refactor: Strongly typed key refactor (sourcenetwork#17)

* Reference correct Key type in documentation

* Remove commented out import

* Remove commented out import

* Remove commented out code

* Remove commented out import

* Replace references to ds.Key with core.Key

* Replace ds.Key with structured data type

* Remove duplicate call

WithPriorityFlag is called within reg.getPriority and should not be the responsibility of the caller

* Remove DataStoreKey from Collection struct

Is not needed and complicates the code

* Remove duplicate call

WithValueFlag is called in writeObjectMarker

* Take docKey string as param instead of DataStoreKey

Is wasteful taking the whole struct (and initing one in most cases)

* Documet commit key changes

client/core.go

@@ -79,7 +79,7 @@ type Collection interface {
 
 	WithTxn(core.Txn) Collection
 
-	GetPrimaryIndexDocKey(ds.Key) ds.Key
+	GetPrimaryIndexDocKey(core.DataStoreKey) core.DataStoreKey
 	GetAllDocKeys(ctx context.Context) (<-chan DocKeysResult, error)
 }
 

core/crdt/base.go

@@ -19,71 +19,38 @@ import (
 	"github.com/sourcenetwork/defradb/core"
 )
 
-var (
-	keysNs         = "k" // /keys namespace /set/k/<key>/{v,p}
-	valueSuffix    = "v" // value key
-	prioritySuffix = "p" // priority key
-)
-
 // baseCRDT is embedded as a base layer into all
 // the core CRDT implementations to reduce code
 // duplication, and better manage the overhead
 // tasks that all the CRDTs need to implement anyway
 type baseCRDT struct {
-	store          core.DSReaderWriter
-	namespace      ds.Key
-	keysNs         string
-	valueSuffix    string
-	prioritySuffix string
+	store core.DSReaderWriter
+	key   core.DataStoreKey
 }
 
-// @todo paramaterize ns/suffix
-func newBaseCRDT(store core.DSReaderWriter, namespace ds.Key) baseCRDT {
+// @TODO paramaterize ns/suffix
+func newBaseCRDT(store core.DSReaderWriter, key core.DataStoreKey) baseCRDT {
 	return baseCRDT{
-		store:          store,
-		namespace:      namespace,
-		keysNs:         keysNs,
-		valueSuffix:    valueSuffix,
-		prioritySuffix: prioritySuffix,
+		store: store,
+		key:   key,
 	}
 }
 
-func (base baseCRDT) keyPrefix(key string) ds.Key {
-	return base.namespace.ChildString(key)
-}
-
-func (base baseCRDT) valueKey(key string) ds.Key {
-	return base.namespace.ChildString(key).Instance(base.valueSuffix)
-}
-
-func (base baseCRDT) priorityKey(key string) ds.Key {
-	return base.namespace.ChildString(key).Instance(base.prioritySuffix)
-}
-
-// Commented because this function is unused (for linter).
-// func (base baseCRDT) typeKey(key string) ds.Key {
-// 	return base.namespace.ChildString(key).Instance(crdtTypeSuffix)
-// }
-
-// func (base baseCRDT) dataTypeKey(key string) ds.Key {
-// 	return base.namespace.ChildString(key).Instance(dataTypeSuffix)
-// }
-
-func (base baseCRDT) setPriority(ctx context.Context, key string, priority uint64) error {
-	prioK := base.priorityKey(key)
+func (base baseCRDT) setPriority(ctx context.Context, key core.DataStoreKey, priority uint64) error {
+	prioK := key.WithPriorityFlag()
 	buf := make([]byte, binary.MaxVarintLen64)
 	n := binary.PutUvarint(buf, priority+1)
 	if n == 0 {
 		return errors.New("error encoding priority")
 	}
 
-	return base.store.Put(ctx, prioK, buf[0:n])
+	return base.store.Put(ctx, prioK.ToDS(), buf[0:n])
 }
 
 // get the current priority for given key
-func (base baseCRDT) getPriority(ctx context.Context, key string) (uint64, error) {
-	pKey := base.priorityKey(key)
-	pbuf, err := base.store.Get(ctx, pKey)
+func (base baseCRDT) getPriority(ctx context.Context, key core.DataStoreKey) (uint64, error) {
+	pKey := key.WithPriorityFlag()
+	pbuf, err := base.store.Get(ctx, pKey.ToDS())
 	if err != nil {
 		if err == ds.ErrNotFound {
 			return 0, nil

core/crdt/base_test.go

@@ -28,58 +28,42 @@ func newSeededDS() core.DSReaderWriter {
 }
 
 func exampleBaseCRDT() baseCRDT {
-	return newBaseCRDT(newSeededDS(), ds.NewKey("test"))
+	return newBaseCRDT(newSeededDS(), core.DataStoreKey{})
 }
 
 func TestBaseCRDTNew(t *testing.T) {
-	base := newBaseCRDT(newDS(), ds.NewKey("test"))
+	base := newBaseCRDT(newDS(), core.DataStoreKey{})
 	if base.store == nil {
 		t.Error("newBaseCRDT needs to init store")
-	} else if base.namespace.String() == "" {
-		t.Error("newBaseCRDT needs to init namespace")
-	} else if base.keysNs == "" {
-		t.Error("newBaseCRDT needs to init KeyNS")
-	} else if base.valueSuffix == "" {
-		t.Error("newBaseCRDT needs to init valueSuffix")
-	} else if base.prioritySuffix == "" {
-		t.Error("newBaseCRDT needs to init prioritySuffix")
-	}
-}
-
-func TestBaseCRDTKeyPrefix(t *testing.T) {
-	base := exampleBaseCRDT()
-	kp := base.keyPrefix("key1")
-	if kp.String() != "/test/key1" {
-		t.Errorf("Incorrect keyPrefix. Have %v, want %v", kp.String(), "/test/key1")
 	}
 }
 
 func TestBaseCRDTvalueKey(t *testing.T) {
 	base := exampleBaseCRDT()
-	vk := base.valueKey("mykey")
-	if vk.String() != "/test/mykey:v" {
-		t.Errorf("Incorrect valueKey. Have %v, want %v", vk.String(), "/test/k/mykey/v")
+	vk := base.key.WithDocKey("mykey").WithValueFlag()
+	if vk.ToString() != "/mykey:v" {
+		t.Errorf("Incorrect valueKey. Have %v, want %v", vk.ToString(), "/mykey:v")
 	}
 }
 
 func TestBaseCRDTprioryKey(t *testing.T) {
 	base := exampleBaseCRDT()
-	pk := base.priorityKey("mykey")
-	if pk.String() != "/test/mykey:p" {
-		t.Errorf("Incorrect priorityKey. Have %v, want %v", pk.String(), "/test/k/mykey/p")
+	pk := base.key.WithDocKey("mykey").WithPriorityFlag()
+	if pk.ToString() != "/mykey:p" {
+		t.Errorf("Incorrect priorityKey. Have %v, want %v", pk.ToString(), "/mykey:p")
 	}
 }
 
 func TestBaseCRDTSetGetPriority(t *testing.T) {
 	base := exampleBaseCRDT()
 	ctx := context.Background()
-	err := base.setPriority(ctx, "mykey", 10)
+	err := base.setPriority(ctx, base.key.WithDocKey("mykey"), 10)
 	if err != nil {
 		t.Errorf("baseCRDT failed to set Priority. err: %v", err)
 		return
 	}
 
-	priority, err := base.getPriority(ctx, "mykey")
+	priority, err := base.getPriority(ctx, base.key.WithDocKey("mykey"))
 	if err != nil {
 		t.Errorf("baseCRDT failed to get priority. err: %v", err)
 		return

core/crdt/composite.go

@@ -19,7 +19,6 @@ import (
 
 	"github.com/sourcenetwork/defradb/core"
 
-	ds "github.com/ipfs/go-datastore"
 	ipld "github.com/ipfs/go-ipld-format"
 	dag "github.com/ipfs/go-merkledag"
 	"github.com/ugorji/go/codec"
@@ -81,7 +80,7 @@ type CompositeDAG struct {
 	schemaID string
 }
 
-func NewCompositeDAG(store core.DSReaderWriter, schemaID string, namespace ds.Key, key string) CompositeDAG {
+func NewCompositeDAG(store core.DSReaderWriter, schemaID string, namespace core.Key, key string) CompositeDAG {
 	return CompositeDAG{
 		key:      key,
 		schemaID: schemaID,

core/crdt/lwwreg.go

@@ -21,7 +21,6 @@ import (
 
 	"github.com/sourcenetwork/defradb/core"
 
-	ds "github.com/ipfs/go-datastore"
 	ipld "github.com/ipfs/go-ipld-format"
 	dag "github.com/ipfs/go-merkledag"
 
@@ -78,14 +77,12 @@ func (delta *LWWRegDelta) Value() interface{} {
 // arbitrary data type that ensures convergence
 type LWWRegister struct {
 	baseCRDT
-	key string
 }
 
 // NewLWWRegister returns a new instance of the LWWReg with the given ID
-func NewLWWRegister(store core.DSReaderWriter, namespace ds.Key, key string) LWWRegister {
+func NewLWWRegister(store core.DSReaderWriter, key core.DataStoreKey) LWWRegister {
 	return LWWRegister{
-		baseCRDT: newBaseCRDT(store, namespace),
-		key:      key,
+		baseCRDT: newBaseCRDT(store, key),
 		// id:    id,
 		// data:  data,
 		// ts:    ts,
@@ -96,8 +93,8 @@ func NewLWWRegister(store core.DSReaderWriter, namespace ds.Key, key string) LWW
 // Value gets the current register value
 // RETURN STATE
 func (reg LWWRegister) Value(ctx context.Context) ([]byte, error) {
-	valueK := reg.valueKey(reg.key)
-	buf, err := reg.store.Get(ctx, valueK)
+	valueK := reg.key.WithValueFlag()
+	buf, err := reg.store.Get(ctx, valueK.ToDS())
 	if err != nil {
 		return nil, err
 	}
@@ -112,12 +109,12 @@ func (reg LWWRegister) Set(value []byte) *LWWRegDelta {
 	// return NewLWWRegister(reg.id, value, reg.clock.Apply(), reg.clock)
 	return &LWWRegDelta{
 		Data:   value,
-		DocKey: []byte(reg.key),
+		DocKey: reg.key.Bytes(),
 	}
 }
 
 func (reg LWWRegister) ID() string {
-	return reg.key
+	return reg.key.ToString()
 }
 
 // RETURN DELTA
@@ -150,19 +147,19 @@ func (reg LWWRegister) setValue(ctx context.Context, val []byte, priority uint64
 	// if the current priority is higher ignore put
 	// else if the current value is lexicographically
 	// greater than the new then ignore
-	valueK := reg.valueKey(reg.key)
+	valueK := reg.key.WithValueFlag()
 	if priority < curPrio {
 		return nil
 	} else if priority == curPrio {
-		curValue, _ := reg.store.Get(ctx, valueK)
+		curValue, _ := reg.store.Get(ctx, valueK.ToDS())
 		if bytes.Compare(curValue, val) >= 0 {
 			return nil
 		}
 	}
 
 	// prepend the value byte array with a single byte indicator for the CRDT Type.
 	buf := append([]byte{byte(core.LWW_REGISTER)}, val...)
-	err = reg.store.Put(ctx, valueK, buf)
+	err = reg.store.Put(ctx, valueK.ToDS(), buf)
 	if err != nil {
 		return fmt.Errorf("Failed to store new value : %w", err)
 	}

core/crdt/lwwreg_test.go

@@ -20,7 +20,6 @@ import (
 	"github.com/sourcenetwork/defradb/core"
 	"github.com/sourcenetwork/defradb/store"
 
-	// "github.com/sourcenetwork/defradb/store"
 	"github.com/ugorji/go/codec"
 
 	ipld "github.com/ipfs/go-ipld-format"
@@ -34,9 +33,8 @@ func newMockStore() core.DSReaderWriter {
 
 func setupLWWRegister() LWWRegister {
 	store := newMockStore()
-	ns := ds.NewKey("defra/test")
-	id := "AAAA-BBBB"
-	return NewLWWRegister(store, ns, id)
+	key := core.DataStoreKey{DocKey: "AAAA-BBBB"}
+	return NewLWWRegister(store, key)
 }
 
 func setupLoadedLWWRegster(ctx context.Context) LWWRegister {

core/data.go

@@ -15,9 +15,9 @@ import "strings"
 // Span is a range of keys from [Start, End)
 type Span interface {
 	// Start returns the starting key of the Span
-	Start() Key
+	Start() DataStoreKey
 	// End returns the ending key of the Span
-	End() Key
+	End() DataStoreKey
 	// Contains returns true of the Span contains the provided Span's range
 	Contains(Span) bool
 	// Equal returns true if the provided Span is equal to the current
@@ -27,24 +27,25 @@ type Span interface {
 }
 
 type span struct {
-	start Key
-	end   Key
+	Span
+	start DataStoreKey
+	end   DataStoreKey
 }
 
-func NewSpan(start, end Key) Span {
+func NewSpan(start, end DataStoreKey) Span {
 	return span{
 		start: start,
 		end:   end,
 	}
 }
 
 // Start returns the starting key of the Span
-func (s span) Start() Key {
+func (s span) Start() DataStoreKey {
 	return s.start
 }
 
 // End returns the ending key of the Span
-func (s span) End() Key {
+func (s span) End() DataStoreKey {
 	return s.end
 }
 
@@ -84,10 +85,10 @@ func (this span) Compare(other Span) SpanComparisonResult {
 		return Equal
 	}
 
-	thisStart := this.start.String()
-	thisEnd := this.end.String()
-	otherStart := other.Start().String()
-	otherEnd := other.End().String()
+	thisStart := this.start.ToString()
+	thisEnd := this.end.ToString()
+	otherStart := other.Start().ToString()
+	otherEnd := other.End().ToString()
 
 	if thisStart < otherStart {
 		if thisEnd == otherStart || isAdjacent(this.end, other.Start()) {
@@ -146,16 +147,21 @@ func (this span) Compare(other Span) SpanComparisonResult {
 	return After
 }
 
-func isAdjacent(this Key, other Key) bool {
-	return len(this.String()) == len(other.String()) && (this.PrefixEnd().String() == other.String() || this.String() == other.PrefixEnd().String())
+func isAdjacent(this DataStoreKey, other DataStoreKey) bool {
+	return len(this.ToString()) == len(other.ToString()) && (this.PrefixEnd().ToString() == other.ToString() || this.ToString() == other.PrefixEnd().ToString())
 }
 
 // Spans is a collection of individual spans
 type Spans []Span
 
-// KeyValue is a KV store response containing the resulting ds.Key and byte array value
+// KeyValue is a KV store response containing the resulting core.Key and byte array value
 type KeyValue struct {
-	Key   Key
+	Key   DataStoreKey
+	Value []byte
+}
+
+type HeadKeyValue struct {
+	Key   HeadStoreKey
 	Value []byte
 }
 
@@ -200,7 +206,7 @@ func (spans Spans) MergeAscending() Spans {
 				uniqueSpanFound = true
 				i++
 			case StartBeforeEndAfter:
-				uniqueSpans = uniqueSpans.removeBefore(i, span.End().String())
+				uniqueSpans = uniqueSpans.removeBefore(i, span.End().ToString())
 				uniqueSpans[i] = NewSpan(span.Start(), span.End())
 				uniqueSpanFound = true
 				// Exit the unique-span loop, this span has been handled
@@ -210,7 +216,7 @@ func (spans Spans) MergeAscending() Spans {
 				// Do nothing, span is contained within an existing unique-span
 				i = len(uniqueSpans)
 			case StartEqualEndAfter, StartWithinEndAfter, StartEqualToEndEndAfter:
-				uniqueSpans = uniqueSpans.removeBefore(i, span.End().String())
+				uniqueSpans = uniqueSpans.removeBefore(i, span.End().ToString())
 				uniqueSpans[i] = NewSpan(uniqueSpan.Start(), span.End())
 				uniqueSpanFound = true
 				// Exit the unique-span loop, this span has been handled
@@ -234,7 +240,7 @@ func (spans Spans) MergeAscending() Spans {
 func (spans Spans) removeBefore(startIndex int, end string) Spans {
 	indexOfLastMatchingItem := -1
 	for i := startIndex; i < len(spans); i++ {
-		if spans[i].End().String() <= end {
+		if spans[i].End().ToString() <= end {
 			indexOfLastMatchingItem = i
 		}
 	}