1 files changed, 55 insertions, 0 deletions
diff --git a/gprofng/src/DataStream.cc b/gprofng/src/DataStream.cc
new file mode 100644
index 00000000000..8e244e22dd5
--- /dev/null
+++ b/gprofng/src/DataStream.cc
@@ -0,0 +1,55 @@
+/* Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Oracle.
+
+   This file is part of GNU Binutils.
+
+   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 3, 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, 51 Franklin Street - Fifth Floor, Boston,
+   MA 02110-1301, USA.  */
+
+#include "config.h"
+#include "util.h"
+#include "DataStream.h"
+#include "debug.h"
+
+DataStream::DataStream (char *filename) : Data_window (filename)
+{
+  set_span (0, -1);
+}
+
+DataStream::~DataStream () { }
+
+void
+DataStream::set_span (int64_t f_offset, int64_t sz)
+{
+  span_offset = 0;
+  span_fileoffset = f_offset;
+  int64_t fsz = get_fsize ();
+  span_size = sz == -1 ? fsz : sz;
+  if (span_fileoffset >= fsz)
+    span_fileoffset = fsz;
+  if (span_size > fsz - span_fileoffset)
+    span_size = fsz - span_fileoffset;
+}
+
+int64_t
+DataStream::read (void *buf, int64_t len)
+{
+  if (len > span_size - span_offset)
+    len = span_size - span_offset;
+  int64_t off = span_offset + span_fileoffset;
+  span_offset += len;
+  get_data (off, len, buf);
+  return len;
+}