Thrift 文件的格式及可用的数据类型

       编写thrift文件是，需要知道thrift文件支持的数据类型有哪些，如果定义Service等。下面是官方文档的说明：

#
# Thrift Tutorial
# Mark Slee (mcslee@facebook.com)
#
# This file aims to teach you how to use Thrift, in a .thrift file. Neato. The
# first thing to notice is that .thrift files support standard shell comments.
# This lets you make your thrift file executable and include your Thrift build
# step on the top line. And you can place comments like this anywhere you like.
#
# Before running this file, you will need to have installed the thrift compiler
# into /usr/local/bin.

/**
* The first thing to know about are types. The available types in Thrift are:
*
*  bool        Boolean, one byte
*  byte        Signed byte
*  i16         Signed 16-bit integer
*  i32         Signed 32-bit integer
*  i64         Signed 64-bit integer
*  double      64-bit floating point value
*  string      String
*  map<t1,t2>  Map from one type to another
*  list<t1>    Ordered list of one type
*  set<t1>     Set of unique elements of one type
*
* Did you also notice that Thrift supports C style comments?
*/

// Just in case you were wondering... yes. We support simple C comments too.

/**
* Thrift files can reference other Thrift files to include common struct
* and service definitions. These are found using the current path, or by
* searching relative to any paths specified with the -I compiler flag.
*
* Included objects are accessed using the name of the .thrift file as a
* prefix. i.e. shared.SharedObject
*/
include "shared.thrift"

/**
* Thrift files can namespace, package, or prefix their output in various
* target languages.
*/
namespace cpp tutorial
namespace java tutorial
php_namespace tutorial
namespace perl tutorial
namespace smalltalk.category Thrift.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.
*              ^ ThriftIDL page says "If no constant value is supplied,
*   the value is either 0 for the first element, or one greater than the
*   preceding value for any subsequent element" so I'm guessing that's a bug.
*   PS: http://enel.ucalgary.ca/People/Norman/enel315_winter1997/enum_types/ states that if values are not supplied, they start at 0 and not 1.
*/
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 what,
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.  NOTE: Overloading of
* methods is not supported; each method requires a unique name.
*/

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 an oneway modifier. That means the client only makes
* a request and does not listen for any response at all. Oneway methods
* must be void.
*
* The server may execute async invocations of the same client in parallel/
* out of order.
*/
oneway void zip(),
}

/**
* It's possible to declare more than one service per Thrift file.
*/
service CalculatorExtreme extends shared.SharedService {
void pingExtreme(),
}

/**
* That just about covers the basics. Take a look in the test/ folder for more
* detailed examples. After you run this file, your generated code shows up
* in folders with names gen-<language>. The generated code isn't too scary
* to look at. It even has pretty indentation.
*/

       从文档中，我们可以知道的数据类型有：

* bool Boolean, one byte
* byte Signed byte
* i16 Signed 16-bit integer
* i32 Signed 32-bit integer
* i64 Signed 64-bit integer
* double 64-bit floating point value
* string String
* map<t1,t2> Map from one type to another
* list<t1> Ordered list of one type
* set<t1> Set of unique elements of one type

      定义支持语言：

//cpp
namespace cpp tutorial
//java
namespace java tutorial{包名}

      最后定义服务：

 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. NOTE: Overloading of
* methods is not supported; each method requires a unique name.
*/

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 an oneway modifier. That means the client only makes
* a request and does not listen for any response at all. Oneway methods
* must be void.
*
* The server may execute async invocations of the same client in parallel/
* out of order.
*/
oneway void zip(),
}


      下面列举一个完整的java thrift服务的定义：

namespace java com.thrift
service TranslationThriftService{
i32 addENRealtimeData(1:string jsonObject)

}

//编译命令 thrift -r -gen java *.thrift
thrift -r -gen java *.thrift