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Refactor MediaSetService.GetPeaksForSegment.
continuous-integration/drone/push Build is failing Details 

- Fix bug where the function would return empty high bins when
  framesPerBin was a low value (< ~10)
- Improve readability
- Add error test cases
This commit is contained in:
Rob Watson 2022-01-07 13:31:52 +01:00
parent 5a4ee4e34f
commit 06fce9af95
3 changed files with 109 additions and 48 deletions
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54
backend/media/service.go
View File

@ -388,44 +388,54 @@ func (s *MediaSetService) GetPeaksForSegment(ctx context.Context, id uuid.UUID,
sampleBuf := make([]int16, readBufSizeBytes/SizeOfInt16)
bytesExpected := (endFrame - startFrame) * int64(channels) * SizeOfInt16
var (
bytesRead int64
closing bool
currPeakIndex int
currFrame int64
)
var bytesRead int64
var closing bool
for bin := 0; bin < numBins; bin++ {
framesRemaining := framesPerBin
if bin == numBins-1 {
framesRemaining += totalFrames % int64(numBins)
}
for {
n, err := modReader.Read(readBuf)
// Read as many bytes as possible, but not exceeding the available buffer
// size nor framesRemaining:
bytesToRead := framesRemaining * int64(channels) * SizeOfInt16
max := int64(len(readBuf))
if bytesToRead > max {
bytesToRead = max
}
n, err := modReader.Read(readBuf[:bytesToRead])
if err == io.EOF {
closing = true
} else if err != nil {
return nil, fmt.Errorf("read error: %v", err)
}
bytesRead += int64(n)
samples := sampleBuf[:n/SizeOfInt16]
if err := binary.Read(bytes.NewReader(readBuf[:n]), binary.LittleEndian, samples); err != nil {
ss := sampleBuf[:n/SizeOfInt16]
if err := binary.Read(bytes.NewReader(readBuf[:n]), binary.LittleEndian, ss); err != nil {
return nil, fmt.Errorf("error interpreting samples: %v", err)
}
for i := 0; i < len(samples); i += channels {
pi := bin * channels
for i := 0; i < len(ss); i += channels {
for j := 0; j < channels; j++ {
samp := sampleBuf[i+j]
if samp < 0 {
samp = -samp
s := ss[i+j]
if s < 0 {
s = -s
}
if s > peaks[pi+j] {
peaks[pi+j] = s
}
if samp > peaks[currPeakIndex+j] {
peaks[currPeakIndex+j] = samp
}
}
if currFrame == framesPerBin {
currFrame = 0
currPeakIndex += channels
} else {
currFrame++
framesRemaining -= int64(n) / int64(channels) / SizeOfInt16
bytesRead += int64(n)
if closing || framesRemaining == 0 {
break
}
}

79
backend/media/service_test.go
View File

@ -4,6 +4,7 @@ import (
"bytes"
"context"
"database/sql"
"errors"
"io"
"os"
"testing"
@ -19,11 +20,31 @@ import (
"go.uber.org/zap"
)
// segmentReader returns an error if provided after reading errBytes bytes.
type segmentReader struct {
r io.Reader
n, errBytes int64
err error
}
func (r *segmentReader) Read(p []byte) (int, error) {
n, err := r.r.Read(p)
r.n += int64(n)
if r.n >= r.errBytes && r.err != nil {
return n, r.err
}
return n, err
}
func (r *segmentReader) Close() error { return nil }
func TestPeaksForSegment(t *testing.T) {
testCases := []struct {
name string
fixturePath string
fixtureLen int64
fixtureReadErrBytes int64
fixtureReadErr error
fixtureMaxRead int64
startFrame, endFrame int64
channels int32
numBins int
@ -31,9 +52,8 @@ func TestPeaksForSegment(t *testing.T) {
wantErr string
}{
{
name: "entire fixture, stereo, 1 bin",
name: "OK, entire fixture, stereo, 1 bin",
fixturePath: "testdata/tone-44100-stereo-int16.raw",
fixtureLen: 176400,
startFrame: 0,
endFrame: 44100,
channels: 2,
@ -41,9 +61,8 @@ func TestPeaksForSegment(t *testing.T) {
wantPeaks: []int16{32747, 32747},
},
{
name: "entire fixture, stereo, 4 bins",
name: "OK, entire fixture, stereo, 4 bins",
fixturePath: "testdata/tone-44100-stereo-int16.raw",
fixtureLen: 176400,
startFrame: 0,
endFrame: 44100,
channels: 2,
@ -51,9 +70,8 @@ func TestPeaksForSegment(t *testing.T) {
wantPeaks: []int16{8173, 8177, 16366, 16370, 24557, 24555, 32747, 32747},
},
{
name: "entire fixture, stereo, 16 bins",
name: "OK, entire fixture, stereo, 16 bins",
fixturePath: "testdata/tone-44100-stereo-int16.raw",
fixtureLen: 176400,
startFrame: 0,
endFrame: 44100,
channels: 2,
@ -61,9 +79,8 @@ func TestPeaksForSegment(t *testing.T) {
wantPeaks: []int16{2029, 2029, 4075, 4076, 6124, 6125, 8173, 8177, 10222, 10221, 12267, 12265, 14314, 14313, 16366, 16370, 18413, 18411, 20453, 20454, 22505, 22508, 24557, 24555, 26604, 26605, 28644, 28643, 30698, 30694, 32747, 32747},
},
{
name: "entire fixture, mono, 1 bin",
name: "OK, entire fixture, mono, 1 bin",
fixturePath: "testdata/tone-44100-mono-int16.raw",
fixtureLen: 88200,
startFrame: 0,
endFrame: 44100,
channels: 1,
@ -71,14 +88,34 @@ func TestPeaksForSegment(t *testing.T) {
wantPeaks: []int16{32748},
},
{
name: "entire fixture, mono, 32 bins",
name: "OK, entire fixture, mono, 32 bins",
fixturePath: "testdata/tone-44100-mono-int16.raw",
fixtureLen: 88200,
startFrame: 0,
endFrame: 44100,
channels: 1,
numBins: 32,
wantPeaks: []int16{1026, 2030, 3071, 4075, 5122, 6126, 7167, 8172, 9213, 10217, 11259, 12264, 13311, 14315, 15360, 16364, 17405, 18412, 19450, 20453, 21497, 22504, 23549, 24554, 25599, 26607, 27641, 28642, 29688, 30738, 31746, 32748},
wantPeaks: []int16{1018, 2030, 3060, 4075, 5092, 6126, 7129, 8172, 9174, 10217, 11227, 12264, 13272, 14315, 15319, 16364, 17370, 18412, 19417, 20453, 21457, 22504, 23513, 24554, 25564, 26607, 27607, 28642, 29647, 30700, 31699, 32748},
},
{
name: "NOK, entire fixture, mono, 32 bins, read returns io.EOF after 50% complete",
fixturePath: "testdata/tone-44100-mono-int16.raw",
fixtureMaxRead: 44100,
startFrame: 0,
endFrame: 44100,
channels: 1,
numBins: 32,
wantPeaks: []int16{1018, 2030, 3060, 4075, 5092, 6126, 7129, 8172, 9174, 10217, 11227, 12264, 13272, 14315, 15319, 16364, 2053, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
},
{
name: "NOK, entire fixture, mono, 32 bins, read error after 50% complete",
fixturePath: "testdata/tone-44100-mono-int16.raw",
fixtureReadErrBytes: 44100,
fixtureReadErr: errors.New("foo"),
startFrame: 0,
endFrame: 44100,
channels: 1,
numBins: 32,
wantErr: "read error: foo",
},
}
@ -87,11 +124,18 @@ func TestPeaksForSegment(t *testing.T) {
startByte := tc.startFrame * int64(tc.channels) * media.SizeOfInt16
endByte := tc.endFrame * int64(tc.channels) * media.SizeOfInt16
expectedBytes := endByte - startByte
if tc.fixtureMaxRead != 0 {
expectedBytes = tc.fixtureMaxRead
}
audioFile, err := os.Open(tc.fixturePath)
fixture, err := os.Open(tc.fixturePath)
require.NoError(t, err)
defer audioFile.Close()
audioData := io.NopCloser(io.LimitReader(audioFile, int64(expectedBytes)))
defer fixture.Close()
sr := segmentReader{
r: io.LimitReader(fixture, int64(expectedBytes)),
err: tc.fixtureReadErr,
errBytes: tc.fixtureReadErrBytes,
}
mediaSet := store.MediaSet{
ID: uuid.New(),
@ -108,13 +152,13 @@ func TestPeaksForSegment(t *testing.T) {
fileStore := &mocks.FileStore{}
fileStore.
On("GetObjectWithRange", mock.Anything, "foo", startByte, endByte).
Return(audioData, nil)
Return(&sr, nil)
service := media.NewMediaSetService(store, nil, fileStore, nil, media.NewTestWorkerPool(), config.Config{}, zap.NewNop().Sugar())
peaks, err := service.GetPeaksForSegment(context.Background(), mediaSet.ID, tc.startFrame, tc.endFrame, tc.numBins)
if tc.wantErr == "" {
assert.NoError(t, err)
require.NoError(t, err)
assert.Equal(t, tc.wantPeaks, peaks)
} else {
assert.EqualError(t, err, tc.wantErr)
@ -129,7 +173,6 @@ func BenchmarkGetPeaksForSegment(b *testing.B) {
endFrame = 1323000
channels = 2
fixturePath = "testdata/tone-44100-stereo-int16-30000ms.raw"
fixtureLen = 5292000
numBins = 2000
)

8
backend/media/test_helper_test.go
View File

@ -12,6 +12,7 @@ import (
"git.netflux.io/rob/clipper/media"
"github.com/stretchr/testify/require"
"go.uber.org/zap"
)
// fixtureReader loads a fixture into a ReadCloser with the provided limit.
@ -92,3 +93,10 @@ func TestHelperProcess(t *testing.T) {
require.NoError(t, err)
}
}
// testLogger returns a functional development logger.
func testLogger(t *testing.T) *zap.Logger {
l, err := zap.NewDevelopment()
require.NoError(t, err)
return l
}