c53ee5f6ad
Subsystem to monitor IMAP mailbox for new messages. Introduces: - intake: worker that uses IDLE or polling to detect new emails. - imap: client wrapper for connection management and IMAP commands. - filter: logic for IMAP search and sender allow-list. - tracker: concurrency control to prevent processing the same UID twice. - backoff: for handling connection retries with jitter.
44 lines
1.0 KiB
Go
44 lines
1.0 KiB
Go
// Package tracker prevents duplicate processing of IMAP messages by
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// maintaining a transient set of active, in-flight UIDs.
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package tracker
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import (
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"sync"
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"github.com/emersion/go-imap/v2"
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)
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// Tracker ensures unique concurrent processing of messages.
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// This prevents race conditions where a message might be fetched
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// again before its initial processing completes.
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type Tracker struct {
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mu sync.Mutex
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ids map[imap.UID]struct{}
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}
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// New returns a ready-to-use Tracker.
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func New() *Tracker {
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return &Tracker{
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ids: make(map[imap.UID]struct{}),
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}
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}
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// TryAcquire attempts to claim exclusive processing rights for a UID.
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// It returns true only if the UID is not currently being tracked.
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func (t *Tracker) TryAcquire(uid imap.UID) bool {
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t.mu.Lock()
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defer t.mu.Unlock()
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if _, exists := t.ids[uid]; exists {
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return false
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}
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t.ids[uid] = struct{}{}
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return true
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}
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// Release relinquishes processing rights for a UID, allowing it to be acquired again.
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func (t *Tracker) Release(uid imap.UID) {
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t.mu.Lock()
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defer t.mu.Unlock()
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delete(t.ids, uid)
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}
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