diff options
Diffstat (limited to 'packages/taler-wallet-core/src')
-rw-r--r-- | packages/taler-wallet-core/src/util/retries.ts | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/packages/taler-wallet-core/src/util/retries.ts b/packages/taler-wallet-core/src/util/retries.ts new file mode 100644 index 000000000..f3a5e7d80 --- /dev/null +++ b/packages/taler-wallet-core/src/util/retries.ts @@ -0,0 +1,92 @@ +/* + This file is part of GNU Taler + (C) 2020 Taler Systems S.A. + + GNU Taler is free software; you can redistribute it and/or modify it under the + terms of the GNU General Public License as published by the Free Software + Foundation; either version 3, or (at your option) any later version. + + GNU Taler 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 General Public License for more details. + + You should have received a copy of the GNU General Public License along with + GNU Taler; see the file COPYING. If not, see <http://www.gnu.org/licenses/> + */ + +/** + * Helpers for dealing with retry timeouts. + */ + +/** + * Imports. + */ +import { Timestamp, Duration, getTimestampNow } from "./time"; + +export interface RetryInfo { + firstTry: Timestamp; + nextRetry: Timestamp; + retryCounter: number; + active: boolean; +} + +export interface RetryPolicy { + readonly backoffDelta: Duration; + readonly backoffBase: number; +} + +const defaultRetryPolicy: RetryPolicy = { + backoffBase: 1.5, + backoffDelta: { d_ms: 200 }, +}; + +export function updateRetryInfoTimeout( + r: RetryInfo, + p: RetryPolicy = defaultRetryPolicy, +): void { + const now = getTimestampNow(); + if (now.t_ms === "never") { + throw Error("assertion failed"); + } + if (p.backoffDelta.d_ms === "forever") { + r.nextRetry = { t_ms: "never" }; + return; + } + r.active = true; + const t = + now.t_ms + p.backoffDelta.d_ms * Math.pow(p.backoffBase, r.retryCounter); + r.nextRetry = { t_ms: t }; +} + +export function getRetryDuration( + r: RetryInfo, + p: RetryPolicy = defaultRetryPolicy, +): Duration { + if (p.backoffDelta.d_ms === "forever") { + return { d_ms: "forever" }; + } + const t = p.backoffDelta.d_ms * Math.pow(p.backoffBase, r.retryCounter); + return { d_ms: t }; +} + +export function initRetryInfo( + active = true, + p: RetryPolicy = defaultRetryPolicy, +): RetryInfo { + if (!active) { + return { + active: false, + firstTry: { t_ms: Number.MAX_SAFE_INTEGER }, + nextRetry: { t_ms: Number.MAX_SAFE_INTEGER }, + retryCounter: 0, + }; + } + const info = { + firstTry: getTimestampNow(), + active: true, + nextRetry: { t_ms: 0 }, + retryCounter: 0, + }; + updateRetryInfoTimeout(info, p); + return info; +}
\ No newline at end of file |