overleaf/services/clsi/app/js/DockerLockManager.js
2020-08-10 17:01:11 +01:00

113 lines
3.4 KiB
JavaScript

/* eslint-disable
handle-callback-err,
*/
// TODO: This file was created by bulk-decaffeinate.
// Fix any style issues and re-enable lint.
/*
* decaffeinate suggestions:
* DS101: Remove unnecessary use of Array.from
* DS102: Remove unnecessary code created because of implicit returns
* DS207: Consider shorter variations of null checks
* Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
*/
let LockManager
const logger = require('logger-sharelatex')
const LockState = {} // locks for docker container operations, by container name
module.exports = LockManager = {
MAX_LOCK_HOLD_TIME: 15000, // how long we can keep a lock
MAX_LOCK_WAIT_TIME: 10000, // how long we wait for a lock
LOCK_TEST_INTERVAL: 1000, // retry time
tryLock(key, callback) {
let lockValue
if (callback == null) {
callback = function (err, gotLock) {}
}
const existingLock = LockState[key]
if (existingLock != null) {
// the lock is already taken, check how old it is
const lockAge = Date.now() - existingLock.created
if (lockAge < LockManager.MAX_LOCK_HOLD_TIME) {
return callback(null, false) // we didn't get the lock, bail out
} else {
logger.error(
{ key, lock: existingLock, age: lockAge },
'taking old lock by force'
)
}
}
// take the lock
LockState[key] = lockValue = { created: Date.now() }
return callback(null, true, lockValue)
},
getLock(key, callback) {
let attempt
if (callback == null) {
callback = function (error, lockValue) {}
}
const startTime = Date.now()
return (attempt = () =>
LockManager.tryLock(key, function (error, gotLock, lockValue) {
if (error != null) {
return callback(error)
}
if (gotLock) {
return callback(null, lockValue)
} else if (Date.now() - startTime > LockManager.MAX_LOCK_WAIT_TIME) {
const e = new Error('Lock timeout')
e.key = key
return callback(e)
} else {
return setTimeout(attempt, LockManager.LOCK_TEST_INTERVAL)
}
}))()
},
releaseLock(key, lockValue, callback) {
if (callback == null) {
callback = function (error) {}
}
const existingLock = LockState[key]
if (existingLock === lockValue) {
// lockValue is an object, so we can test by reference
delete LockState[key] // our lock, so we can free it
return callback()
} else if (existingLock != null) {
// lock exists but doesn't match ours
logger.error(
{ key, lock: existingLock },
'tried to release lock taken by force'
)
return callback()
} else {
logger.error(
{ key, lock: existingLock },
'tried to release lock that has gone'
)
return callback()
}
},
runWithLock(key, runner, callback) {
if (callback == null) {
callback = function (error) {}
}
return LockManager.getLock(key, function (error, lockValue) {
if (error != null) {
return callback(error)
}
return runner((error1, ...args) =>
LockManager.releaseLock(key, lockValue, function (error2) {
error = error1 || error2
if (error != null) {
return callback(error)
}
return callback(null, ...Array.from(args))
})
)
})
}
}