kvstore

The kvstore built-in module is available only inside a PubNub Function. It stores persistent values by subscribe key, so Functions on the same keyset share the same store.

1const db = require('kvstore');

Storage constraints

• A KV store key can be up to 1,000 characters.
• A KV store value can be up to 32,000 characters.
• A KV store entry lives for 1 day by default, and a per-entry TTL can range from 1 minute up to 1 year. A TTL below the minimum becomes the minimum. A TTL above the maximum becomes the maximum.

set

set(key, value, ttl?)

* required

Parameter	Description
key * Type: String	Storage key.
value * Type: Object	JSON-serializable value to store.
ttl Type: Number	Time to live, in minutes. Defaults and clamps as described above.

Returns: Promise.

1const db = require('kvstore');
2db.set('key', { value: true }, 2880);

The third argument sets the TTL in minutes (2880 minutes = 2 days).

get

get(key)

* required

Parameter	Description
key * Type: String	Storage key to retrieve.

Returns: Promise resolving to the stored value.

1const db = require('kvstore');
2db.get('key').then((value) => {
3    console.log('value', value);
4});

setItem

setItem(key, stringValue, ttl?)

* required

Parameter	Description
key * Type: String	Storage key.
stringValue * Type: String	String value to store.
ttl Type: Number	Time to live, in minutes. Same defaulting and clamping as set().

Same as set(), optimized for string values. Returns: Promise.

1const db = require('kvstore');
2db.setItem('key', 'value', 2880);

getItem

getItem(key)

* required

Parameter	Description
key * Type: String	Storage key to retrieve.

Same as get(), optimized for string values. Returns: Promise resolving to the stored string.

1const db = require('kvstore');
2db.getItem('key').then((value) => {
3    console.log('value', value);
4});

removeItem

removeItem(key)

* required

Parameter	Description
key * Type: String	Storage key to remove.

Returns: Promise.

1const db = require('kvstore');
2db.removeItem('key');

getKeys

getKeys(pagination_key?)

* required

Parameter	Description
pagination_key Type: String	Last key returned from a previous call. Omit for the first page.

Returns: Promise resolving to an array of keys, up to the maximum keys per call listed in API limits. Do not rely on a static index (such as result[99]) into the returned array, since the page size can change.

1const db = require('kvstore');
2db.getKeys().then((keys) => {
3    for (let i = 0; i < keys.length; i++) {
4        console.log(keys[i]);
5    }
6});

Counters

Counters increment a stored number atomically, so concurrent Function executions do not overwrite each other's updates. Counters are not subject to TTL.

getCounter

getCounter(key)

* required

Parameter	Description
key * Type: String	Counter key to retrieve.

Returns: Promise resolving to the counter value, or 0 if no counter under key has yet been incremented.

1const db = require('kvstore');
2db.getCounter('key').then((counter) => {
3    console.log('counter', counter);
4});

incrCounter

incrCounter(key, number?)

* required

Parameter	Description
key * Type: String	Counter key to increment. Created and initialized to zero if it doesn't exist.
number Type: Number	Amount to increment by. Defaults to 1.

Returns: Promise.

1const db = require('kvstore');
2db.incrCounter('key', 5);

getCounterKeys

getCounterKeys(pagination_key?)

* required

Parameter	Description
pagination_key Type: String	Last key returned from a previous call. Omit for the first page.

Returns: Promise resolving to an array of counter keys, up to the maximum keys per call listed in API limits.

1const db = require('kvstore');
2db.getCounterKeys().then((counterKeys) => {
3    for (let i = 0; i < counterKeys.length; i++) {
4        console.log(counterKeys[i]);
5    }
6});

Related reference

• Modules and libraries. Every built-in module available inside a Function.
• API limits. Per-execution operation caps and KV store size limits.