Add public constants

Export constants regarding the dictionary size and the member size.

CHANGELOG.adoc

@@ -14,6 +14,13 @@ All notable changes to this project will be documented in this file.
 The format is based on https://keepachangelog.com/[Keep a Changelog], and this
 project adheres to https://semver.org/[Semantic Versioning].
 
+== {compare-url}/v0.1.0\...HEAD[Unreleased]
+
+=== Changed
+
+* Export constants regarding the dictionary size and the member size
+  ({pull-request-url}/3[#3])
+
 == {project-url}/releases/tag/v0.1.0[0.1.0] - 2024-04-04
 
 === Added

export_test.go

@@ -5,22 +5,14 @@
 package lzip
 
 const (
-	MagicSize   = magicSize
 	HeaderSize  = headerSize
 	TrailerSize = trailerSize
 )
 
 const Magic = magic
+const MagicSize = magicSize
 
 const (
 	Version0 = version0
 	Version1 = version1
 )
-
-const (
-	MinDictSize     = minDictSize
-	MaxDictSize     = maxDictSize
-	DefaultDictSize = defaultDictSize
-)
-
-const MaxMemberSize = maxMemberSize

lzip.go

@@ -18,12 +18,12 @@ import (
 )
 
 const (
-	magicSize   = 4
 	headerSize  = 6
 	trailerSize = 20
 )
 
 const magic = "LZIP"
+const magicSize = 4
 
 type version uint8
 
@@ -33,12 +33,18 @@ const (
 )
 
 const (
-	minDictSize     = lzma.MinDictCap
-	maxDictSize     = 1 << 29
-	defaultDictSize = 0x800000
+	// MinDictSize is the minimum dictionary size, which is 4 KiB.
+	MinDictSize = lzma.MinDictCap
+
+	// MaxDictSize is the maximum dictionary size, which is 512 MiB.
+	MaxDictSize = 1 << 29
+
+	// DefaultDictSize is the default dictionary size, which is 8 MiB.
+	DefaultDictSize = 0x800000
 )
 
-const maxMemberSize = 0x8000000000000
+// MaxMemberSize is the maximum member size, which is 2 PiB.
+const MaxMemberSize = 0x8000000000000
 
 type header struct {
 	magic [magicSize]byte
@@ -49,7 +55,7 @@ type header struct {
 func newHeader(dictSize int) *header {
 	ds := bits.Len(uint(dictSize - 1))
 
-	if dictSize > minDictSize {
+	if dictSize > MinDictSize {
 		base := 1 << dictSize
 		frac := base / 16
 

lzip_test.go

@@ -11,14 +11,6 @@ import (
 	"github.com/sorairolake/lzip-go"
 )
 
-func TestMagicSize(t *testing.T) {
-	t.Parallel()
-
-	if size := lzip.MagicSize; size != 4 {
-		t.Errorf("expected magic number size `%v`, got `%v`", 4, size)
-	}
-}
-
 func TestHeaderSize(t *testing.T) {
 	t.Parallel()
 
@@ -43,6 +35,14 @@ func TestMagic(t *testing.T) {
 	}
 }
 
+func TestMagicSize(t *testing.T) {
+	t.Parallel()
+
+	if size := lzip.MagicSize; size != 4 {
+		t.Errorf("expected magic number size `%v`, got `%v`", 4, size)
+	}
+}
+
 func TestVersion(t *testing.T) {
 	t.Parallel()
 

reader.go

@@ -49,9 +49,9 @@ func NewReader(r io.Reader) (*Reader, error) {
 	dictSize -= (dictSize / 16) * int((header[5]>>5)&0x07)
 
 	switch {
-	case dictSize < minDictSize:
+	case dictSize < MinDictSize:
 		return nil, ErrDictSizeTooSmall
-	case dictSize > maxDictSize:
+	case dictSize > MaxDictSize:
 		return nil, ErrDictSizeTooLarge
 	}
 
@@ -67,7 +67,7 @@ func NewReader(r io.Reader) (*Reader, error) {
 	copy(lzmaHeader[5:], rb[len(rb)-16:len(rb)-8])
 
 	z.trailer.memberSize = uint64(headerSize + len(rb))
-	if z.trailer.memberSize > maxMemberSize {
+	if z.trailer.memberSize > MaxMemberSize {
 		return nil, ErrMemberSizeTooLarge
 	}
 

writer.go

@@ -32,17 +32,17 @@ type WriterOptions struct {
 }
 
 func newWriterOptions() *WriterOptions {
-	opt := &WriterOptions{defaultDictSize}
+	opt := &WriterOptions{DefaultDictSize}
 
 	return opt
 }
 
 // Verify checks if [WriterOptions] is valid.
 func (o *WriterOptions) Verify() error {
 	switch {
-	case o.DictSize < minDictSize:
+	case o.DictSize < MinDictSize:
 		return ErrDictSizeTooSmall
-	case o.DictSize > maxDictSize:
+	case o.DictSize > MaxDictSize:
 		return ErrDictSizeTooLarge
 	}
 
@@ -137,7 +137,7 @@ func (z *Writer) Close() error {
 	binary.LittleEndian.PutUint64(trailer[4:12], z.trailer.dataSize)
 	binary.LittleEndian.PutUint64(trailer[12:], headerSize+uint64(len(cb))+trailerSize)
 
-	if binary.LittleEndian.Uint64(trailer[12:]) > maxMemberSize {
+	if binary.LittleEndian.Uint64(trailer[12:]) > MaxMemberSize {
 		return ErrMemberSizeTooLarge
 	}