Return to buffer.h CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / dhcp / includes / omapip

Annotation of embedaddon/dhcp/includes/omapip/buffer.h, revision 1.1.1.1

1.1       misho       1: /* buffer.h
                      2: 
                      3:    Definitions for the object management API protocol buffering... */
                      4: 
                      5: /*
                      6:  * Copyright (c) 2004,2009 by Internet Systems Consortium, Inc. ("ISC")
                      7:  * Copyright (c) 1996-2003 by Internet Software Consortium
                      8:  *
                      9:  * Permission to use, copy, modify, and distribute this software for any
                     10:  * purpose with or without fee is hereby granted, provided that the above
                     11:  * copyright notice and this permission notice appear in all copies.
                     12:  *
                     13:  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
                     14:  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
                     15:  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
                     16:  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
                     17:  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
                     18:  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
                     19:  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
                     20:  *
                     21:  *   Internet Systems Consortium, Inc.
                     22:  *   950 Charter Street
                     23:  *   Redwood City, CA 94063
                     24:  *   <info@isc.org>
                     25:  *   https://www.isc.org/
                     26:  *
                     27:  * This software has been written for Internet Systems Consortium
                     28:  * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
                     29:  * To learn more about Internet Systems Consortium, see
                     30:  * ``https://www.isc.org/''.  To learn more about Vixie Enterprises,
                     31:  * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
                     32:  * ``http://www.nominum.com''.
                     33:  */
                     34: 
                     35: /* OMAPI buffers are ring buffers, which means that the beginning of the
                     36:    buffer and the end of the buffer chase each other around.   As long as
                     37:    the tail never catches up to the head, there's room in the buffer for
                     38:    data.
                     39: 
                     40:        - If the tail and the head are equal, the buffer is empty.
                     41: 
                     42:        - If the tail is less than the head, the contents of the buffer
                     43:          are the bytes from the head to the end of buffer, and in addition,
                     44:          the bytes between the beginning of the buffer and the tail, not
                     45:          including the byte addressed by the tail.
                     46: 
                     47:        - If the tail is greater than the head, then the buffer contains
                     48:          valid bytes starting with the byte addressed by the head, and
                     49:          ending with the byte before the byte addressed by the tail.
                     50: 
                     51:    There will always be at least one byte of waste, because the tail can't
                     52:    increase so that it's equal to the head (that would represent an empty
                     53:    buffer. */
                     54: #define OMAPI_BUF_SIZE 4048
                     55: typedef struct _omapi_buffer {
                     56:        struct _omapi_buffer *next;     /* Buffers can be chained. */
                     57:        u_int32_t refcnt;               /* Buffers are reference counted. */
                     58:        u_int16_t head, tail;           /* Buffers are organized in a ring. */
                     59:        char buf [OMAPI_BUF_SIZE];      /* The actual buffer is included in
                     60:                                           the buffer data structure. */
                     61: } omapi_buffer_t;      
                     62: 
                     63: #define BUFFER_BYTES_FREE(x)   \
                     64:        ((x) -> tail > (x) -> head \
                     65:          ? sizeof ((x) -> buf) - ((x) -> tail - (x) -> head) \
                     66:          : (x) -> head - (x) -> tail)
                     67: 
                     68: #define BYTES_IN_BUFFER(x)     \
                     69:        ((x) -> tail > (x) -> head \
                     70:         ? (x) -> tail - (x) -> head - 1 \
                     71:         : sizeof ((x) -> buf) - ((x) -> head - (x) -> tail) - 1)
                     72: 
                     73: isc_result_t omapi_connection_require (omapi_object_t *, unsigned);
                     74: isc_result_t omapi_connection_copyout (unsigned char *,
                     75:                                       omapi_object_t *, unsigned);
                     76: isc_result_t omapi_connection_copyin (omapi_object_t *,
                     77:                                      const unsigned char *, unsigned);
                     78: isc_result_t omapi_connection_flush (omapi_object_t *);
                     79: isc_result_t omapi_connection_get_uint32 (omapi_object_t *, u_int32_t *);
                     80: isc_result_t omapi_connection_put_uint32 (omapi_object_t *, u_int32_t);
                     81: isc_result_t omapi_connection_get_uint16 (omapi_object_t *, u_int16_t *);
                     82: isc_result_t omapi_connection_put_uint16 (omapi_object_t *, u_int32_t);
                     83: