From 328860c8ba572fd9b8032e6ed07704d79f62234e Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@duempel.org>
Date: Sat, 15 Mar 2014 23:29:07 +0100
Subject: util/CircularBuffer: add method GetSpace()

---
 src/util/CircularBuffer.hxx | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'src/util/CircularBuffer.hxx')

diff --git a/src/util/CircularBuffer.hxx b/src/util/CircularBuffer.hxx
index 0321b91f6..da6f412a5 100644
--- a/src/util/CircularBuffer.hxx
+++ b/src/util/CircularBuffer.hxx
@@ -107,6 +107,18 @@ public:
 			: capacity - head + tail;
 	}
 
+	/**
+	 * Returns the number of elements that can be added to this
+	 * buffer.
+	 */
+	constexpr size_type GetSpace() const {
+		/* space = capacity - size - 1 */
+		return (head <= tail
+			? capacity - tail + head
+			: head - tail)
+			- 1;
+	}
+
 	/**
 	 * Prepares writing.  Returns a buffer range which may be written.
 	 * When you are finished, call Append().
-- 
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