From 07a9b8b58802575e1ec29a3c8b00e5fae1a94008 Mon Sep 17 00:00:00 2001
From: Michael Graff <mgraff@isc.org>
Date: Fri, 10 Sep 1999 21:13:39 +0000
Subject: [PATCH] Make a few helper macros which will return lengths of regions
 rather than requiring an isc_region_t to fill in.  Use these macros in a few
 places.

---
 lib/isc/buffer.c             | 16 ----------------
 lib/isc/bufferlist.c         |  4 ++--
 lib/isc/include/isc/buffer.h | 37 +++++++++++++++++-------------------
 lib/isc/unix/socket.c        | 20 +++++++++----------
 4 files changed, 29 insertions(+), 48 deletions(-)

diff --git a/lib/isc/buffer.c b/lib/isc/buffer.c
index 602a652e30..0f87b314f3 100644
--- a/lib/isc/buffer.c
+++ b/lib/isc/buffer.c
@@ -99,14 +99,6 @@ isc_buffer_used(isc_buffer_t *b, isc_region_t *r) {
 	r->length = b->used;
 }
 
-unsigned int
-isc_buffer_usedcount(isc_buffer_t *b)
-{
-	REQUIRE(ISC_BUFFER_VALID(b));
-
-	return (b->used);
-}
-
 void
 isc_buffer_available(isc_buffer_t *b, isc_region_t *r) {
 	/*
@@ -120,14 +112,6 @@ isc_buffer_available(isc_buffer_t *b, isc_region_t *r) {
 	r->length = b->length - b->used;
 }
 
-unsigned int
-isc_buffer_availablecount(isc_buffer_t *b)
-{
-	REQUIRE(ISC_BUFFER_VALID(b));
-
-	return (b->length - b->used);
-}
-
 void
 isc_buffer_add(isc_buffer_t *b, unsigned int n) {
 	/*
diff --git a/lib/isc/bufferlist.c b/lib/isc/bufferlist.c
index f701d1ef4e..945578a003 100644
--- a/lib/isc/bufferlist.c
+++ b/lib/isc/bufferlist.c
@@ -34,7 +34,7 @@ isc_bufferlist_usedcount(isc_bufferlist_t *bl)
 	buffer = ISC_LIST_HEAD(*bl);
 	while (buffer != NULL) {
 		REQUIRE(ISC_BUFFER_VALID(buffer));
-		length += buffer->used;
+		length += ISC_BUFFER_USEDCOUNT(buffer);
 		buffer = ISC_LIST_NEXT(buffer, link);
 	}
 
@@ -53,7 +53,7 @@ isc_bufferlist_availablecount(isc_bufferlist_t *bl)
 	buffer = ISC_LIST_HEAD(*bl);
 	while (buffer != NULL) {
 		REQUIRE(ISC_BUFFER_VALID(buffer));
-		length += (buffer->length - buffer->used);
+		length += ISC_BUFFER_AVAILABLECOUNT(buffer);
 		buffer = ISC_LIST_NEXT(buffer, link);
 	}
 
diff --git a/lib/isc/include/isc/buffer.h b/lib/isc/include/isc/buffer.h
index a265b8ff60..86f4618f26 100644
--- a/lib/isc/include/isc/buffer.h
+++ b/lib/isc/include/isc/buffer.h
@@ -117,6 +117,23 @@ ISC_LANG_BEGINDECLS
 #define ISC_BUFFER_VALID(b)		((b) != NULL && \
 					 (b)->magic == ISC_BUFFER_MAGIC)
 
+/*
+ * The following macros MUST be used only on valid buffers.  It is the
+ * caller's responsibility to ensure this by using the ISC_BUFFER_VALID
+ * check above, or by calling another isc_buffer_*() function (rather than
+ * another macro.)
+ */
+
+/*
+ * Get the length of the used region of buffer "b"
+ */
+#define ISC_BUFFER_USEDCOUNT(b)		((b)->used)
+
+/*
+ * Get the length of the available region of buffer "b"
+ */
+#define ISC_BUFFER_AVAILABLECOUNT(b)	((b)->length - (b)->used)
+
 /***
  *** Types
  ***/
@@ -254,16 +271,6 @@ isc_buffer_used(isc_buffer_t *b, isc_region_t *r);
  *	'r' points to a region structure.
  */
 
-unsigned int
-isc_buffer_usedcount(isc_buffer_t *b);
-/*
- * Return the size of the used region of buffer 'b'
- *
- * Requires:
- *
- *	'b' is a valid buffer.
- */
-
 void
 isc_buffer_available(isc_buffer_t *b, isc_region_t *r);
 /*
@@ -276,16 +283,6 @@ isc_buffer_available(isc_buffer_t *b, isc_region_t *r);
  *	'r' points to a region structure.
  */
 
-unsigned int
-isc_buffer_availablecount(isc_buffer_t *b);
-/*
- * Return the size of the available region of buffer 'b'
- *
- * Requires:
- *
- *	'b' is a valid buffer.
- */
-
 void
 isc_buffer_add(isc_buffer_t *b, unsigned int n);
 /*
diff --git a/lib/isc/unix/socket.c b/lib/isc/unix/socket.c
index a9f926a54e..11e25bfb37 100644
--- a/lib/isc/unix/socket.c
+++ b/lib/isc/unix/socket.c
@@ -350,10 +350,10 @@ build_msghdr_send(isc_socket_t *sock, isc_socketevent_t *dev,
 	 */
 	skip_count = dev->n;
 	while (buffer != NULL) {
-		isc_buffer_used(buffer, &used);
-		if (skip_count < used.length)
+		REQUIRE(ISC_BUFFER_VALID(buffer));
+		if (skip_count < ISC_BUFFER_USEDCOUNT(buffer))
 			break;
-		skip_count -= used.length;
+		skip_count -= ISC_BUFFER_USEDCOUNT(buffer);
 		buffer = ISC_LIST_NEXT(buffer, link);
 	}
 
@@ -447,8 +447,8 @@ build_msghdr_recv(isc_socket_t *sock, isc_socketevent_t *dev,
 	 * Skip empty buffers.
 	 */
 	while (buffer != NULL) {
-		isc_buffer_available(buffer, &available);
-		if (available.length != 0)
+		REQUIRE(ISC_BUFFER_VALID(buffer));
+		if (ISC_BUFFER_AVAILABLECOUNT(buffer) != 0)
 			break;
 		buffer = ISC_LIST_NEXT(buffer, link);
 	}
@@ -539,7 +539,6 @@ doio_recv(isc_socket_t *sock, isc_socketevent_t *dev)
 	size_t actual_count;
 	struct msghdr msghdr;
 	isc_buffer_t *buffer;
-	isc_region_t available;
 
 	build_msghdr_recv(sock, dev, &msghdr, iov,
 			  ISC_SOCKET_MAXSCATTERGATHER, &read_count);
@@ -613,10 +612,11 @@ doio_recv(isc_socket_t *sock, isc_socketevent_t *dev)
 	actual_count = cc;
 	buffer = ISC_LIST_HEAD(dev->bufferlist);
 	while (buffer != NULL && actual_count > 0) {
-		isc_buffer_available(buffer, &available);
-		if (available.length <= actual_count) {
-			actual_count -= available.length;
-			isc_buffer_add(buffer, available.length);
+		REQUIRE(ISC_BUFFER_VALID(buffer));
+		if (ISC_BUFFER_AVAILABLECOUNT(buffer) <= actual_count) {
+			actual_count -= ISC_BUFFER_AVAILABLECOUNT(buffer);
+			isc_buffer_add(buffer,
+				       ISC_BUFFER_AVAILABLECOUNT(buffer));
 		} else {
 			isc_buffer_add(buffer, actual_count);
 			actual_count = 0;