RequestClient.h File Reference

Request-system client side: RequestReply futures, RequestQueue, gateway connection records and the RequestClient itself. More...

#include "NetworkManager.h"
#include "MovingAverage.h"
#include "jsmn.h"

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Classes
class	cmlabs::RequestReply
	Future/handle for one in-flight request: holds the request message, the eventual reply, status, timing and routing references. More...
class	cmlabs::RequestQueue
	Priority-ordered queue of pending RequestReply objects (per executor connection). More...
struct	cmlabs::RequestConnection
	Gateway-side record of one connected client or executor. More...
struct	cmlabs::RequestGatewayConnection
	Client/executor-side record of one gateway it connects to. More...
class	cmlabs::RequestClient
	Application-facing client of the request system: posts DataMessage requests to one or more RequestGateways and delivers replies. More...
class	cmlabs::TestRequestClient
	Load-test client driving a RequestGateway with binary-protocol requests at a configurable frequency/payload (used by RequestGateway::UnitTest()). More...
class	cmlabs::TestWebRequestClient
	Load-test client driving a RequestGateway over plain HTTP web requests. More...
class	cmlabs::TestWebSocketRequestClient
	Load-test client driving a RequestGateway over WebSocket connections. More...

Namespaces
namespace	cmlabs

Typedefs
typedef void(*	cmlabs::RequestCallbackFunction) (RequestReply &reply)
	Signature for asynchronous completion callbacks registered on a RequestReply.

Enumerations
enum	cmlabs::RequestStatus {   cmlabs::NONE = 0 , cmlabs::IDLE = 1 , cmlabs::QUEUED = 2 , cmlabs::PROCESSING = 3 ,   cmlabs::SENT = 4 , cmlabs::SUCCESS = 5 , cmlabs::FAILED = 6 , cmlabs::TIMEOUT = 7 ,   cmlabs::TOOBUSY = 8 , cmlabs::LOCALERROR = 9 , cmlabs::NETWORKERROR = 10 , cmlabs::SERVERERROR = 11 }
	Lifecycle states of a request as it moves through client, gateway and executor. More...

Functions
THREAD_RET THREAD_FUNCTION_CALL	cmlabs::RequestClientRun (THREAD_ARG arg)
	Thread entry point for the RequestClient worker loop.
THREAD_RET THREAD_FUNCTION_CALL	cmlabs::TestRequestClientRun (THREAD_ARG arg)
THREAD_RET THREAD_FUNCTION_CALL	cmlabs::TestWebRequestClientRun (THREAD_ARG arg)
THREAD_RET THREAD_FUNCTION_CALL	cmlabs::TestWebSocketRequestClientRun (THREAD_ARG arg)

Detailed Description

Request-system client side: RequestReply futures, RequestQueue, gateway connection records and the RequestClient itself.

The CMSDK request system is a distributed request/response fabric built on the message protocol of NetworkManager. Three roles cooperate:

• RequestClient (this file): application-facing. Wraps each outgoing DataMessage in a RequestReply "future", sends it to a RequestGateway and lets the caller either block on waitForResult() or register a callback.
• RequestGateway (RequestGateway.h): the router/load balancer. Accepts requests from many clients (binary, HTTP or WebSocket), queues them, picks the best RequestExecutor (short vs long requests, queue sizes, heartbeats) and routes replies back to the originating client.
• RequestExecutor (RequestExecutor.h): the worker/server. Pulls requests from its gateway connection, processes them and replies.

A request round-trip looks like this:

RequestClient client;
client.addGateway(1, "gateway.host", 9000);       // connect to a gateway
client.waitForConnection(5000);
 
DataMessage* msg = RequestClient::CreateRequestMessage(
    HTTP_GET, "status", "detail", "full");          // build the request
RequestReply* reply = client.postRequest(msg);     // async send
if (reply->waitForResult(3000) == SUCCESS) {       // block for the answer
    DataMessage* answer = reply->peekReplyMessage(); // owned by reply
    // ... use answer ...
}
client.finishRequest(reply);                       // release the slot

Clients keep a list of gateways (RequestGatewayConnection) and reconnect automatically; requests survive brief gateway outages by re-queuing.

Definition in file RequestClient.h.