A module to gather very common services.
This module contains various common injectable services that are often used into a wide range of applications.
The services provided here are meant to have a very tiny surface API in order to be easily mocked but also implemented with different technologies.
For example, the counter
service could be implemented with a distributed
architecture, the codeGenerator
though a database...
The services are designed to be used with Knifecycle a simple but feature complete dependency injection tool but can also be used by hand.
- initCodeGenerator(services) ⇒
Promise.<function()>
|Promise.<function()>
Instantiate the codeGenerator service
- initCounter(services) ⇒
Promise.<function()>
Instantiate the counter service
- initDelay(services) ⇒
Promise.<Object>
Instantiate the delay service
- initImporter(path) ⇒
Promise.<Object>
Allow to import ES modules.
- initLock(services) ⇒
Promise.<Object>
Instantiate the lock service
- initLog(services) ⇒
Promise.<function()>
Instantiate the logging service
- initRandom(services) ⇒
Promise.<function()>
Instantiate the LRU Pool service
- initRandom(services) ⇒
Promise.<function()>
Instantiate the random service
- initResolve(services) ⇒
Promise.<function()>
Instantiate the
resolve
service- resolve(path) ⇒
Promise.<string>
Allow to resolve a path with the module system.
- initTime(services) ⇒
Promise.<function()>
Instantiate the time service
Instantiate the codeGenerator service
Kind: global function
Param | Type | Default | Description |
---|---|---|---|
services | Object |
The services to inject | |
[services.CHARS_SET] | Object |
EXPLICIT_CHARS |
An optional char set to pick cars into |
[services.random] | Object |
Math.random |
An optional random function to replace the Math.random one used by default |
[services.log] | Object |
noop |
An optional logging function |
Example
import {
DEFAULT_LOGGER,
initCodeGenerator,
initLog,
} from 'common-services';
const log = await initLog({
logger: DEFAULT_LOGGER,
});
const codeGenerator = await initCodeGenerator({
log,
});
Returns a random code
Kind: inner method of initCodeGenerator
Returns: Promise.<String>
- A promise of the generated code
Param | Type | Default | Description |
---|---|---|---|
[length] | Number |
6 |
An optional custon code length (defaults to 6) |
Example
console.log([
codeGenerator(),
codeGenerator(),
codeGenerator(),
]);
// Prints: ABCDEF,GHJKMN,PRSTUV
Instantiate the counter service
Kind: global function
Returns: Promise.<function()>
- A promise of the counter function
Param | Type | Default | Description |
---|---|---|---|
services | Object |
The services to inject | |
[services.COUNTER] | Object |
DEFAULT_COUNTER |
An optional configuration object |
[services.log] | Object |
noop |
An optional logging function |
Example
import {
initCounter,
initLog,
} from 'common-services';
const log = await initLog({
logger: DEFAULT_LOGGER
});
const counter = await initCounter({
COUNTER: { firstCount: 1 },
log,
});
Returns the current count and increment the counter
Kind: inner method of initCounter
Returns: Promise.<number>
- A promise of the current count
Example
console.log([
counter(),
counter(),
counter(),
]);
// Prints: 1,2,3
Instantiate the delay service
Kind: global function
Returns: Promise.<Object>
- A promise of the delay service
Param | Type | Default | Description |
---|---|---|---|
services | Object |
The services to inject | |
[services.log] | function |
noop |
A logging function |
Example
import {
DEFAULT_LOGGER,
initDelay,
initLog,
} from 'common-services';
const log = await initLog({
logger: DEFAULT_LOGGER
});
const delay = await initDelay({
log,
});
- initDelay(services) ⇒
Promise.<Object>
- ~create(delay) ⇒
Promise
- ~clear(promise) ⇒
Promise
- ~create(delay) ⇒
Create a new delay
Kind: inner method of initDelay
Returns: Promise
- A promise to be resolved after that delay
or rejected if it is cancelled.
Param | Type | Description |
---|---|---|
delay | Number |
The delay in ms |
Example
await delay.create(1000);
console.log('1000 ms elapsed!');
Cancel an earlier created delay
Kind: inner method of initDelay
Returns: Promise
- A promise resolved when cancellation is done.
Param | Type | Description |
---|---|---|
promise | Promise |
The promise of the delay to cancel |
Example
try {
const delayPromise = delay.create(1000);
await Promise.all(delayPromise, delay.clear(delayPromise));
console.log('1000 ms elapsed!');
} catch (err) {
if(err.code != 'E_DELAY_CLEARED') {
trow err;
}
console.log('Cancelled!'));
}
// Prints: Cancelled!
Allow to import ES modules.
Kind: global function
Returns: Promise.<Object>
- A promise of an imported module.
Param | Type | Description |
---|---|---|
path | string |
The module path |
Instantiate the lock service
Kind: global function
Returns: Promise.<Object>
- A promise of the lock service
Param | Type | Default | Description |
---|---|---|---|
services | Object |
The services to inject | |
[services.LOCKS_MAP] | Map |
A map to store le current locks (optional) | |
[services.LOCK_TIMEOUT] | Number |
Infitiny |
The timeout in milliseconds for the lock to be released. |
[services.log] | function |
A logging function | |
[services.delay] | Object |
A delay service like the common-services one |
Example
import {
DEFAULT_LOGGER,
initLog,
initDelay,
initLock
} from 'common-services';
import ms from 'ms';
const log = await initLog({
logger: DEFAULT_LOGGER
});
const delay = await initDelay({ log });
const lock = await initLock({
LOCK_TIMEOUT: ms('5s'),
delay,
log,
});
run();
async function run() {
// The following async jobs are done sequentially
// if they have the same `resourceKey` value
await Promise.all(asynTasks.map(async (asyncTask) => {
await lock.take(asyncTask.resourceKey);
await myAsyncStuff1(asyncTask);
await myAsyncStuff2(asyncTask);
await myAsyncStuff3(asyncTask);
lock.release(asyncTask.resourceKey);
});
}
- initLock(services) ⇒
Promise.<Object>
- ~take(key) ⇒
Promise
- ~release(key) ⇒
void
- ~take(key) ⇒
Take the lock on the given resource key
Kind: inner method of initLock
Returns: Promise
- A promise to be resolved when the lock
is gained or rejected if the lock release
timeout is reached.
Param | Type | Description |
---|---|---|
key | String |
A unique key for the locked resource |
Release the lock on the given resource key
Kind: inner method of initLock
Param | Type | Description |
---|---|---|
key | String |
A unique key for the resource to release |
Instantiate the logging service
Kind: global function
Returns: Promise.<function()>
- A promise of the logging function
Param | Type | Description |
---|---|---|
services | Object |
The services to inject |
services.logger | Object |
The logger object that output the logs |
Example
import {
DEFAULT_LOGGER,
initLog,
} from 'common-services';
const log = await initLog({
logger: DEFAULT_LOGGER,
});
Logging function
Kind: inner method of initLog
Param | Type | Description |
---|---|---|
type | String |
Log type |
...args | * |
Log contents |
Example
log('debug', 'Luke, I am your father!')
Instantiate the LRU Pool service
Kind: global function
Returns: Promise.<function()>
- A promise of the LRUPool service
Param | Type | Default | Description |
---|---|---|---|
services | Object |
The services to inject | |
[services.log] | Object |
noop |
A logging function |
Example
import {
DEFAULT_LOGGER,
initLog,
initLRUPool
} from 'common-services';
const log = await initLog({
logger: DEFAULT_LOGGER,
});
const random = await initLRUPool({
MAX_POOL_SIZE: 50,
poolManager: {
// ...
},
log,
});
Returns a new random number
Kind: inner method of initRandom
Returns: number
- The random number
Example
random()
// Prints: 0.3141592653589793
Instantiate the random service
Kind: global function
Returns: Promise.<function()>
- A promise of the random function
Param | Type | Default | Description |
---|---|---|---|
services | Object |
The services to inject | |
[services.log] | Object |
noop |
A logging function |
Example
import {
DEFAULT_LOGGER,
initLog,
initRandom
} from 'common-services';
const log = await initLog({
logger: DEFAULT_LOGGER,
});
const random = await initRandom({
log,
});
Returns a new random number
Kind: inner method of initRandom
Returns: number
- The random number
Example
random()
// Prints: 0.3141592653589793
Instantiate the resolve
service
Kind: global function
Returns: Promise.<function()>
- A promise of the resolve
service
Param | Type | Description |
---|---|---|
services | Object |
The services to inject |
services.MAIN_FILE_URL | String |
An URL pointing to the main file run |
[services.log] | function |
A logging function |
Example
import {
DEFAULT_LOGGER,
initLog,
initResolve,
} from 'common-services';
const log = await initLog({
logger: DEFAULT_LOGGER,
});
const resolve = initResolve({
MAIN_FILE_URL: import.meta.url,
log,
});
resolve('./myfile.ts');
}
Allow to resolve a path with the module system.
Kind: global function
Returns: Promise.<string>
- A promise of a fully qualified module path
Param | Type | Description |
---|---|---|
path | string |
The serializable constants to gather |
Instantiate the time service
Kind: global function
Returns: Promise.<function()>
- A promise of the time function
Param | Type | Default | Description |
---|---|---|---|
services | Object |
The services to inject | |
[services.log] | Object |
noop |
A logging function |
Example
import {
DEFAULT_LOGGER,
initLog,
initTime,
} from 'common-services';
const log = await initLog({
logger: DEFAULT_LOGGER,
});
const time = await initTime({
log,
});
Returns the current timestamp
Kind: inner method of initTime
Returns: number
- The current timestamp
Example
time()
// Prints: 1326585600000