wip: zim lib rewrite

go.mod

@@ -1,6 +1,6 @@
 module forge.cadoles.com/arcad/edge
 
-go 1.20
+go 1.21
 
 require (
 	github.com/hashicorp/golang-lru/v2 v2.0.7

pkg/app/option.go

@@ -0,0 +1,36 @@
+package app
+
+import (
+	"context"
+
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/logger"
+)
+
+type Options struct {
+	ModuleFactories []ServerModuleFactory
+	ErrorHandler    func(ctx context.Context, err error)
+}
+
+type OptionFunc func(opts *Options)
+
+func NewOptions(funcs ...OptionFunc) *Options {
+	opts := &Options{
+		ModuleFactories: make([]ServerModuleFactory, 0),
+		ErrorHandler: func(ctx context.Context, err error) {
+			logger.Error(ctx, err.Error(), logger.E(errors.WithStack(err)))
+		},
+	}
+
+	for _, fn := range funcs {
+		fn(opts)
+	}
+
+	return opts
+}
+
+func WithModulesFactories(factories ...ServerModuleFactory) OptionFunc {
+	return func(opts *Options) {
+		opts.ModuleFactories = factories
+	}
+}

pkg/bundle/oldzim/article.go

@@ -150,10 +150,12 @@ func (a *Article) Data() ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	s, err := a.z.bytesRangeAt(start, start+1)
 	if err != nil {
 		return nil, err
 	}
+
 	compression := uint8(s[0])
 
 	// blob starts at offset, blob ends at offset

pkg/bundle/oldzim/error.go

@@ -0,0 +1,7 @@
+package zim
+
+import "errors"
+
+var (
+	ErrNotFound = errors.New("not found")
+)

pkg/bundle/oldzim/favicon.go

@@ -0,0 +1,49 @@
+package zim
+
+import "github.com/pkg/errors"
+
+func (z *ZimReader) Favicon() (*Article, error) {
+	illustration, err := z.getMetadataIllustration()
+	if err != nil && !errors.Is(err, ErrNotFound) {
+		return nil, errors.WithStack(err)
+	}
+
+	if illustration != nil {
+		return illustration, nil
+	}
+
+	namespaces := []string{"-", "I"}
+	entryNames := []string{"favicon", "favicon.png"}
+
+	for _, ns := range namespaces {
+		for _, en := range entryNames {
+			article, err := z.GetPageNoIndex(ns + "/" + en)
+			if err != nil && !errors.Is(err, ErrNotFound) {
+				return nil, errors.WithStack(err)
+			}
+
+			if article != nil {
+				return article, nil
+			}
+		}
+	}
+
+	return nil, errors.WithStack(ErrNotFound)
+}
+
+func (z *ZimReader) getMetadataIllustration() (*Article, error) {
+	metadata, err := z.Metadata(MetadataIllustration96x96at2, MetadataIllustration48x48at1)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	if _, exists := metadata[MetadataIllustration96x96at2]; exists {
+		return z.GetPageNoIndex("M/" + string(MetadataIllustration96x96at2))
+	}
+
+	if _, exists := metadata[MetadataIllustration48x48at1]; exists {
+		return z.GetPageNoIndex("M/" + string(MetadataIllustration48x48at1))
+	}
+
+	return nil, errors.WithStack(ErrNotFound)
+}

pkg/bundle/oldzim/metadata.go

@@ -0,0 +1,69 @@
+package zim
+
+import (
+	"github.com/pkg/errors"
+)
+
+type MetadataKey string
+
+// See https://wiki.openzim.org/wiki/Metadata
+const (
+	MetadataName                 MetadataKey = "Name"
+	MetadataTitle                MetadataKey = "Title"
+	MetadataDescription          MetadataKey = "Description"
+	MetadataLongDescription      MetadataKey = "LongDescription"
+	MetadataCreator              MetadataKey = "Creator"
+	MetadataTags                 MetadataKey = "Tags"
+	MetadataDate                 MetadataKey = "Date"
+	MetadataPublisher            MetadataKey = "Publisher"
+	MetadataFlavour              MetadataKey = "Flavour"
+	MetadataSource               MetadataKey = "Source"
+	MetadataLanguage             MetadataKey = "Language"
+	MetadataIllustration48x48at1 MetadataKey = "Illustration_48x48@1"
+	MetadataIllustration96x96at2 MetadataKey = "Illustration_96x96@2"
+)
+
+var knownKeys = []MetadataKey{
+	MetadataName,
+	MetadataTitle,
+	MetadataDescription,
+	MetadataLongDescription,
+	MetadataCreator,
+	MetadataPublisher,
+	MetadataLanguage,
+	MetadataTags,
+	MetadataDate,
+	MetadataFlavour,
+	MetadataSource,
+	MetadataIllustration48x48at1,
+	MetadataIllustration96x96at2,
+}
+
+// Metadata returns a copy of the internal metadata map of the ZIM file.
+func (z *ZimReader) Metadata(keys ...MetadataKey) (map[MetadataKey]string, error) {
+	if len(keys) == 0 {
+		keys = knownKeys
+	}
+
+	metadata := make(map[MetadataKey]string)
+
+	for _, key := range keys {
+		article, err := z.GetPageNoIndex("M/" + string(key))
+		if err != nil {
+			if errors.Is(err, ErrNotFound) {
+				continue
+			}
+
+			return nil, errors.WithStack(err)
+		}
+
+		data, err := article.Data()
+		if errors.Is(err, ErrNotFound) {
+			continue
+		}
+
+		metadata[key] = string(data)
+	}
+
+	return metadata, nil
+}

pkg/bundle/oldzim/zim.go

@@ -100,6 +100,7 @@ func (z *ZimReader) ListArticles() <-chan *Article {
 
 			if art == nil {
 				// TODO: deal with redirect continue
+				continue
 			}
 			ch <- art
 		}

pkg/bundle/oldzim/zim_test.go

@@ -0,0 +1,153 @@
+package zim
+
+import (
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"testing"
+
+	"github.com/pkg/errors"
+)
+
+var testCases = []func(t *testing.T, z *ZimReader){
+	testOpen,
+	testData,
+	testDisplayArticle,
+	testDisplayInfost,
+	testFavicon,
+	testListArticles,
+	testMainPage,
+	testMetadata,
+	testMime,
+	testURLAtIdx,
+}
+
+func TestZim(t *testing.T) {
+	zimFiles, err := filepath.Glob("testdata/*.zim")
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	for _, zf := range zimFiles {
+		zr, err := NewReader(zf)
+		if err != nil {
+			t.Fatalf("%+v", errors.WithStack(err))
+		}
+
+		base := filepath.Base(zf)
+
+		t.Run(base, func(t *testing.T) {
+			for _, fn := range testCases {
+				testName := runtime.FuncForPC(reflect.ValueOf(fn).Pointer()).Name()
+				t.Run(testName, func(t *testing.T) {
+					fn(t, zr)
+				})
+			}
+		})
+	}
+}
+
+func testOpen(t *testing.T, zr *ZimReader) {
+	if zr.ArticleCount == 0 {
+		t.Errorf("No article found")
+	}
+}
+
+func testMime(t *testing.T, zr *ZimReader) {
+	if len(zr.MimeTypes()) == 0 {
+		t.Errorf("No mime types found")
+	}
+}
+
+func testDisplayInfost(t *testing.T, zr *ZimReader) {
+	info := zr.String()
+	if len(info) < 0 {
+		t.Errorf("Can't read infos")
+	}
+	t.Log(info)
+}
+
+func testURLAtIdx(t *testing.T, zr *ZimReader) {
+	// addr 0 is a redirect
+	p, _ := zr.OffsetAtURLIdx(5)
+	a, _ := zr.ArticleAt(p)
+	if a == nil {
+		t.Errorf("Can't find 1st url")
+	}
+}
+
+func testDisplayArticle(t *testing.T, zr *ZimReader) {
+	// addr 0 is a redirect
+	p, _ := zr.OffsetAtURLIdx(5)
+	a, _ := zr.ArticleAt(p)
+	if a == nil {
+		t.Errorf("Can't find 1st url")
+	}
+
+	t.Log(a)
+}
+
+func testListArticles(t *testing.T, zr *ZimReader) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode.")
+	}
+
+	var i uint32
+
+	for a := range zr.ListArticles() {
+		i++
+		t.Log(a.String())
+	}
+
+	if i == 0 {
+		t.Errorf("Can't find any urls")
+	}
+
+	if i != zr.ArticleCount-1 {
+		t.Errorf("Can't find the exact ArticleCount urls %d vs %d", i, zr.ArticleCount)
+	}
+}
+
+func testMainPage(t *testing.T, zr *ZimReader) {
+	a, _ := zr.MainPage()
+	if a == nil {
+		t.Errorf("Can't find the mainpage article")
+	}
+
+	t.Log(a)
+}
+
+func testFavicon(t *testing.T, zr *ZimReader) {
+	favicon, err := zr.Favicon()
+	if err != nil {
+		t.Errorf("%+v", errors.WithStack(err))
+	}
+	if favicon == nil {
+		t.Errorf("Can't find the favicon article")
+	}
+}
+
+func testMetadata(t *testing.T, zr *ZimReader) {
+	metadata, err := zr.Metadata()
+	if err != nil {
+		t.Errorf("%+v", errors.WithStack(err))
+	}
+	if metadata == nil {
+		t.Errorf("Can't find the metadata")
+	}
+}
+
+func testData(t *testing.T, zr *ZimReader) {
+	// addr 0 is a redirect
+	p, _ := zr.OffsetAtURLIdx(5)
+	a, _ := zr.ArticleAt(p)
+	b, _ := a.Data()
+	data := string(b)
+	if a.EntryType != RedirectEntry {
+		if len(data) == 0 {
+			t.Error("can't read data")
+		}
+	}
+	t.Log(a.String())
+	t.Log(data)
+}

pkg/bundle/zim/blob_reader.go

@@ -0,0 +1,8 @@
+package zim
+
+import "io"
+
+type BlobReader interface {
+	io.ReadCloser
+	Size() (int64, error)
+}

pkg/bundle/zim/compressed_blob_reader.go

@@ -0,0 +1,163 @@
+package zim
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+	"os"
+	"sync"
+
+	"github.com/pkg/errors"
+)
+
+type CompressedBlobReader struct {
+	reader         *Reader
+	decoderFactory BlobDecoderFactory
+
+	clusterStartOffset uint64
+	clusterEndOffset   uint64
+	blobIndex          uint32
+	blobSize           int
+	readOffset         uint64
+
+	loadCluster    sync.Once
+	loadClusterErr error
+
+	data   []byte
+	closed bool
+}
+
+// Size implements BlobReader.
+func (r *CompressedBlobReader) Size() (int64, error) {
+	if err := r.loadClusterData(); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	return int64(len(r.data)), nil
+}
+
+// Close implements io.ReadCloser.
+func (r *CompressedBlobReader) Close() error {
+	clear(r.data)
+	r.closed = true
+	return nil
+}
+
+// Read implements io.ReadCloser.
+func (r *CompressedBlobReader) Read(p []byte) (int, error) {
+	if err := r.loadClusterData(); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	length := len(p)
+	remaining := len(r.data) - int(r.readOffset)
+	if length > remaining {
+		length = remaining
+	}
+
+	chunk := make([]byte, length)
+
+	copy(chunk, r.data[r.readOffset:int(r.readOffset)+length])
+	copy(p, chunk)
+
+	if length == remaining {
+		return length, io.EOF
+	}
+
+	r.readOffset += uint64(length)
+
+	return length, nil
+}
+
+func (r *CompressedBlobReader) loadClusterData() error {
+	if r.closed {
+		return errors.WithStack(os.ErrClosed)
+	}
+
+	r.loadCluster.Do(func() {
+		compressedData := make([]byte, r.clusterEndOffset-r.clusterStartOffset)
+		if err := r.reader.readRange(int64(r.clusterStartOffset+1), compressedData); err != nil {
+			r.loadClusterErr = errors.WithStack(err)
+			return
+		}
+
+		blobBuffer := bytes.NewBuffer(compressedData)
+
+		decoder, err := r.decoderFactory(blobBuffer)
+		if err != nil {
+			r.loadClusterErr = errors.WithStack(err)
+			return
+		}
+
+		defer decoder.Close()
+
+		uncompressedData, err := io.ReadAll(decoder)
+		if err != nil {
+			r.loadClusterErr = errors.WithStack(err)
+			return
+		}
+
+		var (
+			blobStart uint64
+			blobEnd   uint64
+		)
+
+		if r.blobSize == 8 {
+			blobStart64, err := readUint64(uncompressedData[r.blobIndex*uint32(r.blobSize):r.blobIndex*uint32(r.blobSize)+uint32(r.blobSize)], binary.LittleEndian)
+			if err != nil {
+				r.loadClusterErr = errors.WithStack(err)
+				return
+			}
+
+			blobStart = blobStart64
+
+			blobEnd64, err := readUint64(uncompressedData[r.blobIndex*uint32(r.blobSize)+uint32(r.blobSize):r.blobIndex*uint32(r.blobSize)+uint32(r.blobSize)+uint32(r.blobSize)], binary.LittleEndian)
+			if err != nil {
+				r.loadClusterErr = errors.WithStack(err)
+				return
+			}
+
+			blobEnd = blobEnd64
+		} else {
+			blobStart32, err := readUint32(uncompressedData[r.blobIndex*uint32(r.blobSize):r.blobIndex*uint32(r.blobSize)+uint32(r.blobSize)], binary.LittleEndian)
+			if err != nil {
+				r.loadClusterErr = errors.WithStack(err)
+				return
+			}
+
+			blobStart = uint64(blobStart32)
+
+			blobEnd32, err := readUint32(uncompressedData[r.blobIndex*uint32(r.blobSize)+uint32(r.blobSize):r.blobIndex*uint32(r.blobSize)+uint32(r.blobSize)+uint32(r.blobSize)], binary.LittleEndian)
+			if err != nil {
+				r.loadClusterErr = errors.WithStack(err)
+				return
+			}
+
+			blobEnd = uint64(blobEnd32)
+		}
+
+		r.data = make([]byte, blobEnd-blobStart)
+		copy(r.data, uncompressedData[blobStart:blobEnd])
+	})
+	if r.loadClusterErr != nil {
+		return errors.WithStack(r.loadClusterErr)
+	}
+
+	return nil
+}
+
+type BlobDecoderFactory func(io.Reader) (io.ReadCloser, error)
+
+func NewCompressedBlobReader(reader *Reader, decoderFactory BlobDecoderFactory, clusterStartOffset, clusterEndOffset uint64, blobIndex uint32, blobSize int) *CompressedBlobReader {
+	return &CompressedBlobReader{
+		reader:             reader,
+		decoderFactory:     decoderFactory,
+		clusterStartOffset: clusterStartOffset,
+		clusterEndOffset:   clusterEndOffset,
+		blobIndex:          blobIndex,
+		blobSize:           blobSize,
+		readOffset:         0,
+	}
+}
+
+var _ BlobReader = &UncompressedBlobReader{}

pkg/bundle/zim/content_entry.go

@@ -0,0 +1,221 @@
+package zim
+
+import (
+	"encoding/binary"
+
+	"github.com/pkg/errors"
+)
+
+type zimCompression int
+
+const (
+	zimCompressionNoneZeno      zimCompression = 0
+	zimCompressionNone          zimCompression = 1
+	zimCompressionNoneZLib      zimCompression = 2
+	zimCompressionNoneBZip2     zimCompression = 3
+	zimCompressionNoneXZ        zimCompression = 4
+	zimCompressionNoneZStandard zimCompression = 5
+)
+
+type ContentEntry struct {
+	*BaseEntry
+	mimeType     string
+	clusterIndex uint32
+	blobIndex    uint32
+}
+
+func (e *ContentEntry) Compression() (int, error) {
+	clusterHeader, _, _, err := e.readClusterInfo()
+	if err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	return int((clusterHeader << 4) >> 4), nil
+}
+
+func (e *ContentEntry) MimeType() string {
+	return e.mimeType
+}
+
+func (e *ContentEntry) Reader() (BlobReader, error) {
+	clusterHeader, clusterStartOffset, clusterEndOffset, err := e.readClusterInfo()
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	compression := (clusterHeader << 4) >> 4
+	extended := (clusterHeader<<3)>>7 == 1
+
+	blobSize := 4
+	if extended {
+		blobSize = 8
+	}
+
+	switch compression {
+
+	// Uncompressed blobs
+	case uint8(zimCompressionNoneZeno):
+		fallthrough
+	case uint8(zimCompressionNone):
+		startPos := clusterStartOffset + 1
+		blobOffset := uint64(e.blobIndex * uint32(blobSize))
+
+		data := make([]byte, blobSize)
+
+		var (
+			blobStart uint64
+			blobEnd   uint64
+		)
+
+		if extended {
+			if err := e.reader.readRange(int64(startPos+blobOffset), data); err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			blobStart64, err := readUint64(data, binary.LittleEndian)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			blobStart = blobStart64
+
+			if err := e.reader.readRange(int64(startPos+blobOffset+uint64(blobSize)), data); err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			blobEnd64, err := readUint64(data, binary.LittleEndian)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			blobEnd = uint64(blobEnd64)
+		} else {
+			if err := e.reader.readRange(int64(startPos+blobOffset), data); err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			blobStart32, err := readUint32(data, binary.LittleEndian)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			blobStart = uint64(blobStart32)
+
+			if err := e.reader.readRange(int64(startPos+blobOffset+uint64(blobSize)), data); err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			blobEnd32, err := readUint32(data, binary.LittleEndian)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			blobEnd = uint64(blobEnd32)
+		}
+
+		return NewUncompressedBlobReader(e.reader, startPos+blobStart, startPos+blobEnd, blobSize), nil
+
+	// Supported compression algorithms
+	case uint8(zimCompressionNoneXZ):
+		return NewXZBlobReader(e.reader, clusterStartOffset, clusterEndOffset, e.blobIndex, blobSize), nil
+
+	case uint8(zimCompressionNoneZStandard):
+		return NewZStdBlobReader(e.reader, clusterStartOffset, clusterEndOffset, e.blobIndex, blobSize), nil
+
+	// Unsupported compression algorithms
+	case uint8(zimCompressionNoneZLib):
+		fallthrough
+	case uint8(zimCompressionNoneBZip2):
+		fallthrough
+	default:
+		return nil, errors.Wrapf(ErrCompressionAlgorithmNotSupported, "unexpected compression algorithm '%d'", compression)
+	}
+}
+
+func (e *ContentEntry) Redirect() (*ContentEntry, error) {
+	return e, nil
+}
+
+func (e *ContentEntry) readClusterInfo() (uint8, uint64, uint64, error) {
+	startClusterOffset, clusterEndOffset, err := e.reader.getClusterOffsets(int(e.clusterIndex))
+	if err != nil {
+		return 0, 0, 0, errors.WithStack(err)
+	}
+
+	data := make([]byte, 1)
+	if err := e.reader.readRange(int64(startClusterOffset), data); err != nil {
+		return 0, 0, 0, errors.WithStack(err)
+	}
+
+	clusterHeader := uint8(data[0])
+
+	return clusterHeader, startClusterOffset, clusterEndOffset, nil
+}
+
+func (r *Reader) parseContentEntry(offset int64, base *BaseEntry) (*ContentEntry, error) {
+	entry := &ContentEntry{
+		BaseEntry: base,
+	}
+
+	data := make([]byte, 2)
+	if err := r.readRange(offset, data); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	mimeTypeIndex, err := readUint16(data, binary.LittleEndian)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	if mimeTypeIndex >= uint16(len(r.mimeTypes)) {
+		return nil, errors.Errorf("mime type index '%d' greater than mime types length '%d'", mimeTypeIndex, len(r.mimeTypes))
+	}
+
+	entry.mimeType = r.mimeTypes[mimeTypeIndex]
+
+	data = make([]byte, 1)
+	if err := r.readRange(offset+3, data); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.namespace = Namespace(data[0])
+
+	data = make([]byte, 4)
+	if err := r.readRange(offset+8, data); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	clusterIndex, err := readUint32(data, binary.LittleEndian)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.clusterIndex = clusterIndex
+
+	if err := r.readRange(offset+12, data); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	blobIndex, err := readUint32(data, binary.LittleEndian)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.blobIndex = blobIndex
+
+	url, read, err := r.readStringAt(offset + 16)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.url = url
+
+	title, _, err := r.readStringAt(offset + 16 + read + 1)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.title = title
+
+	return entry, nil
+}

pkg/bundle/zim/entry.go

@@ -0,0 +1,138 @@
+package zim
+
+import (
+	"encoding/binary"
+	"fmt"
+
+	"github.com/pkg/errors"
+)
+
+type Entry interface {
+	Redirect() (*ContentEntry, error)
+	Namespace() Namespace
+	URL() string
+	FullURL() string
+	Title() string
+}
+
+type BaseEntry struct {
+	mimeTypeIndex uint16
+	namespace     Namespace
+	url           string
+	title         string
+	reader        *Reader
+}
+
+func (e *BaseEntry) Namespace() Namespace {
+	return e.namespace
+}
+
+func (e *BaseEntry) Title() string {
+	if e.title == "" {
+		return e.url
+	}
+
+	return e.title
+}
+
+func (e *BaseEntry) URL() string {
+	return e.url
+}
+
+func (e *BaseEntry) FullURL() string {
+	return toFullURL(e.Namespace(), e.URL())
+}
+
+func (r *Reader) parseBaseEntry(offset int64) (*BaseEntry, error) {
+	entry := &BaseEntry{
+		reader: r,
+	}
+
+	data := make([]byte, 2)
+	if err := r.readRange(offset, data); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	mimeTypeIndex, err := readUint16(data, binary.LittleEndian)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.mimeTypeIndex = mimeTypeIndex
+
+	data = make([]byte, 1)
+	if err := r.readRange(offset+3, data); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.namespace = Namespace(data[0])
+
+	return entry, nil
+}
+
+type RedirectEntry struct {
+	*BaseEntry
+	redirectIndex uint32
+}
+
+func (e *RedirectEntry) Redirect() (*ContentEntry, error) {
+	if e.redirectIndex >= uint32(len(e.reader.urlIndex)) {
+		return nil, errors.Wrapf(ErrInvalidEntryIndex, "entry index '%d' out of bounds", e.redirectIndex)
+	}
+
+	entryPtr := e.reader.urlIndex[e.redirectIndex]
+	entry, err := e.reader.parseEntryAt(int64(entryPtr))
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry, err = entry.Redirect()
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	contentEntry, ok := entry.(*ContentEntry)
+	if !ok {
+		return nil, errors.WithStack(ErrInvalidRedirect)
+	}
+
+	return contentEntry, nil
+}
+
+func (r *Reader) parseRedirectEntry(offset int64, base *BaseEntry) (*RedirectEntry, error) {
+	entry := &RedirectEntry{
+		BaseEntry: base,
+	}
+
+	data := make([]byte, 4)
+	if err := r.readRange(offset+8, data); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	redirectIndex, err := readUint32(data, binary.LittleEndian)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.redirectIndex = redirectIndex
+
+	url, read, err := r.readStringAt(offset + 12)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.url = url
+
+	title, _, err := r.readStringAt(offset + 12 + read)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	entry.title = title
+
+	return entry, nil
+}
+
+func toFullURL(ns Namespace, url string) string {
+	return fmt.Sprintf("%s/%s", ns, url)
+}

pkg/bundle/zim/entry_iterator.go

@@ -0,0 +1,46 @@
+package zim
+
+import "github.com/pkg/errors"
+
+type EntryIterator struct {
+	index  int
+	entry  Entry
+	err    error
+	reader *Reader
+}
+
+func (it *EntryIterator) Next() bool {
+	if it.err != nil {
+		return false
+	}
+
+	entryCount := it.reader.EntryCount()
+
+	if it.index >= int(entryCount-1) {
+		return false
+	}
+
+	entry, err := it.reader.EntryAt(it.index)
+	if err != nil {
+		it.err = errors.WithStack(err)
+
+		return false
+	}
+
+	it.entry = entry
+	it.index++
+
+	return true
+}
+
+func (it *EntryIterator) Err() error {
+	return it.err
+}
+
+func (it *EntryIterator) Index() int {
+	return it.index
+}
+
+func (it *EntryIterator) Entry() Entry {
+	return it.entry
+}

pkg/bundle/zim/error.go

@@ -2,4 +2,9 @@ package zim
 
 import "errors"
 
-var ErrNotFound = errors.New("not found")
+var (
+	ErrInvalidEntryIndex                = errors.New("invalid entry index")
+	ErrNotFound                         = errors.New("not found")
+	ErrInvalidRedirect                  = errors.New("invalid redirect")
+	ErrCompressionAlgorithmNotSupported = errors.New("compression algorithm not supported")
+)

pkg/bundle/zim/favicon.go

@@ -2,8 +2,8 @@ package zim
 
 import "github.com/pkg/errors"
 
-func (z *ZimReader) Favicon() (*Article, error) {
-	illustration, err := z.getMetadataIllustration()
+func (r *Reader) Favicon() (*ContentEntry, error) {
+	illustration, err := r.getMetadataIllustration()
 	if err != nil && !errors.Is(err, ErrNotFound) {
 		return nil, errors.WithStack(err)
 	}
@@ -12,37 +12,54 @@ func (z *ZimReader) Favicon() (*Article, error) {
 		return illustration, nil
 	}
 
-	namespaces := []string{"-", "I"}
-	entryNames := []string{"favicon", "favicon.png"}
+	namespaces := []Namespace{V5NamespaceLayout, V5NamespaceImageFile}
+	urls := []string{"favicon", "favicon.png"}
 
 	for _, ns := range namespaces {
-		for _, en := range entryNames {
-			article, err := z.GetPageNoIndex(ns + "/" + en)
+		for _, url := range urls {
+			entry, err := r.EntryWithURL(ns, url)
 			if err != nil && !errors.Is(err, ErrNotFound) {
 				return nil, errors.WithStack(err)
 			}
 
-			if article != nil {
-				return article, nil
+			if errors.Is(err, ErrNotFound) {
+				continue
 			}
+
+			content, err := entry.Redirect()
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			return content, nil
 		}
 	}
 
 	return nil, errors.WithStack(ErrNotFound)
 }
 
-func (z *ZimReader) getMetadataIllustration() (*Article, error) {
-	metadata, err := z.Metadata(MetadataIllustration96x96at2, MetadataIllustration48x48at1)
+func (r *Reader) getMetadataIllustration() (*ContentEntry, error) {
+	keys := []MetadataKey{MetadataIllustration96x96at2, MetadataIllustration48x48at1}
+
+	metadata, err := r.Metadata(keys...)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
 
-	if _, exists := metadata[MetadataIllustration96x96at2]; exists {
-		return z.GetPageNoIndex("M/" + string(MetadataIllustration96x96at2))
-	}
+	for _, k := range keys {
+		if _, exists := metadata[k]; exists {
+			entry, err := r.EntryWithURL(V5NamespaceMetadata, string(k))
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
 
-	if _, exists := metadata[MetadataIllustration48x48at1]; exists {
-		return z.GetPageNoIndex("M/" + string(MetadataIllustration48x48at1))
+			content, err := entry.Redirect()
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			return content, nil
+		}
 	}
 
 	return nil, errors.WithStack(ErrNotFound)

pkg/bundle/zim/metadata.go

@@ -1,6 +1,8 @@
 package zim
 
 import (
+	"io"
+
 	"github.com/pkg/errors"
 )
 
@@ -40,7 +42,7 @@ var knownKeys = []MetadataKey{
 }
 
 // Metadata returns a copy of the internal metadata map of the ZIM file.
-func (z *ZimReader) Metadata(keys ...MetadataKey) (map[MetadataKey]string, error) {
+func (r *Reader) Metadata(keys ...MetadataKey) (map[MetadataKey]string, error) {
 	if len(keys) == 0 {
 		keys = knownKeys
 	}
@@ -48,7 +50,7 @@ func (z *ZimReader) Metadata(keys ...MetadataKey) (map[MetadataKey]string, error
 	metadata := make(map[MetadataKey]string)
 
 	for _, key := range keys {
-		article, err := z.GetPageNoIndex("M/" + string(key))
+		entry, err := r.EntryWithURL(V5NamespaceMetadata, string(key))
 		if err != nil {
 			if errors.Is(err, ErrNotFound) {
 				continue
@@ -57,9 +59,19 @@ func (z *ZimReader) Metadata(keys ...MetadataKey) (map[MetadataKey]string, error
 			return nil, errors.WithStack(err)
 		}
 
-		data, err := article.Data()
-		if errors.Is(err, ErrNotFound) {
-			continue
+		content, err := entry.Redirect()
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		reader, err := content.Reader()
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		data, err := io.ReadAll(reader)
+		if err != nil {
+			return nil, errors.WithStack(err)
 		}
 
 		metadata[key] = string(data)

pkg/bundle/zim/namespace.go

@@ -0,0 +1,23 @@
+package zim
+
+type Namespace string
+
+const (
+	V6NamespaceContent   Namespace = "C"
+	V6NamespaceMetadata  Namespace = "M"
+	V6NamespaceWellKnown Namespace = "W"
+	V6NamespaceSearch    Namespace = "X"
+)
+
+const (
+	V5NamespaceLayout              Namespace = "-"
+	V5NamespaceArticle             Namespace = "A"
+	V5NamespaceArticleMetadata     Namespace = "B"
+	V5NamespaceImageFile           Namespace = "I"
+	V5NamespaceImageText           Namespace = "J"
+	V5NamespaceMetadata            Namespace = "M"
+	V5NamespaceCategoryText        Namespace = "U"
+	V5NamespaceCategoryArticleList Namespace = "V"
+	V5NamespaceCategoryPerArticle  Namespace = "W"
+	V5NamespaceSearch              Namespace = "X"
+)

pkg/bundle/zim/option.go

@@ -0,0 +1,30 @@
+package zim
+
+import "time"
+
+type Options struct {
+	URLCacheSize int
+	URLCacheTTL  time.Duration
+	CacheSize    int
+}
+
+type OptionFunc func(opts *Options)
+
+func NewOptions(funcs ...OptionFunc) *Options {
+	funcs = append([]OptionFunc{
+		WithCacheSize(2048),
+	}, funcs...)
+
+	opts := &Options{}
+	for _, fn := range funcs {
+		fn(opts)
+	}
+
+	return opts
+}
+
+func WithCacheSize(size int) OptionFunc {
+	return func(opts *Options) {
+		opts.CacheSize = size
+	}
+}

pkg/bundle/zim/reader.go

@@ -0,0 +1,568 @@
+package zim
+
+import (
+	"context"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"sync"
+
+	lru "github.com/hashicorp/golang-lru/v2"
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/logger"
+)
+
+const zimFormatMagicNumber uint32 = 0x44D495A
+const nullByte = '\x00'
+const zimRedirect = 0xffff
+
+type Reader struct {
+	majorVersion  uint16
+	minorVersion  uint16
+	uuid          string
+	entryCount    uint32
+	clusterCount  uint32
+	urlPtrPos     uint64
+	titlePtrPos   uint64
+	clusterPtrPos uint64
+	mimeListPos   uint64
+	mainPage      uint32
+	layoutPage    uint32
+	checksumPos   uint64
+
+	mimeTypes []string
+
+	urlIndex []uint64
+
+	cache *lru.Cache[string, Entry]
+
+	seeker     io.ReadSeekCloser
+	seekerLock sync.Mutex
+}
+
+func (r *Reader) Version() (majorVersion, minorVersion uint16) {
+	return r.majorVersion, r.minorVersion
+}
+
+func (r *Reader) EntryCount() uint32 {
+	return r.entryCount
+}
+
+func (r *Reader) ClusterCount() uint32 {
+	return r.clusterCount
+}
+
+func (r *Reader) UUID() string {
+	return r.uuid
+}
+
+func (r *Reader) Close() error {
+	if err := r.seeker.Close(); err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
+}
+
+func (r *Reader) MainPage() (Entry, error) {
+	if r.mainPage == 0xffffffff {
+		return nil, errors.WithStack(ErrNotFound)
+	}
+
+	entry, err := r.EntryAt(int(r.mainPage))
+	if err != nil {
+		return nil, errors.WithStack(ErrNotFound)
+	}
+
+	return entry, nil
+}
+
+func (r *Reader) Entries() *EntryIterator {
+	return &EntryIterator{
+		reader: r,
+	}
+}
+
+func (r *Reader) EntryAt(idx int) (Entry, error) {
+	if idx >= len(r.urlIndex) || idx < 0 {
+		return nil, errors.Wrapf(ErrInvalidEntryIndex, "index '%d' out of bounds", idx)
+	}
+
+	entryPtr := r.urlIndex[idx]
+
+	entry, err := r.parseEntryAt(int64(entryPtr))
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	r.cacheEntry(entryPtr, entry)
+
+	return entry, nil
+}
+
+func (r *Reader) EntryWithURL(ns Namespace, url string) (Entry, error) {
+	entry, found := r.getEntryByURLFromCache(toFullURL(ns, url))
+	if found {
+		logger.Debug(context.Background(), "found entry with url from cache", logger.F("fullURL", entry.FullURL()))
+		return entry, nil
+	}
+
+	iterator := r.Entries()
+
+	for iterator.Next() {
+		entry := iterator.Entry()
+
+		if entry.Namespace() == ns && (entry.URL() == url || entry.FullURL() == url) {
+			return entry, nil
+		}
+	}
+	if err := iterator.Err(); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return nil, errors.WithStack(ErrNotFound)
+}
+
+func (r *Reader) EntryWithTitle(ns Namespace, title string) (Entry, error) {
+	entry, found := r.getEntryByTitleFromCache(ns, title)
+	if found {
+		logger.Debug(context.Background(), "found entry with title from cache", logger.F("entry", entry.FullURL()))
+		return entry, nil
+	}
+
+	iterator := r.Entries()
+
+	for iterator.Next() {
+		entry := iterator.Entry()
+
+		if entry.Title() == title && entry.Namespace() == ns {
+			return entry, nil
+		}
+	}
+	if err := iterator.Err(); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return nil, errors.WithStack(ErrNotFound)
+}
+
+func (r *Reader) getURLCacheKey(fullURL string) string {
+	return "url:" + fullURL
+}
+
+func (r *Reader) getTitleCacheKey(ns Namespace, title string) string {
+	return fmt.Sprintf("title:%s/%s", ns, title)
+}
+
+func (r *Reader) cacheEntry(offset uint64, entry Entry) {
+	urlKey := r.getURLCacheKey(entry.FullURL())
+	titleKey := r.getTitleCacheKey(entry.Namespace(), entry.Title())
+
+	_, urlFound := r.cache.Peek(urlKey)
+	_, titleFound := r.cache.Peek(titleKey)
+
+	if urlFound && titleFound {
+		return
+	}
+
+	r.cache.Add(urlKey, entry)
+	r.cache.Add(titleKey, entry)
+}
+
+func (r *Reader) getEntryByURLFromCache(fullURL string) (Entry, bool) {
+	key := r.getURLCacheKey(fullURL)
+	return r.cache.Get(key)
+}
+
+func (r *Reader) getEntryByTitleFromCache(namespace Namespace, title string) (Entry, bool) {
+	key := r.getTitleCacheKey(namespace, title)
+	return r.cache.Get(key)
+}
+
+func (r *Reader) parse() error {
+	if err := r.parseHeader(); err != nil {
+		return errors.WithStack(err)
+	}
+
+	if err := r.parseMimeTypes(); err != nil {
+		return errors.WithStack(err)
+	}
+
+	if err := r.parseURLIndex(); err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
+}
+
+func (r *Reader) parseHeader() error {
+	magicNumber, err := r.readUint32At(0)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	if magicNumber != zimFormatMagicNumber {
+		return errors.Errorf("invalid zim magic number '%d'", magicNumber)
+	}
+
+	majorVersion, err := r.readUint16At(4)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.majorVersion = majorVersion
+
+	minorVersion, err := r.readUint16At(6)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.minorVersion = minorVersion
+
+	if err := r.parseUUID(); err != nil {
+		return errors.WithStack(err)
+	}
+
+	entryCount, err := r.readUint32At(24)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.entryCount = entryCount
+
+	clusterCount, err := r.readUint32At(28)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.clusterCount = clusterCount
+
+	urlPtrPos, err := r.readUint64At(32)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.urlPtrPos = urlPtrPos
+
+	titlePtrPos, err := r.readUint64At(40)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.titlePtrPos = titlePtrPos
+
+	clusterPtrPos, err := r.readUint64At(48)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.clusterPtrPos = clusterPtrPos
+
+	mimeListPos, err := r.readUint64At(56)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.mimeListPos = mimeListPos
+
+	mainPage, err := r.readUint32At(64)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.mainPage = mainPage
+
+	layoutPage, err := r.readUint32At(68)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.layoutPage = layoutPage
+
+	checksumPos, err := r.readUint64At(72)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.checksumPos = checksumPos
+
+	return nil
+}
+
+func (r *Reader) parseUUID() error {
+	data := make([]byte, 16)
+	if err := r.readRange(8, data); err != nil {
+		return errors.WithStack(err)
+	}
+
+	parts := make([]string, 0, 5)
+
+	val32, err := readUint32(data[0:4], binary.BigEndian)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	parts = append(parts, fmt.Sprintf("%08x", val32))
+
+	val16, err := readUint16(data[4:6], binary.BigEndian)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	parts = append(parts, fmt.Sprintf("%04x", val16))
+
+	val16, err = readUint16(data[6:8], binary.BigEndian)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	parts = append(parts, fmt.Sprintf("%04x", val16))
+
+	val16, err = readUint16(data[8:10], binary.BigEndian)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	parts = append(parts, fmt.Sprintf("%04x", val16))
+
+	val32, err = readUint32(data[10:14], binary.BigEndian)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	val16, err = readUint16(data[14:16], binary.BigEndian)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	parts = append(parts, fmt.Sprintf("%x%x", val32, val16))
+
+	r.uuid = strings.Join(parts, "-")
+
+	return nil
+}
+
+func (r *Reader) parseMimeTypes() error {
+	mimeTypes := make([]string, 0)
+
+	offset := int64(r.mimeListPos)
+	for {
+		mimeType, read, err := r.readStringAt(offset)
+		if err != nil {
+			return errors.WithStack(err)
+		}
+
+		if mimeType == "" {
+			break
+		}
+
+		mimeTypes = append(mimeTypes, mimeType)
+
+		offset += read + 1
+	}
+
+	r.mimeTypes = mimeTypes
+
+	return nil
+}
+
+func (r *Reader) parseURLIndex() error {
+	urlIndex, err := r.parseEntryIndex(int64(r.urlPtrPos))
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	r.urlIndex = urlIndex
+
+	return nil
+}
+
+func (r *Reader) parseEntryAt(offset int64) (Entry, error) {
+	base, err := r.parseBaseEntry(offset)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	var entry Entry
+
+	if base.mimeTypeIndex == zimRedirect {
+		entry, err = r.parseRedirectEntry(offset, base)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+	} else {
+		entry, err = r.parseContentEntry(offset, base)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+	}
+
+	return entry, nil
+}
+
+func (r *Reader) parseEntryIndex(startAddr int64) ([]uint64, error) {
+	index := make([]uint64, r.entryCount)
+
+	data := make([]byte, 8)
+	for i := int64(0); i < int64(r.entryCount); i++ {
+		if err := r.readRange(startAddr+i*8, data); err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		ptr, err := readUint64(data, binary.LittleEndian)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		index[i] = ptr
+	}
+
+	return index, nil
+}
+
+func (r *Reader) getClusterOffsets(clusterIndex int) (uint64, uint64, error) {
+	data := make([]byte, 8)
+
+	startClusterPtrOffset := r.clusterPtrPos + (uint64(clusterIndex) * 8)
+	if err := r.readRange(int64(startClusterPtrOffset), data); err != nil {
+		return 0, 0, errors.WithStack(err)
+	}
+
+	startClusterOffset, err := readUint64(data, binary.LittleEndian)
+	if err != nil {
+		return 0, 0, errors.WithStack(err)
+	}
+
+	endClusterPtrOffset := r.clusterPtrPos + (uint64(clusterIndex+1) * 8)
+	if err := r.readRange(int64(endClusterPtrOffset), data); err != nil {
+		return 0, 0, errors.WithStack(err)
+	}
+
+	endClusterOffset, err := readUint64(data, binary.LittleEndian)
+	if err != nil {
+		return 0, 0, errors.WithStack(err)
+	}
+	endClusterOffset--
+
+	return startClusterOffset, endClusterOffset, nil
+}
+
+func (r *Reader) readRange(offset int64, v []byte) error {
+	r.seekerLock.Lock()
+	defer r.seekerLock.Unlock()
+
+	if _, err := r.seeker.Seek(offset, io.SeekStart); err != nil {
+		return errors.WithStack(err)
+	}
+
+	read, err := r.seeker.Read(v)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	if read != len(v) {
+		return errors.New("could not read enough bytes")
+	}
+
+	return nil
+}
+
+func (r *Reader) readUint32At(offset int64) (uint32, error) {
+	data := make([]byte, 4)
+	if err := r.readRange(offset, data); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	value, err := readUint32(data, binary.LittleEndian)
+	if err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	return value, nil
+}
+
+func (r *Reader) readUint16At(offset int64) (uint16, error) {
+	data := make([]byte, 2)
+	if err := r.readRange(offset, data); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	value, err := readUint16(data, binary.LittleEndian)
+	if err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	return value, nil
+}
+
+func (r *Reader) readUint64At(offset int64) (uint64, error) {
+	data := make([]byte, 8)
+	if err := r.readRange(offset, data); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	value, err := readUint64(data, binary.LittleEndian)
+	if err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	return value, nil
+}
+
+func (r *Reader) readStringAt(offset int64) (string, int64, error) {
+	data := make([]byte, 1)
+	var sb strings.Builder
+	read := int64(0)
+	for {
+		if err := r.readRange(offset+read, data); err != nil {
+			return "", read, errors.WithStack(err)
+		}
+
+		if err := sb.WriteByte(data[0]); err != nil {
+			return "", read, errors.WithStack(err)
+		}
+
+		if data[0] == nullByte {
+			str := strings.TrimRight(sb.String(), "\x00")
+			return str, read, nil
+		}
+
+		read++
+	}
+}
+
+func NewReader(seeker io.ReadSeekCloser, funcs ...OptionFunc) (*Reader, error) {
+	opts := NewOptions(funcs...)
+
+	cache, err := lru.New[string, Entry](opts.CacheSize)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	reader := &Reader{
+		seeker: seeker,
+		cache:  cache,
+	}
+
+	if err := reader.parse(); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return reader, nil
+}
+
+func Open(path string, funcs ...OptionFunc) (*Reader, error) {
+	file, err := os.OpenFile(path, os.O_RDONLY, os.ModePerm)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	reader, err := NewReader(file, funcs...)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return reader, nil
+}

pkg/bundle/zim/reader_test.go

@@ -0,0 +1,133 @@
+package zim
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/logger"
+)
+
+type readerTestCase struct {
+	UUID       string `json:"uuid"`
+	EntryCount uint32 `json:"entryCount"`
+	Entries    []struct {
+		Namespace   Namespace `json:"namespace"`
+		URL         string    `json:"url"`
+		Size        int64     `json:"size"`
+		Compression int       `json:"compression"`
+		MimeType    string    `json:"mimeType"`
+		Title       string    `json:"title"`
+	} `json:"entries"`
+}
+
+func TestReader(t *testing.T) {
+	if testing.Verbose() {
+		logger.SetLevel(logger.LevelDebug)
+		logger.SetFormat(logger.FormatHuman)
+	}
+
+	files, err := filepath.Glob("testdata/*.zim")
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	for _, zf := range files {
+		testName := filepath.Base(zf)
+		testCase, err := loadZimFileTestCase(zf)
+		if err != nil {
+			t.Fatalf("%+v", errors.WithStack(err))
+		}
+
+		t.Run(testName, func(t *testing.T) {
+			reader, err := Open(zf)
+			if err != nil {
+				t.Fatalf("%+v", errors.WithStack(err))
+			}
+
+			defer func() {
+				if err := reader.Close(); err != nil {
+					t.Errorf("%+v", errors.WithStack(err))
+				}
+			}()
+
+			if e, g := testCase.UUID, reader.UUID(); e != g {
+				t.Errorf("reader.UUID(): expected '%s', got '%s'", e, g)
+			}
+
+			if e, g := testCase.EntryCount, reader.EntryCount(); e != g {
+				t.Errorf("reader.EntryCount(): expected '%v', got '%v'", e, g)
+			}
+
+			if testCase.Entries == nil {
+				return
+			}
+
+			for _, entryTestCase := range testCase.Entries {
+				testName := fmt.Sprintf("Entry/%s/%s", entryTestCase.Namespace, entryTestCase.URL)
+				t.Run(testName, func(t *testing.T) {
+					entry, err := reader.EntryWithURL(entryTestCase.Namespace, entryTestCase.URL)
+					if err != nil {
+						t.Fatalf("%+v", errors.WithStack(err))
+					}
+
+					content, err := entry.Redirect()
+					if err != nil {
+						t.Errorf("%+v", errors.WithStack(err))
+					}
+
+					if e, g := entryTestCase.MimeType, content.MimeType(); e != g {
+						t.Errorf("content.MimeType(): expected '%v', got '%v'", e, g)
+					}
+
+					if e, g := entryTestCase.Title, content.Title(); e != g {
+						t.Errorf("content.Title(): expected '%v', got '%v'", e, g)
+					}
+
+					compression, err := content.Compression()
+					if err != nil {
+						t.Errorf("%+v", errors.WithStack(err))
+					}
+
+					if e, g := entryTestCase.Compression, compression; e != g {
+						t.Errorf("content.Compression(): expected '%v', got '%v'", e, g)
+					}
+
+					contentReader, err := content.Reader()
+					if err != nil {
+						t.Errorf("%+v", errors.WithStack(err))
+					}
+
+					size, err := contentReader.Size()
+					if err != nil {
+						t.Errorf("%+v", errors.WithStack(err))
+					}
+
+					if e, g := entryTestCase.Size, size; e != g {
+						t.Errorf("content.Size(): expected '%v', got '%v'", e, g)
+					}
+				})
+			}
+		})
+	}
+}
+
+func loadZimFileTestCase(zimFile string) (*readerTestCase, error) {
+	testCaseFile, _ := strings.CutSuffix(zimFile, ".zim")
+
+	data, err := os.ReadFile(testCaseFile + ".json")
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	testCase := &readerTestCase{}
+	if err := json.Unmarshal(data, testCase); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return testCase, nil
+}

pkg/bundle/zim/testdata/beer.stackexchange.com_en_all_2023-05.json

@@ -0,0 +1,14 @@
+{
+    "uuid": "8d141c3b-115d-bf73-294a-ee3c2e6b97b0",
+    "entryCount": 6223,
+    "entries": [
+        {
+            "namespace": "C",
+            "url": "users_page=9",
+            "compression": 5,
+            "size": 58646,
+            "mimeType": "text/html",
+            "title": "users_page=9"
+        }
+    ]
+}

pkg/bundle/zim/testdata/cadoles.json

@@ -0,0 +1,22 @@
+{
+    "uuid": "cf81f094-d802-c790-b854-c74ad9701ddb",
+    "entryCount": 271,
+    "entries": [
+        {
+            "namespace": "C",
+            "url": "blog/202206-ShowroomInnovation.jpg",
+            "compression": 1,
+            "size": 260260,
+            "mimeType": "image/jpeg",
+            "title": "blog/202206-ShowroomInnovation.jpg"
+        },
+        {
+            "namespace": "C",
+            "url": "team/index.html",
+            "compression": 5,
+            "size": 93185,
+            "mimeType": "text/html",
+            "title": "Cadoles - Notre équipe"
+        }
+    ]
+}

pkg/bundle/zim/testdata/wikibooks_af_all_maxi_2023-06.json

@@ -0,0 +1,14 @@
+{
+    "uuid": "ad4f406c-2021-2db8-c729-297568bbe376",
+    "entryCount": 330,
+    "entries": [
+        {
+            "namespace": "M",
+            "url": "Illustration_48x48@1",
+            "compression": 5,
+            "size": 5365,
+            "mimeType": "text/plain",
+            "title": "Illustration_48x48@1"
+        }
+    ]
+}

pkg/bundle/zim/uncompressed_blob_reader.go

@@ -0,0 +1,63 @@
+package zim
+
+import (
+	"io"
+
+	"github.com/pkg/errors"
+)
+
+type UncompressedBlobReader struct {
+	reader          *Reader
+	blobStartOffset uint64
+	blobEndOffset   uint64
+	blobSize        int
+	readOffset      uint64
+}
+
+// Size implements BlobReader.
+func (r *UncompressedBlobReader) Size() (int64, error) {
+	return int64(r.blobEndOffset - r.blobStartOffset), nil
+}
+
+// Close implements io.ReadCloser.
+func (*UncompressedBlobReader) Close() error {
+	return nil
+}
+
+// Read implements io.ReadCloser.
+func (r *UncompressedBlobReader) Read(p []byte) (n int, err error) {
+	len := len(p)
+	remaining := int(r.blobEndOffset - (r.blobStartOffset + r.readOffset))
+	if len > remaining {
+		len = remaining
+	}
+
+	data := make([]byte, len)
+
+	err = r.reader.readRange(int64(r.blobStartOffset+r.readOffset), data)
+	if err != nil {
+		return len, errors.WithStack(err)
+	}
+
+	r.readOffset += uint64(len)
+
+	copy(p, data)
+
+	if len == remaining {
+		return len, io.EOF
+	}
+
+	return len, nil
+}
+
+func NewUncompressedBlobReader(reader *Reader, blobStartOffset, blobEndOffset uint64, blobSize int) *UncompressedBlobReader {
+	return &UncompressedBlobReader{
+		reader:          reader,
+		blobStartOffset: blobStartOffset,
+		blobEndOffset:   blobEndOffset,
+		blobSize:        blobSize,
+		readOffset:      0,
+	}
+}
+
+var _ BlobReader = &UncompressedBlobReader{}

pkg/bundle/zim/util.go

@@ -0,0 +1,52 @@
+package zim
+
+import (
+	"bytes"
+	"encoding/binary"
+
+	"github.com/pkg/errors"
+)
+
+// read a little endian uint64
+func readUint64(b []byte, order binary.ByteOrder) (uint64, error) {
+	var v uint64
+	buf := bytes.NewBuffer(b)
+	if err := binary.Read(buf, order, &v); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	return v, nil
+}
+
+// read a little endian uint32
+func readUint32(b []byte, order binary.ByteOrder) (uint32, error) {
+	var v uint32
+	buf := bytes.NewBuffer(b)
+	if err := binary.Read(buf, order, &v); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	return v, nil
+}
+
+// read a little endian uint16
+func readUint16(b []byte, order binary.ByteOrder) (uint16, error) {
+	var v uint16
+	buf := bytes.NewBuffer(b)
+	if err := binary.Read(buf, order, &v); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	return v, nil
+}
+
+// read a little endian uint8
+func readUint8(b []byte, order binary.ByteOrder) (uint8, error) {
+	var v uint8
+	buf := bytes.NewBuffer(b)
+	if err := binary.Read(buf, order, &v); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	return v, nil
+}

pkg/bundle/zim/xz_blob_reader.go

@@ -0,0 +1,42 @@
+package zim
+
+import (
+	"io"
+
+	"github.com/pkg/errors"
+	"github.com/ulikunitz/xz"
+)
+
+type XZBlobReader struct {
+	decoder *xz.Reader
+}
+
+// Close implements io.ReadCloser.
+func (r *XZBlobReader) Close() error {
+	return nil
+}
+
+// Read implements io.ReadCloser.
+func (r *XZBlobReader) Read(p []byte) (n int, err error) {
+	return r.decoder.Read(p)
+}
+
+var _ io.ReadCloser = &XZBlobReader{}
+
+func NewXZBlobReader(reader *Reader, clusterStartOffset, clusterEndOffset uint64, blobIndex uint32, blobSize int) *CompressedBlobReader {
+	return NewCompressedBlobReader(
+		reader,
+		func(r io.Reader) (io.ReadCloser, error) {
+			decoder, err := xz.NewReader(r)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			return &XZBlobReader{decoder}, nil
+		},
+		clusterStartOffset,
+		clusterEndOffset,
+		blobIndex,
+		blobSize,
+	)
+}

pkg/bundle/zim/zim_test.go

@@ -1,150 +0,0 @@
-package zim
-
-import (
-	"log"
-	"testing"
-
-	"github.com/pkg/errors"
-)
-
-var Z *ZimReader
-
-func init() {
-	var err error
-	Z, err = NewReader("testdata/wikibooks_af_all_maxi_2023-06.zim")
-	if err != nil {
-		log.Panicf("Can't read %v", err)
-	}
-}
-
-func TestOpen(t *testing.T) {
-	if Z.ArticleCount == 0 {
-		t.Errorf("No article found")
-	}
-}
-
-func TestMime(t *testing.T) {
-	if len(Z.MimeTypes()) == 0 {
-		t.Errorf("No mime types found")
-	}
-}
-
-func TestDisplayInfost(t *testing.T) {
-	info := Z.String()
-	if len(info) < 0 {
-		t.Errorf("Can't read infos")
-	}
-	t.Log(info)
-}
-
-func TestURLAtIdx(t *testing.T) {
-	// addr 0 is a redirect
-	p, _ := Z.OffsetAtURLIdx(5)
-	a, _ := Z.ArticleAt(p)
-	if a == nil {
-		t.Errorf("Can't find 1st url")
-	}
-}
-
-func TestDisplayArticle(t *testing.T) {
-	// addr 0 is a redirect
-	p, _ := Z.OffsetAtURLIdx(5)
-	a, _ := Z.ArticleAt(p)
-	if a == nil {
-		t.Errorf("Can't find 1st url")
-	}
-
-	t.Log(a)
-}
-
-func TestPageNoIndex(t *testing.T) {
-	a, _ := Z.GetPageNoIndex("A/Dracula:Capitol_1.html")
-	if a == nil {
-		t.Errorf("Can't find existing url")
-	}
-}
-
-func TestListArticles(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping test in short mode.")
-	}
-
-	var i uint32
-
-	for a := range Z.ListArticles() {
-		i++
-		t.Log(a.String())
-	}
-
-	if i == 0 {
-		t.Errorf("Can't find any urls")
-	}
-
-	if i != Z.ArticleCount-1 {
-		t.Errorf("Can't find the exact ArticleCount urls %d vs %d", i, Z.ArticleCount)
-	}
-}
-
-func TestMainPage(t *testing.T) {
-	a, _ := Z.MainPage()
-	if a == nil {
-		t.Errorf("Can't find the mainpage article")
-	}
-
-	t.Log(a)
-}
-
-func TestFavicon(t *testing.T) {
-	favicon, err := Z.Favicon()
-	if err != nil {
-		t.Errorf("%+v", errors.WithStack(err))
-	}
-	if favicon == nil {
-		t.Errorf("Can't find the favicon article")
-	}
-}
-
-func TestMetadata(t *testing.T) {
-	metadata, err := Z.Metadata()
-	if err != nil {
-		t.Errorf("%+v", errors.WithStack(err))
-	}
-	if metadata == nil {
-		t.Errorf("Can't find the metadata")
-	}
-}
-
-func TestData(t *testing.T) {
-	// addr 0 is a redirect
-	p, _ := Z.OffsetAtURLIdx(2)
-	a, _ := Z.ArticleAt(p)
-	b, _ := a.Data()
-	data := string(b)
-	if a.EntryType != RedirectEntry {
-		if len(data) == 0 {
-			t.Error("can't read data")
-		}
-	}
-	t.Log(a.String())
-	t.Log(data)
-}
-
-func BenchmarkArticleBytes(b *testing.B) {
-	// addr 0 is a redirect
-	p, _ := Z.OffsetAtURLIdx(5)
-	a, _ := Z.ArticleAt(p)
-	if a == nil {
-		b.Errorf("Can't find 1st url")
-	}
-	data, err := a.Data()
-	if err != nil {
-		b.Error(err)
-	}
-
-	b.SetBytes(int64(len(data)))
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		a.Data()
-		bcache.Purge() // prevent memiozing value
-	}
-}

pkg/bundle/zim/zstd_blob_reader.go

@@ -0,0 +1,43 @@
+package zim
+
+import (
+	"io"
+
+	"github.com/klauspost/compress/zstd"
+	"github.com/pkg/errors"
+)
+
+type ZstdBlobReader struct {
+	decoder *zstd.Decoder
+}
+
+// Close implements io.ReadCloser.
+func (r *ZstdBlobReader) Close() error {
+	r.decoder.Close()
+	return nil
+}
+
+// Read implements io.ReadCloser.
+func (r *ZstdBlobReader) Read(p []byte) (n int, err error) {
+	return r.decoder.Read(p)
+}
+
+var _ io.ReadCloser = &ZstdBlobReader{}
+
+func NewZStdBlobReader(reader *Reader, clusterStartOffset, clusterEndOffset uint64, blobIndex uint32, blobSize int) *CompressedBlobReader {
+	return NewCompressedBlobReader(
+		reader,
+		func(r io.Reader) (io.ReadCloser, error) {
+			decoder, err := zstd.NewReader(r)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			return &ZstdBlobReader{decoder}, nil
+		},
+		clusterStartOffset,
+		clusterEndOffset,
+		blobIndex,
+		blobSize,
+	)
+}

pkg/bundle/zim_bundle.go

@@ -3,19 +3,18 @@ package bundle
 import (
 	"bytes"
 	"context"
-	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"os"
 	"path/filepath"
-	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"golang.org/x/net/html"
 
 	"forge.cadoles.com/arcad/edge/pkg/bundle/zim"
+	lru "github.com/hashicorp/golang-lru/v2"
 	"github.com/pkg/errors"
 	"gitlab.com/wpetit/goweb/logger"
 	"gopkg.in/yaml.v2"
@@ -23,6 +22,12 @@ import (
 
 type ZimBundle struct {
 	archivePath string
+
+	initOnce sync.Once
+	initErr  error
+
+	reader            *zim.Reader
+	urlNamespaceCache *lru.Cache[string, zim.Namespace]
 }
 
 func (b *ZimBundle) File(filename string) (io.ReadCloser, os.FileInfo, error) {
@@ -41,7 +46,7 @@ func (b *ZimBundle) File(filename string) (io.ReadCloser, os.FileInfo, error) {
 	case "public":
 		return b.renderDirectory(ctx, filename)
 	case "public/index.html":
-		return b.redirectToMainPage(ctx, filename)
+		return b.renderMainPage(ctx, filename)
 
 	default:
 		return b.renderURL(ctx, filename)
@@ -49,58 +54,16 @@ func (b *ZimBundle) File(filename string) (io.ReadCloser, os.FileInfo, error) {
 }
 
 func (b *ZimBundle) Dir(dirname string) ([]os.FileInfo, error) {
-	reader, err := b.openArchive()
-	if err != nil {
-		return nil, err
-	}
-
-	defer func() {
-		if err := reader.Close(); err != nil {
-			panic(errors.WithStack(err))
-		}
-	}()
-
 	files := make([]os.FileInfo, 0)
-	// ctx := context.Background()
-
-	// for _, f := range reader.File {
-	// 	if !strings.HasPrefix(f.Name, dirname) {
-	// 		continue
-	// 	}
-
-	// 	relPath, err := filepath.Rel(dirname, f.Name)
-	// 	if err != nil {
-	// 		return nil, errors.Wrap(err, "could not get relative path")
-	// 	}
-
-	// 	logger.Debug(
-	// 		ctx, "checking file prefix",
-	// 		logger.F("dirname", dirname),
-	// 		logger.F("filename", f.Name),
-	// 		logger.F("relpath", relPath),
-	// 	)
-
-	// 	if relPath == filepath.Base(f.Name) {
-	// 		files = append(files, f.FileInfo())
-	// 	}
-	// }
-
 	return files, nil
 }
 
 func (b *ZimBundle) renderFakeManifest(ctx context.Context) (io.ReadCloser, os.FileInfo, error) {
-	reader, err := b.openArchive()
-	if err != nil {
+	if err := b.init(); err != nil {
 		return nil, nil, errors.WithStack(err)
 	}
 
-	defer func() {
-		if err := reader.Close(); err != nil {
-			panic(errors.WithStack(err))
-		}
-	}()
-
-	metadata, err := reader.Metadata()
+	metadata, err := b.reader.Metadata()
 	if err != nil {
 		return nil, nil, errors.WithStack(err)
 	}
@@ -117,7 +80,7 @@ func (b *ZimBundle) renderFakeManifest(ctx context.Context) (io.ReadCloser, os.F
 
 		manifest["id"] = strings.ToLower(replacer.Replace(name)) + ".zim.edge.app"
 	} else {
-		manifest["id"] = strconv.FormatUint(uint64(reader.UUID), 10) + ".zim.edge.app"
+		manifest["id"] = b.reader.UUID() + ".zim.edge.app"
 	}
 
 	if title, exists := metadata[zim.MetadataTitle]; exists {
@@ -130,7 +93,7 @@ func (b *ZimBundle) renderFakeManifest(ctx context.Context) (io.ReadCloser, os.F
 		manifest["description"] = description
 	}
 
-	favicon, err := reader.Favicon()
+	favicon, err := b.reader.Favicon()
 	if err != nil && !errors.Is(err, zim.ErrNotFound) {
 		return nil, nil, errors.WithStack(err)
 	}
@@ -165,7 +128,7 @@ func (b *ZimBundle) renderFakeManifest(ctx context.Context) (io.ReadCloser, os.F
 	}
 
 	buf := bytes.NewBuffer(data)
-	file := ioutil.NopCloser(buf)
+	file := io.NopCloser(buf)
 
 	return file, stat, nil
 }
@@ -180,62 +143,77 @@ func (b *ZimBundle) renderFakeServerMain(ctx context.Context) (io.ReadCloser, os
 	}
 
 	buf := bytes.NewBuffer(nil)
-	file := ioutil.NopCloser(buf)
+	file := io.NopCloser(buf)
 
 	return file, stat, nil
 }
 
 func (b *ZimBundle) renderURL(ctx context.Context, url string) (io.ReadCloser, os.FileInfo, error) {
-	zr, err := b.openArchive()
-	if err != nil {
+	if err := b.init(); err != nil {
 		return nil, nil, errors.WithStack(err)
 	}
 
-	defer func() {
-		if err := zr.Close(); err != nil {
-			panic(errors.WithStack(err))
-		}
-	}()
-
 	filename := filepath.Base(url)
 	url = strings.TrimPrefix(url, "public/")
 
-	article, err := zr.GetPageNoIndex(url)
+	entry, err := b.searchEntryFromURL(ctx, url)
 	if err != nil {
 		if errors.Is(err, zim.ErrNotFound) {
-			return nil, nil, errors.WithStack(fs.ErrNotExist)
+			return nil, nil, os.ErrNotExist
 		}
 
 		return nil, nil, errors.WithStack(err)
 	}
 
-	if article.EntryType == zim.RedirectEntry {
-		redirectIndex, err := article.RedirectIndex()
-		if err != nil {
-			return nil, nil, errors.WithStack(err)
-		}
+	logger.Debug(
+		ctx, "found zim entry",
+		logger.F("webURL", url),
+		logger.F("zimFullURL", entry.FullURL()),
+	)
 
-		ra, err := zr.ArticleAtURLIdx(redirectIndex)
-		if err != nil {
-			return nil, nil, errors.WithStack(err)
-		}
-
-		return b.renderRedirect(ctx, filename, ra.FullURL())
-	}
-
-	data, err := article.Data()
+	content, err := entry.Redirect()
 	if err != nil {
 		return nil, nil, errors.WithStack(err)
 	}
 
-	mimeType := article.MimeType()
-	if mimeType == "text/html" {
-		injected, err := b.injectEdgeScriptTag(data)
-		if err != nil {
-			logger.Error(ctx, "could not inject edge script", logger.E(errors.WithStack(err)))
-		} else {
-			data = injected
+	contentReader, err := content.Reader()
+	if err != nil {
+		return nil, nil, errors.WithStack(err)
+	}
+
+	size, err := contentReader.Size()
+	if err != nil {
+		return nil, nil, errors.WithStack(err)
+	}
+
+	mimeType := content.MimeType()
+	if mimeType != "text/html" {
+		zimFile := &zimFile{
+			fileInfo: &zimFileInfo{
+				isDir:   false,
+				modTime: time.Time{},
+				mode:    0,
+				name:    filename,
+				size:    size,
+			},
+			reader: contentReader,
 		}
+
+		return zimFile, zimFile.fileInfo, nil
+	}
+
+	// Read HTML file and inject Edge scripts
+
+	data, err := io.ReadAll(contentReader)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	injected, err := b.injectEdgeScriptTag(data)
+	if err != nil {
+		logger.Error(ctx, "could not inject edge script", logger.E(errors.WithStack(err)))
+	} else {
+		data = injected
 	}
 
 	zimFile := &zimFile{
@@ -244,26 +222,114 @@ func (b *ZimBundle) renderURL(ctx context.Context, url string) (io.ReadCloser, o
 			modTime: time.Time{},
 			mode:    0,
 			name:    filename,
-			size:    int64(len(data)),
+			size:    size,
 		},
-		buff: bytes.NewBuffer(data),
+		reader: io.NopCloser(bytes.NewBuffer(data)),
 	}
 
 	return zimFile, zimFile.fileInfo, nil
 }
 
-func (b *ZimBundle) renderDirectory(ctx context.Context, filename string) (io.ReadCloser, os.FileInfo, error) {
-	zr, err := b.openArchive()
-	if err != nil {
-		return nil, nil, errors.WithStack(err)
+func (b *ZimBundle) searchEntryFromURL(ctx context.Context, url string) (zim.Entry, error) {
+	ctx = logger.With(ctx, logger.F("webURL", url))
+
+	logger.Debug(ctx, "searching entry namespace in local cache")
+
+	// Search URL namespace from cache
+	if namespace, found := b.urlNamespaceCache.Get(url); found {
+		logger.Debug(ctx, "found entry namespace in cache")
+
+		entry, err := b.reader.EntryWithURL(namespace, url)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		return entry, nil
 	}
 
-	defer func() {
-		if err := zr.Close(); err != nil {
-			panic(errors.WithStack(err))
-		}
-	}()
+	// Try to access entry directly if the URL match the pattern <NS>/<URL>
+	urlParts := strings.SplitN(url, "/", 2)
+	if len(urlParts) == 2 && len(urlParts[0]) == 1 {
+		namespace := zim.Namespace(urlParts[0])
+		url = urlParts[1]
 
+		logger.Debug(
+			ctx, "trying to access entry directly",
+			logger.F("zimNamespace", namespace),
+			logger.F("zimURL", url),
+		)
+
+		entry, err := b.reader.EntryWithURL(namespace, url)
+		if err != nil && !errors.Is(err, zim.ErrNotFound) {
+			return nil, errors.WithStack(err)
+		}
+
+		if entry != nil {
+			b.urlNamespaceCache.Add(url, entry.Namespace())
+			return entry, nil
+		}
+	}
+
+	contentNamespaces := []zim.Namespace{
+		zim.V6NamespaceContent,
+		zim.V6NamespaceMetadata,
+		zim.V5NamespaceLayout,
+		zim.V5NamespaceArticle,
+		zim.V5NamespaceImageFile,
+		zim.V5NamespaceMetadata,
+	}
+
+	logger.Debug(
+		ctx, "make educated guesses about potential url namespace",
+		logger.F("zimNamespaces", contentNamespaces),
+	)
+
+	for _, ns := range contentNamespaces {
+		logger.Debug(
+			ctx, "trying to access entry directly",
+			logger.F("zimNamespace", ns),
+			logger.F("zimURL", url),
+		)
+
+		entry, err := b.reader.EntryWithURL(ns, url)
+		if err != nil && !errors.Is(err, zim.ErrNotFound) {
+			return nil, errors.WithStack(err)
+		}
+
+		if entry != nil {
+			b.urlNamespaceCache.Add(url, entry.Namespace())
+			return entry, nil
+		}
+	}
+
+	logger.Debug(ctx, "doing full entries scan")
+
+	var entry zim.Entry
+
+	iterator := b.reader.Entries()
+	for iterator.Next() {
+		current := iterator.Entry()
+
+		if current.FullURL() != url && current.URL() != url {
+			continue
+		}
+
+		entry = current
+		b.urlNamespaceCache.Add(url, entry.Namespace())
+		break
+	}
+	if err := iterator.Err(); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	if entry == nil {
+		return nil, errors.WithStack(zim.ErrNotFound)
+	}
+
+	return entry, nil
+}
+
+func (b *ZimBundle) renderDirectory(ctx context.Context, filename string) (io.ReadCloser, os.FileInfo, error) {
 	zimFile := &zimFile{
 		fileInfo: &zimFileInfo{
 			isDir:   true,
@@ -272,55 +338,23 @@ func (b *ZimBundle) renderDirectory(ctx context.Context, filename string) (io.Re
 			name:    filename,
 			size:    0,
 		},
-		buff: bytes.NewBuffer(nil),
+		reader: io.NopCloser(bytes.NewBuffer(nil)),
 	}
 
 	return zimFile, zimFile.fileInfo, nil
 }
 
-func (b *ZimBundle) renderRedirect(ctx context.Context, filename string, to string) (io.ReadCloser, os.FileInfo, error) {
-	logger.Debug(ctx, "rendering redirect", logger.F("url", to))
-
-	data := fmt.Sprintf(`
-	<html>
-		<head>
-			<meta http-equiv="refresh" content="0; url=/%s" />
-		</head>
-	</html>
-	`, to)
-
-	stat := &zimFileInfo{
-		isDir:   false,
-		modTime: time.Time{},
-		mode:    0,
-		name:    filename,
-		size:    int64(len(data)),
+func (b *ZimBundle) renderMainPage(ctx context.Context, filename string) (io.ReadCloser, os.FileInfo, error) {
+	if err := b.init(); err != nil {
+		return nil, nil, errors.WithStack(err)
 	}
 
-	buf := bytes.NewBuffer([]byte(data))
-	reader := ioutil.NopCloser(buf)
-
-	return reader, stat, nil
-}
-
-func (b *ZimBundle) redirectToMainPage(ctx context.Context, filename string) (io.ReadCloser, os.FileInfo, error) {
-	zr, err := b.openArchive()
+	main, err := b.reader.MainPage()
 	if err != nil {
 		return nil, nil, errors.WithStack(err)
 	}
 
-	defer func() {
-		if err := zr.Close(); err != nil {
-			panic(errors.WithStack(err))
-		}
-	}()
-
-	main, err := zr.MainPage()
-	if err != nil {
-		return nil, nil, errors.WithStack(err)
-	}
-
-	return b.renderRedirect(ctx, filename, main.FullURL())
+	return b.renderURL(ctx, main.FullURL())
 }
 
 func (b *ZimBundle) injectEdgeScriptTag(data []byte) ([]byte, error) {
@@ -369,13 +403,29 @@ func (b *ZimBundle) injectEdgeScriptTag(data []byte) ([]byte, error) {
 	return buff.Bytes(), nil
 }
 
-func (b *ZimBundle) openArchive() (*zim.ZimReader, error) {
-	zm, err := zim.NewReader(b.archivePath)
-	if err != nil {
-		return nil, errors.Wrapf(err, "could not open '%v'", b.archivePath)
+func (b *ZimBundle) init() error {
+	b.initOnce.Do(func() {
+		reader, err := zim.Open(b.archivePath)
+		if err != nil {
+			b.initErr = errors.Wrapf(err, "could not open '%v'", b.archivePath)
+			return
+		}
+
+		b.reader = reader
+
+		cache, err := lru.New[string, zim.Namespace](128)
+		if err != nil {
+			b.initErr = errors.Wrap(err, "could not initialize cache")
+			return
+		}
+
+		b.urlNamespaceCache = cache
+	})
+	if b.initErr != nil {
+		return errors.WithStack(b.initErr)
 	}
 
-	return zm, nil
+	return nil
 }
 
 func NewZimBundle(archivePath string) *ZimBundle {
@@ -386,17 +436,30 @@ func NewZimBundle(archivePath string) *ZimBundle {
 
 type zimFile struct {
 	fileInfo *zimFileInfo
-	buff     *bytes.Buffer
+	reader   io.ReadCloser
 }
 
 // Close implements fs.File.
 func (f *zimFile) Close() error {
+	if err := f.reader.Close(); err != nil {
+		return errors.WithStack(err)
+	}
+
 	return nil
 }
 
 // Read implements fs.File.
 func (f *zimFile) Read(d []byte) (int, error) {
-	return f.buff.Read(d)
+	n, err := f.reader.Read(d)
+	if err != nil {
+		if errors.Is(err, io.EOF) {
+			return n, err
+		}
+
+		return n, errors.WithStack(err)
+	}
+
+	return n, nil
 }
 
 // Stat implements fs.File.