introduce macro SIZE_LEFT and function buf_grow() from OpenRCS

buf_grow() replaces macro BUF_GROW()

ok nicm@, ray@

diff --git a/usr.bin/cvs/buf.c b/usr.bin/cvs/buf.c
index 85a3ebe..dd16124 100644 (file)
--- a/usr.bin/cvs/buf.c
+++ b/usr.bin/cvs/buf.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: buf.c,v 1.76 2010/07/23 21:46:05 ray Exp $    */
+/*     $OpenBSD: buf.c,v 1.77 2010/07/31 16:28:31 zinovik Exp $        */
 /*
  * Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
  * All rights reserved.
@@ -38,11 +38,6 @@
 #include "buf.h"
 
 #define BUF_INCR       128
-#define BUF_GROW(bp, len)                                              \
-       do {                                                            \
-               b->cb_buf = xrealloc(b->cb_buf, 1, b->cb_size + len);   \
-               b->cb_size += len;                                      \
-       } while (0);
 
 struct buf {
        u_char  *cb_buf;
@@ -50,6 +45,10 @@ struct buf {
        size_t   cb_len;
 };
 
+#define SIZE_LEFT(b)   (b->cb_size - b->cb_len)
+
+static void    buf_grow(BUF *, size_t);
+
 BUF *
 buf_alloc(size_t len)
 {
@@ -130,7 +129,7 @@ buf_putc(BUF *b, int c)
 
        bp = b->cb_buf + b->cb_len;
        if (bp == (b->cb_buf + b->cb_size)) {
-               BUF_GROW(b, BUF_INCR);
+               buf_grow(b, BUF_INCR);
                bp = b->cb_buf + b->cb_len;
        }
        *bp = (u_char)c;
@@ -147,17 +146,14 @@ void
 buf_append(BUF *b, const void *data, size_t len)
 {
        size_t left;
-       u_char *bp, *bep;
+       u_char *bp;
 
-       bp = b->cb_buf + b->cb_len;
-       bep = b->cb_buf + b->cb_size;
-       left = bep - bp;
+       left = SIZE_LEFT(b);
 
-       if (left < len) {
-               BUF_GROW(b, len - left);
-               bp = b->cb_buf + b->cb_len;
-       }
+       if (left < len)
+               buf_grow(b, len - left);
 
+       bp = b->cb_buf + b->cb_len;
        memcpy(bp, data, len);
        b->cb_len += len;
 }
@@ -241,3 +237,16 @@ buf_differ(const BUF *b1, const BUF *b2)
 
        return (memcmp(b1->cb_buf, b2->cb_buf, b1->cb_len));
 }
+
+/*
+ * buf_grow()
+ *
+ * Grow the buffer <b> by <len> bytes.  The contents are unchanged by this
+ * operation regardless of the result.
+ */
+static void
+buf_grow(BUF *b, size_t len)
+{
+       b->cb_buf = xrealloc(b->cb_buf, 1, b->cb_size + len);
+       b->cb_size += len;
+}