Port read/write functions take bytevectors

This will allow better Scheme integration for ports.

* libguile/ports.h (scm_t_port_buffer): Change "holder" member to be a
  bytevector defined to have "buf" as its starting point.
  (scm_t_ptob_descriptor): Change read and write functions to take
  bytevectors as arguments and to return the number of octets read or
  written.
  (scm_make_port_type): Adapt accordingly.
  (scm_c_read_bytes, scm_c_write_bytes): New functions that take
  bytevectors.
* libguile/ports.c (scm_make_port_type): Adapt to read/write function
  prototype change.
  (scm_c_make_port_buffer): Arrange to populate the "bytevector" field.
  (scm_i_read_bytes_unlocked): New function.
  (scm_i_read_unlocked): Use scm_i_read_bytes_unlocked.
  (scm_c_read_bytes_unlocked): New function.
  (scm_c_read_unlocked): Update comment, and always go through the
  buffer.
  (scm_c_read_bytes): New function.
  (scm_flush_unlocked): Use scm_i_write_unlocked instead of the port's
  write function.
  (scm_i_write_bytes_unlocked): New function.
  (scm_i_write_unlocked): Use scm_i_write_bytes_unlocked.
  (scm_c_write_bytes_unlocked): New function.
  (scm_c_write_unlocked): Always write through the buffer.
  (scm_c_write_bytes): New function.
  (scm_truncate_file): Remove unused variable.
  (void_port_read, void_port_write): Adapt to read/write prototype
  change.
* libguile/fports.c (fport_read, fport_write):
* libguile/r6rs-ports.c (bytevector_input_port_read)
  (custom_binary_input_port_read, bytevector_output_port_write)
  (custom_binary_output_port_write, transcoded_port_write)
  (transcoded_port_read): Adapt to read/write prototype
  change.
  (scm_get_bytevector_n, scm_get_bytevector_n_x)
  (scm_get_bytevector_all): Use scm_c_read_bytes.
  (scm_put_bytevector): Use scm_c_write_bytes.
* libguile/strports.c (string_port_read, string_port_write):
* libguile/vports.c (soft_port_write, soft_port_read): Adapt to
  read/write prototype change.
* test-suite/standalone/test-scm-c-read.c (custom_port_read): Fix for
  read API change.

1 files changed, 13 insertions, 14 deletions

diff --git a/libguile/strports.c b/libguile/strports.c
index 6ad7d18f2..e8ce67a8f 100644
--- a/libguile/strports.c
+++ b/libguile/strports.c
@@ -60,31 +60,29 @@ struct string_port {
   size_t len;
 };
 
-static void
-string_port_read (SCM port, scm_t_port_buffer *dst)
+static size_t
+string_port_read (SCM port, SCM dst, size_t start, size_t count)
 {
-  size_t count;
   struct string_port *stream = (void *) SCM_STREAM (port);
 
   if (stream->pos >= stream->len)
-    return;
+    return 0;
 
-  count = stream->len - stream->pos;
-  if (count > dst->size - dst->end)
-    count = dst->size - dst->end;
+  if (count > stream->len - stream->pos)
+    count = stream->len - stream->pos;
 
-  memcpy (dst->buf + dst->end,
+  memcpy (SCM_BYTEVECTOR_CONTENTS (dst) + start,
           SCM_BYTEVECTOR_CONTENTS (stream->bytevector) + stream->pos,
           count);
-  dst->end += count;
+
   stream->pos += count;
+  return count;
 }
 
-static void
-string_port_write (SCM port, scm_t_port_buffer *src)
+static size_t
+string_port_write (SCM port, SCM src, size_t start, size_t count)
 {
   struct string_port *stream = (void *) SCM_STREAM (port);
-  size_t count = src->end - src->cur;
 
   if (SCM_BYTEVECTOR_LENGTH (stream->bytevector) < stream->pos + count)
     {
@@ -101,12 +99,13 @@ string_port_write (SCM port, scm_t_port_buffer *src)
     }
 
   memcpy (SCM_BYTEVECTOR_CONTENTS (stream->bytevector) + stream->pos,
-          src->buf + src->cur,
+          SCM_BYTEVECTOR_CONTENTS (src) + start,
           count);
-  src->cur += count;
   stream->pos += count;
   if (stream->pos > stream->len)
     stream->len = stream->pos;
+
+  return count;
 }
 
 static scm_t_off