Ice3.7.0技术手册：架构与多语言应用开发

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"ICE3.7文档是ZeroC公司2017年发布的关于Ice框架的3.7.0版本的官方手册。手册包含了对Ice的全面介绍、架构概述、服务概览以及多种编程语言（如C++、C#、Java、JavaScript、Objective-C、PHP、Python和Ruby）下编写Ice应用程序的详细步骤。此外，还详细阐述了Slice语言的编译过程、源文件结构、词法规则、模块系统和用户自定义类型等核心概念。" 在ICE3.7文档中，我们首先了解到Ice是一个分布式中间件，它提供了用于构建分布式应用的完整框架。文档的"1.1 Ice Overview"部分深入解析了Ice的架构，包括术语解释、Slice（Ice的规范语言）、语言映射的概述、客户端和服务器结构以及Ice协议的概览。这有助于开发者理解Ice如何工作以及如何设计其分布式系统。术语部分（1.1.1.1 Terminology）定义了如“ Slice”、“Proxy”、“Stub”和“Skeleton”等关键概念，这对于理解和使用Ice至关重要。Slice（1.1.1.2）是Ice的接口定义语言，用于描述服务的接口和数据类型。语言映射（1.1.1.3）讨论了Slice如何在不同的编程语言中实现。 Ice的客户端和服务器结构（1.1.1.4）描述了如何通过网络进行通信，而Ice协议（1.1.1.5）部分则介绍了协议的细节，包括消息格式和交互模式。在1.1.2 Ice Services Overview中，文档可能涵盖了Ice提供的服务，如负载均衡、身份验证和事务管理等功能。 "1.2 Hello World Application"章节是新手入门的起点，通过一步步教程展示了如何用不同语言创建第一个Ice应用。这些教程详细解释了Slice定义、编写C++11和C++98应用程序、C#、Java、JavaCompat（兼容旧版Java）、JavaScript、Objective-C、PHP、Python和Ruby的应用程序开发流程。 "1.3 The Slice Language"部分是关于Slice语言的详细指南，包括编译过程（1.3.1）、源文件组织（1.3.2）、词法规则（1.3.3）、模块系统（1.3.4）以及基本和用户定义的类型（1.3.5和1.3.6）。这部分内容对于深入理解并有效使用Slice语言至关重要。 ICE3.7文档为开发者提供了全面的参考资料，无论是在理解Ice架构、设计分布式系统，还是在具体编程实践中，都能提供有力支持。

Ice 3.7.0 Documentation

Ice Manual

Distributed Programming with Ice

The Internet Communications Engine (Ice) is an object-oriented RPC framework that helps you build distributed applications with minimal

effort. Ice allows you to focus your efforts on your application logic, and it takes care of all interactions with low-level network programming

interfaces. With Ice, there is no need to worry about details such as opening network connections, serializing and deserializing data for

network transmission, or retrying failed connection attempts.

The main design goals of Ice are:

Provide an object-oriented RPC framework suitable for use in heterogeneous environments.

Provide a full set of features that support development of realistic distributed applications for a wide variety of domains.

Avoid unnecessary complexity, making the platform easy to learn and to use.

Provide an implementation that is efficient in network bandwidth, memory use, and CPU overhead.

Provide an implementation that has built-in security, making it suitable for use over insecure public networks.

In simpler terms, the Ice design goals could be stated as "Let's build a powerful middleware platform that makes the developer's life easier."

Getting Help with Ice

If you have a question and you cannot find an answer in this manual, you can visit our to see if another developer hasdeveloper forums

encountered the same issue. If you still need help, feel free to post your question on the forum, which ZeroC's developers monitor regularly.

Note, however, that we can provide only limited free support in our forums. For guaranteed response and problem resolution times, we

highly recommend purchasing .commercial support

Feedback about the Manual

We would very much like to hear from you in case you find any bugs (however minor) in this manual. We also would like to hear your opinion

on the contents, and any suggestions as to how it might be improved. You can contact us via e-mail at .icebook@zeroc.com

Legal Notices

Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those

designations appear in this book and ZeroC was aware of the trademark claim, the designations have been printed in initial caps or all caps.

The authors and publisher have taken care in the preparation of this book, but make no expressed or implied warranty of any kind and

assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising

out of the use of the information or programs contained herein.

License

This manual is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.

The acronym "Ice" is pronounced as a single syllable, like the word for frozen water.

Ice 3.7.0 Documentation
20 Copyright 2017, ZeroC, Inc.
Terminology
Every computing technology creates its own vocabulary as it evolves. Ice is no exception. However, the amount of new jargon used by Ice is
minimal. Rather than inventing new terms, we have used existing terminology as much as possible. If you have used another middleware
technology in the past, you will be familiar with much of what follows. (However, we suggest you at least skim the material because a few
terms used by Ice   differ from the corresponding terms used by other middleware.)do
On this page:
Clients and Servers
Ice Objects
Proxies
Stringified Proxies
Direct Proxies
Indirect Proxies
Direct Versus Indirect Binding
Fixed Proxies
Routed Proxies
Replication
Replica Groups
Servants
At-Most-Once Semantics
Synchronous Method Invocation
Asynchronous Method Invocation
Asynchronous Method Dispatch
Oneway Method Invocation
Batched Oneway Method Invocation
Datagram Invocations
Batched Datagram Invocations
Run-Time Exceptions
User Exceptions
Properties
Clients and Servers
The terms   and   are not firm designations for particular parts of an application; rather, they denote roles that are taken by parts ofclient server
an application for the duration of a request:
Clients are active entities. They issue requests for service to servers.
Servers are passive entities. They provide services in response to client requests.
Frequently, servers are not "pure" servers, in the sense that they never issue requests and only respond to requests. Instead, servers often
act as a server on behalf of some client but, in turn, act as a client to another server in order to satisfy their client's request.
Similarly, clients often are not "pure" clients, in the sense that they only request service from an object. Instead, clients are frequently
client-server hybrids. For example, a client might start a long-running operation on a server; as part of starting the operation, the client can
provide a   to the server that is used by the server to notify the client when the operation is complete. In that case, the clientcallback object
acts as a client when it starts the operation, and as a server when it is notified that the operation is complete.
Such role reversal is common in many systems, so, frequently, client-server systems could be more accurately described as   sypeer-to-peer
stems.
Ice Objects
An   is a conceptual entity, or abstraction. An Ice object can be characterized by the following points:Ice object
An Ice object is an entity in the local or a remote address space that can respond to client requests.
A single Ice object can be instantiated in a single server or, redundantly, in multiple servers. If an object has multiple simultaneous
instantiations, it is still a single Ice object.
Each Ice object has one or more  . An interface is a collection of named   that are supported by an object. Clientsinterfaces operations
issue requests by invoking operations.
An operation has zero or more   as well as a  . Parameters and return values have a specific  . Parametersparameters return value type
are named and have a direction: in-parameters are initialized by the client and passed to the server; out-parameters are initialized
by the server and passed to the client. (The return value is simply a special out-parameter.)
An Ice object has a distinguished interface, known as its  . In addition, an Ice object can provide zero or more alternatemain interface
interfaces, known as  . Clients can select among the facets of an object to choose the interface they want to work with.facets