go-aah/aah#156 vfs progress

file.go

@@ -0,0 +1,86 @@
+// Copyright (c) Jeevanandam M. (https://github.com/jeevatkm)
+// aahframework.org/vfs source code and usage is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package vfs
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+)
+
+var _ File = (*file)(nil)
+var _ Gziper = (*file)(nil)
+
+// File struct represents the virtual file or directory.
+//
+// Implements interface `vfs.File`.
+type file struct {
+	*node
+	rs  io.ReadSeeker
+	pos int
+}
+
+//‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+// File and Directory operations
+//______________________________________________________________________________
+
+func (f *file) Read(b []byte) (int, error) {
+	return f.rs.Read(b)
+}
+
+func (f *file) Seek(offset int64, whence int) (int64, error) {
+	return f.rs.Seek(offset, whence)
+}
+
+func (f *file) Readdir(count int) ([]os.FileInfo, error) {
+	if !f.IsDir() {
+		return []os.FileInfo{}, &os.PathError{Op: "read", Path: f.node.name, Err: errors.New("vfs: cannot find the specified path")}
+	}
+
+	if f.pos >= len(f.node.childInfos) && count > 0 {
+		return nil, io.EOF
+	}
+
+	if count <= 0 || count > len(f.node.childInfos)-f.pos {
+		count = len(f.node.childInfos) - f.pos
+	}
+
+	ci := f.node.childInfos[f.pos : f.pos+count]
+	f.pos += count
+
+	return ci, nil
+}
+
+func (f *file) Readdirnames(count int) (names []string, err error) {
+	var list []string
+	infos, err := f.Readdir(count)
+	if err != nil {
+		return list, err
+	}
+
+	for _, v := range infos {
+		list = append(list, v.Name())
+	}
+
+	return list, nil
+}
+
+func (f *file) Stat() (os.FileInfo, error) {
+	return f, nil
+}
+
+func (f *file) Close() error {
+	if f.IsGzip() {
+		return f.rs.(io.Closer).Close()
+	}
+	return nil
+}
+
+// String method Stringer interface.
+func (f file) String() string {
+	return fmt.Sprintf(`file(name=%s dir=%v gzip=%v)`,
+		f.node.name, f.IsDir(), f.IsGzip())
+}

fs.go

@@ -0,0 +1,141 @@
+// Copyright (c) Jeevanandam M. (https://github.com/jeevatkm)
+// aahframework.org/vfs source code and usage is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package vfs
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+)
+
+var (
+	_ FileSystem = (*VFS)(nil)
+
+	// ErrNotExists = errors.New("file or directory does not exist")
+)
+
+// VFS represents Virtual File System (VFS), it operates in-memory.
+// if file/directory doesn't exists on in-memory then it tries physical file system.
+//
+// VFS implements `vfs.FileSystem`, its a combination of package `os` and `ioutil`
+// focused on Read-Only operations.
+//
+// Single point of access for all mounted virtual directories in aah application.
+type VFS struct {
+	mounts map[string]*Mount
+}
+
+//‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+// VFS FileSystem interface methods
+//______________________________________________________________________________
+
+// Open method behaviour is same as `os.Open`.
+func (v *VFS) Open(name string) (File, error) {
+	m, err := v.FindMount(name)
+	if err != nil {
+		return nil, err
+	}
+	return m.Open(name)
+}
+
+// Lstat method behaviour is same as `os.Lstat`.
+func (v *VFS) Lstat(name string) (os.FileInfo, error) {
+	m, err := v.FindMount(name)
+	if err != nil {
+		return nil, err
+	}
+	return m.Lstat(name)
+}
+
+// Stat method behaviour is same as `os.Stat`
+func (v *VFS) Stat(name string) (os.FileInfo, error) {
+	m, err := v.FindMount(name)
+	if err != nil {
+		return nil, err
+	}
+	return m.Stat(name)
+}
+
+// ReadFile method behaviour is same as `ioutil.ReadFile`.
+func (v *VFS) ReadFile(filename string) ([]byte, error) {
+	m, err := v.FindMount(filename)
+	if err != nil {
+		return nil, err
+	}
+	return m.ReadFile(filename)
+}
+
+// ReadDir method behaviour is same as `ioutil.ReadDir`.
+func (v *VFS) ReadDir(dirname string) ([]os.FileInfo, error) {
+	m, err := v.FindMount(dirname)
+	if err != nil {
+		return nil, err
+	}
+	return m.ReadDir(dirname)
+}
+
+//‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+// VFS methods
+//______________________________________________________________________________
+
+// FindMount method finds the mounted virtual directory by mount path.
+// if found then returns `Mount` instance otherwise nil and error.
+//
+// Mount implements `vfs.FileSystem`, its a combination of package `os` and `ioutil`
+// focused on Read-Only operations.
+func (v *VFS) FindMount(name string) (*Mount, error) {
+	name = path.Clean(name)
+	for _, m := range v.mounts {
+		if m.vroot == name || strings.HasPrefix(name, m.tree.name+"/") {
+			return m, nil
+		}
+	}
+	return nil, &os.PathError{Op: "read", Path: name, Err: fmt.Errorf("mount not exist")}
+}
+
+// AddMount method used to mount physical directory as a virtual mounted directory.
+//
+// Basically aah scans and application source files and builds each file from
+// mounted source dierctory into binary for single binary build.
+func (v *VFS) AddMount(mountPath, physicalPath string) error {
+	pp, err := filepath.Abs(filepath.Clean(physicalPath))
+	if err != nil {
+		return err
+	}
+
+	fi, err := os.Lstat(pp)
+	if err != nil {
+		return err
+	}
+
+	if !fi.IsDir() {
+		return &os.PathError{Op: "addmount", Path: pp, Err: errors.New("is a file")}
+	}
+
+	mp := filepath.ToSlash(path.Clean(mountPath))
+	if mp == "" {
+		mp = path.Base(pp)
+	}
+	mp = path.Clean("/" + mp)
+
+	if v.mounts == nil {
+		v.mounts = make(map[string]*Mount)
+	}
+
+	if _, found := v.mounts[mp]; found {
+		return &os.PathError{Op: "addmount", Path: mp, Err: errors.New("already exists")}
+	}
+
+	v.mounts[mp] = &Mount{
+		vroot: mp,
+		proot: pp,
+		tree:  newNode(mp, fi),
+	}
+
+	return nil
+}