2 files changed, 267 insertions, 0 deletions
diff --git a/pkg/metricsx/geohash.go b/pkg/metricsx/geohash.go
new file mode 100644
index 0000000..1073f97
--- /dev/null
+++ b/pkg/metricsx/geohash.go
@@ -0,0 +1,148 @@
+package metricsx
+
+import (
+	"io"
+	"strconv"
+	"strings"
+	"sync/atomic"
+
+	"github.com/VictoriaMetrics/metrics"
+	"github.com/mmcloughlin/geohash"
+)
+
+// GeoCounter is like a *metrics.Counter, but split by location using geohashes.
+type GeoCounter struct {
+	level uint
+	ctr   []*metrics.Counter
+	unk   *metrics.Counter
+	set   *metrics.Set
+	base  string
+	arg   string
+}
+
+// NewGeoCounter creates a new GeoCounter writing to metrics in set named name,
+// with level chars in the geohash.
+func NewGeoCounter(set *metrics.Set, name string, level uint) *GeoCounter {
+	if h, p := geohash.ConvertStringToInt(strings.Repeat("z", int(level))); h != 1<<(5*level)-1 || p != 5*uint(level) {
+		panic("wtf") // this shouldn't happen... geohashes are base32, and int encoding is 5 bits per char
+	}
+	base, arg := splitName(name)
+	return &GeoCounter{
+		level: level,
+		ctr:   make([]*metrics.Counter, 1<<(5*level)),
+		unk:   set.NewCounter(formatName(base, arg, "geohash", "")),
+		set:   set,
+		base:  base,
+		arg:   arg,
+	}
+}
+
+// Inc increments the counter for the specified latitude and longitude.
+func (c *GeoCounter) Inc(lat, lng float64) {
+	c.Counter(lat, lng).Inc()
+}
+
+// Set sets the counter for the specified latitude and longitude.
+func (c *GeoCounter) Set(lat, lng float64, v uint64) {
+	c.Counter(lat, lng).Set(v)
+}
+
+// IncUnknown increments the unknown counter.
+func (c *GeoCounter) IncUnknown() {
+	c.unk.Inc()
+}
+
+// SetUnknown sets the unknown counter.
+func (c *GeoCounter) SetUnknown(v uint64) {
+	c.unk.Set(v)
+}
+
+// Counter gets the underlying counter for the specified latitude and longitude.
+func (c *GeoCounter) Counter(lat, lng float64) *metrics.Counter {
+	h := geohash.EncodeIntWithPrecision(lat, lng, c.level*5)
+	if int(h) >= len(c.ctr) {
+		return nil // wtf (this shouldn't even be possible, but we don't panic here for performance reasons)
+	}
+	m := c.ctr[h]
+	if m == nil {
+		m = c.set.NewCounter(formatName(c.base, c.arg, "geohash", geohash.EncodeWithPrecision(lat, lng, c.level)))
+		c.ctr[h] = m
+	}
+	return m
+}
+
+// CounterUnknown gets the underlying counter for unknown positions.
+func (c *GeoCounter) CounterUnknown() *metrics.Counter {
+	return c.unk
+}
+
+// GeoCounter2 is an optimized standalone level 2 geocounter metric. It must not
+// be copied (it uses atomics).
+type GeoCounter2 struct {
+	name string
+	ctr  [1 << (5 * 2)]uint64
+	unk  uint64
+}
+
+// NewGeoCounter2 creates a new GeoCounter2 with the provided metric name.
+//
+// Note: The maximum cardinality of metrics produced will be 1024.
+func NewGeoCounter2(name string) *GeoCounter2 {
+	b, a := splitName(name)
+	n := formatName(b, a, "geohash", "")
+	if !strings.HasSuffix(n, `geohash=""}`) {
+		panic("wtf") // should never happen
+	}
+	return &GeoCounter2{name: n}
+}
+
+// Inc increments the counter for the specified latitude and longitude.
+func (c *GeoCounter2) Inc(lat, lng float64) {
+	if c != nil {
+		// this should always be true, but we need it to satisfy the bounds checker
+		if h := geohash2(lat, lng); h < 1<<(5*2) {
+			atomic.AddUint64(&c.ctr[h], 1)
+		}
+	}
+}
+
+// Set sets the counter for the specified latitude and longitude.
+func (c *GeoCounter2) Set(lat, lng float64, v uint64) {
+	if c != nil {
+		// this should always be true, but we need it to satisfy the bounds checker
+		if h := geohash2(lat, lng); h < 1<<(5*2) {
+			atomic.StoreUint64(&c.ctr[h], 1)
+		}
+	}
+}
+
+// IncUnknown increments the unknown counter.
+func (c *GeoCounter2) IncUnknown() {
+	atomic.AddUint64(&c.unk, 1)
+}
+
+// SetUnknown sets the unknown counter.
+func (c *GeoCounter2) SetUnknown(v uint64) {
+	atomic.StoreUint64(&c.unk, v)
+}
+
+// WritePrometheus writes the Promethus text metrics.
+func (c *GeoCounter2) WritePrometheus(w io.Writer) {
+	n := len(c.name)
+	b := make([]byte, 0, n+2+1+20+1)
+	b = append(b, c.name...)
+	w.Write(append(strconv.AppendUint(append(b, ' '), atomic.LoadUint64(&c.unk), 10), '\n'))
+	b = append(b, `"} `...)
+	_ = b[n-2] // bounds check hint
+	for h := uint64(0); h < 1<<(5*2); h++ {
+		if v := atomic.LoadUint64(&c.ctr[h]); v != 0 {
+			b[n-1] = "0123456789bcdefghjkmnpqrstuvwxyz"[(h>>0)&0x1f]
+			b[n-2] = "0123456789bcdefghjkmnpqrstuvwxyz"[(h>>5)&0x1f]
+			w.Write(append(strconv.AppendUint(b, v, 10), '\n'))
+		}
+	}
+}
+
+func geohash2(lat, lng float64) uint64 {
+	return geohash.EncodeIntWithPrecision(lat, lng, 5*2)
+}
diff --git a/pkg/metricsx/geohash_test.go b/pkg/metricsx/geohash_test.go
new file mode 100644
index 0000000..03cd12e
--- /dev/null
+++ b/pkg/metricsx/geohash_test.go
@@ -0,0 +1,119 @@
+package metricsx
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/base64"
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/VictoriaMetrics/metrics"
+)
+
+func TestGeoCounter(t *testing.T) {
+	var exp string
+	if d, err := gzip.NewReader(base64.NewDecoder(base64.StdEncoding, strings.NewReader(``+
+		`H4sIAAAAAAAA/4zZSW7lVACG0TmriN6YQZzndlCLwb1s2bjvUPaOEPPKmV9dquDg/8vNVq3bP2XdlHXz67WW9VrWrz+b6u/2r7X99Xp9f3z+8fsjn5+v74/4p0PB6/vj/dOhr9f3x9dPh96v74/gp0OR/OMSuSmVP1MmN+VyUyE3VXKokUOd/Hsa5KZJblrkpk0OHXLo`+
+		`kkMPHAo+4b9dEMhNYjwQ40Ekh8R4IMYDMR6I8UCMB2I8EONBJ4fEeDDJITEeiPFAjAdiPBDjX5/wf/DXl9wUyk2x3JTKoVwOlXKolkOt/O16uWmUm2a5aZVDuxw65dANh96fckg8vUM5JJ7e4uktnt7i6S2e3q0cEk/vUQ6Jp7d4eount3h6i6fwP0/hT4cCGKBQNjiU`+
+		`DQ4juUk2OJQNDmWDQ9ngUDY4lA0OZYPDTv5MssHhJDfJBoeywaFscCgbHMoGR9KZkXRmJMYjMR5JZ0ZiPBLjkRiPxHgkxiMxHonxSDozEuORdGYkxiMxHonxSIxHYjwW47F0QRzKTdIFsXRBLF0QSxfE0gVxK3876YJ4lJukC2Lpgli6IJYuiKULEunMRDwl0pmJeErE`+
+		`UyKeEvGUiKdEOjMRT4l0ZiKeEvGUiKdEPCXiKZWfg1N5z0wFXSobnMp7ZiobnIrMVDY4Fb6pbHAqG5zKBqfynpnKBqfynpnKBqeywalscCobnMoGZ/LNzKQzMzGeifFMOjMT45kYz8R4JsYzMZ6J8UyMZ9KZmRjPpDMzMZ6J8UyMZ2I8E+O5fMdz4ZvLe2YuXZCLzFzQ`+
+		`5dIFuXRBLu+ZuXRBLu+ZuXRBLl2QSxfk0gW5dEEh38xCPBXSmYV4KsRTIZ4K8VSIp0I6sxBPhXRmIZ4K8VSIp0I8FeKplJ+DS3nPLAVdKRtcyntmKRtcisxSNrgUvqVscCkbXMoGl/KeWcoGl/KeWcoGl7LBpWxwKRtcygZX8s2spDMrMV6J8Uo6sxLjlRivxHglxisx`+
+		`XonxSoxX0pmVGK+kMysxXonxSoxXYrwS47V8x2vhW8t7Zi1dUIvMWtDV0gW1dEEt75m1dEEt75m1dEEtXVBLF9TSBbV0QSPfzEY8NdKZjXhqxFMjnhrx1IinRjqzEU+NdGYjnhrx1IinRjw14qmV35u30pmt/E6xlQ1upTNb2eBWfqfYyga38jvFVja4lQ1uZYNb6cxW`+
+		`NriVzmxlg1vZ4FY2uJUNbmWDO9ngTjqzE+OdGO+kMzsx3onxTox3YrwT450Y78R4J53ZifFOOrMT450Y78R4J8Y7Md6L8V66oJfO7KULeumCXrqgly7opQt66cxeuqCXzuylC3rpgl66oJcu6KULBunMQTwN0pmDeBrE0yCeBvE0iKdBOnMQT4N05iCeBvE0iKdBPA3i`+
+		`aZTOHKUzR9ngUTZ4lM4cZYNH2eBRNniUDR5lg0fZ4FE2eJTOHGWDR+nMUTZ4lA0eZYNH2eBRNniSDZ6kMycxPonxSTpzEuOTGJ/E+CTGJzE+ifFJjE/SmZMYn6QzJzE+ifFJjE9ifBLjsxifpQtm6cxZumCWLpilC2bpglm6YJbOnKULZunMWbpgli6YpQtm6YJZumCR`+
+		`zlzE0yKduYinRTwt4mkRT4t4WqQzF/G0SGcu4mkRT4t4WsTTIp5W+T6t0pmroFtlg1fpzFU2eBWZq2zwKnxX2eBVNniVDV6lM1fZ4FU6c5UNXmWDV9ngVTZ4lQ3e5Ju5SWduYnwT45t05ibGNzG+ifFNjG9ifBPjmxjfpDM3Mb5JZ25ifBPjmxjfxPgmxnf5ju/Cd5fO`+
+		`3KULdpG5C7pdumCXLtilM3fpgl06c5cu2KULdumCXbpgly445Jt5iKdDOvMQT4d4OsTTIZ4O8XRIZx7i6ZDOPMTTIZ4O8XSIp0M8nfJ9OqUzT0F3ygaf0pmnbPApMk/Z4FP4nrLBp2zwKRt8SmeessGndOYpG3zKBp+ywads8CkbfMk385LOvMT4JcYv6cxLjF9i/BLj`+
+		`lxi/xPglxi8xfklnXmL8ks68xPglxi8xfonxS4zf8h2/he8tnXlLF9wi8xZ0t3TBLV1wS2fe0gW3dOYtXXBLF9zSBbd0wS1d8Mg38xFPj3TmI54e8fSIp0c8PeLpkc58xNMjnfmIp0c8PeLpEU/P/57+DQAA//8lgllOY1MAAA==`,
+	))); err != nil {
+		panic(err)
+	} else if x, err := io.ReadAll(d); err != nil {
+		panic(err)
+	} else {
+		exp = strings.TrimSpace(string(x))
+	}
+
+	set := metrics.NewSet()
+	name := `test{dfgdfg="sdfsdf"}`
+	gc1 := NewGeoCounter(set, name, 2)
+	gc2 := NewGeoCounter2(name)
+
+	for lat := float64(-90); lat <= 90; lat += 10 {
+		for lng := float64(-180); lng <= 180; lng += 10 {
+			gc1.Inc(lat, lng)
+			gc2.Inc(lat, lng)
+		}
+	}
+
+	var b1 strings.Builder
+	set.WritePrometheus(&b1)
+
+	var b2 strings.Builder
+	gc2.WritePrometheus(&b2)
+
+	t.Run("GeoCounter", func(t *testing.T) {
+		if a := strings.TrimSpace(b1.String()); a != exp {
+			t.Errorf("expected:\n\t%s\n, got\n\t%s", strings.ReplaceAll(exp, "\n", "\n\t"), strings.ReplaceAll(a, "\n", "\n\t"))
+		}
+	})
+
+	t.Run("GeoCounter2", func(t *testing.T) {
+		if a := strings.TrimSpace(b2.String()); a != exp {
+			t.Errorf("expected:\n\t%s\n, got\n\t%s", strings.ReplaceAll(exp, "\n", "\n\t"), strings.ReplaceAll(a, "\n", "\n\t"))
+		}
+	})
+}
+
+func BenchmarkGeoCounter2(b *testing.B) {
+	var pts [][2]float64
+	for lat := float64(-90); lat <= 90; lat += 10 {
+		for lng := float64(-180); lng <= 180; lng += 10 {
+			pts = append(pts, [2]float64{lat, lng})
+		}
+	}
+
+	b.Run("GeoCounter", func(b *testing.B) {
+		set := metrics.NewSet()
+		ctr := NewGeoCounter(set, `test{dfgdfg="sdfsdf"}`, 2)
+
+		b.Run("Inc", func(b *testing.B) {
+			for n := 0; n < b.N; n++ {
+				pt := pts[n%len(pts)]
+				ctr.Inc(pt[0], pt[1])
+			}
+		})
+
+		b.Run("WritePrometheus", func(b *testing.B) {
+			var buf bytes.Buffer
+			set.WritePrometheus(&buf)
+			b.ResetTimer()
+
+			for n := 0; n < b.N; n++ {
+				buf.Reset()
+				set.WritePrometheus(&buf)
+			}
+		})
+	})
+
+	b.Run("GeoCounter2", func(b *testing.B) {
+		ctr := NewGeoCounter2(`test{dfgdfg="sdfsdf"}`)
+
+		b.Run("Inc", func(b *testing.B) {
+			for n := 0; n < b.N; n++ {
+				pt := pts[n%len(pts)]
+				ctr.Inc(pt[0], pt[1])
+			}
+		})
+
+		b.Run("WritePrometheus", func(b *testing.B) {
+			var buf bytes.Buffer
+			ctr.WritePrometheus(&buf)
+			b.ResetTimer()
+
+			for n := 0; n < b.N; n++ {
+				buf.Reset()
+				ctr.WritePrometheus(&buf)
+			}
+		})
+	})
+}