From 456161cfef8899161c46836fed31509e1abb3a1f Mon Sep 17 00:00:00 2001
From: Stelian Ionescu <sionescu@common-lisp.net>
Date: Sun, 2 Mar 2008 17:46:20 +0100
Subject: [PATCH] Added READ-BUFFER-SIZE, READ-BUFFER-EMPTY-P,
 WRITE-BUFFER-SIZE, WRITE-BUFFER-EMPTY-P and DRAIN-INPUT-BUFFER.

Signed-off-by: Stelian Ionescu <sionescu@common-lisp.net>
---
 io.streams/gray/classes.lisp             | 15 +++++++++++++++
 io.streams/gray/gray-stream-methods.lisp | 29 +++++++++++++++++++++++++++++
 io.streams/gray/pkgdcl.lisp              |  5 +++++
 3 files changed, 49 insertions(+)

diff --git a/io.streams/gray/classes.lisp b/io.streams/gray/classes.lisp
index 58684e7..38453d3 100644
--- a/io.streams/gray/classes.lisp
+++ b/io.streams/gray/classes.lisp
@@ -133,6 +133,21 @@
 (defgeneric (setf external-format-of) (external-format stream)
   (:documentation "placeholder"))
 
+(defgeneric drain-input-buffer (stream sequence &key start end)
+  (:documentation ""))
+
+(defgeneric read-buffer-size (stream)
+  (:documentation ""))
+
+(defgeneric read-buffer-empty-p (stream)
+  (:documentation ""))
+
+(defgeneric write-buffer-size (stream)
+  (:documentation ""))
+
+(defgeneric write-buffer-empty-p (stream)
+  (:documentation ""))
+
 (defclass dual-channel-single-fd-gray-stream
     (dual-channel-gray-stream dual-channel-single-fd-mixin)
   ()
diff --git a/io.streams/gray/gray-stream-methods.lisp b/io.streams/gray/gray-stream-methods.lisp
index f77d507..ded7d6a 100644
--- a/io.streams/gray/gray-stream-methods.lisp
+++ b/io.streams/gray/gray-stream-methods.lisp
@@ -160,6 +160,21 @@
     ((stream dual-channel-gray-stream) sequence start end &key)
   (%read-sequence stream sequence start end))
 
+(defmethod drain-input-buffer
+    ((stream dual-channel-gray-stream) sequence &key (start 0) end)
+  (check-bounds sequence start end)
+  (with-accessors ((ib input-buffer-of))
+      stream
+    (let ((nbytes (min (- end start)
+                       (iobuf-length ib))))
+      (iobuf-copy-into-lisp-array ib (iobuf-start ib)
+                                  sequence start
+                                  nbytes)
+      (incf (iobuf-start ib) nbytes)
+      (let ((len (iobuf-length ib)))
+        (values (+ start nbytes)
+                (and (plusp len) len))))))
+
 ;;;; Output Methods
 
 (defun %write-n-bytes (write-fn fd buf nbytes &optional timeout)
@@ -548,3 +563,17 @@
       stream
     (%flush-obuf-if-needed stream)
     (iobuf-push-octet ob integer)))
+
+;;;; Buffer-related stuff
+
+(defmethod input-buffer-size ((stream dual-channel-gray-stream))
+  (iobuf-length (input-buffer-of stream)))
+
+(defmethod input-buffer-empty-p ((stream dual-channel-gray-stream))
+  (iobuf-empty-p (input-buffer-of stream)))
+
+(defmethod output-buffer-size ((stream dual-channel-gray-stream))
+  (iobuf-length (output-buffer-of stream)))
+
+(defmethod output-buffer-empty-p ((stream dual-channel-gray-stream))
+  (iobuf-empty-p (output-buffer-of stream)))
diff --git a/io.streams/gray/pkgdcl.lisp b/io.streams/gray/pkgdcl.lisp
index 6533f03..3293e96 100644
--- a/io.streams/gray/pkgdcl.lisp
+++ b/io.streams/gray/pkgdcl.lisp
@@ -51,7 +51,12 @@
    #:input-fd-of
    #:output-fd-non-blocking
    #:output-fd-of
+   #:read-buffer-size
+   #:read-buffer-empty-p
+   #:write-buffer-size
+   #:write-buffer-empty-p
 
    #:read-sequence*
    #:write-sequence*
+   #:drain-input-buffer
    ))
-- 
2.11.4.GIT