1 files changed, 66 insertions, 0 deletions
diff --git a/src/PcmUtils.hxx b/src/PcmUtils.hxx
new file mode 100644
index 00000000..d77c4194
--- /dev/null
+++ b/src/PcmUtils.hxx
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2003-2011 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * 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.
+ */
+
+#ifndef MPD_PCM_UTILS_H
+#define MPD_PCM_UTILS_H
+
+#include "gcc.h"
+
+#include <limits>
+
+#include <stdint.h>
+
+/**
+ * Add a byte count to the specified pointer.  This is a utility
+ * function to convert a source pointer and a byte count to an "end"
+ * pointer for use in loops.
+ */
+template<typename T>
+static inline const T *
+pcm_end_pointer(const T *p, size_t size)
+{
+	return (const T *)((const uint8_t *)p + size);
+}
+
+/**
+ * Check if the value is within the range of the provided bit size,
+ * and caps it if necessary.
+ */
+template<typename T, typename U, unsigned bits>
+gcc_const
+static inline T
+PcmClamp(U x)
+{
+	constexpr U MIN_VALUE = -(U(1) << (bits - 1));
+	constexpr U MAX_VALUE = (U(1) << (bits - 1)) - 1;
+
+	typedef std::numeric_limits<T> limits;
+	static_assert(MIN_VALUE >= limits::min(), "out of range");
+	static_assert(MAX_VALUE <= limits::max(), "out of range");
+
+	if (gcc_unlikely(x < MIN_VALUE))
+		return T(MIN_VALUE);
+
+	if (gcc_unlikely(x > MAX_VALUE))
+		return T(MAX_VALUE);
+
+	return T(x);
+}
+
+#endif