Use encoded type info to deduplicate extra data

Currently, we use TypeInfo.Identifier() to deduplicate extra data
and type info.  However, TypeInfo.Identifier() is implemented in
another package and we can't enforce its uniqueness for different
types.  If TypeInfo.Identifier() returns same ID for different
types, different types is wrongly deduplicated.

This commit uses encoded type info via TypeInfo.Encode() to
deduplicate extra data.  This prevents differently encoded type
info from being deduplicated by mistake.

This commit also uses sync.Pool to reuse buffer for type info
encoding.

array.go

@@ -720,15 +720,16 @@ func (a *ArrayDataSlab) encodeAsInlined(enc *Encoder) error {
 			fmt.Errorf("failed to encode standalone array data slab as inlined"))
 	}
 
-	extraDataIndex := enc.inlinedExtraData().addArrayExtraData(a.extraData)
+	extraDataIndex, err := enc.inlinedExtraData().addArrayExtraData(a.extraData)
+	if err != nil {
+		return NewEncodingError(err)
+	}
 
 	if extraDataIndex > maxInlinedExtraDataIndex {
 		return NewEncodingError(
 			fmt.Errorf("failed to encode inlined array data slab: extra data index %d exceeds limit %d", extraDataIndex, maxInlinedExtraDataIndex))
 	}
 
-	var err error
-
 	// Encode tag number and array head of 3 elements
 	err = enc.CBOR.EncodeRawBytes([]byte{
 		// tag number

cmd/stress/utils.go

@@ -19,12 +19,16 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
 	"math"
 	"math/rand"
 	"reflect"
+	"sync"
 	"time"
 
+	"github.com/fxamacker/cbor/v2"
+
 	"github.com/onflow/atree"
 )
 
@@ -540,5 +544,40 @@ func (v mapValue) Storable(atree.SlabStorage, atree.Address, uint64) (atree.Stor
 }
 
 var typeInfoComparator = func(a atree.TypeInfo, b atree.TypeInfo) bool {
-	return a.Identifier() == b.Identifier()
+	aID, _ := getEncodedTypeInfo(a)
+	bID, _ := getEncodedTypeInfo(b)
+	return aID == bID
+}
+
+func getEncodedTypeInfo(ti atree.TypeInfo) (string, error) {
+	b := getTypeIDBuffer()
+	defer putTypeIDBuffer(b)
+
+	enc := cbor.NewStreamEncoder(b)
+	err := ti.Encode(enc)
+	if err != nil {
+		return "", err
+	}
+	enc.Flush()
+
+	return b.String(), nil
+}
+
+const defaultTypeIDBufferSize = 256
+
+var typeIDBufferPool = sync.Pool{
+	New: func() interface{} {
+		e := new(bytes.Buffer)
+		e.Grow(defaultTypeIDBufferSize)
+		return e
+	},
+}
+
+func getTypeIDBuffer() *bytes.Buffer {
+	return typeIDBufferPool.Get().(*bytes.Buffer)
+}
+
+func putTypeIDBuffer(e *bytes.Buffer) {
+	e.Reset()
+	typeIDBufferPool.Put(e)
 }

map.go

@@ -3007,14 +3007,15 @@ func (m *MapDataSlab) encodeAsInlined(enc *Encoder) error {
 
 func (m *MapDataSlab) encodeAsInlinedMap(enc *Encoder) error {
 
-	extraDataIndex := enc.inlinedExtraData().addMapExtraData(m.extraData)
+	extraDataIndex, err := enc.inlinedExtraData().addMapExtraData(m.extraData)
+	if err != nil {
+		return NewEncodingError(err)
+	}
 
 	if extraDataIndex > maxInlinedExtraDataIndex {
 		return NewEncodingError(fmt.Errorf("extra data index %d exceeds limit %d", extraDataIndex, maxInlinedExtraDataIndex))
 	}
 
-	var err error
-
 	// Encode tag number and array head of 3 elements
 	err = enc.CBOR.EncodeRawBytes([]byte{
 		// tag number
@@ -3067,7 +3068,10 @@ func encodeAsInlinedCompactMap(
 	values []Storable,
 ) error {
 
-	extraDataIndex, cachedKeys := enc.inlinedExtraData().addCompactMapExtraData(extraData, hkeys, keys)
+	extraDataIndex, cachedKeys, err := enc.inlinedExtraData().addCompactMapExtraData(extraData, hkeys, keys)
+	if err != nil {
+		return NewEncodingError(err)
+	}
 
 	if len(keys) != len(cachedKeys) {
 		return NewEncodingError(fmt.Errorf("number of elements %d is different from number of elements in cached compact map type %d", len(keys), len(cachedKeys)))
@@ -3078,8 +3082,6 @@ func encodeAsInlinedCompactMap(
 		return NewEncodingError(fmt.Errorf("extra data index %d exceeds limit %d", extraDataIndex, maxInlinedExtraDataIndex))
 	}
 
-	var err error
-
 	// Encode tag number and array head of 3 elements
 	err = enc.CBOR.EncodeRawBytes([]byte{
 		// tag number