.\" (C) 2023, NGINX, Inc.
.\"
.TH nxt_unit_response_buf_alloc 3 (date) "NGINX Unit (unreleased)"
.SH Name
nxt_unit_response_buf_alloc,
nxt_unit_buf_send
\-
allocate buffer for response in Unit app
.SH Library
NGINX Unit library
.RI ( libunit ", " -lunit )
.SH Synopsis
.nf
.B #include <nxt_unit.h>
.PP
.B [[gnu::malloc(nxt_unit_buf_send)]]
.B nxt_unit_buf_t *_Nullable
.BI "nxt_unit_response_buf_alloc(nxt_unit_request_info_t *" req ", uint32_t " size );
.PP
.BI "int nxt_unit_buf_send(nxt_unit_buf_t *" buf );
.fi
.SH Arguments
.TP
.I req
Request object.
.TP
.I size
Size of the buffer.
.TP
.I buf
Buffer.
.SH Description
.MR nxt_unit_response_buf_alloc 3
allocates a buffer for a response to a request,
or for a chunk of it.
.PP
.MR nxt_unit_buf_send 3
sends and deallocates the buffer previously allocated with
.MR nxt_unit_response_buf_alloc 3 .
.SH Return value
.TP
.MR nxt_unit_response_buf_alloc 3
A pointer to the allocated buffer on success,
or NULL on error.
.TP
.MR nxt_unit_buf_send 3
0 on success,
or a non-zero error code on error.
.SH Errors
Errors will be reported in the Unit debug log.
.TP
.B NXT_UNIT_ERROR
.RS
.PD 0
.IP \[bu] 3
.I size
was too big.
.IP \[bu]
Allocation failed.
.IP \[bu]
Failed to share the buffer with
.MR unitd 8 .
.PD
.RE
.SH Examples
Below is a request and response pair,
and the source code to produce it.
.PP
See
.MR nxt_unit_init 3
for an example where the
.IR request_handler ()
function defined below is used.
.SS Request
.EX
.RB $ " echo \-e \[aq]GET / HTTP/1.1\er\enHost: _\en\[aq] | ncat localhost 80;"
HTTP/1.1 200 OK
Content\-Type: text/plain
Server: Unit/1.30.0
Date: Sat, 20 May 2023 19:08:22 GMT
Transfer\-Encoding: chunked
\&
22
Hello world!
But send this first.
\&
15
Some extra contents.
\&
e
And some more
\&
0
\&
.EE
.SS C code
.EX
#define _GNU_SOURCE
#include <string.h>
\&
#include <nxt_unit.h>
\&
void
request_handler(nxt_unit_request_info_t *req)
{
int rc;
nxt_unit_buf_t *buf, *buf2;
\&
rc = nxt_unit_response_init(req, 200, 1, strlen("Content\-Type")
+ strlen("text/plain")
+ strlen("Hello world!\en"));
if (rc != 0) {
goto fail;
}
\&
rc = nxt_unit_response_add_field(req, "Content\-Type",
strlen("Content\-Type"),
"text/plain",
strlen("text/plain"));
if (rc != 0) {
goto fail;
}
\&
rc = nxt_unit_response_add_content(req, "Hello world!\en",
strlen("Hello world!\en"));
if (rc != 0) {
goto fail;
}
\&
rc = nxt_unit_response_send(req);
if (rc != 0) {
goto fail;
}
\&
buf = nxt_unit_response_buf_alloc(req,
strlen("Some extra contents.\en"));
if (buf == NULL) {
rc = NXT_UNIT_ERROR;
goto fail;
}
\&
buf2 = nxt_unit_response_buf_alloc(req,
strlen("But send this first.\en"));
if (buf2 == NULL) {
rc = NXT_UNIT_ERROR;
goto fail;
}
\&
buf2\->free = mempcpy(buf2\->free, "But send this first.\en",
strlen("But send this first.\en"));
buf\->free = mempcpy(buf\->free, "Some extra contents.\en",
strlen("Some extra contents.\en"));
\&
rc = nxt_unit_buf_send(buf2);
if (rc != 0) {
goto fail;
}
\&
rc = nxt_unit_buf_send(buf);
if (rc != 0) {
goto fail;
}
\&
rc = nxt_unit_response_write(req, "And some more\en",
strlen("And some more\en"));
if (rc != 0) {
goto fail;
}
\&
fail:
nxt_unit_request_done(req, rc);
}
.EE
.SH Copyright
(C) 2017-2023, NGINX, Inc.
.PP
SPDX-License-Identifier: Apache-2.0
.SH See also
.MR nxt_unit_init 3 ,
.MR nxt_unit_response_init 3 ,
.MR nxt_unit_response_write 3 ,
.MR unitd 8
.PP
.UR https://unit.nginx.org
Website
.UE
.PP
.UR https://mailman.nginx.org/mailman/listinfo/unit
Mailing list
.UE
.PP
.UR https://github.com/nginx/unit
GitHub
.UE
