Completed minimal Ledger implementation, first tests in chron-cli

cmd/chron-cli/main.go

@@ -1,46 +1,140 @@
 package main
 
 import (
+	"context"
+	"encoding/hex"
+	"errors"
 	"fmt"
-	"time"
+	"sort"
 
 	"git.michelsen.id/chron/core"
-	"github.com/google/uuid"
-	"lukechampine.com/blake3"
 )
 
-func main() {
+type InProcEntryStore struct {
-	payload := []byte{0, 1, 0, 1}
+	entries map[core.EntryID]core.Entry
-	payloadDigest := blake3.Sum256(payload)
+}
-
+
-	entryID, err := uuid.NewV7()
+func (e *InProcEntryStore) Store(ctx context.Context, entry core.Entry) error {
-	entryIDBytes, err := entryID.MarshalBinary()
+	if _, ok := e.entries[entry.EntryID]; ok {
-	if err != nil {
+		return errors.New("entry already exists")
-		return
+	}
-	}
+	e.entries[entry.EntryID] = entry
-	ledgerID, err := uuid.NewV7()
+	return nil
-	ledgerIDBytes, err := ledgerID.MarshalBinary()
+}
-	if err != nil {
+
-		return
+func (e *InProcEntryStore) Load(ctx context.Context, id core.EntryID) (core.Entry, error) {
-	}
+	entry, ok := e.entries[id]
-	payloadID, err := uuid.NewV7()
+	if !ok {
-	payloadIDBytes, err := payloadID.MarshalBinary()
+		return core.Entry{}, errors.New("entry does not exist")
-	if err != nil {
+	}
-		return
+	return entry, nil
-	}
+}
-
+
-	entry := core.Entry{
+func (e *InProcEntryStore) Exists(ctx context.Context, id core.EntryID) (bool, error) {
-		EntryID:       core.EntryID(entryIDBytes),
+	_, ok := e.entries[id]
-		LedgerID:      core.LedgerID(ledgerIDBytes),
+	return ok, nil
-		Seq:           1,
+}
-		Timestamp:     time.Now(),
+
-		PayloadID:     core.PayloadID(payloadIDBytes),
+func (e *InProcEntryStore) Delete(ctx context.Context, id core.EntryID) error {
-		PayloadDigest: payloadDigest,
+	if _, ok := e.entries[id]; !ok {
-	}
+		return errors.New("entry does not exist")
-
+	}
-	entryHash := core.HashEntry(entry)
+	delete(e.entries, id)
-	entry.EntryHash = entryHash
+	return nil
-
+}
-	fmt.Printf("Entry: %+v\n", entry)
+
-	fmt.Printf("EntryHash: %x\n", entryHash)
+type InProcReferenceStore struct {
+	references map[string]core.EntryID
+}
+
+func (r *InProcReferenceStore) Set(ctx context.Context, name string, entryID core.EntryID) error {
+	r.references[name] = entryID
+	return nil
+}
+
+func (r *InProcReferenceStore) Get(ctx context.Context, name string) (core.EntryID, bool, error) {
+	entryID, ok := r.references[name]
+	if !ok {
+		return core.EntryID{}, false, nil
+	}
+	return entryID, true, nil
+}
+
+func (r *InProcReferenceStore) Delete(ctx context.Context, name string) error {
+	if _, ok := r.references[name]; !ok {
+		return errors.New("reference does not exist")
+	}
+	delete(r.references, name)
+	return nil
+}
+
+func main() {
+	ctx := context.TODO()
+
+	entryStore := InProcEntryStore{
+		entries: make(map[core.EntryID]core.Entry),
+	}
+	referenceStore := InProcReferenceStore{
+		references: make(map[string]core.EntryID),
+	}
+
+	ledger, err := core.NewLedger(&entryStore, &referenceStore)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	for i := range 500 {
+		data := fmt.Sprintf("test%d", i)
+
+		err = ledger.Append(ctx, []byte(data))
+		if err != nil {
+			fmt.Println(err)
+			return
+		}
+	}
+
+	entries := make([]core.Entry, 0, len(entryStore.entries))
+	for _, e := range entryStore.entries {
+		entries = append(entries, e)
+	}
+
+	sort.Slice(entries, func(i, j int) bool {
+		if entries[i].Timestamp.Equal(entries[j].Timestamp) {
+			return hex.EncodeToString(entries[i].EntryID[:]) <
+				hex.EncodeToString(entries[j].EntryID[:])
+		}
+		return entries[i].Timestamp.Before(entries[j].Timestamp)
+	})
+
+	fmt.Println("Entries:")
+	if len(entries) == 0 {
+		fmt.Println("  (none)")
+	} else {
+		for _, e := range entries {
+			fmt.Printf("  ts=%d id=%s prev=%s payload=%q\n",
+				e.Timestamp.UnixNano(),
+				hex.EncodeToString(e.EntryID[:]),
+				hex.EncodeToString(e.Previous[:]),
+				e.Payload,
+			)
+		}
+	}
+
+	// ---- Print references (name -> EntryID hex) ----
+	names := make([]string, 0, len(referenceStore.references))
+	for name := range referenceStore.references {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+
+	fmt.Println("References:")
+	if len(names) == 0 {
+		fmt.Println("  (none)")
+	} else {
+		for _, name := range names {
+			id := referenceStore.references[name]
+			fmt.Printf("  %s -> %s\n", name, hex.EncodeToString(id[:]))
+		}
+	}
 }

core/interfaces.go

@@ -13,6 +13,6 @@ type EntryStore interface {
 
 type ReferenceStore interface {
 	Set(ctx context.Context, name string, entryID EntryID) error
-	Get(ctx context.Context, name string) (EntryID, error)
+	Get(ctx context.Context, name string) (EntryID, bool, error)
 	Delete(ctx context.Context, name string) error
 }

core/ledger.go

@@ -1,6 +1,10 @@
 package core
 
-import ()
+import (
+	"context"
+	"errors"
+	"time"
+)
 
 type Ledger struct {
 	entryStore     EntryStore
@@ -14,10 +18,111 @@ func NewLedger(entryStore EntryStore, referenceStore ReferenceStore) (*Ledger, e
 	}, nil
 }
 
-func (l *Ledger) Append()            {}
+func (l *Ledger) Append(ctx context.Context, payload []byte) error {
-func (l *Ledger) AppendToReference() {}
+	currentHeadEntryID, ok, err := l.referenceStore.Get(ctx, "HEAD")
-func (l *Ledger) Get()               {}
+	if err != nil {
-func (l *Ledger) GetFromReference()  {}
+		return err
-func (l *Ledger) SetHead()           {}
+	}
-func (l *Ledger) SetReference()      {}
+
-func (l *Ledger) RemoveReference()   {}
+	if !ok {
+		l.referenceStore.Set(ctx, "HEAD", EntryID{})
+		currentHeadEntryID = EntryID{}
+	}
+
+	entryTime := time.Now()
+	entryID := ComputeEntryID(currentHeadEntryID, entryTime, payload)
+
+	entry := Entry{
+		EntryID:   entryID,
+		Previous:  currentHeadEntryID,
+		Timestamp: entryTime,
+		Payload:   payload,
+	}
+
+	if ComputeEntryID(entry.Previous, entry.Timestamp, entry.Payload) != entryID {
+		panic("EntryID hash mismatch fuckup")
+	}
+
+	err = l.entryStore.Store(ctx, entry)
+	if err != nil {
+		return err
+	}
+
+	err = l.referenceStore.Set(ctx, "HEAD", entry.EntryID)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (l *Ledger) AppendTo(ctx context.Context, prevEntryID EntryID, payload []byte) error {
+	entryTime := time.Now()
+	entryID := ComputeEntryID(prevEntryID, entryTime, payload)
+
+	entry := Entry{
+		EntryID:   entryID,
+		Previous:  prevEntryID,
+		Timestamp: entryTime,
+		Payload:   payload,
+	}
+
+	if ComputeEntryID(entry.Previous, entry.Timestamp, entry.Payload) != entryID {
+		panic("EntryID hash mismatch fuckup")
+	}
+
+	err := l.entryStore.Store(ctx, entry)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (l *Ledger) Get(ctx context.Context) (Entry, error) {
+	headEntryID, ok, err := l.referenceStore.Get(ctx, "HEAD")
+	if err != nil {
+		return Entry{}, err
+	}
+
+	if !ok {
+		return Entry{}, errors.New("HEAD not set")
+	}
+
+	entry, err := l.entryStore.Load(ctx, headEntryID)
+	if err != nil {
+		return Entry{}, err
+	}
+
+	return entry, nil
+}
+
+func (l *Ledger) GetFromReference(ctx context.Context, reference string) (Entry, error) {
+	referenceEntryID, ok, err := l.referenceStore.Get(ctx, reference)
+	if err != nil {
+		return Entry{}, err
+	}
+
+	if !ok {
+		return Entry{}, errors.New("HEAD not set")
+	}
+
+	entry, err := l.entryStore.Load(ctx, referenceEntryID)
+	if err != nil {
+		return Entry{}, err
+	}
+
+	return entry, nil
+}
+
+func (l *Ledger) SetHead(ctx context.Context, entryID EntryID) error {
+	return l.referenceStore.Set(ctx, "HEAD", entryID)
+}
+
+func (l *Ledger) SetReference(ctx context.Context, reference string, entryID EntryID) error {
+	return l.referenceStore.Set(ctx, reference, entryID)
+}
+
+func (l *Ledger) RemoveReference(ctx context.Context, reference string) error {
+	return l.referenceStore.Delete(ctx, reference)
+}

go.mod

@@ -5,6 +5,16 @@ go 1.25.5
 require github.com/google/uuid v1.6.0
 
 require (
+	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/klauspost/cpuid/v2 v2.0.9 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/ncruces/go-strftime v1.0.0 // indirect
+	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
+	golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 // indirect
+	golang.org/x/sys v0.37.0 // indirect
 	lukechampine.com/blake3 v1.4.1 // indirect
+	modernc.org/libc v1.67.6 // indirect
+	modernc.org/mathutil v1.7.1 // indirect
+	modernc.org/memory v1.11.0 // indirect
+	modernc.org/sqlite v1.45.0 // indirect
 )

go.sum

@@ -1,6 +1,27 @@
+github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
+github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/klauspost/cpuid/v2 v2.0.9 h1:lgaqFMSdTdQYdZ04uHyN2d/eKdOMyi2YLSvlQIBFYa4=
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
+github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/ncruces/go-strftime v1.0.0 h1:HMFp8mLCTPp341M/ZnA4qaf7ZlsbTc+miZjCLOFAw7w=
+github.com/ncruces/go-strftime v1.0.0/go.mod h1:Fwc5htZGVVkseilnfgOVb9mKy6w1naJmn9CehxcKcls=
+github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec h1:W09IVJc94icq4NjY3clb7Lk8O1qJ8BdBEF8z0ibU0rE=
+github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
+golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 h1:mgKeJMpvi0yx/sU5GsxQ7p6s2wtOnGAHZWCHUM4KGzY=
+golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546/go.mod h1:j/pmGrbnkbPtQfxEe5D0VQhZC6qKbfKifgD0oM7sR70=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.37.0 h1:fdNQudmxPjkdUTPnLn5mdQv7Zwvbvpaxqs831goi9kQ=
+golang.org/x/sys v0.37.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 lukechampine.com/blake3 v1.4.1 h1:I3Smz7gso8w4/TunLKec6K2fn+kyKtDxr/xcQEN84Wg=
 lukechampine.com/blake3 v1.4.1/go.mod h1:QFosUxmjB8mnrWFSNwKmvxHpfY72bmD2tQ0kBMM3kwo=
+modernc.org/libc v1.67.6 h1:eVOQvpModVLKOdT+LvBPjdQqfrZq+pC39BygcT+E7OI=
+modernc.org/libc v1.67.6/go.mod h1:JAhxUVlolfYDErnwiqaLvUqc8nfb2r6S6slAgZOnaiE=
+modernc.org/mathutil v1.7.1 h1:GCZVGXdaN8gTqB1Mf/usp1Y/hSqgI2vAGGP4jZMCxOU=
+modernc.org/mathutil v1.7.1/go.mod h1:4p5IwJITfppl0G4sUEDtCr4DthTaT47/N3aT6MhfgJg=
+modernc.org/memory v1.11.0 h1:o4QC8aMQzmcwCK3t3Ux/ZHmwFPzE6hf2Y5LbkRs+hbI=
+modernc.org/memory v1.11.0/go.mod h1:/JP4VbVC+K5sU2wZi9bHoq2MAkCnrt2r98UGeSK7Mjw=
+modernc.org/sqlite v1.45.0 h1:r51cSGzKpbptxnby+EIIz5fop4VuE4qFoVEjNvWoObs=
+modernc.org/sqlite v1.45.0/go.mod h1:CzbrU2lSB1DKUusvwGz7rqEKIq+NUd8GWuBBZDs9/nA=