Remove "buf" field from port buffers

* libguile/ports-internal.h (scm_port_buffer_reset_end): New helper.
  (scm_port_buffer_putback): New helper.
* libguile/ports.h (scm_t_port_buffer): Remove "buf" field.
  (scm_get_byte_or_eof_unlocked, scm_peek_byte_or_eof_unlocked): Adapt.
* libguile/ports.c (scm_c_make_port_buffer): No more "buf" field.
  (scm_i_unget_bytes_unlocked): Use helper.
* libguile/read.c (scm_i_scan_for_encoding): No more "buf" field.

1 files changed, 20 insertions, 0 deletions

diff --git a/libguile/ports-internal.h b/libguile/ports-internal.h
index b3f15e187..14d00c2a6 100644
--- a/libguile/ports-internal.h
+++ b/libguile/ports-internal.h
@@ -22,6 +22,8 @@
 #ifndef SCM_PORTS_INTERNAL
 #define SCM_PORTS_INTERNAL
 
+#include <assert.h>
+
 #include "libguile/_scm.h"
 #include "libguile/ports.h"
 
@@ -37,6 +39,12 @@ scm_port_buffer_reset (scm_t_port_buffer *buf)
   buf->cur = buf->end = 0;
 }
 
+static inline void
+scm_port_buffer_reset_end (scm_t_port_buffer *buf)
+{
+  buf->cur = buf->end = scm_port_buffer_size (buf);
+}
+
 static inline size_t
 scm_port_buffer_can_take (scm_t_port_buffer *buf)
 {
@@ -96,6 +104,18 @@ scm_port_buffer_put (scm_t_port_buffer *buf, const scm_t_uint8 *src,
   return count;
 }
 
+static inline void
+scm_port_buffer_putback (scm_t_port_buffer *buf, const scm_t_uint8 *src,
+                         size_t count)
+{
+  assert (count <= buf->cur);
+
+  /* Sometimes used to move around data within a buffer, so we must use
+     memmove.  */
+  buf->cur -= count;
+  memmove (SCM_BYTEVECTOR_CONTENTS (buf->bytevector) + buf->cur, src, count);
+}
+
 enum scm_port_encoding_mode {
   SCM_PORT_ENCODING_MODE_UTF8,
   SCM_PORT_ENCODING_MODE_LATIN1,