Feature/fix memory leak

LICENSE

@@ -1,4 +1,5 @@
 Copyright (c) 2011 Matt Jibson <[email protected]>
+Copyright (c) 2023 NectGmbH <[email protected]>
 
 Permission to use, copy, modify, and distribute this software for any
 purpose with or without fee is hereby granted, provided that the above

README.md

@@ -4,23 +4,23 @@ go-dsp is a digital signal processing package for the [Go programming language](
 
 ## Packages
 
-* **[dsputils](http://godoc.org/github.com/mjibson/go-dsp/dsputils)** - utilities and data structures for DSP
-* **[fft](http://godoc.org/github.com/mjibson/go-dsp/fft)** - fast Fourier transform
-* **[spectral](http://godoc.org/github.com/mjibson/go-dsp/spectral)** - power spectral density functions (e.g., Pwelch)
-* **[wav](http://godoc.org/github.com/mjibson/go-dsp/wav)** - wav file reader functions
-* **[window](http://godoc.org/github.com/mjibson/go-dsp/window)** - window functions (e.g., Hamming, Hann, Bartlett)
+* **[dsputils](http://godoc.org/github.com/NectGmbH/go-dsp/dsputils)** - utilities and data structures for DSP
+* **[fft](http://godoc.org/github.com/NectGmbH/go-dsp/fft)** - fast Fourier transform
+* **[spectral](http://godoc.org/github.com/NectGmbH/go-dsp/spectral)** - power spectral density functions (e.g., Pwelch)
+* **[wav](http://godoc.org/github.com/NectGmbH/go-dsp/wav)** - wav file reader functions
+* **[window](http://godoc.org/github.com/NectGmbH/go-dsp/window)** - window functions (e.g., Hamming, Hann, Bartlett)
 
 ## Installation and Usage
 
-```$ go get github.com/mjibson/go-dsp/fft```
+```$ go get github.com/NectGmbH/go-dsp/fft```
 
 ```
 package main
 
 import (
         "fmt"
-        
-        "github.com/mjibson/go-dsp/fft"
+
+        "github.com/NectGmbH/go-dsp/fft"
 )
 
 func main() {

fft/bluestein.go

@@ -18,50 +18,45 @@ package fft
 
 import (
 	"math"
-	"sync"
 
-	"github.com/mjibson/go-dsp/dsputils"
-)
+	"github.com/NectGmbH/go-dsp/dsputils"
 
-var (
-	bluesteinLock       sync.RWMutex
-	bluesteinFactors    = map[int][]complex128{}
-	bluesteinInvFactors = map[int][]complex128{}
+	"github.com/Code-Hex/go-generics-cache/policy/lfu"
 )
 
-func getBluesteinFactors(input_len int) ([]complex128, []complex128) {
-	bluesteinLock.RLock()
+type factors struct {
+	normal  []complex128
+	inverse []complex128
+}
+
+var bluesteinFactorCache = lfu.NewCache[int, factors](lfu.WithCapacity(64))
 
-	if hasBluesteinFactors(input_len) {
-		defer bluesteinLock.RUnlock()
-		return bluesteinFactors[input_len], bluesteinInvFactors[input_len]
+func getBluesteinFactors(input_len int) ([]complex128, []complex128) {
+	factor, exists := bluesteinFactorCache.Get(input_len)
+	if exists {
+		return factor.normal, factor.inverse
 	}
 
-	bluesteinLock.RUnlock()
-	bluesteinLock.Lock()
-	defer bluesteinLock.Unlock()
-
-	if !hasBluesteinFactors(input_len) {
-		bluesteinFactors[input_len] = make([]complex128, input_len)
-		bluesteinInvFactors[input_len] = make([]complex128, input_len)
-
-		var sin, cos float64
-		for i := 0; i < input_len; i++ {
-			if i == 0 {
-				sin, cos = 0, 1
-			} else {
-				sin, cos = math.Sincos(math.Pi / float64(input_len) * float64(i*i))
-			}
-			bluesteinFactors[input_len][i] = complex(cos, sin)
-			bluesteinInvFactors[input_len][i] = complex(cos, -sin)
+	normal := make([]complex128, input_len)
+	inverse := make([]complex128, input_len)
+
+	var sin, cos float64
+	for i := 0; i < input_len; i++ {
+		if i == 0 {
+			sin, cos = 0, 1
+		} else {
+			sin, cos = math.Sincos(math.Pi / float64(input_len) * float64(i*i))
 		}
+		normal[i] = complex(cos, sin)
+		inverse[i] = complex(cos, -sin)
 	}
 
-	return bluesteinFactors[input_len], bluesteinInvFactors[input_len]
-}
+	bluesteinFactorCache.Set(input_len, factors{
+		normal:  normal,
+		inverse: inverse,
+	})
 
-func hasBluesteinFactors(idx int) bool {
-	return bluesteinFactors[idx] != nil
+	return normal, inverse
 }
 
 // bluesteinFFT returns the FFT calculated using the Bluestein algorithm.

fft/fft.go

@@ -18,7 +18,7 @@
 package fft
 
 import (
-	"github.com/mjibson/go-dsp/dsputils"
+	"github.com/NectGmbH/go-dsp/dsputils"
 )
 
 // FFTReal returns the forward FFT of the real-valued slice.
@@ -86,9 +86,7 @@ func FFT(x []complex128) []complex128 {
 	return bluesteinFFT(x)
 }
 
-var (
-	worker_pool_size = 0
-)
+var worker_pool_size = 0
 
 // SetWorkerPoolSize sets the number of workers during FFT computation on multicore systems.
 // If n is 0 (the default), then GOMAXPROCS workers will be created.
@@ -192,7 +190,8 @@ func computeFFTN(m *dsputils.Matrix, fftFunc func([]complex128) []complex128) *d
 }
 
 // decrDim decrements an element of x by 1, skipping all -1s, and wrapping up to d.
-// If a value is 0, it will be reset to its correspending value in d, and will carry one from the next non -1 value to the right.
+// If a value is 0, it will be reset to its correspending value in d, and will carry one from the
+// next non -1 value to the right.
 // Returns true if decremented, else false.
 func decrDim(x, d []int) bool {
 	for n, v := range x {

fft/fft_test.go

@@ -23,7 +23,7 @@ import (
 	"runtime"
 	"testing"
 
-	"github.com/mjibson/go-dsp/dsputils"
+	"github.com/NectGmbH/go-dsp/dsputils"
 )
 
 const (
@@ -59,7 +59,8 @@ var fftTests = []fftTest{
 			complex(1, 0),
 			complex(1, 0),
 			complex(1, 0),
-			complex(1, 0)},
+			complex(1, 0),
+		},
 	},
 
 	// shifted impulse response
@@ -81,7 +82,8 @@ var fftTests = []fftTest{
 			complex(-1, 0),
 			complex(-sqrt2_2, sqrt2_2),
 			complex(0, 1),
-			complex(sqrt2_2, sqrt2_2)},
+			complex(sqrt2_2, sqrt2_2),
+		},
 	},
 
 	// other
@@ -91,15 +93,17 @@ var fftTests = []fftTest{
 			complex(10, 0),
 			complex(-2, 2),
 			complex(-2, 0),
-			complex(-2, -2)},
+			complex(-2, -2),
+		},
 	},
 	{
 		[]float64{1, 3, 5, 7},
 		[]complex128{
 			complex(16, 0),
 			complex(-4, 4),
 			complex(-4, 0),
-			complex(-4, -4)},
+			complex(-4, -4),
+		},
 	},
 	{
 		[]float64{1, 2, 3, 4, 5, 6, 7, 8},
@@ -111,7 +115,8 @@ var fftTests = []fftTest{
 			complex(-4, 0),
 			complex(-4, -1.65685425),
 			complex(-4, -4),
-			complex(-4, -9.65685425)},
+			complex(-4, -9.65685425),
+		},
 	},
 
 	// non power of 2 lengths
@@ -122,21 +127,24 @@ var fftTests = []fftTest{
 			complex(1, 0),
 			complex(1, 0),
 			complex(1, 0),
-			complex(1, 0)},
+			complex(1, 0),
+		},
 	},
 	{
 		[]float64{1, 2, 3},
 		[]complex128{
 			complex(6, 0),
 			complex(-1.5, 0.8660254),
-			complex(-1.5, -0.8660254)},
+			complex(-1.5, -0.8660254),
+		},
 	},
 	{
 		[]float64{1, 1, 1},
 		[]complex128{
 			complex(3, 0),
 			complex(0, 0),
-			complex(0, 0)},
+			complex(0, 0),
+		},
 	},
 }
 
@@ -150,14 +158,34 @@ var fft2Tests = []fft2Test{
 		[][]float64{{1, 2, 3}, {3, 4, 5}},
 		[][]complex128{
 			{complex(18, 0), complex(-3, 1.73205081), complex(-3, -1.73205081)},
-			{complex(-6, 0), complex(0, 0), complex(0, 0)}},
+			{complex(-6, 0), complex(0, 0), complex(0, 0)},
+		},
 	},
 	{
 		[][]float64{{0.1, 0.2, 0.3, 0.4, 0.5}, {1, 2, 3, 4, 5}, {3, 2, 1, 0, -1}},
 		[][]complex128{
-			{complex(21.5, 0), complex(-0.25, 0.34409548), complex(-0.25, 0.08122992), complex(-0.25, -0.08122992), complex(-0.25, -0.34409548)},
-			{complex(-8.5, -8.66025404), complex(5.70990854, 4.6742225), complex(1.15694356, 4.41135694), complex(-1.65694356, 4.24889709), complex(-6.20990854, 3.98603154)},
-			{complex(-8.5, 8.66025404), complex(-6.20990854, -3.98603154), complex(-1.65694356, -4.24889709), complex(1.15694356, -4.41135694), complex(5.70990854, -4.6742225)}},
+			{
+				complex(21.5, 0),
+				complex(-0.25, 0.34409548),
+				complex(-0.25, 0.08122992),
+				complex(-0.25, -0.08122992),
+				complex(-0.25, -0.34409548),
+			},
+			{
+				complex(-8.5, -8.66025404),
+				complex(5.70990854, 4.6742225),
+				complex(1.15694356, 4.41135694),
+				complex(-1.65694356, 4.24889709),
+				complex(-6.20990854, 3.98603154),
+			},
+			{
+				complex(-8.5, 8.66025404),
+				complex(-6.20990854, -3.98603154),
+				complex(-1.65694356, -4.24889709),
+				complex(1.15694356, -4.41135694),
+				complex(5.70990854, -4.6742225),
+			},
+		},
 	},
 }
 
@@ -176,7 +204,8 @@ var fftnTests = []fftnTest{
 			complex(-42, 0), complex(-10.5, 6.06217783), complex(-10.5, -6.06217783),
 
 			complex(-48, 0), complex(-4.5, -11.25833025), complex(-4.5, 11.25833025),
-			complex(22, 0), complex(8.5, -6.06217783), complex(8.5, 6.06217783)},
+			complex(22, 0), complex(8.5, -6.06217783), complex(8.5, 6.06217783),
+		},
 	},
 }
 
@@ -203,7 +232,14 @@ func TestFFT(t *testing.T) {
 
 		vi := IFFT(ft.out)
 		if !dsputils.PrettyCloseC(vi, dsputils.ToComplex(ft.in)) {
-			t.Error("IFFT error\ninput:", ft.out, "\noutput:", vi, "\nexpected:", dsputils.ToComplex(ft.in))
+			t.Error(
+				"IFFT error\ninput:",
+				ft.out,
+				"\noutput:",
+				vi,
+				"\nexpected:",
+				dsputils.ToComplex(ft.in),
+			)
 		}
 	}
 }
@@ -217,7 +253,14 @@ func TestFFT2(t *testing.T) {
 
 		vi := IFFT2(ft.out)
 		if !dsputils.PrettyClose2(vi, dsputils.ToComplex2(ft.in)) {
-			t.Error("IFFT2 error\ninput:", ft.out, "\noutput:", vi, "\nexpected:", dsputils.ToComplex2(ft.in))
+			t.Error(
+				"IFFT2 error\ninput:",
+				ft.out,
+				"\noutput:",
+				vi,
+				"\nexpected:",
+				dsputils.ToComplex2(ft.in),
+			)
 		}
 	}
 }
@@ -243,7 +286,16 @@ func TestReverseBits(t *testing.T) {
 		v := reverseBits(rt.in, rt.sz)
 
 		if v != rt.out {
-			t.Error("reverse bits error\ninput:", rt.in, "\nsize:", rt.sz, "\noutput:", v, "\nexpected:", rt.out)
+			t.Error(
+				"reverse bits error\ninput:",
+				rt.in,
+				"\nsize:",
+				rt.sz,
+				"\noutput:",
+				v,
+				"\nexpected:",
+				rt.out,
+			)
 		}
 	}
 }
@@ -279,7 +331,8 @@ func BenchmarkFFT(b *testing.B) {
 	}
 }
 
-// This example is adapted from Richard Lyon's "Understanding Digital Signal Processing," section 3.1.1.
+// This example is adapted from Richard Lyon's "Understanding Digital Signal Processing," section
+// 3.1.1.
 func ExampleFFTReal() {
 	numSamples := 8
 

go.mod

@@ -0,0 +1,5 @@
+module github.com/NectGmbH/go-dsp
+
+go 1.18
+
+require github.com/Code-Hex/go-generics-cache v1.2.1

go.sum

@@ -0,0 +1,2 @@
+github.com/Code-Hex/go-generics-cache v1.2.1 h1:jKof8Hk8mr28lcEAo9g90oj7H3vb8y2DdccoGpL4lyE=
+github.com/Code-Hex/go-generics-cache v1.2.1/go.mod h1:qxcC9kRVrct9rHeiYpFWSoW1vxyillCVzX13KZG8dl4=

spectral/pwelch.go

@@ -20,9 +20,9 @@ import (
 	"math"
 	"math/cmplx"
 
-	"github.com/mjibson/go-dsp/dsputils"
-	"github.com/mjibson/go-dsp/fft"
-	"github.com/mjibson/go-dsp/window"
+	"github.com/NectGmbH/go-dsp/dsputils"
+	"github.com/NectGmbH/go-dsp/fft"
+	"github.com/NectGmbH/go-dsp/window"
 )
 
 type PwelchOptions struct {