C++Windows C++Windows C++Posix C++Windows C++ Storage & Playback Tutorial for Realtime Apps

Storage & Playback Overview

Requires that the Storage and Playback add-on is enabled for your key. How do I enable add-on features for my keys? - see http://www.pubnub.com/knowledge-base/discussion/644/how-do-i-enable-add-on-features-for-my-keys
PubNub's Storage and Playback feature enables developers to store messages as they are published, and retrieve them at a later time. Before using this feature it must be enabled in the PubNub Admin Console.

Storage Applications

Being able to pull an archive of messages from storage has many applications:
  • Populate chat, collaboration and machine configuration on app load.
  • Store message streams with real-time data management.
  • Retrieve historical data streams for reporting, auditing and compliance (HIPAA, SOX, Data Protection Directive, and more).
  • Replay live events with delivery of real-time data during rebroadcasting.

Storage API Features

As needed, specific messages can be marked "do not archive" when published to prevent archiving on a per-message basis, and storage retention time can range from 1 day to forever.

PubNub Storage Windows C++ Code Samples

These code samples build off code defined in the Pub & Sub tutorial, so before proceeding, be sure you have completed the Pub & Sub tutorial first.

Preparing the channel for history operations

To begin, lets populate a new channel with some test publishes that we'll pull from storage using the history() method.

We'll define a callback for response handing that is applicable for both publish() and history() methods.
//Only for Functions calling pattern

static void on_publish(pubnub::context &pn, pubnub_res res) {
  if (PNR_OK == res) {
    std::cout << message << " status: "<< pn.last_publish_result() << std::endl;
    if (i < 500) {
      i++;
      publish(pn);
    }
  } else {
    std::cout << "Failed with code " << res << std::endl;
  }
}

Seeding the Channel with Messages

Before we can pull history for a channel, that channel must first have had messages published on it. We'll do just that by publishing some messages onto a channel to "seed" it for a history call.
//Sync
static void publish(pubnub::context &pn) {
  std::string channel("history_channel");
  std::stringstream message;
  enum pubnub_res res;
  int i;

  try {
    for (i = 0; i <= 500; i++) {
      message.str("");
      message << "\"message#" << i << "\"";

      res = pn.publish(channel, message.str()).await();

      if (PNR_OK == res) {
        std::cout << message.str() << " status: "<< pn.last_publish_result() << std::endl;
      } else {
        std::cout << "Failed with code " << res << std::endl;
      }

    }
  } catch (std::exception &ex) {
    std::cout << "Exception: " << ex.what() << std::endl;
  }
}

//Lambdas
static void publish(pubnub::context &ipn) {
  std::string channel("history_channel");
  std::stringstream msg_stream;
  std::string message;
  int i;

  msg_stream << "\"message#" << i << "\"";
  message = msg_stream.str();

  for (i = 0; i < 500; i++) {
    ipn.publish(channel, message)
      .then([&](pubnub::context &pn, pubnub_res res) {
        msg_stream.str(std::string());
        msg_stream << "\"message#" << i << "\"";
        message = msg_stream.str();

        if (PNR_OK == res || PNR_PUBLISH_FAILED  == res) {
          std::cout << message << " status: "<< pn.last_publish_result() << std::endl;
        } else {
          std::cout << "Failed with code " << res << std::endl;
        }
    });
  }
}

//Functions
static const std::string channel("history_channel");
static std::string message;
static std::stringstream msg_stream;
static int i;

static void on_publish(pubnub::context &pn, pubnub_res res) {
  if (PNR_OK == res || PNR_PUBLISH_FAILED  == res) {
    std::cout << message << " status: "<< pn.last_publish_result() << std::endl;
  } else {
    std::cout << "Failed with code " << res << std::endl;
  }
}

static void publish(pubnub::context &ipn) {
  for (i = 0; i < 500; i++) {
    msg_stream.str(std::string());
    msg_stream << "\"message#" << i << "\"";
    message = msg_stream.str();

    ipn.publish(channel, message).then(on_publish);
  }
}
In the above example, we publish a barrage of test messages to history_channel.

Pulling from storage with a History call

Now that we've populated the channel (and thus the backend storage system), we can pull from storage using the history() method call:
// Sync
void history(pubnub::context &pn) {
  enum pubnub_res res;
 
  res = pn.history("history_channel", 100).await();;
 
  if (PNR_OK == res) {
    std::vector<std::string> msg = pn.get_all();
  
    for (std::vector<std::string>::iterator it = msg.begin(); it != msg.end(); ++it) {
      std::cout << *it << std::endl;
    }
  } else {
    std::cout << "History request failed" << std::endl;
  }
}

// Lambdas
void history(pubnub::context &ipn) {
  ipn.history("history_channel").then([=](pubnub::context &pn, pubnub_res res) {
    auto msg = pn.get_all();
 
    if (PNR_OK == res) {
      for (auto &&m: msg) {
        std::cout << m << std::endl;
      }
    } else {
      std::cout << "Request failed" << std::endl;
    }
  });
}
 
// Functions
void on_history(pubnub::context &pn, pubnub_res res) {
  if (PNR_OK == res) {
    std::vector<std::string> msg = pn.get_all();
  
    for (std::vector<std::string>::iterator it = msg.begin(); it != msg.end(); ++it) {
      std::cout << *it << std::endl;
    }
  } else {
    std::cout << "History request failed" << std::endl;
  }
}
 
void history(pubnub::context &pn) {
  pn.history("history_channel", 100).then(on_history);
}
The response format is

[
	["message1", "message2", "message3",... ],
	"Start Time Token",
	"End Time Token"
]

Setting the Count

The default value of the count parameter is 100, but, due to the way that default parameters work in C++, if you want to set the include_token parameter, you'll have to set the count, too. So, if you don't have a better idea what to use for count in that case, use 100.

Converting from Timetokens to UNIXTIME

The timetoken response value is a string, representing 17-digit precision unix time (UTC). To convert PubNub's timetoken to Unix timestamp (seconds), divide the timetoken number by 10,000,000 (10^7).
Additional Resources for Data Streams with Publish and Subscribe: 
Message Update Delete