Ns_UrlSpecificGet(3) Store and retrieve URL-specific data

Other Alias

Ns_UrlSpecificAlloc, Ns_UrlSpecificDestroy, Ns_UrlSpecificGetExact, Ns_UrlSpecificGetFast, Ns_UrlSpecificSet

SYNOPSIS

#include "ns.h"



int
Ns_UrlSpecificAlloc(void)


void *
Ns_UrlSpecificDestroy(char *server, char *method, char *url,
int id, int flags
)


void *
Ns_UrlSpecificGet(char *server, char *method, char *url,
int id
)


void *
Ns_UrlSpecificGetExact(char *server, char *method, char *url,
int id, int flags
)


void *
Ns_UrlSpecificGetFast(char *server, char *method, char *url,
int id
)


void
Ns_UrlSpecificSet(char *server, char *method, char *url,
int id, void *data, int flags, void (*deletefunc) (void *)
)



DESCRIPTION

These functions allow you to store URL-specific data in memory for later retrieval. They are used when registering procedures for example.

Ns_UrlSpecificAlloc()

Return a unique ID used to identify a unique virtual URL-space that is then used with the Ns_UrlSpecific storage functions. You should only call this function at server startup, and not after. Here is an example:

static int myId;
void
Init(void)
{
    /* Allocate the id once at startup. */
    myId = Ns_UrlSpecificAlloc();
}
void
Store(char *server, char *method, char *url, char *data)
{
    Ns_UrlSpecificSet(server, method, url, myId,
    data, 0, NULL);
}
char *
Fetch(char *server, char *method, char *url)
{
    char *data;
    data = Ns_UrlSpecificGet(server, method, url, myId);
    return (char *) data;
}
Ns_UrlSpecificDestroy(server, method, url, id, flags)

The Ns_UrlSpecificDestroy function deletes URL-specific data previously stored with Ns_UrlSpecificSet with the same method/URL combination and the same inheritance setting.

An id of -1 matches all ids. For example, Ns_UrlSpecificDestroy("myserver", "GET", "/", -1, NS_OP_RECURSE) removes all data for the method GET for server "myserver".

The flags argument can be:

NS_OP_NODELETE - If set, the deletefunc specified in Ns_UrlSpeciciSet is run.
NS_OP_RECURSE - If set, then data for all URLs more specific than the passed-in URL are also destroyed.
NS_OP_NOINHERIT - If set, data that was stored with this flag in Ns_UrlSpecificSet will be deleted. If not set, the data stored without this flag will be deleted.
Ns_UrlSpecificGet(server, method, url, id)

The Ns_UrlSpecificGet function retrieves the best match that it can find for in the URL subspace identified by id that the passed-in URL matches. For instance, suppose you had previously registered a handle/method/url/id combination of {myserver, GET, /, 1} and {myserver, GET, /inventory, 1}. The following call would match the data registered at {myserver, GET, /inventory, 1}:

Ns_UrlSpecificGet("myserver", "GET", "/inventory/RJ45", 1)
Ns_UrlSpecificGetExact(server, method, url, id, flags)

Retrieves stored data for the exact method/URL/id combination specified that was stored with the same inheritance setting.

If the flags argument is set to NS_OP_NOINHERIT, the data stored with NS_OP_NOINHERIT will be retrieved. If the flags argument is set to 0, the data stored without NS_OP_NOINHERIT will be retrieved.

Ns_UrlSpecificGetFast(server, method, url, id)

Same as Ns_UrlSpecificGet but does not support wildcards, making it much faster.

Ns_UrlSpecificSet(server, method, url, id, data, flags, deletefunc)

The Ns_UrlSpecificSet function stores data in memory, allowing subsequent retrieval using handle, method, url, id, and inheritance flag.

The flags argument can be NS_OP_NOINHERIT or NS_OP_NODELETE. You can store two sets of data based on the same handle, method, url, and id combination-- one set with inheritance on and one set with inheritance off. If the NS_OP_NOINHERIT flag is set, the data is stored based on the exact URL. If NS_OP_NOINHERIT is omitted, the data is stored based on the specified URL and any URL below it. In this case, Ns_UrlSpecificGetExact will match to the closest URL when retrieving the data.

The deletefunc argument is called with data as an argument when this handle/url/method/id combination is re-registered or deleted, or when this server shuts down. unless NS_OP_NODELETE is set.

Normally, calling Ns_UrlSpecificSet on a handle/url/method/id combination which already has an operation registered for it causes the previous operation's delete procedure to be called. You can override this behavior by adding the NS_OP_NODELETE flag.

KEYWORDS