Trouble getting the Request Body of a HTTP Post
mdounin at mdounin.ru
Fri Dec 18 00:58:11 MSK 2009
On Thu, Dec 17, 2009 at 03:33:04PM -0500, Tronman wrote:
> Great! Your response cleared up nearly everything for me, the
> only other thing I'm not completely clear on is the difference
> ngx_chain_t *bufs;
> ngx_buf_t *buf;
> in ngx_http_request_body_t. What is the difference between them?
> When should I use either to access the body?
You should use ->bufs. Here is the comment from
ngx_http_request_body.c which should be helpful:
* on completion ngx_http_read_client_request_body() adds to
* r->request_body->bufs one or two bufs:
* *) one memory buf that was preread in r->header_in;
* *) one memory or file buf that contains the rest of the body
Simple example of using request_body may be found in
ngx_http_variables.c, in function
> So if I specify "client_body_in_single_buffer" as "true", does
> it store the entire client request in r->request_body->buf?
No. It will be in first buffer of r->request_body->bufs, either
in memory if it fits into client_body_buffer_size or in file.
> But if not, does it separate the client request body into the
> chunks of whatever client_body_buffer_size is set to, and then
> you use the chain to gain access to the entire thing?
Not exactly. Currently r->request_body->bufs will contain up to two
buffers: one for data preread with headers, and one for data got
later. If there are more data than client_body_buffer_size - the
last buffer will be in temporary file.
It's probably a good idea to spend some time reading
ngx_http_request_body.c for better clue what happens in various
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