Filetap library, version 0.001

This is intended as the "tap library" for fileshark.  Right now its basically just a very stripped down (and renamed) copy of the wiretap library.  The goal is to remove "capture" and "wire" specific functionality out of the file handling to make it easier/simpler to support non-capture type files in the epan architecture.

svn path=/trunk/; revision=54531

1 files changed, 163 insertions, 0 deletions

diff --git a/filetap/buffer.c b/filetap/buffer.c
new file mode 100644
index 0000000000..fc12c6a987
--- /dev/null
+++ b/filetap/buffer.c
@@ -0,0 +1,163 @@
+/* buffer.c
+ *
+ * $Id$
+ *
+ * Wiretap Library
+ * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
+ *
+ * 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; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+#include "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <glib.h>
+
+#include "buffer.h"
+
+/* Initializes a buffer with a certain amount of allocated space */
+void
+buffer_init(Buffer* buffer, gsize space)
+{
+	buffer->data = (guint8*)g_malloc(space);
+	buffer->allocated = space;
+	buffer->start = 0;
+	buffer->first_free = 0;
+}
+
+/* Frees the memory used by a buffer, and the buffer struct */
+void
+buffer_free(Buffer* buffer)
+{
+	g_free(buffer->data);
+}
+
+/* Assures that there are 'space' bytes at the end of the used space
+	so that another routine can copy directly into the buffer space. After
+	doing that, the routine will also want to run
+	buffer_increase_length(). */
+void
+buffer_assure_space(Buffer* buffer, gsize space)
+{
+	gsize available_at_end = buffer->allocated - buffer->first_free;
+	gsize space_used;
+	gboolean space_at_beginning;
+
+	/* If we've got the space already, good! */
+	if (space <= available_at_end) {
+		return;
+	}
+
+	/* Maybe we don't have the space available at the end, but we would
+		if we moved the used space back to the beginning of the
+		allocation. The buffer could have become fragmented through lots
+		of calls to buffer_remove_start(). I'm using buffer->start as the
+		same as 'available_at_start' in this comparison. */
+
+	/* or maybe there's just no more room. */
+
+	space_at_beginning = buffer->start >= space;
+	if (space_at_beginning || buffer->start > 0) {
+		space_used = buffer->first_free - buffer->start;
+		/* this memory copy better be safe for overlapping memory regions! */
+		memmove(buffer->data, buffer->data + buffer->start, space_used);
+		buffer->start = 0;
+		buffer->first_free = space_used;
+	}
+	/*if (buffer->start >= space) {*/
+	if (space_at_beginning) {
+		return;
+	}
+
+	/* We'll allocate more space */
+	buffer->allocated += space + 1024;
+	buffer->data = (guint8*)g_realloc(buffer->data, buffer->allocated);
+}
+
+void
+buffer_append(Buffer* buffer, guint8 *from, gsize bytes)
+{
+	buffer_assure_space(buffer, bytes);
+	memcpy(buffer->data + buffer->first_free, from, bytes);
+	buffer->first_free += bytes;
+}
+
+void
+buffer_remove_start(Buffer* buffer, gsize bytes)
+{
+	if (buffer->start + bytes > buffer->first_free) {
+		g_error("buffer_remove_start trying to remove %" G_GINT64_MODIFIER "u bytes. s=%" G_GINT64_MODIFIER "u ff=%" G_GINT64_MODIFIER "u!\n",
+			(guint64)bytes, (guint64)buffer->start,
+			(guint64)buffer->first_free);
+		/** g_error() does an abort() and thus never returns **/
+	}
+	buffer->start += bytes;
+
+	if (buffer->start == buffer->first_free) {
+		buffer->start = 0;
+		buffer->first_free = 0;
+	}
+}
+
+
+#ifndef SOME_FUNCTIONS_ARE_DEFINES
+void
+buffer_clean(Buffer* buffer)
+{
+	buffer_remove_start(buffer, buffer_length(buffer));
+}
+#endif
+
+#ifndef SOME_FUNCTIONS_ARE_DEFINES
+void
+buffer_increase_length(Buffer* buffer, gsize bytes)
+{
+	buffer->first_free += bytes;
+}
+#endif
+
+#ifndef SOME_FUNCTIONS_ARE_DEFINES
+gsize
+buffer_length(Buffer* buffer)
+{
+	return buffer->first_free - buffer->start;
+}
+#endif
+
+#ifndef SOME_FUNCTIONS_ARE_DEFINES
+guint8 *
+buffer_start_ptr(Buffer* buffer)
+{
+	return buffer->data + buffer->start;
+}
+#endif
+
+#ifndef SOME_FUNCTIONS_ARE_DEFINES
+guint8 *
+buffer_end_ptr(Buffer* buffer)
+{
+	return buffer->data + buffer->first_free;
+}
+#endif
+
+#ifndef SOME_FUNCTIONS_ARE_DEFINES
+void
+buffer_append_buffer(Buffer* buffer, Buffer* src_buffer)
+{
+	buffer_append(buffer, buffer_start_ptr(src_buffer), buffer_length(src_buffer));
+}
+#endif