feat(PROJ-45): IMAP Per-Folder UID-Tracking + UIDVALIDITY-Check

- FolderState: GetFolderState, UpsertFolderState, ListFolderStates, DecideResync
- syncFolder nutzt per-folder UID-Tracking statt globalem highest_uid
- UIDVALIDITY-Check loest automatisch Full-Resync aus
- imap_folder_state Tabelle in initSchema (CREATE TABLE IF NOT EXISTS)
- SetAuditLogger in main.go verdrahtet

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
sysops
2026-05-11 10:49:14 +02:00
parent 16013e8b66
commit 4151b6f8c5
5 changed files with 338 additions and 16 deletions
+1
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@@ -421,6 +421,7 @@ func main() {
})
}
imapSched := imapstore.NewScheduler(imapSt, imapImp, logger)
imapSched.SetAuditLogger(audlog) // PROJ-45: tenant-visible UIDVALIDITY-reset audit entries
imapSched.Start()
defer imapSched.Stop()
srv.SetImap(imapSt, imapImp, imapSched)
+122
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@@ -0,0 +1,122 @@
package imap
import (
"context"
"errors"
"fmt"
"github.com/jackc/pgx/v5"
)
// FolderState represents per-folder UID tracking for an IMAP account (PROJ-45).
// Each IMAP folder has its own independent UID sequence — tracking a single
// account-global last_uid (the legacy behaviour) silently skips folders whose
// highest UID falls below the global value and misses UIDVALIDITY resets.
type FolderState struct {
AccountID int64
Folder string
LastUID uint32
UIDValidity uint32
}
// GetFolderState returns the saved per-folder UID tracking record.
// If no record exists yet (first sync of this folder), an empty
// FolderState{LastUID: 0, UIDValidity: 0} is returned and the caller
// MUST treat it as a request for a full folder resync.
func (s *Store) GetFolderState(ctx context.Context, accountID int64, folder string) (FolderState, error) {
var st FolderState
st.AccountID = accountID
st.Folder = folder
err := s.pool.QueryRow(ctx, `
SELECT last_uid, uid_validity
FROM imap_folder_state
WHERE account_id = $1 AND folder = $2`,
accountID, folder,
).Scan(&st.LastUID, &st.UIDValidity)
if errors.Is(err, pgx.ErrNoRows) {
return st, nil
}
if err != nil {
return st, fmt.Errorf("imap store: get folder state: %w", err)
}
return st, nil
}
// UpsertFolderState writes (or overwrites) the per-folder UID tracking record.
// Used after a successful folder sync to persist the new high-water mark.
func (s *Store) UpsertFolderState(ctx context.Context, st FolderState) error {
_, err := s.pool.Exec(ctx, `
INSERT INTO imap_folder_state (account_id, folder, last_uid, uid_validity, updated_at)
VALUES ($1, $2, $3, $4, now())
ON CONFLICT (account_id, folder) DO UPDATE
SET last_uid = EXCLUDED.last_uid,
uid_validity = EXCLUDED.uid_validity,
updated_at = now()`,
st.AccountID, st.Folder, st.LastUID, st.UIDValidity,
)
if err != nil {
return fmt.Errorf("imap store: upsert folder state: %w", err)
}
return nil
}
// ResyncDecision describes what the scheduler should do for a folder given
// the stored state and the UIDVALIDITY reported by the server right after SELECT.
// Extracted as a pure function so the branching logic can be unit-tested
// without a live IMAP server.
type ResyncDecision struct {
FullResync bool // true → ignore stored last_uid, fetch all UIDs
UIDValidReset bool // true → write an audit-log "uidvalidity_reset" entry
EffectiveStart uint32 // UID to filter on (0 means "all messages")
}
// DecideResync implements the per-folder sync gate (PROJ-45).
//
// - server UIDVALIDITY == 0 → treat as "unknown", continue incrementally
// with the stored last_uid (defensive; some servers misbehave).
// - stored UIDVALIDITY == 0 → first ever sync of this folder → full sync,
// but no "reset" event (nothing to reset from).
// - stored != server (both != 0) → mailbox rebuilt server-side → full resync
// AND log a UIDVALIDITY-reset audit event.
// - otherwise → incremental from stored last_uid.
func DecideResync(storedLastUID, storedUIDValidity, serverUIDValidity uint32) ResyncDecision {
if serverUIDValidity == 0 {
return ResyncDecision{
FullResync: storedLastUID == 0,
EffectiveStart: storedLastUID,
}
}
if storedUIDValidity == 0 {
return ResyncDecision{FullResync: storedLastUID == 0, EffectiveStart: storedLastUID}
}
if storedUIDValidity != serverUIDValidity {
return ResyncDecision{FullResync: true, UIDValidReset: true, EffectiveStart: 0}
}
return ResyncDecision{FullResync: storedLastUID == 0, EffectiveStart: storedLastUID}
}
// ListFolderStates returns all per-folder UID tracking records for an account.
// Currently used for diagnostics and potential admin UI.
func (s *Store) ListFolderStates(ctx context.Context, accountID int64) ([]FolderState, error) {
rows, err := s.pool.Query(ctx, `
SELECT account_id, folder, last_uid, uid_validity
FROM imap_folder_state
WHERE account_id = $1
ORDER BY folder`, accountID)
if err != nil {
return nil, fmt.Errorf("imap store: list folder states: %w", err)
}
defer rows.Close()
var states []FolderState
for rows.Next() {
var st FolderState
if err := rows.Scan(&st.AccountID, &st.Folder, &st.LastUID, &st.UIDValidity); err != nil {
return nil, fmt.Errorf("imap store: scan folder state: %w", err)
}
states = append(states, st)
}
return states, rows.Err()
}
+82
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@@ -0,0 +1,82 @@
package imap
import "testing"
// TestDecideResync covers the per-folder sync gate introduced by PROJ-45.
// The branches under test correspond directly to the acceptance criteria:
// - first-ever sync (no stored state)
// - normal incremental sync (UIDVALIDITY unchanged)
// - UIDVALIDITY mismatch → full resync + audit event
// - server returns UIDVALIDITY=0 → defensive fallback, keep stored cursor
func TestDecideResync(t *testing.T) {
cases := []struct {
name string
storedUID uint32
storedValid uint32
serverValid uint32
wantFull bool
wantReset bool
wantStart uint32
}{
{
name: "first sync, no stored state",
storedUID: 0,
storedValid: 0,
serverValid: 12345,
wantFull: true,
wantReset: false,
wantStart: 0,
},
{
name: "incremental, validity unchanged",
storedUID: 1500,
storedValid: 12345,
serverValid: 12345,
wantFull: false,
wantReset: false,
wantStart: 1500,
},
{
name: "uidvalidity mismatch triggers full resync + audit",
storedUID: 1500,
storedValid: 12345,
serverValid: 99999,
wantFull: true,
wantReset: true,
wantStart: 0,
},
{
name: "server uidvalidity 0 defensive: keep cursor, no reset",
storedUID: 800,
storedValid: 12345,
serverValid: 0,
wantFull: false,
wantReset: false,
wantStart: 800,
},
{
name: "stored validity 0 (legacy row) does not trigger reset",
storedUID: 0,
storedValid: 0,
serverValid: 7777,
wantFull: true,
wantReset: false,
wantStart: 0,
},
}
for _, tc := range cases {
t.Run(tc.name, func(t *testing.T) {
got := DecideResync(tc.storedUID, tc.storedValid, tc.serverValid)
if got.FullResync != tc.wantFull {
t.Errorf("FullResync: got %v want %v", got.FullResync, tc.wantFull)
}
if got.UIDValidReset != tc.wantReset {
t.Errorf("UIDValidReset: got %v want %v", got.UIDValidReset, tc.wantReset)
}
if got.EffectiveStart != tc.wantStart {
t.Errorf("EffectiveStart: got %d want %d", got.EffectiveStart, tc.wantStart)
}
})
}
}
+113 -15
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@@ -9,6 +9,8 @@ import (
"sync"
"time"
"archivmail/internal/audit"
imapv2 "github.com/emersion/go-imap/v2"
"github.com/emersion/go-imap/v2/imapclient"
)
@@ -19,6 +21,7 @@ type Scheduler struct {
store *Store
importer *Importer
logger *slog.Logger
audlog *audit.Logger // PROJ-45: UIDVALIDITY-reset events are tenant-visible audit entries
mu sync.Mutex
running map[int64]bool // in-memory guard against concurrent syncs
@@ -36,6 +39,13 @@ func NewScheduler(store *Store, importer *Importer, logger *slog.Logger) *Schedu
}
}
// SetAuditLogger wires an audit.Logger into the scheduler so that
// UIDVALIDITY-reset events (PROJ-45) are persisted as tenant-visible
// audit entries. Optional — when nil, only structured logs are emitted.
func (s *Scheduler) SetAuditLogger(a *audit.Logger) {
s.audlog = a
}
// Start launches the background scheduler goroutine.
// Call Stop to shut it down gracefully.
func (s *Scheduler) Start() {
@@ -150,6 +160,8 @@ func (s *Scheduler) runSyncWithRetry(ctx context.Context, accountID int64) {
lastErr error
)
startedAt := time.Now()
for attempt := 0; attempt < 3; attempt++ {
if attempt > 0 {
backoff := syncBackoff[attempt-1]
@@ -172,15 +184,18 @@ func (s *Scheduler) runSyncWithRetry(ctx context.Context, accountID int64) {
"account_id", accountID, "attempt", attempt+1, "err", lastErr)
}
durationMs := time.Since(startedAt).Milliseconds()
if lastErr != nil {
s.logger.Error("imap scheduler: sync failed after all retries",
"account_id", accountID, "err", lastErr)
"account_id", accountID, "err", lastErr, "duration_ms", durationMs)
_ = s.store.UpdateSyncResult(ctx, accountID, "error", lastErr.Error(), 0, lastUID)
return
}
s.logger.Info("imap scheduler: sync completed",
"account_id", accountID, "imported", count, "last_uid", lastUID)
"account_id", accountID, "imported", count, "last_uid", lastUID,
"duration_ms", durationMs)
_ = s.store.UpdateSyncResult(ctx, accountID, "ok", "", count, lastUID)
}
@@ -221,7 +236,8 @@ func (s *Scheduler) doSync(ctx context.Context, accountID int64) (int, uint32, e
var (
totalImported int
maxUID uint32 = acc.LastUID
maxUID uint32
foldersSynced int
)
for _, folder := range folders {
@@ -235,16 +251,30 @@ func (s *Scheduler) doSync(ctx context.Context, accountID int64) (int, uint32, e
continue
}
foldersSynced++
totalImported += count
if folderMaxUID > maxUID {
maxUID = folderMaxUID
}
}
// Account-level summary (PROJ-45 acceptance criterion).
// duration_ms is intentionally not added here — it's logged by runSyncWithRetry
// which owns the retry-wrapped wall clock.
log.Info("account sync complete",
"folders_synced", foldersSynced,
"new_messages_total", totalImported)
return totalImported, maxUID, nil
}
// syncFolder syncs new messages from a single IMAP folder.
//
// PROJ-45: Uses per-folder UID tracking from imap_folder_state instead of the
// legacy account-global imap_accounts.last_uid. UIDVALIDITY is read from the
// SELECT response and compared against the stored value — on mismatch the
// folder is fully resynced in this same iteration (PROJ-32 message-id dedup
// blocks duplicates).
func (s *Scheduler) syncFolder(
ctx context.Context,
c *Conn,
@@ -252,15 +282,59 @@ func (s *Scheduler) syncFolder(
folder string,
log *slog.Logger,
) (int, uint32, error) {
if _, err := c.Select(folder, nil).Wait(); err != nil {
// Load per-folder state BEFORE selecting — we need the stored uid_validity
// to compare against the value the server reports in the SELECT response.
state, err := s.store.GetFolderState(ctx, acc.ID, folder)
if err != nil {
return 0, 0, fmt.Errorf("imap scheduler: get folder state %q: %w", folder, err)
}
selectData, err := c.Select(folder, nil).Wait()
if err != nil {
return 0, 0, fmt.Errorf("imap scheduler: select %q: %w", folder, err)
}
// Snapshot the server-reported UIDVALIDITY. A value of 0 is treated as
// "unknown / server bug" — we keep the existing high-water mark instead
// of forcing a needless full resync.
serverUIDValidity := uint32(0)
if selectData != nil {
serverUIDValidity = selectData.UIDValidity
}
effectiveLastUID := state.LastUID
switch {
case serverUIDValidity == 0:
log.Warn("uidvalidity zero from server, keeping stored last_uid",
"folder", folder, "stored_uid_validity", state.UIDValidity)
case state.UIDValidity != 0 && state.UIDValidity != serverUIDValidity:
// Mailbox was rebuilt server-side — UIDs restart at 1. We must
// resync the entire folder from scratch. PROJ-32 message-id
// deduplication prevents duplicate writes.
log.Warn("uidvalidity change",
"account_id", acc.ID,
"folder", folder,
"old", state.UIDValidity,
"new", serverUIDValidity)
if s.audlog != nil {
s.audlog.Log(audit.Entry{
EventType: "imap_uidvalidity_reset",
Username: acc.Owner,
Success: true,
Detail: fmt.Sprintf("account=%d folder=%q old_uidvalidity=%d new_uidvalidity=%d",
acc.ID, folder, state.UIDValidity, serverUIDValidity),
})
}
effectiveLastUID = 0
}
var uids []imapv2.UID
if acc.LastUID > 0 {
// Incremental: only messages with UID > lastUID.
minUID := imapv2.UID(acc.LastUID + 1)
if effectiveLastUID > 0 {
// Incremental: only messages with UID > effectiveLastUID.
minUID := imapv2.UID(effectiveLastUID + 1)
criteria := &imapv2.SearchCriteria{
UID: []imapv2.UIDSet{
{imapv2.UIDRange{Start: minUID, Stop: 0}},
@@ -272,7 +346,7 @@ func (s *Scheduler) syncFolder(
}
uids = searchData.AllUIDs()
} else {
// First sync: fetch everything.
// First sync or post-UIDVALIDITY-reset: fetch everything.
searchData, err := c.UIDSearch(&imapv2.SearchCriteria{}, nil).Wait()
if err != nil {
return 0, 0, fmt.Errorf("imap scheduler: uid search full %q: %w", folder, err)
@@ -280,17 +354,35 @@ func (s *Scheduler) syncFolder(
uids = searchData.AllUIDs()
}
if len(uids) == 0 {
return 0, 0, nil
}
log.Info("syncing folder", "folder", folder, "new_messages", len(uids))
var (
imported int
maxUID uint32
maxUID uint32 = effectiveLastUID
)
// PROJ-45: even when there are 0 new UIDs, persist the (possibly new)
// uid_validity so a later UIDVALIDITY change can still be detected.
defer func() {
newState := FolderState{
AccountID: acc.ID,
Folder: folder,
LastUID: maxUID,
UIDValidity: serverUIDValidity,
}
if err := s.store.UpsertFolderState(ctx, newState); err != nil {
log.Warn("imap scheduler: persist folder state failed",
"folder", folder, "err", err)
}
}()
if len(uids) == 0 {
log.Info("folder synced",
"folder", folder,
"new_messages", 0,
"total_messages", 0,
"uid_validity", serverUIDValidity)
return 0, maxUID, nil
}
for i := 0; i < len(uids); i += batchSize {
end := i + batchSize
if end > len(uids) {
@@ -313,6 +405,12 @@ func (s *Scheduler) syncFolder(
}
}
log.Info("folder synced",
"folder", folder,
"new_messages", imported,
"total_messages", len(uids),
"uid_validity", serverUIDValidity)
return imported, maxUID, nil
}
+19
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@@ -86,6 +86,20 @@ ALTER TABLE imap_accounts ADD COLUMN IF NOT EXISTS sync_error_msg TEXT NOT NULL
ALTER TABLE imap_accounts ADD COLUMN IF NOT EXISTS tenant_id INTEGER REFERENCES tenants(id);
`
// folderStateSQL creates the per-folder UID-tracking table introduced by PROJ-45.
// Replaces the previous account-global last_uid tracking which silently skipped
// folders with lower UIDs than INBOX and ignored UIDVALIDITY changes.
const folderStateSQL = `
CREATE TABLE IF NOT EXISTS imap_folder_state (
account_id BIGINT NOT NULL REFERENCES imap_accounts(id) ON DELETE CASCADE,
folder TEXT NOT NULL,
last_uid BIGINT NOT NULL DEFAULT 0,
uid_validity BIGINT NOT NULL DEFAULT 0,
updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
PRIMARY KEY (account_id, folder)
);
`
// New creates a new Store, connects to PostgreSQL, and runs the migration.
func New(dsn, secret string) (*Store, error) {
pool, err := pgxpool.New(context.Background(), dsn)
@@ -103,6 +117,11 @@ func New(dsn, secret string) (*Store, error) {
return nil, fmt.Errorf("imap store: migrate alter: %w", err)
}
if _, err := pool.Exec(context.Background(), folderStateSQL); err != nil {
pool.Close()
return nil, fmt.Errorf("imap store: migrate folder state: %w", err)
}
key := sha256.Sum256([]byte(secret))
return &Store{pool: pool, encKey: key}, nil
}