[Guile-commits] 04/15: Remove port rw_active field

[Andy Wingo]

wingo pushed a commit to branch wip-port-refactor
in repository guile.

commit 69a1b83f31824cc23c7c4d60144de2225517c76f
Author: Andy Wingo <address@hidden>
Date:   Fri Apr 22 21:08:30 2016 +0200

    Remove port rw_active field
    
    * libguile/ports.h (scm_t_port_rw_active): Move type definition to
      ports-internal.h.
      (scm_t_port): Remove rw_active field.  It's sufficient to check the
      port buffer cursors.
    * libguile/read.c (scm_i_scan_for_encoding): Just call
      scm_flush_unlocked; it's idempotent.
    * libguile/ports.c (scm_c_make_port_with_encoding): Remove rw_active
      field.
      (scm_c_read_bytes_unlocked, scm_c_read, scm_i_unget_bytes_unlocked)
      (scm_end_input_unlocked, scm_flush_unlocked, scm_fill_input_unlocked)
      (scm_port_write_buffer, scm_port_read_buffer)
      (scm_c_write_bytes_unlocked, scm_c_write_unlocked, scm_seek): Remove
      management of rw_active field.
---
 libguile/ports-internal.h |    6 +++++
 libguile/ports.c          |   63 +++++++--------------------------------------
 libguile/ports.h          |   12 ---------
 libguile/read.c           |    6 +----
 4 files changed, 17 insertions(+), 70 deletions(-)

diff --git a/libguile/ports-internal.h b/libguile/ports-internal.h
index 19e49a7..5eeefb9 100644
--- a/libguile/ports-internal.h
+++ b/libguile/ports-internal.h
@@ -232,6 +232,12 @@ typedef struct scm_port_internal scm_t_port_internal;
 
 #define SCM_PORT_GET_INTERNAL(x)  (SCM_PTAB_ENTRY(x)->internal)
 
+typedef enum scm_t_port_rw_active {
+  SCM_PORT_NEITHER = 0,
+  SCM_PORT_READ = 1,
+  SCM_PORT_WRITE = 2
+} scm_t_port_rw_active;
+
 SCM_INTERNAL scm_t_iconv_descriptors *
 scm_i_port_iconv_descriptors (SCM port, scm_t_port_rw_active mode);
 
diff --git a/libguile/ports.c b/libguile/ports.c
index a59c8d8..8181056 100644
--- a/libguile/ports.c
+++ b/libguile/ports.c
@@ -698,7 +698,6 @@ scm_c_make_port_with_encoding (scm_t_bits tag, unsigned 
long mode_bits,
   /* By default, any port type with a seek function has random-access
      ports.  */
   entry->rw_random = ptob->seek != NULL;
-  entry->rw_active = SCM_PORT_NEITHER;
   entry->port = ret;
   entry->stream = stream;
 
@@ -1502,11 +1501,7 @@ scm_c_read_bytes_unlocked (SCM port, SCM dst, size_t 
start, size_t count)
   read_buf = pt->read_buf;
 
   if (pt->rw_random)
-    {
-      if (pt->rw_active == SCM_PORT_WRITE)
-        scm_flush_unlocked (port);
-      pt->rw_active = SCM_PORT_READ;
-    }
+    scm_flush_unlocked (port);
 
   /* Take bytes first from the port's read buffer. */
   {
@@ -1569,16 +1564,7 @@ scm_c_read (SCM port, void *buffer, size_t size)
   read_buf = pt->read_buf;
 
   if (pt->rw_random)
-    {
-      int needs_flush;
-      scm_i_pthread_mutex_lock (pt->lock);
-      needs_flush = pt->rw_active == SCM_PORT_WRITE;
-      pt->rw_active = SCM_PORT_READ;
-      scm_i_pthread_mutex_unlock (pt->lock);
-
-      if (needs_flush)
-        scm_flush (port);
-    }
+    scm_flush (port);
 
   while (copied < size)
     {
@@ -2033,11 +2019,7 @@ scm_i_unget_bytes_unlocked (const scm_t_uint8 *buf, 
size_t len, SCM port)
   SCM read_buf = pt->read_buf;
 
   if (pt->rw_random)
-    {
-      if (pt->rw_active == SCM_PORT_WRITE)
-        scm_flush_unlocked (port);
-      pt->rw_active = SCM_PORT_READ;
-    }
+    scm_flush_unlocked (port);
 
   if (scm_port_buffer_can_putback (read_buf) < len)
     {
@@ -2488,7 +2470,6 @@ scm_end_input_unlocked (SCM port)
 
   if (discarded != 0)
     SCM_PORT_DESCRIPTOR (port)->seek (port, -discarded, SEEK_CUR);
-  pt->rw_active = SCM_PORT_NEITHER;
 }
 
 void
@@ -2531,7 +2512,6 @@ scm_flush_unlocked (SCM port)
   SCM buf = SCM_PTAB_ENTRY (port)->write_buf;
   if (scm_port_buffer_can_take (buf))
     scm_i_write_unlocked (port, buf);
-  SCM_PTAB_ENTRY (port)->rw_active = SCM_PORT_NEITHER;
 }
 
 void
@@ -2555,11 +2535,7 @@ scm_fill_input_unlocked (SCM port)
     return read_buf;
 
   if (pt->rw_random)
-    {
-      if (pt->rw_active == SCM_PORT_WRITE)
-        scm_flush_unlocked (pt->port);
-      pt->rw_active = SCM_PORT_READ;
-    }
+    scm_flush_unlocked (pt->port);
 
   /* It could be that putback caused us to enlarge the buffer; now that
      we've read all the bytes we need to shrink it again.  */
@@ -2587,11 +2563,7 @@ SCM_DEFINE (scm_port_read_buffer, "port-read-buffer", 1, 
0, 0,
   pt = SCM_PTAB_ENTRY (port);
 
   if (pt->rw_random)
-    {
-      if (pt->rw_active == SCM_PORT_WRITE)
-        scm_flush (pt->port);
-      pt->rw_active = SCM_PORT_READ;
-    }
+    scm_flush (pt->port);
 
   return pt->read_buf;
 }
@@ -2611,11 +2583,7 @@ SCM_DEFINE (scm_port_write_buffer, "port-write-buffer", 
1, 0, 0,
   pt = SCM_PTAB_ENTRY (port);
 
   if (pt->rw_random)
-    {
-      if (pt->rw_active == SCM_PORT_READ)
-        scm_end_input (pt->port);
-      pt->rw_active = SCM_PORT_WRITE;
-    }
+    scm_end_input (pt->port);
 
   return pt->write_buf;
 }
@@ -2698,11 +2666,7 @@ scm_c_write_bytes_unlocked (SCM port, SCM src, size_t 
start, size_t count)
   write_buf = pt->write_buf;
 
   if (pt->rw_random)
-    {
-      if (pt->rw_active == SCM_PORT_READ)
-        scm_end_input_unlocked (port);
-      pt->rw_active = SCM_PORT_WRITE;
-    }
+    scm_end_input_unlocked (port);
 
   if (count < scm_port_buffer_size (write_buf))
     {
@@ -2759,11 +2723,7 @@ scm_c_write_unlocked (SCM port, const void *ptr, size_t 
size)
   write_buf = pt->write_buf;
 
   if (pt->rw_random)
-    {
-      if (pt->rw_active == SCM_PORT_READ)
-        scm_end_input_unlocked (port);
-      pt->rw_active = SCM_PORT_WRITE;
-    }
+    scm_end_input_unlocked (port);
 
   while (written < size)
     {
@@ -2937,11 +2897,8 @@ SCM_DEFINE (scm_seek, "seek", 3, 0, 0,
       /* FIXME: Avoid flushing buffers for SEEK_CUR with an offset of
          0.  */
 
-      if (pt->rw_active == SCM_PORT_READ)
-        scm_end_input_unlocked (pt->port);
-      else if (pt->rw_active == SCM_PORT_WRITE)
-        scm_flush_unlocked (pt->port);
-      pt->rw_active = SCM_PORT_NEITHER;
+      scm_end_input_unlocked (pt->port);
+      scm_flush_unlocked (pt->port);
 
       rv = ptob->seek (fd_port, off, how);
 
diff --git a/libguile/ports.h b/libguile/ports.h
index 2b05a22..816005d 100644
--- a/libguile/ports.h
+++ b/libguile/ports.h
@@ -41,13 +41,6 @@
 
 
 
-/* values for the rw_active flag.  */
-typedef enum scm_t_port_rw_active {
-  SCM_PORT_NEITHER = 0,
-  SCM_PORT_READ = 1,
-  SCM_PORT_WRITE = 2
-} scm_t_port_rw_active;
-
 /* An internal-only structure defined in ports-internal.h. */
 struct scm_port_internal;
 
@@ -123,11 +116,6 @@ typedef struct
      and so on.  */
   int rw_random;
 
-  /* For random access ports, indicates which of the buffers is
-     currently in use.  Can be SCM_PORT_WRITE, SCM_PORT_READ, or
-     SCM_PORT_NEITHER.  */
-  scm_t_port_rw_active rw_active;
-
   /* Character encoding support.  */
   char *encoding;
   scm_t_string_failed_conversion_handler ilseq_handler;
diff --git a/libguile/read.c b/libguile/read.c
index 75f0423..c7ba4e7 100644
--- a/libguile/read.c
+++ b/libguile/read.c
@@ -2068,11 +2068,7 @@ scm_i_scan_for_encoding (SCM port)
   buf = pt->read_buf;
 
   if (pt->rw_random)
-    {
-      if (pt->rw_active == SCM_PORT_WRITE)
-        scm_flush_unlocked (port);
-      pt->rw_active = SCM_PORT_READ;
-    }
+    scm_flush_unlocked (port);
 
   if (scm_port_buffer_can_take (buf) == 0)
     {