_subdirectory(proxy)
+      else()
+        message(WARNING "GRAPHQL_BUILD_HTTP_SAMPLE requires the Boost.Beast header-only library, but it was not found in ${Boost_INCLUDE_DIR}.")
+      endif()
+    else()
+      message(WARNING "GRAPHQL_BUILD_HTTP_SAMPLE requires the Boost.Beast header-only library >= 1.81.0, but only ${Boost_VERSION} was found in ${Boost_INCLUDE_DIR}.")
+    endif()
+  endif()
+endif()

samples/learn/CMakeLists.txt

@@ -14,6 +14,7 @@ add_library(star_wars STATIC
   StarWarsData.cpp)
 target_link_libraries(star_wars PUBLIC learn_schema)
 target_include_directories(star_wars PUBLIC star_wars)
+target_include_directories(star_wars INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
 
 add_executable(learn_star_wars sample.cpp)
 target_link_libraries(learn_star_wars PRIVATE

samples/proxy/CMakeLists.txt

@@ -0,0 +1,49 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+cmake_minimum_required(VERSION 3.15)
+
+add_subdirectory(query)
+add_subdirectory(schema)
+
+add_executable(client client.cpp)
+target_link_libraries(client PRIVATE
+  proxy_schema
+  proxy_client
+  graphqljson)
+target_include_directories(client PRIVATE
+  proxy_schema
+  proxy_client)
+
+add_executable(server server.cpp)
+target_link_libraries(server PRIVATE
+  star_wars
+  graphqljson)
+
+if(MSVC)
+  target_compile_options(client PRIVATE "-wd4702")
+  target_compile_options(server PRIVATE "-wd4702")
+endif()
+
+if(WIN32 AND BUILD_SHARED_LIBS)
+  add_custom_command(OUTPUT copied_sample_dlls
+    COMMAND ${CMAKE_COMMAND} -E copy_if_different
+      $<TARGET_FILE:graphqlservice>
+      $<TARGET_FILE:graphqljson>
+      $<TARGET_FILE:graphqlpeg>
+      $<TARGET_FILE:graphqlresponse>
+      $<TARGET_FILE:graphqlclient>
+      ${CMAKE_CURRENT_BINARY_DIR}
+    COMMAND ${CMAKE_COMMAND} -E touch copied_sample_dlls
+    DEPENDS
+      graphqlservice
+      graphqljson
+      graphqlpeg
+      graphqlresponse
+      graphqlclient)
+
+  add_custom_target(copy_proxy_sample_dlls DEPENDS copied_sample_dlls)
+
+  add_dependencies(client copy_proxy_sample_dlls)
+  add_dependencies(server copy_proxy_sample_dlls)
+endif()

samples/proxy/LICENSE

@@ -0,0 +1,31 @@
+Portions of the files in this directory are copied from the Boost.Beast
+examples, and they fall under the Boost Sofware License:
+https://www.boost.org/doc/libs/1_82_0/libs/beast/doc/html/beast/examples.html.
+
+This license text is also available from https://www.boost.org/LICENSE_1_0.txt.
+
+-------------------------------------------------------------------------------
+
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

samples/proxy/README.md

@@ -0,0 +1,38 @@
+# HTTP Proxy Sample
+
+## Dependencies
+
+This sample requires the [Boost.Beast](https://www.boost.org/doc/libs/1_82_0/libs/beast/doc/html/index.html)
+header-only library. If you are using [vcpkg](https://github.com/microsoft/vcpkg), it can install that component
+for you on-demand. Otherwise, you may need to install it separately if you have a selective installation of
+`Boost`.
+
+## Server
+
+The `server` executable listens for HTTP connections on http://127.0.0.1:8080/ (port 8080 of `localhost`). It
+is expecting POST requests with a JSON payload in the request body that looks like this:
+```json
+{
+	"query": "GraphQL query document goes here",
+	"operationName": "(optional) GraphQL operation name goes here",
+	"variables": "(optional) JSON object embedded in a string with GraphQL operation variables"
+}
+```
+
+It has a single thread accepting requests, and it uses C++20 coroutines. The GraphQL service which actually
+resolves the requests is the same Star Wars learning sample in [../learn](../learn/).
+
+## Client
+
+The `client` executable works like most of the other command line samples, it can take a single argument for
+the operation name and it will read the GraphQL query document from standard input. It packages the query
+parameters in variables for a pre-parsed [query/query.graphql](query/query.graphql), and it implements an
+in-proc GraphQL service with the [schema/schema.graphql](schema/schema.graphql) schema using an asynchronous
+field resolver. The field resolver packages the parameters into a JSON message and sends it to the `server`
+process waiting on http://127.0.0.1:8080/.
+
+When it gets a response, `client` uses the same pre-parsed query in [query/query.graphql](query/query.graphql)
+to parse the result and return the JSON document in the field returned from the `server` process.
+
+As long as you start the `server` process first, the behavior of `client` should be almost identical to the
+`learn_star_wars` executable sample produced by [../learn](../learn/).