xesite/vendor/github.com/GeertJohan/go.rice/box.go

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2017-05-20 22:43:42 +00:00
package rice
import (
"bytes"
"errors"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"runtime"
"strings"
"time"
"github.com/GeertJohan/go.rice/embedded"
)
// Box abstracts a directory for resources/files.
// It can either load files from disk, or from embedded code (when `rice --embed` was ran).
type Box struct {
name string
absolutePath string
embed *embedded.EmbeddedBox
appendd *appendedBox
}
var defaultLocateOrder = []LocateMethod{LocateEmbedded, LocateAppended, LocateFS}
func findBox(name string, order []LocateMethod) (*Box, error) {
b := &Box{name: name}
// no support for absolute paths since gopath can be different on different machines.
// therefore, required box must be located relative to package requiring it.
if filepath.IsAbs(name) {
return nil, errors.New("given name/path is absolute")
}
var err error
for _, method := range order {
switch method {
case LocateEmbedded:
if embed := embedded.EmbeddedBoxes[name]; embed != nil {
b.embed = embed
return b, nil
}
case LocateAppended:
appendedBoxName := strings.Replace(name, `/`, `-`, -1)
if appendd := appendedBoxes[appendedBoxName]; appendd != nil {
b.appendd = appendd
return b, nil
}
case LocateFS:
// resolve absolute directory path
err := b.resolveAbsolutePathFromCaller()
if err != nil {
continue
}
// check if absolutePath exists on filesystem
info, err := os.Stat(b.absolutePath)
if err != nil {
continue
}
// check if absolutePath is actually a directory
if !info.IsDir() {
err = errors.New("given name/path is not a directory")
continue
}
return b, nil
case LocateWorkingDirectory:
// resolve absolute directory path
err := b.resolveAbsolutePathFromWorkingDirectory()
if err != nil {
continue
}
// check if absolutePath exists on filesystem
info, err := os.Stat(b.absolutePath)
if err != nil {
continue
}
// check if absolutePath is actually a directory
if !info.IsDir() {
err = errors.New("given name/path is not a directory")
continue
}
return b, nil
}
}
if err == nil {
err = fmt.Errorf("could not locate box %q", name)
}
return nil, err
}
// FindBox returns a Box instance for given name.
// When the given name is a relative path, it's base path will be the calling pkg/cmd's source root.
// When the given name is absolute, it's absolute. derp.
// Make sure the path doesn't contain any sensitive information as it might be placed into generated go source (embedded).
func FindBox(name string) (*Box, error) {
return findBox(name, defaultLocateOrder)
}
// MustFindBox returns a Box instance for given name, like FindBox does.
// It does not return an error, instead it panics when an error occurs.
func MustFindBox(name string) *Box {
box, err := findBox(name, defaultLocateOrder)
if err != nil {
panic(err)
}
return box
}
// This is injected as a mutable function literal so that we can mock it out in
// tests and return a fixed test file.
var resolveAbsolutePathFromCaller = func(name string, nStackFrames int) (string, error) {
_, callingGoFile, _, ok := runtime.Caller(nStackFrames)
if !ok {
return "", errors.New("couldn't find caller on stack")
}
// resolve to proper path
pkgDir := filepath.Dir(callingGoFile)
// fix for go cover
const coverPath = "_test/_obj_test"
if !filepath.IsAbs(pkgDir) {
if i := strings.Index(pkgDir, coverPath); i >= 0 {
pkgDir = pkgDir[:i] + pkgDir[i+len(coverPath):] // remove coverPath
pkgDir = filepath.Join(os.Getenv("GOPATH"), "src", pkgDir) // make absolute
}
}
return filepath.Join(pkgDir, name), nil
}
func (b *Box) resolveAbsolutePathFromCaller() error {
path, err := resolveAbsolutePathFromCaller(b.name, 4)
if err != nil {
return err
}
b.absolutePath = path
return nil
}
func (b *Box) resolveAbsolutePathFromWorkingDirectory() error {
path, err := os.Getwd()
if err != nil {
return err
}
b.absolutePath = filepath.Join(path, b.name)
return nil
}
// IsEmbedded indicates wether this box was embedded into the application
func (b *Box) IsEmbedded() bool {
return b.embed != nil
}
// IsAppended indicates wether this box was appended to the application
func (b *Box) IsAppended() bool {
return b.appendd != nil
}
// Time returns how actual the box is.
// When the box is embedded, it's value is saved in the embedding code.
// When the box is live, this methods returns time.Now()
func (b *Box) Time() time.Time {
if b.IsEmbedded() {
return b.embed.Time
}
//++ TODO: return time for appended box
return time.Now()
}
// Open opens a File from the box
// If there is an error, it will be of type *os.PathError.
func (b *Box) Open(name string) (*File, error) {
if Debug {
fmt.Printf("Open(%s)\n", name)
}
if b.IsEmbedded() {
if Debug {
fmt.Println("Box is embedded")
}
// trim prefix (paths are relative to box)
name = strings.TrimLeft(name, "/")
if Debug {
fmt.Printf("Trying %s\n", name)
}
// search for file
ef := b.embed.Files[name]
if ef == nil {
if Debug {
fmt.Println("Didn't find file in embed")
}
// file not found, try dir
ed := b.embed.Dirs[name]
if ed == nil {
if Debug {
fmt.Println("Didn't find dir in embed")
}
// dir not found, error out
return nil, &os.PathError{
Op: "open",
Path: name,
Err: os.ErrNotExist,
}
}
if Debug {
fmt.Println("Found dir. Returning virtual dir")
}
vd := newVirtualDir(ed)
return &File{virtualD: vd}, nil
}
// box is embedded
if Debug {
fmt.Println("Found file. Returning virtual file")
}
vf := newVirtualFile(ef)
return &File{virtualF: vf}, nil
}
if b.IsAppended() {
// trim prefix (paths are relative to box)
name = strings.TrimLeft(name, "/")
// search for file
appendedFile := b.appendd.Files[name]
if appendedFile == nil {
return nil, &os.PathError{
Op: "open",
Path: name,
Err: os.ErrNotExist,
}
}
// create new file
f := &File{
appendedF: appendedFile,
}
// if this file is a directory, we want to be able to read and seek
if !appendedFile.dir {
// looks like malformed data in zip, error now
if appendedFile.content == nil {
return nil, &os.PathError{
Op: "open",
Path: "name",
Err: errors.New("error reading data from zip file"),
}
}
// create new bytes.Reader
f.appendedFileReader = bytes.NewReader(appendedFile.content)
}
// all done
return f, nil
}
// perform os open
if Debug {
fmt.Printf("Using os.Open(%s)", filepath.Join(b.absolutePath, name))
}
file, err := os.Open(filepath.Join(b.absolutePath, name))
if err != nil {
return nil, err
}
return &File{realF: file}, nil
}
// Bytes returns the content of the file with given name as []byte.
func (b *Box) Bytes(name string) ([]byte, error) {
file, err := b.Open(name)
if err != nil {
return nil, err
}
defer file.Close()
content, err := ioutil.ReadAll(file)
if err != nil {
return nil, err
}
return content, nil
}
// MustBytes returns the content of the file with given name as []byte.
// panic's on error.
func (b *Box) MustBytes(name string) []byte {
bts, err := b.Bytes(name)
if err != nil {
panic(err)
}
return bts
}
// String returns the content of the file with given name as string.
func (b *Box) String(name string) (string, error) {
// check if box is embedded, optimized fast path
if b.IsEmbedded() {
// find file in embed
ef := b.embed.Files[name]
if ef == nil {
return "", os.ErrNotExist
}
// return as string
return ef.Content, nil
}
bts, err := b.Bytes(name)
if err != nil {
return "", err
}
return string(bts), nil
}
// MustString returns the content of the file with given name as string.
// panic's on error.
func (b *Box) MustString(name string) string {
str, err := b.String(name)
if err != nil {
panic(err)
}
return str
}
// Name returns the name of the box
func (b *Box) Name() string {
return b.name
}