From 12710a075c4f01bc927e2d24e1b031d3854f2026 Mon Sep 17 00:00:00 2001
From: short <>
Date: Thu, 12 Dec 2002 03:59:22 +0000
Subject: [PATCH] +captive_giochannel_size(): detect 'GIOChannel' file/device
 size

---
 src/libcaptive/storage/Makefile.am |  3 +-
 src/libcaptive/storage/size.c      | 74 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 src/libcaptive/storage/size.c

diff --git a/src/libcaptive/storage/Makefile.am b/src/libcaptive/storage/Makefile.am
index a1a09e0..78e1c81 100644
--- a/src/libcaptive/storage/Makefile.am
+++ b/src/libcaptive/storage/Makefile.am
@@ -21,4 +21,5 @@ include $(top_srcdir)/src/libcaptive/Makefile-libcaptive.am
 
 noinst_LTLIBRARIES=libstorage.la
 libstorage_la_SOURCES= \
-		cdrom.c
+		cdrom.c \
+		size.c
diff --git a/src/libcaptive/storage/size.c b/src/libcaptive/storage/size.c
new file mode 100644
index 0000000..47948e9
--- /dev/null
+++ b/src/libcaptive/storage/size.c
@@ -0,0 +1,74 @@
+/* $Id$
+ * Detect media size of given GIOChannel for libcaptive
+ * Copyright (C) 2002 Jan Kratochvil <project-captive@jankratochvil.net>
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; exactly version 2 of June 1991 is required
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+
+#include "config.h"
+
+#include "captive/storage.h"	/* self */
+#include <glib/gmessages.h>
+#include <glib/gtypes.h>
+
+
+guint64 captive_giochannel_size(GIOChannel *iochannel)
+{
+gint fd;
+gint64 low,high,mid;
+GIOStatus erriostatus;
+gchar bufchar;
+gsize bufchargot;
+
+	g_return_val_if_fail(iochannel!=NULL,0);
+
+	fd=g_io_channel_unix_get_fd(iochannel);
+	g_return_val_if_fail(fd!=-1,0);
+
+	/* FIXME: TODO: ioctl() detection */
+
+	/* low  ==high: low (high)
+	 * low+1==high: mid==low; NORMAL: no change: high
+	 * low+1==high: mid==low; EOF   : high=mid => 'low==high' case
+	 */
+	for (low=0,
+			high=
+					G_MAXINT;	/* FIXME: 'G_MAXINT64' fails on g_io_channel_seek_position() */
+			low+1<high;) {
+		mid=low+(high-low)/2;	/* beware of 'gint64' overflow! */
+
+		erriostatus=g_io_channel_seek_position(iochannel,mid,G_SEEK_SET,
+				NULL);	/* error */
+		g_assert(erriostatus==G_IO_STATUS_NORMAL);
+		g_assert(sizeof(bufchar)==1);
+		erriostatus=g_io_channel_read_chars(iochannel,
+				&bufchar, /* buf */
+				sizeof(bufchar),	/* count */
+				&bufchargot,	/* bytes_read */
+				NULL);	/* error */
+		g_assert(erriostatus==G_IO_STATUS_NORMAL || erriostatus==G_IO_STATUS_EOF);
+		g_assert(0
+				|| (erriostatus==G_IO_STATUS_NORMAL && bufchargot==1)
+				|| (erriostatus==G_IO_STATUS_EOF    && bufchargot==0));
+
+		if (erriostatus==G_IO_STATUS_NORMAL)
+			low=mid;
+		else
+			high=mid;
+		}
+	
+	g_assert(high>=0);
+	return high;
+}
-- 
1.8.3.1