remove migrations code from go-ipfs, in favor of fs-repo-migrations repo

repo/fsrepo/migrations/0-to-1/main.go

-package main
-
-import (
-	"fmt"
-	"os"
-	"strings"
-
-	migrate "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-migrate"
-	mfsr "github.com/ipfs/go-ipfs/repo/fsrepo/migrations"
-)
-
-type migration struct {
-}
-
-// Version is the int version number. This could be a string
-// in future versions
-func (m migration) Versions() string {
-	return "0-to-1"
-}
-
-// Reversible returns whether this migration can be reverted.
-// Endeavor to make them all reversible. This is here only to warn users
-// in case this is not the case.
-func (m migration) Reversible() bool {
-	return true
-}
-
-// Apply applies the migration in question.
-// This migration merely adds a version file.
-func (m migration) Apply(opts migrate.Options) error {
-	repo := mfsr.RepoPath(opts.Path)
-
-	// first, check if there is a version file.
-	// if there is, bail out.
-	if v, err := repo.Version(); err == nil {
-		return fmt.Errorf("repo at %s is version %s (not 0)", opts.Path, v)
-	} else if !strings.Contains(err.Error(), "no version file in repo") {
-		return err
-	}
-
-	// add the version file
-	if err := repo.WriteVersion("1"); err != nil {
-		return err
-	}
-
-	return nil
-}
-
-// Revert un-applies the migration in question. This should be best-effort.
-// Some migrations are definitively one-way. If so, return an error.
-func (m migration) Revert(opts migrate.Options) error {
-	repo := mfsr.RepoPath(opts.Path)
-
-	if err := repo.CheckVersion("1"); err != nil {
-		return err
-	}
-
-	// remove the version file
-	if err := os.Remove(repo.VersionFile()); err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func main() {
-	m := migration{}
-	migrate.Main(&m)
-}

repo/fsrepo/migrations/1-to-2/main.go

-package main
-
-import (
-	"encoding/json"
-	"fmt"
-	"os"
-	"path"
-	"strings"
-
-	dstore "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore"
-	flatfs "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore/flatfs"
-	leveldb "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore/leveldb"
-	dsq "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore/query"
-	migrate "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-migrate"
-	mfsr "github.com/ipfs/go-ipfs/repo/fsrepo/migrations"
-
-	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
-)
-
-var _ = context.Background
-
-const peerKeyName = "peer.key"
-
-type migration struct{}
-
-func (m migration) Versions() string {
-	return "1-to-2"
-}
-
-func (m migration) Reversible() bool {
-	return true
-}
-
-func (m migration) Apply(opts migrate.Options) error {
-	repo := mfsr.RepoPath(opts.Path)
-
-	if err := repo.CheckVersion("1"); err != nil {
-		return err
-	}
-
-	// 1) run some sanity checks to make sure we should even bother
-	err := sanityChecks(opts)
-	if err != nil {
-		return err
-	}
-
-	// 2) Transfer blocks out of leveldb into flatDB
-	err = transferBlocksToFlatDB(opts.Path)
-	if err != nil {
-		return err
-	}
-
-	// 3) move ipfs path from .go-ipfs to .ipfs
-	newpath, err := moveIpfsDir(opts.Path)
-	if err != nil {
-		return err
-	}
-
-	// 4) Update version number
-	repo = mfsr.RepoPath(newpath)
-	err = repo.WriteVersion("2")
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func (m migration) Revert(opts migrate.Options) error {
-	repo := mfsr.RepoPath(opts.Path)
-	if err := repo.CheckVersion("2"); err != nil {
-		return err
-	}
-
-	// 1) Move directory back to .go-ipfs
-	npath, err := reverseIpfsDir(opts.Path)
-	if err != nil {
-		return err
-	}
-
-	// 2) move blocks back from flatfs to leveldb
-	err = transferBlocksFromFlatDB(npath)
-	if err != nil {
-		return err
-	}
-
-	// 3) change version number back down
-	repo = mfsr.RepoPath(npath)
-	err = repo.WriteVersion("1")
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-// sanityChecks performs a set of tests to make sure the migration will go
-// smoothly
-func sanityChecks(opts migrate.Options) error {
-	npath := strings.Replace(opts.Path, ".go-ipfs", ".ipfs", 1)
-
-	// make sure we can move the repo from .go-ipfs to .ipfs
-	err := os.Mkdir(npath, 0777)
-	if err != nil {
-		return err
-	}
-
-	// we can? good, remove it now
-	err = os.Remove(npath)
-	if err != nil {
-		// this is weird... not worth continuing
-		return err
-	}
-
-	return nil
-}
-
-func transferBlocksToFlatDB(repopath string) error {
-	ldbpath := path.Join(repopath, "datastore")
-	ldb, err := leveldb.NewDatastore(ldbpath, nil)
-	if err != nil {
-		return err
-	}
-
-	blockspath := path.Join(repopath, "blocks")
-	err = os.Mkdir(blockspath, 0777)
-	if err != nil && !os.IsExist(err) {
-		return err
-	}
-
-	fds, err := flatfs.New(blockspath, 4)
-	if err != nil {
-		return err
-	}
-
-	return transferBlocks(ldb, fds, "/b/", "")
-}
-
-func transferBlocksFromFlatDB(repopath string) error {
-
-	ldbpath := path.Join(repopath, "datastore")
-	blockspath := path.Join(repopath, "blocks")
-	fds, err := flatfs.New(blockspath, 4)
-	if err != nil {
-		return err
-	}
-
-	ldb, err := leveldb.NewDatastore(ldbpath, nil)
-	if err != nil {
-		return err
-	}
-
-	err = transferBlocks(fds, ldb, "", "/b/")
-	if err != nil {
-		return err
-	}
-
-	// Now remove the blocks directory
-	err = os.RemoveAll(blockspath)
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func transferBlocks(from, to dstore.Datastore, fpref, tpref string) error {
-	q := dsq.Query{Prefix: fpref, KeysOnly: true}
-	res, err := from.Query(q)
-	if err != nil {
-		return err
-	}
-
-	fmt.Println("Starting query")
-	for result := range res.Next() {
-		nkey := fmt.Sprintf("%s%s", tpref, result.Key[len(fpref):])
-
-		fkey := dstore.NewKey(result.Key)
-		val, err := from.Get(fkey)
-		if err != nil {
-			return err
-		}
-
-		err = to.Put(dstore.NewKey(nkey), val)
-		if err != nil {
-			return err
-		}
-
-		err = from.Delete(fkey)
-		if err != nil {
-			return err
-		}
-	}
-	fmt.Println("Query done")
-
-	return nil
-}
-
-func moveIpfsDir(curpath string) (string, error) {
-	newpath := strings.Replace(curpath, ".go-ipfs", ".ipfs", 1)
-	return newpath, os.Rename(curpath, newpath)
-}
-
-func reverseIpfsDir(curpath string) (string, error) {
-	newpath := strings.Replace(curpath, ".ipfs", ".go-ipfs", 1)
-	return newpath, os.Rename(curpath, newpath)
-}
-
-func loadConfigJSON(repoPath string) (map[string]interface{}, error) {
-	cfgPath := path.Join(repoPath, "config")
-	fi, err := os.Open(cfgPath)
-	if err != nil {
-		return nil, err
-	}
-
-	var out map[string]interface{}
-	err = json.NewDecoder(fi).Decode(&out)
-	if err != nil {
-		return nil, err
-	}
-
-	return out, nil
-}
-
-func saveConfigJSON(repoPath string, cfg map[string]interface{}) error {
-	cfgPath := path.Join(repoPath, "config")
-	fi, err := os.Create(cfgPath)
-	if err != nil {
-		return err
-	}
-
-	out, err := json.MarshalIndent(cfg, "", "\t")
-	if err != nil {
-		return err
-	}
-
-	_, err = fi.Write(out)
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func main() {
-	m := migration{}
-	migrate.Main(&m)
-}

repo/fsrepo/migrations/mfsr.go

-package mfsr
-
-import (
-	"errors"
-	"fmt"
-	"io/ioutil"
-	"os"
-	"path"
-	"strings"
-)
-
-const VersionFile = "version"
-
-type RepoPath string
-
-func (rp RepoPath) VersionFile() string {
-	return path.Join(string(rp), VersionFile)
-}
-
-func (rp RepoPath) Version() (string, error) {
-	if rp == "" {
-		return "", fmt.Errorf("invalid repo path \"%s\"", rp)
-	}
-
-	fn := rp.VersionFile()
-	if _, err := os.Stat(fn); os.IsNotExist(err) {
-		return "", errors.New("no version file in repo at " + string(rp))
-	}
-
-	c, err := ioutil.ReadFile(fn)
-	if err != nil {
-		return "", err
-	}
-
-	s := string(c)
-	s = strings.TrimSpace(s)
-	return s, nil
-}
-
-func (rp RepoPath) CheckVersion(version string) error {
-	v, err := rp.Version()
-	if err != nil {
-		return err
-	}
-
-	if v != version {
-		return fmt.Errorf("versions differ (expected: %s, actual:%s)", version, v)
-	}
-
-	return nil
-}
-
-func (rp RepoPath) WriteVersion(version string) error {
-	fn := rp.VersionFile()
-	return ioutil.WriteFile(fn, []byte(version+"\n"), 0644)
-}