aerc/worker/imap/open.go
Tim Culverhouse 7aa71d334b imap: add option to cache headers
Add option to cache headers for imap accounts. Cache db is located at
$XDG_CACHE_DIR/aerc/{account name}. The cache is cleaned of stale
entries when aerc is first opened.

Two new account level configuration options are introduced:
* cache-headers (Default: false)
* cache-max-age (Default: 30 days (720 hours))

The change in worker/imap/open.go is to set the selected directory. This
is required to access the UIDVALIDITY field, which is used in
combination with the message ID to form the key for use in the cache db.
The key structure is: "header.{UIDVALIDITY}.{UID}"

Where reasonable, cache does not stop aerc from running. In general, if
there is an error in the cache, aerc should continue working as usual.
Errors are either displayed to the user or logged.

All messages are stored without flags, and when retrieved have the flags
set to SEEN. This is to prevent UI flashes. A new method to
FetchMessageFlags is introduced to update flags of cached headers. This
is done asynchronously, and the user will see their messages appear and
then any flags updated. The message will initially show as SEEN, but
will update to unread. I considered updating the cache with the
last-known flag state, however it seems prudent to spare the R/W cycle
and assume that - eventually - all messages will end up read, and if it
isn't the update will occur rather quickly.

Note that leveldb puts a lock on the database, preventing multiple
instances of aerc from accessing the cache at the same time.

Much of this work is based on previous efforts by Vladimír Magyar.

Implements: https://todo.sr.ht/~rjarry/aerc/2
Thanks: Vladimír Magyar <vladimir@mgyar.me>
Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Tested-by: inwit <inwit@sindominio.net>
Reviewed-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>
2022-06-22 11:26:13 +02:00

158 lines
4.2 KiB
Go

package imap
import (
"sort"
"github.com/emersion/go-imap"
sortthread "github.com/emersion/go-imap-sortthread"
"git.sr.ht/~rjarry/aerc/worker/types"
)
func (imapw *IMAPWorker) handleOpenDirectory(msg *types.OpenDirectory) {
imapw.worker.Logger.Printf("Opening %s", msg.Directory)
sel, err := imapw.client.Select(msg.Directory, false)
if err != nil {
imapw.worker.PostMessage(&types.Error{
Message: types.RespondTo(msg),
Error: err,
}, nil)
} else {
imapw.selected = sel
imapw.worker.PostMessage(&types.Done{Message: types.RespondTo(msg)}, nil)
}
}
func (imapw *IMAPWorker) handleFetchDirectoryContents(
msg *types.FetchDirectoryContents) {
imapw.worker.Logger.Printf("Fetching UID list")
seqSet := &imap.SeqSet{}
seqSet.AddRange(1, imapw.selected.Messages)
searchCriteria := &imap.SearchCriteria{
SeqNum: seqSet,
}
sortCriteria := translateSortCriterions(msg.SortCriteria)
var uids []uint32
// If the server supports the SORT extension, do the sorting server side
ok, err := imapw.client.sort.SupportSort()
if err == nil && ok && len(sortCriteria) > 0 {
uids, err = imapw.client.sort.UidSort(sortCriteria, searchCriteria)
// copy in reverse as msgList displays backwards
for i, j := 0, len(uids)-1; i < j; i, j = i+1, j-1 {
uids[i], uids[j] = uids[j], uids[i]
}
} else {
if err != nil {
// Non fatal, but we do want to print to get some debug info
imapw.worker.Logger.Printf("can't check for SORT support: %v", err)
}
uids, err = imapw.client.UidSearch(searchCriteria)
}
if err != nil {
imapw.worker.PostMessage(&types.Error{
Message: types.RespondTo(msg),
Error: err,
}, nil)
} else {
imapw.worker.Logger.Printf("Found %d UIDs", len(uids))
if len(imapw.seqMap) < len(uids) {
imapw.seqMap = make([]uint32, len(uids))
}
imapw.worker.PostMessage(&types.DirectoryContents{
Message: types.RespondTo(msg),
Uids: uids,
}, nil)
imapw.worker.PostMessage(&types.Done{Message: types.RespondTo(msg)}, nil)
}
}
type sortFieldMapT map[types.SortField]sortthread.SortField
// caution, incomplete mapping
var sortFieldMap sortFieldMapT = sortFieldMapT{
types.SortArrival: sortthread.SortArrival,
types.SortCc: sortthread.SortCc,
types.SortDate: sortthread.SortDate,
types.SortFrom: sortthread.SortFrom,
types.SortSize: sortthread.SortSize,
types.SortSubject: sortthread.SortSubject,
types.SortTo: sortthread.SortTo,
}
func translateSortCriterions(
cs []*types.SortCriterion) []sortthread.SortCriterion {
result := make([]sortthread.SortCriterion, 0, len(cs))
for _, c := range cs {
if f, ok := sortFieldMap[c.Field]; ok {
result = append(result, sortthread.SortCriterion{Field: f, Reverse: c.Reverse})
}
}
return result
}
func (imapw *IMAPWorker) handleDirectoryThreaded(
msg *types.FetchDirectoryThreaded) {
imapw.worker.Logger.Printf("Fetching threaded UID list")
seqSet := &imap.SeqSet{}
seqSet.AddRange(1, imapw.selected.Messages)
threads, err := imapw.client.thread.UidThread(sortthread.References,
&imap.SearchCriteria{SeqNum: seqSet})
if err != nil {
imapw.worker.PostMessage(&types.Error{
Message: types.RespondTo(msg),
Error: err,
}, nil)
} else {
aercThreads, count := convertThreads(threads, nil)
sort.Sort(types.ByUID(aercThreads))
imapw.worker.Logger.Printf("Found %d threaded messages", count)
imapw.seqMap = make([]uint32, count)
imapw.worker.PostMessage(&types.DirectoryThreaded{
Message: types.RespondTo(msg),
Threads: aercThreads,
}, nil)
imapw.worker.PostMessage(&types.Done{Message: types.RespondTo(msg)}, nil)
}
}
func convertThreads(threads []*sortthread.Thread, parent *types.Thread) ([]*types.Thread, int) {
if threads == nil {
return nil, 0
}
conv := make([]*types.Thread, len(threads))
count := 0
for i := 0; i < len(threads); i++ {
t := threads[i]
conv[i] = &types.Thread{
Uid: t.Id,
}
// Set the first child node
children, childCount := convertThreads(t.Children, conv[i])
if len(children) > 0 {
conv[i].FirstChild = children[0]
}
// Set the parent node
if parent != nil {
conv[i].Parent = parent
// elements of threads are siblings
if i > 0 {
conv[i].PrevSibling = conv[i-1]
conv[i-1].NextSibling = conv[i]
}
}
count += childCount + 1
}
return conv, count
}