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| author | Max Kellermann <max@duempel.org> | 2014-03-15 23:29:07 +0100 |
|---|---|---|
| committer | Max Kellermann <max@duempel.org> | 2014-03-16 00:28:42 +0100 |
| commit | 328860c8ba572fd9b8032e6ed07704d79f62234e (patch) | |
| tree | af43c49241a2bf8b910008da7e127d70b924541a | |
| parent | 89ac111853eb4bae2fc358087c4c4657939321c0 (diff) | |
| download | mpd-328860c8ba572fd9b8032e6ed07704d79f62234e.tar.gz mpd-328860c8ba572fd9b8032e6ed07704d79f62234e.tar.xz mpd-328860c8ba572fd9b8032e6ed07704d79f62234e.zip | |
util/CircularBuffer: add method GetSpace()
| -rw-r--r-- | src/util/CircularBuffer.hxx | 12 | ||||
| -rw-r--r-- | test/TestCircularBuffer.hxx | 10 |
2 files changed, 22 insertions, 0 deletions
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 @@ -108,6 +108,18 @@ public: } /** + * 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(). */ diff --git a/test/TestCircularBuffer.hxx b/test/TestCircularBuffer.hxx index 88b0a9ea8..c808d85dc 100644 --- a/test/TestCircularBuffer.hxx +++ b/test/TestCircularBuffer.hxx @@ -33,6 +33,7 @@ public: CPPUNIT_ASSERT_EQUAL(true, buffer.IsEmpty()); CPPUNIT_ASSERT_EQUAL(false, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(size_t(0), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(7), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(true, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(false, buffer.Write().IsEmpty()); CPPUNIT_ASSERT_EQUAL(&data[0], buffer.Write().data); @@ -45,6 +46,7 @@ public: CPPUNIT_ASSERT_EQUAL(false, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(false, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(size_t(1), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(6), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(size_t(1), buffer.Read().size); CPPUNIT_ASSERT_EQUAL(&data[0], buffer.Read().data); CPPUNIT_ASSERT_EQUAL(false, buffer.Write().IsEmpty()); @@ -58,6 +60,7 @@ public: CPPUNIT_ASSERT_EQUAL(true, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(false, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(size_t(7), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(0), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(size_t(7), buffer.Read().size); CPPUNIT_ASSERT_EQUAL(&data[0], buffer.Read().data); CPPUNIT_ASSERT_EQUAL(true, buffer.Write().IsEmpty()); @@ -69,6 +72,7 @@ public: CPPUNIT_ASSERT_EQUAL(false, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(false, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(size_t(6), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(1), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(size_t(6), buffer.Read().size); CPPUNIT_ASSERT_EQUAL(&data[1], buffer.Read().data); CPPUNIT_ASSERT_EQUAL(false, buffer.Write().IsEmpty()); @@ -83,6 +87,7 @@ public: CPPUNIT_ASSERT_EQUAL(true, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(false, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(size_t(7), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(0), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(size_t(7), buffer.Read().size); CPPUNIT_ASSERT_EQUAL(&data[1], buffer.Read().data); CPPUNIT_ASSERT_EQUAL(true, buffer.Write().IsEmpty()); @@ -94,6 +99,7 @@ public: CPPUNIT_ASSERT_EQUAL(false, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(false, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(size_t(4), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(3), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(size_t(4), buffer.Read().size); CPPUNIT_ASSERT_EQUAL(&data[4], buffer.Read().data); CPPUNIT_ASSERT_EQUAL(false, buffer.Write().IsEmpty()); @@ -107,6 +113,7 @@ public: CPPUNIT_ASSERT_EQUAL(false, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(false, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(size_t(6), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(1), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(size_t(4), buffer.Read().size); CPPUNIT_ASSERT_EQUAL(&data[4], buffer.Read().data); CPPUNIT_ASSERT_EQUAL(false, buffer.Write().IsEmpty()); @@ -120,6 +127,7 @@ public: CPPUNIT_ASSERT_EQUAL(true, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(false, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(size_t(7), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(0), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(size_t(4), buffer.Read().size); CPPUNIT_ASSERT_EQUAL(&data[4], buffer.Read().data); CPPUNIT_ASSERT_EQUAL(true, buffer.Write().IsEmpty()); @@ -131,6 +139,7 @@ public: CPPUNIT_ASSERT_EQUAL(false, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(false, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(size_t(3), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(4), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(size_t(3), buffer.Read().size); CPPUNIT_ASSERT_EQUAL(&data[0], buffer.Read().data); CPPUNIT_ASSERT_EQUAL(false, buffer.Write().IsEmpty()); @@ -145,6 +154,7 @@ public: CPPUNIT_ASSERT_EQUAL(true, buffer.IsEmpty()); CPPUNIT_ASSERT_EQUAL(false, buffer.IsFull()); CPPUNIT_ASSERT_EQUAL(size_t(0), buffer.GetSize()); + CPPUNIT_ASSERT_EQUAL(size_t(7), buffer.GetSpace()); CPPUNIT_ASSERT_EQUAL(true, buffer.Read().IsEmpty()); CPPUNIT_ASSERT_EQUAL(false, buffer.Write().IsEmpty()); CPPUNIT_ASSERT_EQUAL(&data[3], buffer.Write().data); |