forked from mirrors/gotosocial
88 lines
2.7 KiB
Go
88 lines
2.7 KiB
Go
// GoToSocial
|
|
// Copyright (C) GoToSocial Authors admin@gotosocial.org
|
|
// SPDX-License-Identifier: AGPL-3.0-or-later
|
|
//
|
|
// This program is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Affero General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Affero General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Affero General Public License
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package cache
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"time"
|
|
|
|
"codeberg.org/gruf/go-cache/v3/result"
|
|
errorsv2 "codeberg.org/gruf/go-errors/v2"
|
|
"github.com/superseriousbusiness/gotosocial/internal/log"
|
|
)
|
|
|
|
// SentinelError is returned to indicate a non-permanent error return,
|
|
// i.e. a situation in which we do not want a cache a negative result.
|
|
var SentinelError = errors.New("BUG: error should not be returned") //nolint:revive
|
|
|
|
// ignoreErrors is an error ignoring function capable of being passed to
|
|
// caches, which specifically catches and ignores our sentinel error type.
|
|
func ignoreErrors(err error) bool {
|
|
return errorsv2.Comparable(
|
|
err,
|
|
SentinelError,
|
|
context.DeadlineExceeded,
|
|
context.Canceled,
|
|
)
|
|
}
|
|
|
|
// nocopy when embedded will signal linter to
|
|
// error on pass-by-value of parent struct.
|
|
type nocopy struct{}
|
|
|
|
func (*nocopy) Lock() {}
|
|
|
|
func (*nocopy) Unlock() {}
|
|
|
|
// tryStart will attempt to start the given cache only if sweep duration > 0 (sweeping is enabled).
|
|
func tryStart[ValueType any](cache *result.Cache[ValueType], sweep time.Duration) {
|
|
if sweep > 0 {
|
|
var z ValueType
|
|
msg := fmt.Sprintf("starting %T cache", z)
|
|
tryUntil(msg, 5, func() bool {
|
|
return cache.Start(sweep)
|
|
})
|
|
}
|
|
}
|
|
|
|
// tryStop will attempt to stop the given cache only if sweep duration > 0 (sweeping is enabled).
|
|
func tryStop[ValueType any](cache *result.Cache[ValueType], sweep time.Duration) {
|
|
if sweep > 0 {
|
|
var z ValueType
|
|
msg := fmt.Sprintf("stopping %T cache", z)
|
|
tryUntil(msg, 5, cache.Stop)
|
|
}
|
|
}
|
|
|
|
// tryUntil will attempt to call 'do' for 'count' attempts, before panicking with 'msg'.
|
|
func tryUntil(msg string, count int, do func() bool) {
|
|
for i := 0; i < count; i++ {
|
|
if do() {
|
|
// success.
|
|
return
|
|
}
|
|
|
|
// Sleep for a little before retry (a bcakoff).
|
|
time.Sleep(time.Millisecond * 1 << (i + 1))
|
|
}
|
|
|
|
// panic on total failure as this shouldn't happen.
|
|
log.Panicf(nil, "failed %s after %d tries", msg, count)
|
|
}
|