dehub/fs/fs.go
mediocregopher 7c891bd5f2 Initial commit, can create master commit and verify previous master commits
message: Initial commit, can create master commit and verify previous master commits
change_hash: ADgeVBdfi1hA0TTDrBIkYHaQQYoxZaInZz1p/BAH35Ng
credentials:
- type: pgp_signature
  pub_key_id: 95C46FA6A41148AC
  body: 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
  account: mediocregopher
2020-02-15 15:13:50 -07:00

101 lines
2.4 KiB
Go

// Package fs implements abstractions for interacting with a filesystem, either
// via a git tree, a staged index, or directly.
package fs
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"os"
"gopkg.in/src-d/go-billy.v4"
"gopkg.in/src-d/go-git.v4"
"gopkg.in/src-d/go-git.v4/plumbing/object"
)
// FS is a simple interface for reading off a snapshot of a filesystem.
type FS interface {
Open(path string) (io.ReadCloser, error)
}
type treeFS struct {
tree *object.Tree
}
// FromTree wraps a git tree object to implement the FS interface. All paths
// will be relative to the root of the tree.
func FromTree(t *object.Tree) FS {
return treeFS{tree: t}
}
func (gt treeFS) Open(path string) (io.ReadCloser, error) {
f, err := gt.tree.File(path)
if err != nil {
return nil, err
}
return f.Blob.Reader()
}
type billyFS struct {
fs billy.Filesystem
}
// FromBillyFilesystem wraps a billy.Filesystem to implement the FS interface.
// All paths will be relative to the filesystem's root.
func FromBillyFilesystem(bfs billy.Filesystem) FS {
return billyFS{fs: bfs}
}
func (bfs billyFS) Open(path string) (io.ReadCloser, error) {
return bfs.fs.Open(path)
}
// FromStagedChangesTree processes the current set of staged changes into a tree
// object, and returns an FS for that tree. All paths will be relative to the
// root of the git repo.
func FromStagedChangesTree(repo *git.Repository) (FS, *object.Tree, error) {
w, err := repo.Worktree()
if err != nil {
return nil, nil, fmt.Errorf("could not open git worktree: %w", err)
}
storer := repo.Storer
idx, err := storer.Index()
if err != nil {
return nil, nil, fmt.Errorf("could not open git staging index: %w", err)
}
th := &buildTreeHelper{
fs: w.Filesystem,
s: storer,
}
treeHash, err := th.BuildTree(idx)
if err != nil {
return nil, nil, fmt.Errorf("could not build staging index tree: %w", err)
}
tree, err := repo.TreeObject(treeHash)
if err != nil {
return nil, nil, fmt.Errorf("could not get staged tree object (%q): %w", treeHash, err)
}
return FromTree(tree), tree, nil
}
// Stub is an implementation of FS based on a map of paths to the file contents
// at that path. Paths should be "clean" or they will not match with anything.
type Stub map[string][]byte
// Open implements the method for the FS interface.
func (s Stub) Open(path string) (io.ReadCloser, error) {
body, ok := s[path]
if !ok {
return nil, os.ErrNotExist
}
return ioutil.NopCloser(bytes.NewReader(body)), nil
}