0. Thrift的特性
1. 安装Thrift编译器
[Todo]
http://thrift.apache.org/docs/install/
http://thrift.apache.org/docs/install/os_x
2. Thrift类型 (Thrift Type)
[Ref]: http://thrift.apache.org/docs/types
基本类型
- bool: A boolean value (true or false)
- byte: An 8-bit signed integer
- i16: A 16-bit signed integer
- i32: A 32-bit signed integer
- i64: A 64-bit signed integer
- double: A 64-bit floating point number
- string: A text string encoded using UTF-8 encoding
特殊类型
binary: a sequence of unencoded bytes
结构体 (Structs)
Thrift structs define a common object -- they are essentially equivalent to classes in OOP languages,
but without inheritance. A struct has a set of strongly typed fields, each with a unique name identifier.
Fields may have various annotations (numeric field IDs, optional default values, etc.)
容器 (Containers)
Thrift containers are strongly typed containers that map to commonly used and commonly available
container types in most programming languages.
三种类型的容器:
list: An ordered list of elements.
set: An unordered set of unique elements. (PHP does not support sets, so it is treated similar to a List)
map: A map of strictly unique keys to values.
容器元素可以是任意合法的Thrift Type.
[注]: For maximal compatibility, the key type for map should be a basic type rather than a struct or container type.
异常 (Exceptions)
Exceptions are functionally equivalent to structs, except that they inherit from the native exception
base class as appropriate in each target programming language, in order to seamlessly integrate with the
native exception handling in any given language.
服务 (Services)
Services are defined using Thrift types. Definition of a service is semantically equivalent to defining an
interface (or a pure virtual abstract class) in object oriented programming. The Thrift compiler generates
fully functional client and server stubs that implement the interface.
A service consists of a set of named functions, each with a list of parameters and a return type.
Note that void is a valid type for a function return, in addition to all other defined Thrift types.
Additionally, an oneway modifier keyword may be added to a void function, which will generate
code that does not wait for a response. Note that a pure void function will return a response to
the client which guarantees that the operation has completed on the server side. With oneway
method calls the client will only be guaranteed that the request succeeded at the transport layer.
Oneway method calls of the same client may be executed in parallel/out of order by the server.
3. IDL
[Ref]: http://thrift.apache.org/docs/idl
A Thrift IDL file is processed by the Thrift code generator to produce code for the various target
languages to support the defined structs and services in the IDL file.
3.1 Document
每个Thrift文档包含0或者多个header，header后紧跟0或者多个definitions.
[1] Document ::= Header* Definition*
3.2 Header
A header is either a Thrift include, a C++ include, or a namespace declaration.
[2] Header ::= Include | CppInclude | Namespace
3.2.1 Thrift Include
An include makes all the symbols from another file visible (with a prefix) and adds corresponding
include statements into the code generated for this Thrift document.
[3] Include ::= 'include' Literal
3.2.2 C++ Include
A C++ include adds a custom C++ include to the output of the C++ code generator for this Thrift document.
[4] CppInclude ::= 'cpp_include' Literal
3.2.3 Namespace
A namespace declares which namespaces/package/module/etc. the type definitions in this file will be declared in
for the target languages. The namespace scope indicates which language the namespace applies to;
a scope of '*' indicates that the namespace applies to all target languages.
[5] Namespace ::= ( 'namespace' ( NamespaceScope Identifier ) | ( 'smalltalk.category' STIdentifier ) | ( 'smalltalk.prefix' Identifier ) ) | ( 'php_namespace' Literal ) | ( 'xsd_namespace' Literal )[6] NamespaceScope ::= '*' | 'cpp' | 'java' | 'py' | 'perl' | 'rb' | 'cocoa' | 'csharp'
3.3 Definition
[7] Definition ::= Const | Typedef | Enum | Senum | Struct | Union | Exception | Service
3.3.1 Const
[8] Const ::= 'const' FieldType Identifier '=' ConstValue ListSeparator?
3.3.2 Typedef
[9] Typedef ::= 'typedef' DefinitionType Identifier
3.3.3 Enum
An enum creates an enumerated type, with named values. 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.
Any constant value that is supplied must be non-negative.
[10] Enum ::= 'enum' Identifier '{ ' (Identifier ('=' IntConstant)? ListSeparator?)* '}'
3.3.4 Senum
Senum (and Slist) are now deprecated and should both be replaced with String.
3.3.5 Struct
[12] Struct ::= 'struct' Identifier 'xsd_all'? '{ ' Field* '}'
xsd_all keyword has some purpose internal to Facebook but serves no purpose in Thrift itself. 3.3.6 Union
[13] Union ::= 'union' Identifier 'xsd_all'? '{ ' Field* '}'
[注]: The xsd_all keyword has some purpose internal to Facebook but serves no purpose in Thrift itself.
Use of this feature is strongly discouraged
3.3.7 Exception
Exceptions are similar to structs except that they are intended to integrate with the native exception
handling mechanisms in the target languages. The name of each field must be unique within the exception.
[14] Exception ::= 'exception' Identifier '{ ' Field* '}'
3.3.8 Service
A service provides the interface for a set of functionality provided by a Thrift server. The interface is simply
a list of functions. A service can extend another service, which simply means that it provides the functions of
the extended service in addition to its own.
[15] Service ::= 'service' Identifier ( 'extends' Identifier )? '{ ' Function* '}'
3.3.9 Field
[16] Field ::= FieldID? FieldReq? FieldType Identifier ('= ConstValue)? XsdFieldOptions ListSeparator?
Field ID
[17] FieldID ::= IntConstant ':'
Field Requiredness
[18] FieldReq ::= 'required' | 'optional'
XSD Options
[注]: These have some internal purpose at Facebook but serve no current purpose in Thrift.
Use of these options is strongly discouraged.
[19] XsdFieldOptions ::= 'xsd_optional'? 'xsd_nillable'? XsdAttrs?[20] XsdAttrs ::= 'xsd_attrs' '{ ' Field* '}'
3.3.10 Functions
[21] Function ::= 'oneway'? FunctionType Identifier '(' Field* ')' Throws? ListSeparator?[22] FunctionType ::= FieldType | 'void'[23] Throws ::= 'throws' '(' Field* ')'
3.3.11 Types
[24] FieldType ::= Identifier | BaseType | ContainerType[25] DefinitionType ::= BaseType | ContainerType[26] BaseType ::= 'bool' | 'byte' | 'i16' | 'i32' | 'i64' | 'double' | 'string' | 'binary' | 'slist'[27] ContainerType ::= MapType | SetType | ListType[28] MapType ::= 'map' CppType? '<' FieldType ',' FieldType '>'[29] SetType ::= 'set' CppType? '<' FieldType '>'[30] ListType ::= 'list' '<' FieldType '>' CppType?[31] CppType ::= 'cpp_type' Literal
3.3.12 Constant Values
[32] ConstValue ::= IntConstant | DoubleConstant | Literal | Identifier | ConstList | ConstMap[33] IntConstant ::= ('+' | '-')? Digit+[34] DoubleConstant ::= ('+' | '-')? Digit* ('.' Digit+)? ( ('E' | 'e') IntConstant )?[35] ConstList ::= '[' (ConstValue ListSeparator?)* ']'[36] ConstMap ::= '{ ' (ConstValue ':' ConstValue ListSeparator?)* '}'
3.3.13 Basic Definitions
Literal
[37] Literal ::= ('"' [^"]* '"') | ("'" [^']* "'")
Identifier
[38] Identifier ::= ( Letter | '_' ) ( Letter | Digit | '.' | '_' )*[39] STIdentifier ::= ( Letter | '_' ) ( Letter | Digit | '.' | '_' | '-' )*
List Separator
[40] ListSeparator ::= ',' | ';'
Letters and Digits
[41] Letter ::= ['A'-'Z'] | ['a'-'z'][42] Digit ::= ['0'-'9']
3.4 例子
[Todo]
http://thrift.apache.org/docs/idl
http://wiki.apache.org/thrift/Tutorial
Where to go