进行Chunked编码传输的HTTP Response会在消息头部设置:
Transfer-Encoding: chunked
表示Content Body将用Chunked编码传输内容。
Chunked编码使用若干个Chunk串连而成,由一个标明长度为0的chunk标示结束。每个Chunk分为头部和正文两部分,头部内容指定下一段正文的字符总数(十六进制的数字)和数量单位(一般不写),正文部分就是指定长度的实际内容,两部分之间用回车换行(CRLF)隔开。在最后一个长度为0的Chunk中的内容是称为footer的内容,是一些附加的Header信息(通常可以直接忽略)。具体的Chunk编码格式如下:
<div class="codetitle"><a style="CURSOR: pointer" data="55852" class="copybut" id="copybut55852" onclick="doCopy('code55852')"> 代码如下:@H_3015@<div class="codebody" id="code55852">
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
@H301_5@
RFC文档中的Chunked解码过程如下:
<div class="codetitle"><a style="CURSOR: pointer" data="47566" class="copybut" id="copybut47566" onclick="doCopy('code47566')"> 代码如下:@H_3015@<div class="codebody" id="code47566">
length := 0
read chunk-size,chunk-ext (if any) and CRLF
while (chunk-size > 0) {
read chunk-data and CRLF
append chunk-data to entity-body
length := length + chunk-size
read chunk-size and CRLF
}
read entity-header
while (entity-header not empty) {
append entity-header to existing header fields
read entity-header
}
Content-Length := length
Remove "chunked" from Transfer-Encoding
@H301_5@
最后提供一段PHP版本的chunked解码代码:
<div class="codetitle"><a style="CURSOR: pointer" data="25540" class="copybut" id="copybut25540" onclick="doCopy('code25540')"> 代码如下:@H_301_5@<div class="codebody" id="code25540">
$chunk_size = (integer)hexdec(fgets( $socket_fd,4096 ) );
while(!feof($socket_fd) && $chunk_size > 0) {
$bodyContent .= fread( $socket_fd,$chunk_size );
fread( $socket_fd,2 ); // skip \r\n
$chunk_size = (integer)hexdec(fgets( $socketfd,4096 ) );
}
@H301_5@