add bytes to string modifier for solana contracts

pkg/codec/byte_string_modifier.go

@@ -1,6 +1,7 @@
 package codec
 
 import (
+	"bytes"
 	"fmt"
 	"reflect"
 
@@ -66,6 +67,41 @@ func NewPathTraverseAddressBytesToStringModifier(
 	return m
 }
 
+func NewConstrainedLengthBytesToStringModifier(
+	fields []string,
+	maxLen int,
+) Modifier {
+	return NewPathTraverseAddressBytesToStringModifier(fields, &constrainedLengthBytesToStringModifier{maxLen: maxLen}, false)
+}
+
+func NewPathTraverseConstrainedLengthBytesToStringModifier(
+	fields []string,
+	maxLen int,
+	enablePathTraverse bool,
+) Modifier {
+	return NewPathTraverseAddressBytesToStringModifier(fields, &constrainedLengthBytesToStringModifier{maxLen: maxLen}, enablePathTraverse)
+}
+
+type constrainedLengthBytesToStringModifier struct {
+	maxLen int
+}
+
+func (m constrainedLengthBytesToStringModifier) EncodeAddress(bts []byte) (string, error) {
+	return string(bytes.Trim(bts, "\x00")), nil
+}
+
+func (m constrainedLengthBytesToStringModifier) DecodeAddress(str string) ([]byte, error) {
+	output := make([]byte, m.maxLen)
+
+	copy(output, []byte(str)[:])
+
+	return output, nil
+}
+
+func (m constrainedLengthBytesToStringModifier) Length() int {
+	return m.maxLen
+}
+
 type bytesToStringModifier struct {
 	// Injected modifier that contains chain-specific logic
 	modifier AddressModifier

pkg/codec/config.go

@@ -59,6 +59,8 @@ func (m *ModifiersConfig) UnmarshalJSON(data []byte) error {
 			(*m)[i] = &PropertyExtractorConfig{}
 		case ModifierAddressToString:
 			(*m)[i] = &AddressBytesToStringModifierConfig{}
+		case ModifierBytesToString:
+			(*m)[i] = &ConstrainedBytesToStringModifierConfig{}
 		case ModifierWrapper:
 			(*m)[i] = &WrapperModifierConfig{}
 		case ModifierPreCodec:
@@ -103,6 +105,7 @@ const (
 	ModifierEpochToTime               ModifierType = "epoch to time"
 	ModifierExtractProperty           ModifierType = "extract property"
 	ModifierAddressToString           ModifierType = "address to string"
+	ModifierBytesToString             ModifierType = "constrained bytes to string"
 	ModifierWrapper                   ModifierType = "wrapper"
 )
 
@@ -368,6 +371,23 @@ func (c *AddressBytesToStringModifierConfig) MarshalJSON() ([]byte, error) {
 	})
 }
 
+type ConstrainedBytesToStringModifierConfig struct {
+	Fields             []string
+	MaxLen             int
+	EnablePathTraverse bool
+}
+
+func (c *ConstrainedBytesToStringModifierConfig) ToModifier(_ ...mapstructure.DecodeHookFunc) (Modifier, error) {
+	return NewPathTraverseConstrainedLengthBytesToStringModifier(c.Fields, c.MaxLen, c.EnablePathTraverse), nil
+}
+
+func (c *ConstrainedBytesToStringModifierConfig) MarshalJSON() ([]byte, error) {
+	return json.Marshal(&modifierMarshaller[ConstrainedBytesToStringModifierConfig]{
+		Type: ModifierBytesToString,
+		T:    c,
+	})
+}
+
 // WrapperModifierConfig replaces each field based on cfg map keys with a struct containing one field with the value of the original field which has is named based on map values.
 // Wrapper modifier does not maintain the original pointers.
 // Wrapper modifier config shouldn't edit fields that affect each other since the results are not deterministic.