Initial curl_multi_socket() stuff, #ifdef'ed out for now but committed for

 * $Id$

 ***************************************************************************/

/*

  This is meant to be the "external" header file. Don't give away any

  internals here!

  This is an "external" header file. Don't give away any internals here!

  This document presents a mixture of ideas from at least:

  - Daniel Stenberg

  - Steve Dekorte

  - Sterling Hughes

  - Ben Greear

  -------------------------------------------

  GOALS

  o Enable a "pull" interface. The application that uses libcurl decides where

typedef void CURLM;

#ifdef HAVE_CURL_MULTI_SOCKET /* this is not set by anything yet */

#ifndef curl_socket_typedef

/* Public socket typedef */

#ifdef WIN32

typedef SOCKET curl_socket_t;

#define CURL_SOCKET_BAD INVALID_SOCKET

#else

typedef int curl_socket_t;

#define CURL_SOCKET_BAD -1

#endif

#define curl_socket_typedef

#endif /* curl_socket_typedef */

#endif /* HAVE_CURL_MULTI_SOCKET */

typedef enum {

  CURLM_CALL_MULTI_PERFORM=-1, /* please call curl_multi_perform() soon */

  CURLM_OK,

 * Name:    curl_multi_init()

 *

 * Desc:    inititalize multi-style curl usage

 *

 * Returns: a new CURLM handle to use in all 'curl_multi' functions.

 */

CURL_EXTERN CURLM *curl_multi_init(void);

 * Name:    curl_multi_add_handle()

 *

 * Desc:    add a standard curl handle to the multi stack

 *

 * Returns: CURLMcode type, general multi error code.

 */

CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle,

  * Name:    curl_multi_remove_handle()

  *

  * Desc:    removes a curl handle from the multi stack again

  *

  * Returns: CURLMcode type, general multi error code.

  */

CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle,

  * Desc:    Ask curl for its fd_set sets. The app can use these to select() or

  *          poll() on. We want curl_multi_perform() called as soon as one of

  *          them are ready.

  *

  * Returns: CURLMcode type, general multi error code.

  */

CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle,

  *          touch any individual easy handles in any way. We need to define

  *          in what state those handles will be if this function is called

  *          in the middle of a transfer.

  *

  * Returns: CURLMcode type, general multi error code.

  */

CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle);

                                          int *msgs_in_queue);

/*

 * NAME curl_multi_strerror()

 * Name:    curl_multi_strerror()

 *

 * DESCRIPTION

 * Desc:    The curl_multi_strerror function may be used to turn a CURLMcode

 *          value into the equivalent human readable error string.  This is

 *          useful for printing meaningful error messages.

 *

 * The curl_multi_strerror function may be used to turn a CURLMcode value

 * into the equivalent human readable error string.  This is useful

 * for printing meaningful error messages.

 * Returns: A pointer to a zero-terminated error message.

 */

CURL_EXTERN const char *curl_multi_strerror(CURLMcode);

#ifdef HAVE_CURL_MULTI_SOCKET

/*

 * Name:    curl_multi_socket() and

 *          curl_multi_socket_all()

 *

 * Desc:    An alternative version of curl_multi_perform() that allows the

 *          application to pass in one of the file descriptors that have been

 *          detected to have "action" on them and let libcurl perform. This

 *          allows libcurl to not have to scan through all possible file

 *          descriptors to check for this. The app is recommended to pass in

 *          the 'easy' argument (or set it to CURL_EASY_NONE) to make libcurl

 *          figure out the internal structure even faster and easier.  If the

 *          easy argument is set to something else than CURL_EASY_NONE, the

 *          's' (socket) argument will be ignored by libcurl.

 *

 *          It also informs the application about updates in the socket (file

 *          descriptor) status by doing none, one or multiple calls to the

 *          curl_socket_callback. It thus updates the status with changes

 *          since the previous time this function was used. If 'callback' is

 *          NULL, no callback will be called. A status change may also be a

 *          new timeout only, having the same IN/OUT status as before.

 *

 *          If a previous wait for socket action(s) timed out, you should call

 *          this function with the socket argument set to

 *          CURL_SOCKET_TIMEOUT. If you want to force libcurl to (re-)check

 *          all its internal sockets, and call the callback with status for

 *          all sockets no matter what the previous state is, you call

 *          curl_multi_socket_all() instead.

 *

 *          curl_multi_perform() is thus the equivalent of calling

 *          curl_multi_socket_all(handle, NULL, NULL);

 *

 *          IMPLEMENTATION: libcurl will need an internal hash table to map

 *          socket numbers to internal easy handles for the cases when 'easy'

 *          is set to CURL_EASY_NONE.

 *

 *          Regarding the timeout argument in the callback: it is the timeout

 *          (in milliseconds) for waiting on action on this socket (and the

 *          given time period starts when the callback is called) until you

 *          should call curl_multi_socket() with the timeout stuff mentioned

 *          above. If "actions" happens on the socket before the timeout

 *          happens, remember that the timout timer keeps ticking until told

 *          otherwise.

 *

 *          The "what" argument has one of five values:

 *

 *            0 CURL_POLL_NONE (0)   - register, not interested in readiness

 *            1 CURL_POLL_IN         - register, interested in read readiness

 *            2 CURL_POLL_OUT        - register, interested in write readiness

 *            3 CURL_POLL_INOUT      - register, interested in both

 *            4 CURL_POLL_REMOVE     - deregister

 */

#define CURL_POLL_NONE   0

#define CURL_POLL_IN     1

#define CURL_POLL_OUT    2

#define CURL_POLL_INOUT  3

#define CURL_POLL_REMOVE 4

#define CURL_EASY_NONE (CURL *)0

#define CURL_EASY_TIMEOUT (CURL *)0

#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD

typedef int (*curl_socket_callback)(CURL *easy,      /* easy handle */

                                    curl_socket_t s, /* socket */

                                    int what,        /* see above */

                                    long ms,         /* timeout for wait */

                                    void *userp);    /* "private" pointer */

CURLMcode curl_multi_socket(CURLM *multi_handle,

                            curl_socket_t s,

                            CURL *easy,

                            curl_socket_callback callback,

                            void *userp); /* passed to callback */

CURLMcode curl_multi_socket_all(CURLM *multi_handle,

                                curl_socket_callback callback,

                                void *userp); /* passed to callback */

/*

 * Name:    curl_multi_timeout()

 *

 * Desc:    Returns the maximum number of milliseconds the app is allowed to

 *          wait before curl_multi_socket() or curl_multi_perform() must be

 *          called (to allow libcurl's timed events to take place).

 *

 * Returns: CURLM error code.

 */

CURLMcode curl_multi_timeout(CURLM *multi_handle, long *milliseconds);

#endif /* HAVE_CURL_MULTI_SOCKET */

#ifdef __cplusplus

} /* end of extern "C" */

#endif