X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/410c8acf139e945dce28bbc0c8b17dcfd0815643..110d564e1b2a4d97b99cc34e1481fa6279ad9695:/buf.c

diff --git a/buf.c b/buf.c
index 9f14cf62..dfa62051 100644
--- a/buf.c
+++ b/buf.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: buf.c,v 1.1 2001/02/03 20:26:37 mdw Exp $
+ * $Id: buf.c,v 1.4 2001/06/19 22:09:54 mdw Exp $
  *
  * Buffer handling
  *
@@ -29,6 +29,16 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: buf.c,v $
+ * 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.
  *
@@ -36,7 +46,11 @@
 
 /*----- Header files ------------------------------------------------------*/
 
-#include "tripe.h"
+#include <string.h>
+
+#include <catacomb/mp.h>
+
+#include "buf.h"
 
 /*----- Main code ---------------------------------------------------------*/
 
@@ -69,6 +83,22 @@ void buf_init(buf *b, void *p, size_t sz)
 
 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
@@ -84,21 +114,22 @@ int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); }
 /* --- @buf_get@ --- *
  *
  * Arguments:	@buf *b@ = pointer to a buffer block
- *		@void *p@ = pointer to a buffer
  *		@size_t sz@ = size of the buffer
  *
- * Returns:	Zero if it worked, nonzero if there wasn't enough data.
+ * Returns:	Pointer to the place in the buffer.
  *
- * Use:		Fetches data from the buffer into some other place.
+ * Use:		Reserves a space in the buffer of the requested size, and
+ *		returns its start address.
  */
 
-int buf_get(buf *b, void *p, size_t sz)
+void *buf_get(buf *b, size_t sz)
 {
+  void *p;
   if (BENSURE(b, sz))
-    return (-1);
-  memcpy(p, BCUR(b), sz);
+    return (0);
+  p = BCUR(b);
   BSTEP(b, sz);
-  return (0);
+  return (p);
 }
 
 /* --- @buf_put@ --- *
@@ -155,7 +186,45 @@ int buf_putbyte(buf *b, int ch)
   return (0);
 }
 
-/* --- @buf_getword@ --- *
+/* --- @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
@@ -165,7 +234,7 @@ int buf_putbyte(buf *b, int ch)
  * Use:		Gets a 32-bit word from a buffer.
  */
 
-int buf_getword(buf *b, uint32 *w)
+int buf_getu32(buf *b, uint32 *w)
 {
   if (BENSURE(b, 4))
     return (-1);
@@ -174,7 +243,7 @@ int buf_getword(buf *b, uint32 *w)
   return (0);
 }
 
-/* --- @buf_putword@ --- *
+/* --- @buf_putu32@ --- *
  *
  * Arguments:	@buf *b@ = pointer to a buffer block
  *		@uint32 w@ = word to write
@@ -184,7 +253,7 @@ int buf_getword(buf *b, uint32 *w)
  * Use:		Puts a 32-but word in a buffer.
  */
 
-int buf_putword(buf *b, uint32 w)
+int buf_putu32(buf *b, uint32 w)
 {
   if (BENSURE(b, 4))
     return (-1);
@@ -202,14 +271,19 @@ int buf_putword(buf *b, uint32 w)
  * Use:		Gets a multiprecision integer from a buffer.
  */
 
-mp *buf_getmp(buf *b, mp *d)
+mp *buf_getmp(buf *b)
 {
-  uint32 sz;
-  if (buf_getword(b, &sz) || buf_ensure(b, sz))
+  uint16 sz;
+  mp *m;
+  if (buf_getu16(b, &sz) || buf_ensure(b, sz))
+    return (0);
+  m = mp_loadb(MP_NEW, BCUR(b), sz);
+  if (mp_octets(m) != sz) {
+    mp_drop(m);
     return (0);
-  d = mp_loadb(d, BCUR(b), sz);
+  }
   BSTEP(b, sz);
-  return (d);
+  return (m);
 }
 
 /* --- @buf_putmp@ --- *
@@ -225,7 +299,8 @@ mp *buf_getmp(buf *b, mp *d)
 int buf_putmp(buf *b, mp *m)
 {
   size_t sz = mp_octets(m);
-  if (buf_putword(b, sz) || buf_ensure(b, sz))
+  assert(sz < MASK16);
+  if (buf_putu16(b, sz) || buf_ensure(b, sz))
     return (-1);
   mp_storeb(m, BCUR(b), sz);
   BSTEP(b, sz);