NOTE: Though most of the make targets are buildable under Mingw, some haven't been ported to Windows yet
and may fail to build (mostly trying to include POSIX headers not available on Mingw).
### Pre-generated Visual Studio solution (DELETED)
*WARNING: This used to be the recommended way to build on Windows, but because of significant limitations (hard to build dependencies including boringssl, .proto codegen is hard to support, ..) we are no longer providing them. Use cmake to build on Windows instead.*
Remote Procedure Calls (RPCs) provide a useful abstraction for building
distributed applications and services. The libraries in this repository
provide a concrete implementation of the gRPC protocol, layered over HTTP/2.
These libraries enable communication between clients and servers using any
combination of the supported languages.
## Interface
Developers using gRPC start with a language agnostic description of an RPC service (a collection
of methods). From this description, gRPC will generate client and server side interfaces
in any of the supported languages. The server implements
the service interface, which can be remotely invoked by the client interface.
By default, gRPC uses [Protocol Buffers](https://github.com/google/protobuf) as the
Interface Definition Language (IDL) for describing both the service interface
and the structure of the payload messages. It is possible to use other
alternatives if desired.
### Invoking & handling remote calls
Starting from an interface definition in a .proto file, gRPC provides
Protocol Compiler plugins that generate Client- and Server-side APIs.
gRPC users call into these APIs on the Client side and implement
the corresponding API on the server side.
#### Synchronous vs. asynchronous
Synchronous RPC calls, that block until a response arrives from the server, are
the closest approximation to the abstraction of a procedure call that RPC
aspires to.
On the other hand, networks are inherently asynchronous and in many scenarios,
it is desirable to have the ability to start RPCs without blocking the current
thread.
The gRPC programming surface in most languages comes in both synchronous and
asynchronous flavors.
## Streaming
gRPC supports streaming semantics, where either the client or the server (or both)
send a stream of messages on a single RPC call. The most general case is
Bidirectional Streaming where a single gRPC call establishes a stream in which both
the client and the server can send a stream of messages to each other. The streamed
messages are delivered in the order they were sent.
# Protocol
The [gRPC protocol](doc/PROTOCOL-HTTP2.md) specifies the abstract requirements for communication between
clients and servers. A concrete embedding over HTTP/2 completes the picture by
fleshing out the details of each of the required operations.
## Abstract gRPC protocol
A gRPC call comprises of a bidirectional stream of messages, initiated by the client. In the client-to-server direction, this stream begins with a mandatory `Call Header`, followed by optional `Initial-Metadata`, followed by zero or more `Payload Messages`. The server-to-client direction contains an optional `Initial-Metadata`, followed by zero or more `Payload Messages` terminated with a mandatory `Status` and optional `Status-Metadata` (a.k.a.,`Trailing-Metadata`).
## Implementation over HTTP/2
The abstract protocol defined above is implemented over [HTTP/2](https://http2.github.io/). gRPC bidirectional streams are mapped to HTTP/2 streams. The contents of `Call Header` and `Initial Metadata` are sent as HTTP/2 headers and subject to HPACK compression. `Payload Messages` are serialized into a byte stream of length prefixed gRPC frames which are then fragmented into HTTP/2 frames at the sender and reassembled at the receiver. `Status` and `Trailing-Metadata` are sent as HTTP/2 trailing headers (a.k.a., trailers).
## Flow Control
gRPC uses the flow control mechanism in HTTP/2. This enables fine-grained control of memory used for buffering in-flight messages.
[gRPC - An RPC library and framework](http://github.com/grpc/grpc)
gRPC - An RPC library and framework
===================================
===================================
gRPC is a modern, open source, high-performance remote procedure call (RPC) framework that can run anywhere. It enables client and server applications to communicate transparently, and makes it easier to build connected systems.
[](https://gitter.im/grpc/grpc?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
[](https://gitter.im/grpc/grpc?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
* [WebJS](https://github.com/grpc/grpc-web): follow the grpc-web instructions
You can find more detailed documentation and examples in the [doc](doc) and [examples](examples) directories respectively.
You can find per-language quickstart guides and tutorials in [Documentation section on grpc.io website](https://grpc.io/docs/). The code examples are available in the [examples](examples) directory.
# Installation & Testing
# To start developing gRPC
See [INSTALL](INSTALL.md) for installation instructions for various platforms.
Contributions are welcome!
See [tools/run_tests](tools/run_tests) for more guidance on how to run various test suites (e.g. unit tests, interop tests, benchmarks)
Please read [How to contribute](CONTRIBUTING.md) which will guide you through the entire workflow of how to build the source code, how to run the tests and how to contribute your changes to
the gRPC codebase.
The document also contains info on how the contributing process works and contains best practices for creating contributions.
# Performance
See [Performance dashboard](http://performance-dot-grpc-testing.appspot.com/explore?dashboard=5636470266134528) for the performance numbers for the latest released version.
See [Performance dashboard](http://performance-dot-grpc-testing.appspot.com/explore?dashboard=5636470266134528) for the performance numbers for the latest released version.
# Repository Structure & Status
# Concepts
See [gRPC Concepts](CONCEPTS.md)
# About This Repository
This repository contains source code for gRPC libraries for multiple languages written on top of shared C core library [src/core](src/core).
This repository contains source code for gRPC libraries for multiple languages written on top of shared C core library [src/core](src/core).
@ -42,70 +77,3 @@ Libraries in different languages may be in different states of development. We a
See [MANIFEST.md](MANIFEST.md) for a listing of top-level items in the
repository.
# Overview
Remote Procedure Calls (RPCs) provide a useful abstraction for building
distributed applications and services. The libraries in this repository
provide a concrete implementation of the gRPC protocol, layered over HTTP/2.
These libraries enable communication between clients and servers using any
combination of the supported languages.
## Interface
Developers using gRPC typically start with the description of an RPC service
(a collection of methods), and generate client and server side interfaces
which they use on the client-side and implement on the server side.
By default, gRPC uses [Protocol Buffers](https://github.com/google/protobuf) as the
Interface Definition Language (IDL) for describing both the service interface
and the structure of the payload messages. It is possible to use other
alternatives if desired.
### Surface API
Starting from an interface definition in a .proto file, gRPC provides
Protocol Compiler plugins that generate Client- and Server-side APIs.
gRPC users typically call into these APIs on the Client side and implement
the corresponding API on the server side.
#### Synchronous vs. asynchronous
Synchronous RPC calls, that block until a response arrives from the server, are
the closest approximation to the abstraction of a procedure call that RPC
aspires to.
On the other hand, networks are inherently asynchronous and in many scenarios,
it is desirable to have the ability to start RPCs without blocking the current
thread.
The gRPC programming surface in most languages comes in both synchronous and
asynchronous flavors.
## Streaming
gRPC supports streaming semantics, where either the client or the server (or both)
send a stream of messages on a single RPC call. The most general case is
Bidirectional Streaming where a single gRPC call establishes a stream where both
the client and the server can send a stream of messages to each other. The streamed
messages are delivered in the order they were sent.
# Protocol
The [gRPC protocol](doc/PROTOCOL-HTTP2.md) specifies the abstract requirements for communication between
clients and servers. A concrete embedding over HTTP/2 completes the picture by
fleshing out the details of each of the required operations.
## Abstract gRPC protocol
A gRPC RPC comprises of a bidirectional stream of messages, initiated by the client. In the client-to-server direction, this stream begins with a mandatory `Call Header`, followed by optional `Initial-Metadata`, followed by zero or more `Payload Messages`. The server-to-client direction contains an optional `Initial-Metadata`, followed by zero or more `Payload Messages` terminated with a mandatory `Status` and optional `Status-Metadata` (a.k.a.,`Trailing-Metadata`).
## Implementation over HTTP/2
The abstract protocol defined above is implemented over [HTTP/2](https://http2.github.io/). gRPC bidirectional streams are mapped to HTTP/2 streams. The contents of `Call Header` and `Initial Metadata` are sent as HTTP/2 headers and subject to HPACK compression. `Payload Messages` are serialized into a byte stream of length prefixed gRPC frames which are then fragmented into HTTP/2 frames at the sender and reassembled at the receiver. `Status` and `Trailing-Metadata` are sent as HTTP/2 trailing headers (a.k.a., trailers).
## Flow Control
gRPC inherits the flow control mechanisms in HTTP/2 and uses them to enable fine-grained control of the amount of memory used for buffering in-flight messages.
NOTE: currently bazel is only supported for building gRPC on Linux.
## make
Currently the default choice for building on UNIX based systems is `make`.
To install gRPC for C++ on your system using `make`, follow the [Building gRPC C++](../../BUILDING.md)
instructions to build from source and then install locally using `make install`.
This also installs the protocol buffer compiler `protoc` (if you don't have it already),
and the C++ gRPC plugin for `protoc`.
WARNING: After installing with `make install` there is no easy way to uninstall, which can cause issues
if you later want to remove the grpc and/or protobuf installation or upgrade to a newer version.
## cmake
`cmake` is the default build option on Windows, but also works on Linux, MacOS. `cmake` has good
support for crosscompiling and can be used for targeting Android platform.
If your project is using cmake, there are several ways to add gRPC dependency.
- install gRPC via cmake first and then locate it with `find_package(gRPC CONFIG)`. [Example](../../examples/cpp/helloworld/CMakeLists.txt)
- via cmake's `ExternalProject_Add` using a technique called "superbuild". [Example](../../examples/cpp/helloworld/cmake_externalproject/CMakeLists.txt)
- add gRPC source tree to your project (preferrably as a git submodule) and add it to your cmake project with `add_subdirectory`. [Example](../../examples/cpp/helloworld/CMakeLists.txt)
## Packaging systems
There's no standard packaging system for C++. We've looked into supporting some (e.g. Conan and vcpkg) but we are not there yet.
Contributions and community-maintained packages for popular packaging systems are welcome!
## Examples & Additional Documentation
You can find out how to build and run our simplest gRPC C++ example in our
You can find out how to build and run our simplest gRPC C++ example in our
[C++ quick start](../../examples/cpp).
[C++ quick start](../../examples/cpp).
@ -25,7 +74,6 @@ documentation site at [grpc.io](https://grpc.io), specifically:
APIs.
APIs.
# Examples
# To start developing gRPC C++
Code examples for gRPC C++ live in this repository's
For instructions on how to build gRPC C++ from source, follow the [Building gRPC C++](../../BUILDING.md) instructions.
- [Mono 4+](https://www.mono-project.com/) (only needed for Linux and MacOS)
- [Mono 4+](https://www.mono-project.com/) (only needed for Linux and MacOS)
- Prerequisites mentioned in [INSTALL.md](../../INSTALL.md#pre-requisites)
- Prerequisites mentioned in [BUILDING.md](../../BUILDING.md#pre-requisites)
to be able to compile the native code.
to be able to compile the native code.
**Windows, Linux or Mac OS X**
**Windows, Linux or Mac OS X**
@ -93,6 +93,6 @@ THE NATIVE DEPENDENCY
Internally, gRPC C# uses a native library written in C (gRPC C core) and invokes its functionality via P/Invoke. The fact that a native library is used should be fully transparent to the users and just installing the `Grpc.Core` NuGet package is the only step needed to use gRPC C# on all supported platforms.
Internally, gRPC C# uses a native library written in C (gRPC C core) and invokes its functionality via P/Invoke. The fact that a native library is used should be fully transparent to the users and just installing the `Grpc.Core` NuGet package is the only step needed to use gRPC C# on all supported platforms.
ncteisen
7 years ago