发信人: kenmlee()
整理人: kenmlee(2000-07-08 16:48:59), 站内信件
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3.6 Transfer Codings
#3.6 传输编码 /#
Transfer coding values are used to indicate an encoding
transformation that has been, can be, or may need to be applied to
an
entity-body in order to ensure "safe transport" through the network
.
This differs from a content coding in that the transfer coding is a
property of the message, not of the original entity.
transfer-coding = "chunked" | transfer-extension
transfer-extension = token
# 传输编码值用于指出对实体体已使用的，能被使用的，或可能需要使用的传输
编码，
这种编码是为了保证实体体在通过网络传输时确保“安全传送”。与内容编码
不同
的是传输编码是消息的属性而不是原来的实体的属性。
transfer-coding = "chunked" | transfer-extension
transfer-extension = token
/#
All transfer-coding values are case-insensitive. HTTP/1.1 uses
transfer coding values in the Transfer-Encoding header field (secti
on
14.40).
# 所有的传输编码值都是大小写不敏感的，HTTP/1.1在传输编码(Transfer-Enc
oding)
头域(见第14.40节)中使用传输编码值。
/#
Transfer codings are analogous to the Content-Transfer-Encoding
values of MIME , which were designed to enable safe transport of
binary data over a 7-bit transport service. However, safe transport
has a different focus for an 8bit-clean transfer protocol. In HTTP,
the only unsafe characteristic of message-bodies is the difficulty
in
determining the exact body length (section 7.2.2), or the desire to
encrypt data over a shared transport.
# 传输编码与MIME的内容传输编码（Content-Transfer-Encoding）值相似，MI
ME是
设计用来允许在7位传输服务之上安全的传输二进制数据。然而，安全传输在
完全8位
的传输协议上的注重点不同，在HTTP中，唯一不安全的消息体特征是决定准确
的消息
体长度的困难（见第7.2.2节)，或者是在共享的传输中加密数据的要求。
/#
The chunked encoding modifies the body of a message in order to
transfer it as a series of chunks, each with its own size indicator
,
followed by an optional footer containing entity-header fields. Thi
s
allows dynamically-produced content to be transferred along with th
e
information necessary for the recipient to verify that it has
received the full message.
Chunked-Body = *chunk
"0" CRLF
footer
CRLF
chunk = chunk-size [ chunk-ext ] CRLF
chunk-data CRLF
hex-no-zero = <HEX excluding "0">
chunk-size = hex-no-zero *HEX
chunk-ext = *( ";" chunk-ext-name [ "=" chunk-ext-value ]
)
chunk-ext-name = token
chunk-ext-val = token | quoted-string
chunk-data = chunk-size(OCTET)
footer = *entity-header
# chunked编码修改消息体使它作为一系列chunk传输，每个头由自己的大小指示
，
并在其后跟着一个可选的注脚包含实体头域，这些允许动态产生传输的内容，
最这些内容传输的信息是接收者能够验证它已接收到了整个消息。
Chunked-Body = *chunk
"0" CRLF
footer
CRLF
chunk = chunk-size [ chunk-ext ] CRLF
chunk-data CRLF
hex-no-zero = <HEX excluding "0">
chunk-size = hex-no-zero *HEX
chunk-ext = *( ";" chunk-ext-name [ "=" chunk-ext-value ]
)
chunk-ext-name = token
chunk-ext-val = token | quoted-string
chunk-data = chunk-size(OCTET)
footer = *entity-header
/#
The chunked encoding is ended by a zero-sized chunk followed by the
footer, which is terminated by an empty line. The purpose of the
footer is to provide an efficient way to supply information about a
n
entity that is generated dynamically; applications MUST NOT send
header fields in the footer which are not explicitly defined as bei
ng
appropriate for the footer, such as Content-MD5 or future extension
s
to HTTP for digital signatures or other facilities.
# chunk编码由一个零大小的chunk结束，接着是注脚，注脚由一个空行结束。注
脚的
目的是一个有效的方法可以为动态生成的实体提供有用的信息；应用程序不能
在注脚
发送没有显示定义可以用于该注脚的头域，如Content-MD5或将来对HTTP做的
数字签
名或其他机制的扩展。
/#
An example process for decoding a Chunked-Body is presented in
appendix 19.4.6.
# 在附录19.4.6有一个解码Chunked-Body的处理的例子。 /#
All HTTP/1.1 applications MUST be able to receive and decode the
"chunked" transfer coding, and MUST ignore transfer coding extensio
ns
they do not understand. A server which receives an entity-body with
a
transfer-coding it does not understand SHOULD return 501
(Unimplemented), and close the connection. A server MUST NOT send
transfer-codings to an HTTP/1.0 client.
# 所有HTTP/1.1的应用程序必须能过够接受和解码"chunked"传输编码，并且必
须忽略它
不能理解的扩展传输编码。但服务器接收到一个不认识的传输编码的实体时，
它应该
返回501（未实现Unimplemented），然后关闭连接。服务器一定不能向HTTP/
1.0客户
应用程序发送传输编码。
/#
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※ 修改:．kenmlee 于 Jul 8 16:30:06 修改本文．[FROM: 61.140.188.222]
※ 来源:．月光软件站 http://www.moon-soft.com．[FROM: 61.140.188.222]
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