/
replica.go
203 lines (182 loc) · 4.24 KB
/
replica.go
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package btrfs
import (
"bytes"
"fmt"
"io"
"log"
"os/exec"
"path"
"time"
"github.com/aws/aws-sdk-go/service/s3"
"github.com/pachyderm/pachyderm/src/s3utils"
)
// localReplica implements the Replica interface using a btrfs repo.
type localReplica struct {
repo string
}
func newLocalReplica(repo string) *localReplica {
return &localReplica{repo}
}
func (r *localReplica) From() (string, error) {
from := ""
err := Commits(r.repo, "", Desc, func(name string) error {
isCommit, err := IsCommit(path.Join(r.repo, name))
if err != nil {
return err
}
if isCommit {
from = name
return ErrComplete
}
return nil
})
if err != nil && err != ErrComplete {
return "", err
}
return from, nil
}
func (r *localReplica) Push(diff io.Reader) error {
return recv(r.repo, diff)
}
func (r *localReplica) Pull(from string, cb Pusher) error {
return Pull(r.repo, from, cb)
}
// s3Replica implements the Replica interface using an s3 replica.
type s3Replica struct {
uri string
count int // number of sent commits
}
func newS3Replica(uri string) *s3Replica {
return &s3Replica{uri, 0}
}
func (r *s3Replica) Push(diff io.Reader) error {
key := fmt.Sprintf("%.10d", r.count)
r.count++
p, err := s3utils.GetPath(r.uri)
if err != nil {
return err
}
return s3utils.PutMulti(r.uri, path.Join(p, key), diff, "application/octet-stream", s3utils.BucketOwnerFull)
}
func (r *s3Replica) Pull(from string, target Pusher) error {
client := s3utils.NewClient(false)
err := s3utils.ForEachFile(r.uri, false, from, func(path string, modtime time.Time) (retErr error) {
response, err := client.GetObject(&s3.GetObjectInput{
Bucket: &r.uri,
Key: &path,
})
f := response.Body
if f == nil {
return fmt.Errorf("Nil file returned.")
}
if err != nil {
return err
}
defer func() {
if err := f.Close(); err != nil && retErr == nil {
retErr = err
}
}()
err = target.Push(f)
if err != nil {
return err
}
return nil
})
if err != nil {
return err
}
return nil
}
func (r *s3Replica) From() (string, error) {
result := ""
err := s3utils.ForEachFile(r.uri, false, "", func(path string, modtime time.Time) error {
result = path
return nil
})
return result, err
}
// send produces a binary diff stream and passes it to cont
func send(repo, commit string, cont func(io.Reader) error) error {
parent := GetMeta(path.Join(repo, commit), "parent")
var cmd *exec.Cmd
if parent == "" {
cmd = exec.Command("btrfs", "send", FilePath(path.Join(repo, commit)))
} else {
cmd = exec.Command("btrfs", "send", "-p", FilePath(path.Join(repo, parent)), FilePath(path.Join(repo, commit)))
}
stdin, stdout := io.Pipe()
stderr := bytes.NewBuffer(nil)
cmd.Stdout = stdout
if err := cmd.Start(); err != nil {
return err
}
errC := make(chan error, 1)
go func() {
errC <- cont(stdin)
}()
waitErr := cmd.Wait()
closeErr := stdout.Close()
if waitErr != nil {
return fmt.Errorf("%s %s", waitErr.Error(), stderr.String())
}
if closeErr != nil {
return closeErr
}
return <-errC
}
// recv reads a binary stream from data and applies it to `repo`
func recv(repo string, data io.Reader) error {
c := exec.Command("btrfs", "receive", FilePath(repo))
stdin, err := c.StdinPipe()
if err != nil {
return err
}
stderr, err := c.StderrPipe()
if err != nil {
return err
}
err = c.Start()
if err != nil {
return err
}
_, err = io.Copy(stdin, data)
if err != nil {
return err
}
err = stdin.Close()
if err != nil {
return err
}
buf := bytes.NewBuffer(nil)
buf.ReadFrom(stderr)
log.Print("Stderr:", buf)
err = c.Wait()
if err != nil {
return err
}
createNewBranch(repo)
return nil
}
// createNewBranch gets called after a new commit has been `Recv`ed it creates
// the branch that should be pointing to the newly made commit.
func createNewBranch(repo string) error {
// TODO this is a kind of ugly way to get the most recent branch we should
// make it better
err := Commits(repo, "", Desc, func(name string) error {
branch := GetMeta(path.Join(repo, name), "branch")
err := subvolumeDeleteAll(path.Join(repo, branch))
if err != nil {
return err
}
err = Branch(repo, name, branch)
if err != nil {
return err
}
return ErrComplete
})
if err != nil && err != ErrComplete {
return err
}
return nil
}