# coherence-js-client

**Repository Path**: mirrors_oracle/coherence-js-client

## Basic Information

- **Project Name**: coherence-js-client
- **Description**: The Coherence JavaScript Client
- **Primary Language**: Unknown
- **License**: UPL-1.0
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-09-01
- **Last Updated**: 2025-09-20

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# JavaScript Client for Oracle Coherence

The JavaScript Client for Oracle Coherence allows Node applications to act as
cache clients to a Coherence Cluster using Google's `gRPC` framework for
the network transport.

### Features
* Familiar `Map`-like interface for manipulating entries
* Cluster-side querying and aggregation of map entries
* Cluster-side manipulation of map entries using `EntryProcessors`
* Registration of listeners to be notified of map mutations

### Requirements
* Coherence CE versions `22.06`, `14.1.2-0-0`, `25.03` or later (or equivalent non-open source editions) with a configured [gRPC Proxy](https://docs.oracle.com/en/middleware/standalone/coherence/14.1.1.2206/develop-remote-clients/using-coherence-grpc-server.html)
* Node `20.19.x` or later
* NPM `9.x` or later

### Usage

Before testing the library, you must ensure a Coherence cluster is available.  For local development, we recommend using the Coherence CE Docker image; it contains everything necessary for the client to operate correctly.

```bash
docker run -d -p 1408:1408 ghcr.io/oracle/coherence-ce:25.03.2
```

or to save some keystrokes/time, use the included npm script, `coh-up` to start a two-member Cluster with the gRPC port at 1408"
```bash
npm run coh-up
```

**Important!** When calling `coh-up` or `coh-down`, the LTS version of Coherence will be used (`22.06.12`).
To use a later Coherence version, such as `25.03.2`, prefix the calls with, or export `COHERENCE_VERSION=<desired-version>`.
For example:
```bash
COHERENCE_VERSION=25.03.2 npm run coh-up
```

For more details on the image, see the [documentation](https://github.com/oracle/coherence/tree/master/prj/coherence-docker).

### Declare Your Dependency

To use the JavaScript Client for Oracle Coherence, simply declare it as a dependency in your
project's `package.json`:
```
...
"dependencies": {
    "@oracle/coherence": "^1.2",
},
...
```

### Compatibility with Java Types
The following table provides a listing of mappings between Java types and Javascript types when working with
Coherence `25.03` or later.  If using Coherence `22.06.x`, these types will be returned as Number.  It is recommended
using `25.03` if intentionally using `java.math.BigInteger` or `java.math.BigDecimal` as part of your application.

| Java Type            | JavascriptType                                                   |
|----------------------|------------------------------------------------------------------|
| java.math.BigInteger | BigInt (ECMA standard)                                           |
| java.math.BigDecimal | Decimal ([decimal.js](https://www.npmjs.com/package/decimal.js)) |

### Examples

> NOTE: The following examples assume the Coherence container is running locally.
> You can start a container by running `npm run coh-up`.

#### Establishing a Session

The Coherence uses the concept of a `Session` to manage a set of related Coherence resources,
such as maps and/or caches. When using the JavaScript Client for Oracle Coherence, a `Session` connects to a specific
gRPC endpoint and uses a specific serialization format to marshal requests and responses.
This means that different sessions using different serializers may connect to the same server endpoint. Typically,
for efficiency the client and server would be configured to use matching serialization formats to avoid
deserialization of data on the server, but this does not have to be the case. If the server is using a different
serializer for the server-side caches, it must be able to deserialize the client's requests, so there must be
a serializer configured on the server to match that used by the client.

> NOTE: Currently, the JavaScript Client for Oracle Coherence only supports JSON serialization

A `Session` is constructed using an `Options` instance, or a generic object with the same keys and values.

The currently supported properties are:
* `address` - the address of the Coherence gRPC proxy.  This defaults to `localhost:1408`.
* `requestTimeoutInMillis` - the gRPC request timeout in milliseconds.  This defaults to `60000`.
* `callOptions` - per-request gRPC call options.
* `tls` - options related to the configuration of TLS.
    - `enabled` - determines if TLS is enabled or not.  This defaults to `false` (NOTE: assumes `true` if all three `COHERENCE_TLS_*` (see subsequent bullets) environment variables are defined)
    - `caCertPath` - the path to the CA certificate.  This may be configured using the environment variable `COHERENCE_TLS_CERTS_PATH`
    - `clientCertPath` - the path to the client certificate. This may be configured with the environment variable `COHERENCE_TLS_CLIENT_CERT`
    - `clientKeyPath` - the path to the client certificate key. This may be configured with the environment variable `COHERENCE_TLS_CLIENT_KEY`

*NOTE*: If testing locally generated certificates, set `COHERENCE_IGNORE_INVALID_CERTS` to `true` to disable
TLS validation of the certificates.

```typescript
const { Session } = require('@oracle/coherence')

let session = new Session()
```

This is the simplest invocation which assumes the following defaults:
* `address` is `localhost:1408`
* `requestTimeoutInMillis` is `60000`
* `tls` is `disabled`

To use values other than the default, create a new `Options` instance, configure as desired,
and pass it to the constructor of the `Session`:

```javascript
const { Session, Options } = require('@oracle/coherence')

const opts = new Options()
opts.address = 'example.com:4444'

let session = new Session(opts)
```

or instead of an `Options` instance, using a generic JavaScript object:

```javascript
const { Session } = require('@oracle/coherence')

const opts = new Options({address: 'example.com:4444'})

let session = new Session(opts)
```

As of v1.2.3 of the JavaScript Client for Oracle Coherence, it's now possible to use the Coherence
NameService to lookup gRPC Proxy endpoints.  The format to enable this feature is
`coherence:///<host>([:port]|[/cluster-name]|[:port/cluster-name])`

For example:
 * `coherence:///localhost` will connect to the name service bound to a local coherence cluster on port `7574` (the default Coherence cluster port).
 * `coherence:///localhost:8000` will connect to the name service bound to a local coherence cluster on port `8000`.
 * `coherence:///localhost/remote-cluster` will connect to the name service bound to a local coherence cluster on port `7574` (the default Coherence cluster port) and look up the name service for the given cluster name.  Note: this typically means both clusters have a local member sharing a cluster port.
 * `coherence:///localhost:8000/remote-cluster` will connect to the name service bound to a local coherence cluster on port `8000` and look up the name service for the given cluster name.  Note: this typically means both clusters have a local member sharing a cluster port.

While this is useful for local development, this may have limited uses in a production environment.  For example,
Coherence running within a container with the cluster port (`7574`) exposed so external clients may connect.  The
lookup will fail to work for the client as the Coherence name service return a private network address which
won't resolve. Lastly, if connecting to a cluster that has multiple proxies bound to different ports, gRPC, by default,
will use the first address returned by the resolver.  It is possible to enable round-robin load balancing by including
a custom channel option when creating the session:

```typescript
const { Session } = require('@oracle/coherence')

const opts = new Options({address: 'coherence:///localhost',
  channelOptions: {'grpc.service_config': JSON.stringify({ loadBalancingConfig: [{ round_robin: {} }], })}})

let session = new Session(opts)
```

*NOTE* The Coherence NameService feature requires Node `20.x` or later.

It's also possible to control the default address the session will bind to by providing
an address via the `COHERENCE_SERVER_ADDRESS` environment variable.  The format of the value would
be the same as if you configured it programmatically as the above example shows.

Once the session has been constructed, it will now be possible to create maps and caches.

#### Basic Map Operations

The map (`NamedMap`) and cache (`NamedCache`) implementations provide the same basic features as the Map provided
by JavaScript except for the following differences:

* key equality isn't restricted to reference equality
* insertion order is not maintained
* `set()` calls cannot be chained because of the asynchronous nature of the API

> NOTE: The only difference between `NamedCache` and `NamedMap` is that the 'NamedCache' allows associating a
> `time-to-live` on the cache entry, while `NamedMap` does not

For the following examples, let's assume that we have a Map defined in Coherence named `Test`.
To get access to the map from the client:

> NOTE: If using the Docker image previously mentioned for testing, you don't need to worry about the details of the map name.  Any name will work.

```javascript
let map = session.getMap('Test')
```

Once we have a handle to our map, we can invoke the same basic operations as a standard JavaScript Map:
```javascript
await map.size
// (zero)

await map.set('key1', 'value1')
await map.set('key2', 'value2')
// returns a Promise vs the map itself, so these can't be chained

await map.size
// (two)

await map.get('key1')
// value1

await map.has('key2')
// true

await map.has('key3')
// false

await map.keys()
// ['key1', 'key2']

await map.values()
// ['value1', 'value2']

await map.entries()
// [{key: 'key1', value: 'value1'}, {key: 'key2', value: 'value2'}]

await map.forEach((value, key) => console.log(key + ': ' + value))
// prints all of the entries
```

#### Querying the Map

Coherence provides a rich set of primitives that allow developers to create advanced queries against
a set of entries returning only those keys and/or values matching the specified criteria.
See the [documentation](https://oracle.github.io/coherence/23.09/api/java/index.html) for details
on the Filters provided by this client.

Let's assume we have a `NamedMap` in which we're storing `string` keys and some objects with the structure of:

```
{
  name: <string>
  age:  <number>
  hobbies: [] // of string
}
```

First, let's insert a few objects:

```javascript
await map.set('0001', {name: "Bill Smith", age: 38, hobbies: ["gardening", "painting"]})
await map.set('0002', {name: "Fred Jones", age: 56, hobbies: ["racing", "golf"]})
await map.set('0003', {name: "Jane Doe", age: 48, hobbies: ["gardening", "photography"]})
```

Using a filter, we can limit the result set returned by the map:

```javascript
const { Filters } = require('@oracle/coherence')

// ...

await map.entries(Filters.greater('age', 40))
// [{key: '0002', value: {name: "Fred Jones"...}}, {key: '0002', value: {name: "Jane Doe"...}}]

await map.keys(Filters.arrayContains('hobbies', 'gardening'))  
// ['0001', '0003']

await map.values(Filters.not(Filters.arrayContains('hobbies', 'gardening')))
// [{name: "Fred Jones", age: 56, hobbies: ["racing", "golf"]}]
```

#### Aggregation

Coherence provides developers with the ability to process some subset of the entries in a map,
resulting in an aggregated result. See the [documentation](https://oracle.github.io/coherence/23.09/api/java/index.html) for aggregators provided by this client.

Assume the same set of keys and values are present from the filtering example above:

```javascript
const { Aggregators, Filters } = require('@oracle/coherence')

// ...

await map.aggregate(Aggregators.average('age'))
// 47.3

await map.aggregate(Aggregators.sum('age'))
// 142

await map.aggregate(Filters.greater('age', 40), Aggregators.count())
// 2
```

#### Entry Processing

An entry processor allows mutation of map entries in-place within the cluster instead of bringing the entire object
to the client, updating, and pushing the value back.  See the [documentation](https://oracle.github.io/coherence/23.09/api/java/index.html) for the processors provided by this client.

Assume the same set of keys and values are present from the filtering and aggregation examples:

```javascript
const { Filters, Processors } = require('@oracle/coherence')

// ...

// targeting a specific entry
await map.invoke('0001', Processors.extract('age'))
// returns: 38

// target all entries across the cluster
await map.invokeAll(Processors.extract('age'))
// returns: [['0001', 38], ['0002', 56], ['0003', 48]]

// target all entries matching filtered critera
await map.invokeAll(Filters.greater('age', 40), Processors.extract('age'))
// returns: [['0002', 56], ['0003', 48]]

// incrementing a number 'in-place'
await map.invokeAll(Filters.greater('age', 40), Processors.increment('age', 1))
// returns [['0002', 57], ['0003', 49]]

// update a value 'in-place'
await map.invoke('0001', Processors.update('age', 100))
// returns true meaning the value was updated
await map.get('0001')
// the value will reflect the new age value
```

### Events

Coherence provides the ability to subscribe to notifications pertaining to a particular map/cache.
Registration works similarly to event registration with Node, with some key differences.  In addition
to listening for specific events, it is possible to listen to events for changes made to a specific key, or using
a Filter, it's possible to limit the events raised to be for a subset of the map entries.

Now, let's register a listener:

```javascript
import { event } from '@oracle/coherence'

const MapEventType = event.MapEventType
const MapListener = event.MapListener

const handler = (event: MapEvent) => { 
  console.log('Event: ' + event.description 
    + ', Key: ' + JSON.stringify(event.key) 
    + ', New Value: ' + JSON.stringify(event.newValue)
    + ', Old Value: ' + JSON.stringify(event.oldValue))
}

const listener = new MapListener()
  .on(MapEventType.INSERT, handler)
  .on(MapEventType.UPDATE, handler)
  .on(MapEventType.DELETE, handler)

// register to receive all event types for all entries within the map
await map.addMapListener(listener)

await map.set('a', 'b')
// Event: insert, Key: a, New Value: b, Old Value: null

await map.set('a', 'c')
// Event: update, Key: a, New Value: c, Old Value: b

await map.delete('a')
// Event: delete, Key: a, New Value: null, Old Value: c

// remove the listeners
await map.removeMapListener(listener)

// =======================================

// Assume the previous listener as well as the following key and values
//   ['0001', {name: "Bill Smith", age: 38, hobbies: ["gardening", "painting"]}]
//   ['0002', {name: "Fred Jones", age: 56, hobbies: ["racing", "golf"]}]
//   ['0003', {name: "Jane Doe", age: 48, hobbies: ["gardening", "photography"]}]

// Add handlers for updates to '0001'
await map.addMapListener(listener, '0001')

await map.update('0002', '0002')
// does not generate any events

await map.invoke('0001', Processors.increment('age', 1))
// Event: update, Key: 0001, New Value: {name: "Bill Smith", age: 39, hobbies: ["gardening", "painting"]}, Old Value: {name: "Bill Smith", age: 38, hobbies: ["gardening", "painting"]}

await map.delete('0001') 
// does not generate any events

// remove the key listener
await map.removeMapListener(listener, '0001')

// =======================================

// Assume the same setup as the previous example, except instead of listening to events for a single key,
// we'll instead listen for events raised for entries that match the filtered criteria.
const filter = Filters.event(Filters.greater('age', 40), filter.MapEventFilter.UPDATED)

// Listen to all updates to entries where the age property of the entry value is greater than 40
await map.addMapListener(listener, filter) 

await map.invokeAll(Processors.increment('age', 1));
// Event: update, Key: 0002, New Value: {name: "Fred Jones", age: 57, hobbies: ["racing", "golf"]}, Old Value: {name: "Fred Jones", age: 56, hobbies: ["racing", "golf"]}
// Event: update, Key: 0003, New Value: "Jane Doe", age: 49, hobbies: ["gardening", "photography"]}, Old Value: "Jane Doe", age: 48, hobbies: ["gardening", "photography"]}

// remove the filter listener
await map.removeMapListener(listener, filter)
```

### Cut/Paste Example
Here's an example that can be pasted into a new node project that is using this library:

```javascript
const { Session } = require('@oracle/coherence')

let session = new Session()
let map = session.getMap('Test')

setImmediate(async () => {
  console.log("Map size is " + (await map.size))

  console.log("Inserting entry (key=1, value=One)")
  await map.set(1, "One")

  console.log("Inserting entry (key=2, value=Two)")
  await map.set(2, "Two")

  let entries = await map.entries();

  console.log("All entries")
  for await (const entry of entries) {
    console.log(entry.key + '=' + entry.value)
  }

  console.log("Key 1 is " + (await map.get(1)))
  console.log("Key 2 is " + (await map.get(2)))

  console.log("Deleting entry (key=1)")
  await map.delete(1)

  console.log("Map size is " + (await map.size))
  await session.close()
})
```

When run, it produces:

```bash
Map size is 0
Inserting entry (key=1, value=One)
Map entry is One
Deleting entry (key=1)
Map size is 0
```

### References
* Oracle Coherence JavaScript Client - https://oracle.github.io/coherence-js-client/
* Oracle Coherence CE Documentation - https://coherence.community/23.09/docs/#/docs/about/01_overview

## Contributing

This project welcomes contributions from the community. Before submitting a pull request, please [review our contribution guide](./CONTRIBUTING.md)

## Security

Please consult the [security guide](./SECURITY.md) for our responsible security vulnerability disclosure process

## License

Copyright (c) 2020, 2023 Oracle and/or its affiliates.

Released under the Universal Permissive License v1.0 as shown at
<https://oss.oracle.com/licenses/upl/>.