emp3-mirror-cache

About

Geospatial data sharing and collaboration service.

Building

Prerequisites

Software

• JDK 1.8
• Maven 3.3.9

Build

$ ./gradlew build publishToMavenLocal
$ cd wildfly-swarm
$ mvn clean package

Running

To launch the server:

$ cd wildfly-swarm
$ java -jar target/wildfly-swarm-swarm.jar

To launch the Java client:

$ ./gradlew :mirrorcache-client:run

To launch the Web client:

visit: 127.0.0.1:8080/client

(NOTE: The Web client assumes a channel named 'inject' exists when performing certain functions.)

To view server state:

visit: 127.0.0.1:8080/status.html

WebSocket Endpoints

Endpoint	Description
ws://127.0.0.1:8080/mirrorcache	All clients interested in participating in MirrorCache message exchanges must connect to this endpoint. Only ProtoMessage objects are recognized.

REST endpoints

Endpoint	Description
/rest/status	This endpoint returns the current state of the system. Returned data currently includes all active WebSocket sessions, all created channels, all created channelGroups, and outbound queues sizes.
/rest/channels	This endpoint returns a listing of channels currently available.
/rest/channelgroups	This endpoint returns a listing of channelGroups currently avaialble.
/rest/queues	This endpoint returns detailed information about each outbound queue.
/rest/cache/channel	This endpoint returns detailed information about each channel cache.
/rest/cache/channelgroup	This endpoint returns detailed information about each channelGroup cache.
/rest/cache/entity	This endpoint returns detailed information about each cached entity.

API Notes

ProtoMessage

A ProtoMessage is a Protocol Buffer defined type. It is declared as follows:

message ProtoMessage {
    string id                    = 1;
    map<string, string> property = 2;
    int32 priority               = 3;
    OneOfOperation operation     = 4;
    ProtoPayload payload         = 5;
}

Channel

A channel represents the path message data travels through. A client can open a channel and produce or consume message data (or both) on it by specificying a flow pattern. Once a channel has been opened data can be published to it or consumed from it.

Channel Types:

Type	Description
TEMPORARY	A temporary channel will exist only while the owning client is still connected.
PERSISTENT	A persistent channel will remain available until it has been explicitly deleted.

Channel Visibility:

Visibility	Description
PUBLIC	A public channel is made available for any other client to discover and subscribe to.
PRIVATE	A private channel can only be discovered and subscribed to after being invited.

Channel Flow:

Flow	Description
INGRESS	An ingress flow denotes a client who is only interested in consuming messages.
EGRESS	An egress flow denotes a client who is only interested in producing messages.
BOTH	A both flow denotes a client interested in producing and consuming.

ChannelGroup

A ChannelGroup represents a collection of channels. Clients who open a channelGroup will receive published data from each channel participating in the channelGroup. The owner of a channelGroup can publish data to the channelGroup, this has the effect of broadcasting data to each participating channel in the channelGroup. A channelGroup will persist until the owning session is closed.

Server Operations

Operation	Properties
GET_CLIENT_INFO	status clientInfo
CREATE_CHANNEL	status channelName type visibility
CREATE_CHANNEL	status channelName type visibility
DELETE_CHANNEL	status channelName
FIND_CHANNELS	status filter channel
CHANNEL_OPEN	status channelName flow filter
CHANNEL_CLOSE	status channelName
CHANNEL_PUBLISH	status channelName
CHANNEL_DELETE	status channelName payloadId sourceId
CHANNEL_CACHE	status channelName entityId
CHANNEL_HISTORY	status channelName startTime endTime history
CREATE_CHANNELGROUP	status channelGroupName
DELETE_CHANNELGROUP	status channelGroupName
FIND_CHANNELGROUPS	status filter channelGroup
CHANNELGROUP_OPEN	status channelGroupName
CHANNELGROUP_CLOSE	status channelGroupName
CHANNELGROUP_ADD_CHANNEL	status channelGroupName channelName
CHANNELGROUP_REMOVE_CHANNEL	status channelGroupName channelName
CHANNELGROUP_PUBLISH	status channelGroupName
CHANNELGROUP_DELETE	status channelGroupName payloadId sourceId
CHANNELGROUP_CACHE	status channelGroupName entityId
CHANNELGROUP_HISTORY	status channelGroupName entityId startTime endTime history

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MirrorCacheProductManager

Manages the list(s) of overlays that are created as products, or feeds.

MirrorCacheCollaborationManager

Manages all the different sessions being used for collaboration. Each collaboration session is essentially a map with numerous overlays, a shared camera, and a list of connected users.

MirrorCacheStorage

Similar to EMP core Storage Manager where it has a store of all the unique data elements and understands all their relationships.

ClientMessageQueue

When messages the user is subscribed to are processed, the result will be inserted in a first in, first out queue. If an update occurs on a piece of data that was already in the queue, that item remains in the same queue position, but has the latest update applied. Because it will likely just be a reference to the actual item in the MirrorCacheStorage, not much needs to happen to client queue if it finds that the updated item already exists in the queue.

MirrorCacheClient

Stores the endpoint, name, uuid, DateTime connected, reference to its ClientMessageQueue, and other user related attributes.

License

Apache 2.0