/* -*-c-*-
*
- * $Id: buf.c,v 1.3 2004/04/01 12:50:09 mdw Exp $
+ * $Id$
*
* Buffer handling
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: buf.c,v $
- * Revision 1.3 2004/04/01 12:50:09 mdw
- * Add cyclic group abstraction, with test code. Separate off exponentation
- * functions for better static linking. Fix a buttload of bugs on the way.
- * Generally ensure that negative exponents do inversion correctly. Add
- * table of standard prime-field subgroups. (Binary field subgroups are
- * currently unimplemented but easy to add if anyone ever finds a good one.)
- *
- * Revision 1.2 2003/11/10 22:18:30 mdw
- * Build fixes.
- *
- * Revision 1.1 2003/10/11 21:02:33 mdw
- * Import buf stuff from tripe.
- *
- * Revision 1.4 2001/06/19 22:09:54 mdw
- * Expose interface, for use in the proxy.
- *
- * Revision 1.3 2001/03/03 12:06:48 mdw
- * Use 16-bit lengths on MPs, since there's a packet limit of 64K anyway.
- *
- * Revision 1.2 2001/02/16 21:23:20 mdw
- * Various minor changes. Check that MPs are in canonical form when
- * loading.
- *
- * Revision 1.1 2001/02/03 20:26:37 mdw
- * Initial checkin.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
#include <string.h>
/*----- Main code ---------------------------------------------------------*/
-/* --- @buf_init@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @void *p@ = pointer to a buffer
- * @size_t sz@ = size of the buffer
- *
- * Returns: ---
- *
- * Use: Initializes the buffer block appropriately.
- */
-
-void buf_init(buf *b, void *p, size_t sz)
-{
- b->base = b->p = p;
- b->limit = b->p + sz;
- b->f = 0;
-}
-
-/* --- @buf_break@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- *
- * Returns: Some negative value.
- *
- * Use: Marks a buffer as broken.
- */
-
-int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); }
-
-/* --- @buf_flip@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- *
- * Returns: ---
- *
- * Use: Flips a buffer so that if you've just been writing to it,
- * you can now read from the bit you've written.
- */
-
-void buf_flip(buf *b)
-{
- b->limit = b->p;
- b->p = b->base;
-}
-
-/* --- @buf_ensure@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @size_t sz@ = size of data wanted
- *
- * Returns: Zero if it worked, nonzero if there wasn't enough space.
- *
- * Use: Ensures that there are @sz@ bytes still in the buffer.
- */
-
-int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); }
-
-/* --- @buf_get@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @size_t sz@ = size of the buffer
- *
- * Returns: Pointer to the place in the buffer.
- *
- * Use: Reserves a space in the buffer of the requested size, and
- * returns its start address.
- */
-
-void *buf_get(buf *b, size_t sz)
-{
- void *p;
- if (BENSURE(b, sz))
- return (0);
- p = BCUR(b);
- BSTEP(b, sz);
- return (p);
-}
-
-/* --- @buf_put@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @const void *p@ = pointer to a buffer
- * @size_t sz@ = size of the buffer
- *
- * Returns: Zero if it worked, nonzero if there wasn't enough space.
- *
- * Use: Fetches data from some place and puts it in the buffer
- */
-
-int buf_put(buf *b, const void *p, size_t sz)
-{
- if (BENSURE(b, sz))
- return (-1);
- memcpy(BCUR(b), p, sz);
- BSTEP(b, sz);
- return (0);
-}
-
-/* --- @buf_getbyte@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- *
- * Returns: A byte, or less than zero if there wasn't a byte there.
- *
- * Use: Gets a single byte from a buffer.
- */
-
-int buf_getbyte(buf *b)
-{
- if (BENSURE(b, 1))
- return (-1);
- return (*b->p++);
-}
-
-/* --- @buf_putbyte@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @int ch@ = byte to write
- *
- * Returns: Zero if OK, nonzero if there wasn't enough space.
- *
- * Use: Puts a single byte in a buffer.
- */
-
-int buf_putbyte(buf *b, int ch)
-{
- if (BENSURE(b, 1))
- return (-1);
- *b->p++ = ch;
- return (0);
-}
-
-/* --- @buf_getu16@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @uint16 *w@ = where to put the word
- *
- * Returns: Zero if OK, or nonzero if there wasn't a word there.
- *
- * Use: Gets a 16-bit word from a buffer.
- */
-
-int buf_getu16(buf *b, uint16 *w)
-{
- if (BENSURE(b, 2))
- return (-1);
- *w = LOAD16(b->p);
- BSTEP(b, 2);
- return (0);
-}
-
-/* --- @buf_putu16@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @uint16 w@ = word to write
- *
- * Returns: Zero if OK, nonzero if there wasn't enough space.
- *
- * Use: Puts a 16-but word in a buffer.
- */
-
-int buf_putu16(buf *b, uint16 w)
-{
- if (BENSURE(b, 2))
- return (-1);
- STORE16(b->p, w);
- BSTEP(b, 2);
- return (0);
-}
-
-/* --- @buf_getu32@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @uint32 *w@ = where to put the word
- *
- * Returns: Zero if OK, or nonzero if there wasn't a word there.
- *
- * Use: Gets a 32-bit word from a buffer.
- */
-
-int buf_getu32(buf *b, uint32 *w)
-{
- if (BENSURE(b, 4))
- return (-1);
- *w = LOAD32(b->p);
- BSTEP(b, 4);
- return (0);
-}
-
-/* --- @buf_putu32@ --- *
- *
- * Arguments: @buf *b@ = pointer to a buffer block
- * @uint32 w@ = word to write
- *
- * Returns: Zero if OK, nonzero if there wasn't enough space.
- *
- * Use: Puts a 32-but word in a buffer.
- */
-
-int buf_putu32(buf *b, uint32 w)
-{
- if (BENSURE(b, 4))
- return (-1);
- STORE32(b->p, w);
- BSTEP(b, 4);
- return (0);
-}
-
/* --- @buf_getmp@ --- *
*
* Arguments: @buf *b@ = pointer to a buffer block