rpc服務框架目前主要有 thrift, grpc, dubbo, HSF等

這裏主要介紹thrift框架

git地址 ：https://github.com/apache/thrift/tree/0.9.1

1. 接口定義　tutorial.thrift

include "shared.thrift"

/**
 * Thrift files can namespace, package, or prefix their output in various
 * target languages.
 */

namespace cl tutorial
namespace cpp tutorial
namespace d tutorial
namespace dart tutorial
namespace java tutorial
namespace php tutorial
namespace perl tutorial
namespace haxe tutorial
namespace netcore tutorial
namespace netstd tutorial

/**
 * Thrift lets you do typedefs to get pretty names for your types. Standard
 * C style here.
 */
typedef i32 MyInteger

/**
 * Thrift also lets you define constants for use across languages. Complex
 * types and structs are specified using JSON notation.
 */
const i32 INT32CONSTANT = 9853
const map<string,string> MAPCONSTANT = {‘hello‘:‘world‘, ‘goodnight‘:‘moon‘}

/**
 * You can define enums, which are just 32 bit integers. Values are optional
 * and start at 1 if not supplied, C style again.
 */
enum Operation {
  ADD = 1,
  SUBTRACT = 2,
  MULTIPLY = 3,
  DIVIDE = 4
}

/**
 * Structs are the basic complex data structures. They are comprised of fields
 * which each have an integer identifier, a type, a symbolic name, and an
 * optional default value.
 *
 * Fields can be declared "optional", which ensures they will not be included
 * in the serialized output if they aren‘t set.  Note that this requires some
 * manual management in some languages.
 */
struct Work {
  1: i32 num1 = 0,
  2: i32 num2,
  3: Operation op,
  4: optional string comment,
}

/**
 * Structs can also be exceptions, if they are nasty.
 */
exception InvalidOperation {
  1: i32 whatOp,
  2: string why
}

/**
 * Ahh, now onto the cool part, defining a service. Services just need a name
 * and can optionally inherit from another service using the extends keyword.
 */
service Calculator extends shared.SharedService {

  /**
   * A method definition looks like C code. It has a return type, arguments,
   * and optionally a list of exceptions that it may throw. Note that argument
   * lists and exception lists are specified using the exact same syntax as
   * field lists in struct or exception definitions.
   */

   void ping(),

   i32 add(1:i32 num1, 2:i32 num2),

   i32 calculate(1:i32 logid, 2:Work w) throws (1:InvalidOperation ouch),

   /**
    * This method has a oneway modifier. That means the client only makes
    * a request and does not listen for any response at all. Oneway methods
    * must be void.
    */
   oneway void zip()

}

2. 根據接口定義文件生成相應的服務接口

thrift -r --gen py tutorial.thrift　根據ｔｈｒｉｆｔ接口定義生成服務接口
執行完後會在當前目錄生成 gen-py文件夾，　下面包含　tutorial shared兩個子文件夾

主要文件就是Calulator.py 定義了相應語言的接口協議

3. 根據接口，實現接口功能，提供服務

這步是最重要的，開始實現接口功能， 上面由接口定義文件service可知， 定義了4個功能： ping add caculate zip

這裏用python實現上述接口， PythonServer.py

import glob
import sys
sys.path.append(‘gen-py‘)
sys.path.insert(0, glob.glob(‘../../lib/py/build/lib*‘)[0])

from tutorial import Calculator
from tutorial.ttypes import InvalidOperation, Operation

from shared.ttypes import SharedStruct

from thrift.transport import TSocket
from thrift.transport import TTransport
from thrift.protocol import TBinaryProtocol
from thrift.server import TServer


class CalculatorHandler:
    def __init__(self):
        self.log = {}

    def ping(self):
        print(‘ping()‘)

    def add(self, n1, n2):
        print(‘add(%d,%d)‘ % (n1, n2))
        return n1 + n2

    def calculate(self, logid, work):
        print(‘calculate(%d, %r)‘ % (logid, work))

        if work.op == Operation.ADD:
            val = work.num1 + work.num2
        elif work.op == Operation.SUBTRACT:
            val = work.num1 - work.num2
        elif work.op == Operation.MULTIPLY:
            val = work.num1 * work.num2
        elif work.op == Operation.DIVIDE:
            if work.num2 == 0:
                x = InvalidOperation()
                x.whatOp = work.op
                x.why = ‘Cannot divide by 0‘
                raise x
            val = work.num1 / work.num2
        else:
            x = InvalidOperation()
            x.whatOp = work.op
            x.why = ‘Invalid operation‘
            raise x

        log = SharedStruct()
        log.key = logid
        log.value = ‘%d‘ % (val)
        self.log[logid] = log

        return val

    def getStruct(self, key):
        print(‘getStruct(%d)‘ % (key))
        return self.log[key]

    def zip(self):
        print(‘zip()‘)


if __name__ == ‘__main__‘:
    handler = CalculatorHandler()
    processor = Calculator.Processor(handler)
    transport = TSocket.TServerSocket(host=‘127.0.0.1‘, port=9090)
    tfactory = TTransport.TBufferedTransportFactory()
    pfactory = TBinaryProtocol.TBinaryProtocolFactory()

    server = TServer.TSimpleServer(processor, transport, tfactory, pfactory)

python PythonServer.py 然後可以看到rpc對外開始提供服務， 這裏註意host， port

4.實現客戶端，連接rpc服務接口

PythonClient.py

import sys
import glob
sys.path.append(‘gen-py‘)
sys.path.insert(0, glob.glob(‘../../lib/py/build/lib*‘)[0])

from tutorial import Calculator
from tutorial.ttypes import InvalidOperation, Operation, Work

from thrift import Thrift
from thrift.transport import TSocket
from thrift.transport import TTransport
from thrift.protocol import TBinaryProtocol


def main():
    # Make socket
    transport = TSocket.TSocket(‘localhost‘, 9090)

    # Buffering is critical. Raw sockets are very slow
    transport = TTransport.TBufferedTransport(transport)

    # Wrap in a protocol
    protocol = TBinaryProtocol.TBinaryProtocol(transport)

    # Create a client to use the protocol encoder
    client = Calculator.Client(protocol)

    # Connect!
    transport.open()

    client.ping()
    print(‘ping()‘)

    sum_ = client.add(1, 1)
    print(‘1+1=%d‘ % sum_)

    work = Work()

    work.op = Operation.DIVIDE
    work.num1 = 1
    work.num2 = 0

    try:
        quotient = client.calculate(1, work)
        print(‘Whoa? You know how to divide by zero?‘)
        print(‘FYI the answer is %d‘ % quotient)
    except InvalidOperation as e:
        print(‘InvalidOperation: %r‘ % e)

    work.op = Operation.SUBTRACT
    work.num1 = 15
    work.num2 = 10

    diff = client.calculate(1, work)
    print(‘15-10=%d‘ % diff)

    log = client.getStruct(1)
    print(‘Check log: %s‘ % log.value)

    # Close!
    transport.close()

啟動客戶端，連接rpc服務

可以看到，已經能get到結果了，通過rpc，可以實現，接口實現與使用的分離， 使用不同語言，而且效率遠比restful接口高效

rpc服務框架thrift介紹