mirror of
https://github.com/mjl-/mox.git
synced 2025-07-10 09:54:40 +03:00
implement exporting of all mailboxes/messages as zip/tgz of mbox/maildir
This commit is contained in:
Mechiel Lukkien
383
store/export.go
Normal file
383
store/export.go
Normal file
@ -0,0 +1,383 @@
|
||||
package store
|
||||
|
||||
import (
|
||||
"archive/tar"
|
||||
"archive/zip"
|
||||
"bufio"
|
||||
"bytes"
|
||||
"fmt"
|
||||
"io"
|
||||
"os"
|
||||
"path/filepath"
|
||||
"sort"
|
||||
"time"
|
||||
|
||||
"github.com/mjl-/bstore"
|
||||
|
||||
"github.com/mjl-/mox/mlog"
|
||||
)
|
||||
|
||||
// Archiver can archive multiple mailboxes and their messages.
|
||||
type Archiver interface {
|
||||
Create(name string, size int64, mtime time.Time) (io.Writer, error)
|
||||
Close() error
|
||||
}
|
||||
|
||||
// TarArchiver is an Archiver that writes to a tar ifle.
|
||||
type TarArchiver struct {
|
||||
*tar.Writer
|
||||
}
|
||||
|
||||
// Create adds a file header to the tar file.
|
||||
func (a TarArchiver) Create(name string, size int64, mtime time.Time) (io.Writer, error) {
|
||||
hdr := tar.Header{
|
||||
Name: name,
|
||||
Size: size,
|
||||
Mode: 0600,
|
||||
ModTime: mtime,
|
||||
Format: tar.FormatPAX,
|
||||
}
|
||||
if err := a.WriteHeader(&hdr); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return a, nil
|
||||
}
|
||||
|
||||
// ZipArchiver is an Archiver that writes to a zip file.
|
||||
type ZipArchiver struct {
|
||||
*zip.Writer
|
||||
}
|
||||
|
||||
// Create adds a file header to the zip file.
|
||||
func (a ZipArchiver) Create(name string, size int64, mtime time.Time) (io.Writer, error) {
|
||||
hdr := zip.FileHeader{
|
||||
Name: name,
|
||||
Method: zip.Deflate,
|
||||
Modified: mtime,
|
||||
UncompressedSize64: uint64(size),
|
||||
}
|
||||
return a.CreateHeader(&hdr)
|
||||
}
|
||||
|
||||
// ExportMessages writes messages to archiver. Either in maildir format, or otherwise in
|
||||
// mbox. If mailboxOpt is empty, all mailboxes are exported, otherwise only the
|
||||
// named mailbox.
|
||||
//
|
||||
// Some errors are not fatal and result in skipped messages. In that happens, a
|
||||
// file "errors.txt" is added to the archive describing the errors. The goal is to
|
||||
// let users export (hopefully) most messages even in the face of errors.
|
||||
func (a *Account) ExportMessages(log *mlog.Log, archiver Archiver, maildir bool, mailboxOpt string) error {
|
||||
// Start transaction without closure, we are going to close it early, but don't
|
||||
// want to deal with declaring many variables now to be able to assign them in a
|
||||
// closure and use them afterwards.
|
||||
tx, err := a.DB.Begin(false)
|
||||
if err != nil {
|
||||
return fmt.Errorf("transaction: %v", err)
|
||||
}
|
||||
defer func() {
|
||||
if tx != nil {
|
||||
tx.Rollback()
|
||||
}
|
||||
}()
|
||||
|
||||
start := time.Now()
|
||||
|
||||
// Set up mailbox names and ids.
|
||||
id2name := map[int64]string{}
|
||||
name2id := map[string]int64{}
|
||||
|
||||
mailboxes, err := bstore.QueryTx[Mailbox](tx).List()
|
||||
xcheckf(err, "query mailboxes")
|
||||
for _, mb := range mailboxes {
|
||||
id2name[mb.ID] = mb.Name
|
||||
name2id[mb.Name] = mb.ID
|
||||
}
|
||||
|
||||
var mailboxID int64
|
||||
if mailboxOpt != "" {
|
||||
var ok bool
|
||||
mailboxID, ok = name2id[mailboxOpt]
|
||||
if !ok {
|
||||
return fmt.Errorf("mailbox not found")
|
||||
}
|
||||
}
|
||||
|
||||
var names []string
|
||||
for _, name := range id2name {
|
||||
if mailboxOpt != "" && name != mailboxOpt {
|
||||
continue
|
||||
}
|
||||
names = append(names, name)
|
||||
}
|
||||
// We need to sort the names because maildirs can create subdirs. Ranging over
|
||||
// id2name directly would randomize the directory names, we would create a sub
|
||||
// maildir before the parent, and fail with "dir exists" when creating the parent
|
||||
// dir.
|
||||
sort.Slice(names, func(i, j int) bool {
|
||||
return names[i] < names[j]
|
||||
})
|
||||
|
||||
mailboxOrder := map[int64]int{}
|
||||
for i, name := range names {
|
||||
mbID := name2id[name]
|
||||
mailboxOrder[mbID] = i
|
||||
}
|
||||
|
||||
// Fetch all messages. This can take quite a bit of memory if the mailbox is large.
|
||||
q := bstore.QueryTx[Message](tx)
|
||||
if mailboxID > 0 {
|
||||
q.FilterNonzero(Message{MailboxID: mailboxID})
|
||||
}
|
||||
msgs, err := q.List()
|
||||
if err != nil {
|
||||
return fmt.Errorf("listing messages: %v", err)
|
||||
}
|
||||
|
||||
// Close transaction. We don't want to hold it for too long. We are now at risk
|
||||
// that a message is be removed while we export, or flags changed. At least the
|
||||
// size won't change. If we cannot open the message later on, we'll skip it and add
|
||||
// an error message to an errors.txt file in the output archive.
|
||||
if err := tx.Rollback(); err != nil {
|
||||
return fmt.Errorf("closing transaction: %v", err)
|
||||
}
|
||||
tx = nil
|
||||
|
||||
// Order the messages by mailbox, received time and finally message ID.
|
||||
sort.Slice(msgs, func(i, j int) bool {
|
||||
iid := msgs[i].MailboxID
|
||||
jid := msgs[j].MailboxID
|
||||
if iid != jid {
|
||||
return mailboxOrder[iid] < mailboxOrder[jid]
|
||||
}
|
||||
t := msgs[i].Received.Compare(msgs[j].Received)
|
||||
if t != 0 {
|
||||
return t < 0
|
||||
}
|
||||
return msgs[i].ID < msgs[j].ID
|
||||
})
|
||||
|
||||
// We keep track of errors reading message files. We continue exporting and add an
|
||||
// errors.txt file to the archive. In case of errors, the user can get (hopefully)
|
||||
// most of their emails, and see something went wrong. For other errors, like
|
||||
// writing to the archiver (e.g. a browser), we abort, because we don't want to
|
||||
// continue with useless work.
|
||||
var errors string
|
||||
|
||||
var curMailboxID int64 // Used to set curMailbox and finish a previous mbox file.
|
||||
var curMailbox string
|
||||
|
||||
var mboxtmp *os.File
|
||||
var mboxwriter *bufio.Writer
|
||||
defer func() {
|
||||
if mboxtmp != nil {
|
||||
mboxtmp.Close()
|
||||
}
|
||||
}()
|
||||
|
||||
finishMbox := func() error {
|
||||
if mboxtmp == nil {
|
||||
return nil
|
||||
}
|
||||
|
||||
if err := mboxwriter.Flush(); err != nil {
|
||||
return fmt.Errorf("flush mbox writer: %v", err)
|
||||
}
|
||||
fi, err := mboxtmp.Stat()
|
||||
if err != nil {
|
||||
return fmt.Errorf("stat temporary mbox file: %v", err)
|
||||
}
|
||||
if _, err := mboxtmp.Seek(0, 0); err != nil {
|
||||
return fmt.Errorf("seek to start of temporary mbox file")
|
||||
}
|
||||
w, err := archiver.Create(curMailbox+".mbox", fi.Size(), fi.ModTime())
|
||||
if err != nil {
|
||||
return fmt.Errorf("add mbox to archive: %v", err)
|
||||
}
|
||||
if _, err := io.Copy(w, mboxtmp); err != nil {
|
||||
return fmt.Errorf("copying temp mbox file to archive: %v", err)
|
||||
}
|
||||
if err := mboxtmp.Close(); err != nil {
|
||||
log.Errorx("closing temporary mbox file", err)
|
||||
// Continue, not fatal.
|
||||
}
|
||||
mboxwriter = nil
|
||||
mboxtmp = nil
|
||||
return nil
|
||||
}
|
||||
|
||||
exportMessage := func(m Message) error {
|
||||
mp := a.MessagePath(m.ID)
|
||||
var mr io.ReadCloser
|
||||
if m.Size == int64(len(m.MsgPrefix)) {
|
||||
mr = io.NopCloser(bytes.NewReader(m.MsgPrefix))
|
||||
} else {
|
||||
mpf, err := os.Open(mp)
|
||||
if err != nil {
|
||||
errors += fmt.Sprintf("open message file for id %d, path %s: %v (message skipped)\n", m.ID, mp, err)
|
||||
return nil
|
||||
}
|
||||
defer mpf.Close()
|
||||
st, err := mpf.Stat()
|
||||
if err != nil {
|
||||
errors += fmt.Sprintf("stat message file for id %d, path %s: %v (message skipped)\n", m.ID, mp, err)
|
||||
return nil
|
||||
}
|
||||
size := st.Size() + int64(len(m.MsgPrefix))
|
||||
if size != m.Size {
|
||||
errors += fmt.Sprintf("message size mismatch for message id %d, database has %d, size is %d+%d=%d, using calculated size\n", m.ID, m.Size, len(m.MsgPrefix), st.Size(), size)
|
||||
}
|
||||
mr = FileMsgReader(m.MsgPrefix, mpf)
|
||||
}
|
||||
|
||||
if maildir {
|
||||
p := curMailbox
|
||||
if m.Flags.Seen {
|
||||
p = filepath.Join(p, "cur")
|
||||
} else {
|
||||
p = filepath.Join(p, "new")
|
||||
}
|
||||
name := fmt.Sprintf("%d.%d.mox:2,", m.Received.Unix(), m.ID)
|
||||
// todo: more flags? forwarded, (non)junk, phishing, mdnsent would be nice. but what is the convention. dovecot-keywords sounds non-standard.
|
||||
if m.Flags.Seen {
|
||||
name += "S"
|
||||
}
|
||||
if m.Flags.Answered {
|
||||
name += "R"
|
||||
}
|
||||
if m.Flags.Flagged {
|
||||
name += "F"
|
||||
}
|
||||
if m.Flags.Draft {
|
||||
name += "D"
|
||||
}
|
||||
p = filepath.Join(p, name)
|
||||
|
||||
// We store messages with \r\n, maildir needs without. But we need to know the
|
||||
// final size. So first convert, then create file with size, and write from buffer.
|
||||
// todo: for large messages, we should go through a temporary file instead of memory.
|
||||
var dst bytes.Buffer
|
||||
r := bufio.NewReader(mr)
|
||||
for {
|
||||
line, rerr := r.ReadBytes('\n')
|
||||
if rerr != io.EOF && rerr != nil {
|
||||
errors += fmt.Sprintf("reading from message for id %d: %v (message skipped)\n", m.ID, err)
|
||||
return nil
|
||||
}
|
||||
if len(line) > 0 {
|
||||
if bytes.HasSuffix(line, []byte("\r\n")) {
|
||||
line = line[:len(line)-1]
|
||||
line[len(line)-1] = '\n'
|
||||
}
|
||||
if _, err = dst.Write(line); err != nil {
|
||||
return fmt.Errorf("writing message: %v", err)
|
||||
}
|
||||
}
|
||||
if rerr == io.EOF {
|
||||
break
|
||||
}
|
||||
}
|
||||
size := int64(dst.Len())
|
||||
w, err := archiver.Create(p, size, m.Received)
|
||||
if err != nil {
|
||||
return fmt.Errorf("adding message to archive: %v", err)
|
||||
}
|
||||
if _, err := io.Copy(w, &dst); err != nil {
|
||||
return fmt.Errorf("copying message to archive: %v", err)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// todo: should we put status flags in Status or X-Status header inside the message?
|
||||
// todo: should we do anything with Content-Length headers? changing the escaping could invalidate those. is anything checking that field?
|
||||
mailfrom := "mox"
|
||||
if m.MailFrom != "" {
|
||||
mailfrom = m.MailFrom
|
||||
}
|
||||
if _, err := fmt.Fprintf(mboxwriter, "From %s %s\n", mailfrom, m.Received.Format(time.ANSIC)); err != nil {
|
||||
return fmt.Errorf("write message line to mbox temp file: %v", err)
|
||||
}
|
||||
r := bufio.NewReader(mr)
|
||||
for {
|
||||
line, rerr := r.ReadBytes('\n')
|
||||
if rerr != io.EOF && rerr != nil {
|
||||
return fmt.Errorf("reading message: %v", err)
|
||||
}
|
||||
if len(line) > 0 {
|
||||
if bytes.HasSuffix(line, []byte("\r\n")) {
|
||||
line = line[:len(line)-1]
|
||||
line[len(line)-1] = '\n'
|
||||
}
|
||||
if bytes.HasPrefix(bytes.TrimLeft(line, ">"), []byte("From ")) {
|
||||
if _, err := fmt.Fprint(mboxwriter, ">"); err != nil {
|
||||
return fmt.Errorf("writing escaping >: %v", err)
|
||||
}
|
||||
}
|
||||
if _, err := mboxwriter.Write(line); err != nil {
|
||||
return fmt.Errorf("writing line: %v", err)
|
||||
}
|
||||
}
|
||||
if rerr == io.EOF {
|
||||
break
|
||||
}
|
||||
}
|
||||
if _, err := fmt.Fprint(mboxwriter, "\n"); err != nil {
|
||||
return fmt.Errorf("writing end of message newline: %v", err)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
for _, m := range msgs {
|
||||
if m.MailboxID != curMailboxID {
|
||||
if err := finishMbox(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
curMailbox = id2name[m.MailboxID]
|
||||
curMailboxID = m.MailboxID
|
||||
if maildir {
|
||||
// Create the directories that show this is a maildir.
|
||||
if _, err := archiver.Create(curMailbox+"/new/", 0, start); err != nil {
|
||||
return fmt.Errorf("adding maildir new directory: %v", err)
|
||||
}
|
||||
if _, err := archiver.Create(curMailbox+"/cur/", 0, start); err != nil {
|
||||
return fmt.Errorf("adding maildir cur directory: %v", err)
|
||||
}
|
||||
if _, err := archiver.Create(curMailbox+"/tmp/", 0, start); err != nil {
|
||||
return fmt.Errorf("adding maildir tmp directory: %v", err)
|
||||
}
|
||||
} else {
|
||||
|
||||
mboxtmp, err = os.CreateTemp("", "mox-mail-export-mbox")
|
||||
if err != nil {
|
||||
return fmt.Errorf("creating temp mbox file: %v", err)
|
||||
}
|
||||
// Remove file immediately, so we are sure we don't leave it around.
|
||||
if err := os.Remove(mboxtmp.Name()); err != nil {
|
||||
return fmt.Errorf("removing temp file just created: %v", err)
|
||||
}
|
||||
mboxwriter = bufio.NewWriter(mboxtmp)
|
||||
}
|
||||
}
|
||||
|
||||
if err := exportMessage(m); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
if err := finishMbox(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
if errors != "" {
|
||||
w, err := archiver.Create("errors.txt", int64(len(errors)), time.Now())
|
||||
if err != nil {
|
||||
log.Errorx("adding errors.txt to archive", err)
|
||||
return err
|
||||
}
|
||||
if _, err := w.Write([]byte(errors)); err != nil {
|
||||
log.Errorx("writing errors.txt to archive", err)
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
Reference in New Issue
Block a user