Transport Layer - Core Components

The HTTP transport layer provides lower-level support for interacting with standard HTTP/1.1 web servers. More...

Classes
class	AuthorizationCredential
	The abstraction used to pass credentials also contains knowledge about how to use the credentials to authorize requests. More...
class	HttpRequest
	Denotes an HTTP request to be sent to an HTTP server. More...
class	HttpResponse
	Captures the response from HttpRequest invocations. More...
class	HttpScribeCensor
	Determines what is appropriate for scribes to record. More...
class	HttpScribe
	Base class for scribe to log HTTP message activity. More...
class	HttpEntryScribe
	A high level but still abstract class for intercepting HTTP requests. More...
class	HttpTransportErrorHandler
	forward declaration More...
class	HttpTransportOptions
	Configures options on an HttpTransport instanceEach HttpTransport instance maintains its own options however typically the default options are set on the HttpTransportFactory so that the options will apply to all transport instances. More...
class	HttpTransportLayerConfig
	Specifies the implementation components for the TransportLayer. More...
class	HttpTransport
	Abstract interface defining an HTTP transport will be specialized for different concrete mechanisms for interacting with HTTP servers. More...
class	HttpTransportFactory
	Abstract interface for creating concrete HttpTransport instances. More...
class	HttpRequestOptions
	Specifies per-request options that control its behavior. More...
class	HttpRequestState
	Denotes the current state of an HttpRequest's lifecycel. More...
class	HttpStatusCode
	This is a helper class for interpreting standard HTTP status codes. More...
Typedefs
typedef std::map< string, string, RequestHeaderLess >	HttpHeaderMap
	Collection of HTTP headers (without repeated headers).
typedef std::multimap< string, string, StringCaseLess >	HttpHeaderMultiMap
	Collection of HTTP headers (allows repeated header values).
typedef Callback1< HttpRequest * >	HttpRequestCallback
	Denotes a callback function that takes an HttpRequest* parameter.

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Detailed Description

The HTTP transport layer provides lower-level support for interacting with standard HTTP/1.1 web servers.

In particular those that are used to host cloud-based services such as the Google Cloud Platform. Much if not all of it can be used for other HTTP servers and uses. In fact, the Google APIs Client Library for C++ uses it in the OAuth 2.0 module for messaging with OAuth 2.0 servers.

The HTTP transport layer is designed as a keystone building block to implement the Google APIs Client Library for C++. One aspect of this is that it does not explicitly dictate a particular implementation for the physical HTTP messaging. Instead it chiefly provides an abstraction for messaging and a means for "plugging in" implementation details for the physical messaging. To be useful, it provides a reasonable implementation suitable for most purposes. However some clients or situations may wish to use some other mechanism, especially pre-existing ones in their runtime environments. This is accomodated by the HttpTransport class.

In addiition to the HttpTransport class, the core HTTP transport layer also includes the HttpRequest, HttpRequestState and HttpResponse and httpTransportErrorHandler classes. It also includes an abstract AuthorizationCredential class for making authorized requests. The Google APIs Client Library for C++ builds on this abstract class to provide OAuth 2.0 support in the OAuth2 2.0 module. Together this allows the transport layer to be used to comply with OAuth 2.0 protected resources without actually depending on a specific client-side implementation of OAuth 2.0.

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Typedef Documentation

typedef std::map<string, string, RequestHeaderLess> HttpHeaderMap

Collection of HTTP headers (without repeated headers).

The map is keyed by case-insensitive header naem. The values are the header values.

typedef std::multimap<string, string, StringCaseLess> HttpHeaderMultiMap

Collection of HTTP headers (allows repeated header values).

The map is keyed by case-insensitive header naem. The values are the header values.

typedef Callback1<HttpRequest*> HttpRequestCallback

Denotes a callback function that takes an HttpRequest* parameter.

Request callbacks are used for notification on asynchronous requests. Typically the owner maintains ownership of the request. If this is called by the ExecuteAsync flow then you can call DestroyWhenDone before executing the request and the request will be destroyed after the callback is called.