staticweb package for easier static web server hosting

pkg/server/zipfs/zipfs.go

@@ -0,0 +1,112 @@
+package zipfs
+
+import (
+	"archive/zip"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+)
+
+type ZipFS struct {
+	*zip.Reader
+}
+
+func NewZipFS(r *zip.Reader) *ZipFS {
+	return &ZipFS{r}
+}
+
+func (z *ZipFS) Open(name string) (fs.File, error) {
+	for _, f := range z.File {
+		if f.Name == name {
+			rc, err := f.Open()
+			if err != nil {
+				return nil, err
+			}
+			return &ZipFile{f, rc, 0}, nil
+		}
+	}
+	return nil, os.ErrNotExist
+}
+
+type ZipFile struct {
+	*zip.File
+	rc     io.ReadCloser
+	offset int64
+}
+
+func (f *ZipFile) Stat() (fs.FileInfo, error) {
+	if f.File != nil {
+		return f.File.FileInfo(), nil
+	}
+	return nil, fmt.Errorf("No file")
+}
+
+func (f *ZipFile) Close() error {
+	if f.rc != nil {
+		return f.rc.Close()
+	}
+	return nil
+}
+
+func (f *ZipFile) Read(b []byte) (int, error) {
+	if f.rc == nil {
+		var err error
+		f.rc, err = f.File.Open()
+		if err != nil {
+			return 0, err
+		}
+	}
+	n, err := f.rc.Read(b)
+	f.offset += int64(n)
+	if err == io.EOF {
+		f.rc.Close()
+		f.rc = nil
+	}
+	return n, err
+
+}
+func (f *ZipFile) Seek(offset int64, whence int) (int64, error) {
+	if f.rc != nil {
+		f.rc.Close()
+		f.rc = nil
+	}
+	switch whence {
+	case io.SeekStart:
+		if offset < 0 {
+			return 0, &fs.PathError{Op: "seek", Path: f.Name, Err: fmt.Errorf("negative position")}
+		}
+		f.offset = offset
+	case io.SeekCurrent:
+		if f.offset+offset < 0 {
+			return 0, &fs.PathError{Op: "seek", Path: f.Name, Err: fmt.Errorf("negative position")}
+		}
+		f.offset += offset
+	case io.SeekEnd:
+		size := int64(f.File.UncompressedSize64)
+		if size+offset < 0 {
+			return 0, &fs.PathError{Op: "seek", Path: f.Name, Err: fmt.Errorf("negative position")}
+		}
+		f.offset = size + offset
+	}
+	return f.offset, nil
+}
+
+/*
+func main() {
+	r, err := zip.OpenReader("path/to/your.zip")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer r.Close()
+
+	fs := NewZipFS(&r.Reader)
+	file, err := fs.Open(path.Join("path", "to", "file"))
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer file.Close()
+
+	// Now you can use 'file' as a fs.File
+}
+*/