feat: add command for retrieving metrics samples for a space

commands/metrics/codec.go

@@ -0,0 +1,129 @@
+//go:build !codegen
+
+package metrics
+
+import (
+	"io"
+
+	jsg "github.com/alanshaw/dag-json-gen"
+	"github.com/fil-forge/libforge/commands/internal/codec"
+	"github.com/fil-forge/ucantone/did"
+	cbg "github.com/whyrusleeping/cbor-gen"
+	xerrors "golang.org/x/xerrors"
+)
+
+// SampleSet has a hand-written codec because cbor-gen / dag-json-gen do not
+// support DID-keyed maps. The CBOR and DAG-JSON primitives live in the shared
+// internal codec package.
+
+func (t SampleSet) MarshalCBOR(w io.Writer) error {
+	cw := cbg.NewCborWriter(w)
+	if err := codec.WriteCborMapHeader(cw, len(t.Entries)); err != nil {
+		return err
+	}
+	for _, k := range codec.SortedDIDs(t.Entries) {
+		if err := codec.WriteCborString(cw, k.String()); err != nil {
+			return err
+		}
+		samples := t.Entries[k]
+		if err := codec.WriteCborArrayHeader(cw, len(samples)); err != nil {
+			return err
+		}
+		for i := range samples {
+			if err := samples[i].MarshalCBOR(cw); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (t *SampleSet) UnmarshalCBOR(r io.Reader) error {
+	cr := cbg.NewCborReader(r)
+	n, err := codec.ReadCborMapHeader(cr)
+	if err != nil {
+		return err
+	}
+	m := make(map[did.DID][]SampleItem, n)
+	for i := uint64(0); i < n; i++ {
+		ks, err := codec.ReadCborString(cr)
+		if err != nil {
+			return err
+		}
+		k, err := did.Parse(ks)
+		if err != nil {
+			return xerrors.Errorf("parsing provider did %q: %w", ks, err)
+		}
+		sn, err := codec.ReadCborArrayHeader(cr)
+		if err != nil {
+			return err
+		}
+		samples := make([]SampleItem, sn)
+		for j := uint64(0); j < sn; j++ {
+			if err := samples[j].UnmarshalCBOR(cr); err != nil {
+				return err
+			}
+		}
+		m[k] = samples
+	}
+	*t = SampleSet{Entries: m}
+	return nil
+}
+
+func (t SampleSet) MarshalDagJSON(w io.Writer) error {
+	jw := jsg.NewDagJsonWriter(w)
+	if err := jw.WriteObjectOpen(); err != nil {
+		return err
+	}
+	for i, k := range codec.SortedDIDs(t.Entries) {
+		if err := codec.WriteJSONKey(jw, k.String(), i > 0); err != nil {
+			return err
+		}
+		if err := jw.WriteArrayOpen(); err != nil {
+			return err
+		}
+		samples := t.Entries[k]
+		for j := range samples {
+			if j > 0 {
+				if err := jw.WriteComma(); err != nil {
+					return err
+				}
+			}
+			if err := samples[j].MarshalDagJSON(jw); err != nil {
+				return err
+			}
+		}
+		if err := jw.WriteArrayClose(); err != nil {
+			return err
+		}
+	}
+	return jw.WriteObjectClose()
+}
+
+func (t *SampleSet) UnmarshalDagJSON(r io.Reader) error {
+	jr := jsg.NewDagJsonReader(r)
+	m := map[did.DID][]SampleItem{}
+	err := codec.ReadJSONObject(jr, func(ks string) error {
+		k, err := did.Parse(ks)
+		if err != nil {
+			return xerrors.Errorf("parsing provider did %q: %w", ks, err)
+		}
+		samples, err := codec.ReadJSONArray(jr, func() (SampleItem, error) {
+			var s SampleItem
+			if err := s.UnmarshalDagJSON(jr); err != nil {
+				return SampleItem{}, err
+			}
+			return s, nil
+		})
+		if err != nil {
+			return err
+		}
+		m[k] = samples
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+	*t = SampleSet{Entries: m}
+	return nil
+}