#include "ns.h"
int
int
Ns_ConnReturnOpenChannel(conn, status, type, chan, len)
int
Ns_ConnReturnOpenFd(conn, status, type, fd, len)
int
Ns_ConnReturnOpenFdex(conn, status, type, fd, off, len)
int
Ns_ConnReturnOpenFile(conn, status, type, fp, len)
- Tcl_Channel chan (in)
- Pointer to Tcl_Channel open for read.
- Ns_Conn conn (in)
- Pointer to open connection.
- FILE *fp (in)
- Pointer to stdio FILE open for read.
- off_t off (in)
- Seek offset.
- int fd (int)
- File descriptor open for read.
- int status (in)
- HTTP status code.
- char *type (in)
- Pointer to mimetype string.
These routines are used to generate complete responses, including
headers, status codes, content types, and the content copied from the given
open file. They all return a status code which is NS_OK if the response was
sent or NS_ERROR if an underlying call to sent the content failed. The
response will include the given HTTP status code, a
content-type header with the given type, and a
content-length header with the length specified by len. No
character output encoding or gzip compression is performed on the
content.
For Ns_ConnReturnOpenFdEx, copying begins at the offset
specified by the off argument Otherwise, these routines copy from the
current read offset in the underlying open file. No attempt is made to
serialize access to the underlying object so independent open file objects
and/or mutex locking is necessary if the same file is being sent
simultaneously to multiple clients.
- Windows Support
- The Ns_ConnReturnOpenFdEx routine is not currently supported on
Windows. When called on Windows, it will always return NS_ERROR.
- Truncated
Result
- The server will construct a content-length header based on the
given len argument. However, the server will send the content with
an underlying call to a cooresponding Ns_ConnSend function, e.g.,
Ns_ConnSendFd for Ns_ConnReturnOpenFd. These functions will
send the requested content or all remaining content in the open file if
less bytes are avilable without reporting an error due to the truncated
response. As the headers will have already been flushed before sending the
content in this case, the content-length header will not be
consistent with the actual bytes sent. If it is not possible to ensure the
remaining bytes will be equal or greater to the requested bytes to send,
it is possible to specify -1 for len to supress the
content-length header entirely. Most browsers will accept this
resonse and simply calculate the length from the bytes receieved up until
the socket is closed.
- Performance
Consideration
- As mentioned, these routines use underlying Ns_ConnSendFd style
routines to copy and send the content from open files. This is not the
approach used by the builtin file-serving code (aka the
"fastpath"). The fastpath operates with filenames, not open file
objects, and maintains a cached of pre-read or memory mapped regions to
accelerate the common case of rapidly sending reasonably sized content to
multiple, simultaneous clients. The Ns_ConnReturnFile routine
utilizes the underlying fastpath and thus could be a faster means to send
static files than directly opening files and calling these API's.
connnection, response, file