Function TestChunkWriter_ReadAfterWrite

tsdb/db_test.go:3033–3211

TestChunkWriter_ReadAfterWrite ensures that chunk segment are cut at the set segment size and that the resulted segments includes the expected chunks data.

(t *testing.T)

// TestChunkWriter_ReadAfterWrite ensures that chunk segment are cut at the set segment size and
// that the resulted segments includes the expected chunks data.
func TestChunkWriter_ReadAfterWrite(t *testing.T) {
	chk1 := assureChunkFromSamples(t, []chunks.Sample{sample{0, 1, 1, nil, nil}})
	chk2 := assureChunkFromSamples(t, []chunks.Sample{sample{0, 1, 2, nil, nil}})
	chk3 := assureChunkFromSamples(t, []chunks.Sample{sample{0, 1, 3, nil, nil}})
	chk4 := assureChunkFromSamples(t, []chunks.Sample{sample{0, 1, 4, nil, nil}})
	chk5 := assureChunkFromSamples(t, []chunks.Sample{sample{0, 1, 5, nil, nil}})
	chunkSize := len(chk1.Chunk.Bytes()) + chunks.MaxChunkLengthFieldSize + chunks.ChunkEncodingSize + crc32.Size

	tests := []struct {
		chks [][]chunks.Meta
		segmentSize,
		expSegmentsCount int
		expSegmentSizes []int
	}{
		// 0:Last chunk ends at the segment boundary so
		// all chunks should fit in a single segment.
		{
			chks: [][]chunks.Meta{
				{
					chk1,
					chk2,
					chk3,
				},
			},
			segmentSize:      3 * chunkSize,
			expSegmentSizes:  []int{3 * chunkSize},
			expSegmentsCount: 1,
		},
		// 1:Two chunks can fit in a single segment so the last one should result in a new segment.
		{
			chks: [][]chunks.Meta{
				{
					chk1,
					chk2,
					chk3,
					chk4,
					chk5,
				},
			},
			segmentSize:      2 * chunkSize,
			expSegmentSizes:  []int{2 * chunkSize, 2 * chunkSize, chunkSize},
			expSegmentsCount: 3,
		},
		// 2:When the segment size is smaller than the size of 2 chunks
		// the last segment should still create a new segment.
		{
			chks: [][]chunks.Meta{
				{
					chk1,
					chk2,
					chk3,
				},
			},
			segmentSize:      2*chunkSize - 1,
			expSegmentSizes:  []int{chunkSize, chunkSize, chunkSize},
			expSegmentsCount: 3,
		},
		// 3:When the segment is smaller than a single chunk