Message Persistence API for PubNub Go SDK

Message Persistence provides real-time access to the history of all messages published to PubNub. Each published message is timestamped to the nearest 10 nanoseconds and is stored across multiple availability zones in several geographical locations. Stored messages can be encrypted with AES-256 message encryption, ensuring that they are not readable while stored on PubNub's network. For more information, refer to Message Persistence.

Messages can be stored for a configurable duration or forever, as controlled by the retention policy that is configured on your account. The following options are available: 1 day, 7 days, 30 days, 3 months, 6 months, 1 year, or Unlimited.

You can retrieve the following:

• Messages
• Message reactions
• File Sharing (using File Sharing API)

Fetch History

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

This function fetches historical messages from one or multiple channels. The includeMessageActions flag also allows you to fetch message reactions along with the messages.

It's possible to control how messages are returned and in what order.

• if you specify only the start parameter (without end), you will receive messages that are older than the start timetoken
• if you specify only the end parameter (without start), you will receive messages from that end timetoken and newer
• if you specify values for both start and end parameters, you will retrieve messages between those timetokens (inclusive of the end value)

You will receive a maximum of 100 messages for a single channel or 25 messages for multiple channels (up to 500). If more messages meet the timetoken criteria, make iterative calls while adjusting the start timetoken to fetch the entire list of messages from Message Persistence.

Method(s)

To run Fetch History, you can use the following method(s) in the Go SDK:

pn.Fetch().
    Channels(channels).
    Count(count).
    Start(start).
    End(end).
    IncludeMeta(bool).
    IncludeMessageType(bool).
    IncludeUUID(bool).
    IncludeMessageActions(bool).
    IncludeCustomMessageType(bool).
    Reverse(reverse).
    QueryParam(queryParam).
    Execute()

Parameter	Type	Required	Default	Description
Channels	string	Yes		Specifies channelsto return history messages. Maximum of 500 channels are allowed.
Count	int	Optional	100 or 25	Specifies the number of historical messages to return. Default and maximum value is 100 for a single channel, 25 for multiple channels, and 25 when IncludeMessageActions is true.
Start	int64	Optional		Timetoken delimiting the start of time slice (exclusive) to pull messages from.
End	int64	Optional		Timetoken delimiting the end of time slice (inclusive) to pull messages from.
IncludeMeta	bool	Optional	false	Whether meta (passed when Publishing the message) should be included in response or not.
IncludeMessageType	bool	Optional	true	Pass true to receive the message type with each history message.
IncludeUUID	bool	Optional	true	Pass true to receive the publisher uuid with each history message.
IncludeMessageActions	bool	Optional	false	Whether MessageActions should be included in response or not. If true, the method is limited to one channel and 25 messages only.
IncludeCustomMessageType	bool	Optional		Indicates whether to retrieve messages with the custom message type. For more information, refer to Retrieving Messages.
Reverse	bool	Optional	false	Setting to true will traverse the time line in reverse starting with the oldest message first.
QueryParam	map[string]string	Optional	nil	QueryParam accepts a map, the keys and values of the map are passed as the query string parameters of the URL called by the API.

Truncated response

If you fetch messages with messages actions, the number of messages in the response may be truncated when internal limits are hit. If the response is truncated, a more property will be returned with additional parameters. Send iterative calls to history adjusting the parameters to fetch more messages.

Basic Usage

Retrieve the last message on a channel:

res, status, err := pn.Fetch().
        Channels([]string{"ch1", "ch2"}).
        Count(25).
        Reverse(true).
        IncludeCustomMessageType(true).
        Execute()

Returns

Method	Type	Description
Message	interface	Message from History.
Timetoken	string	{{Timetoken}} of the message.
Meta	interface	The meta data (if sent, when publishing the message)
MessageType	number	Returns 4 for file messages.
CustomMessageType	string	The custom message type.
Uuid	string	Publisher uuid of the message.
MessageActions	map[string]PNHistoryMessageActionsTypeMap	The message reactions associated with the message. Details of type PNHistoryMessageActionsTypeMap are here

PNHistoryMessageActionsTypeMap

Property Name	Type	Description
ActionsTypeValues	map[string][]PNHistoryMessageActionTypeVal	Details of type PNHistoryMessageActionTypeVal are here

PNHistoryMessageActionTypeVal

Property Name	Type	Description
UUID	string	The UUID of the publisher.
ActionTimetoken	string	The publish timetoken of the action.

Response

Method	Type
Error	error
Category	StatusCategory
Operation	OperationType
StatusCode	int
TLSEnabled	bool
UUID	string
AuthKey	string
Origin	string
OriginalResponse	string
Request	string
AffectedChannels	[]string
AffectedChannelGroups	[]string

Delete Messages from History

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Removes the messages from the history of a specific channel.

Required setting

There is a setting to accept delete from history requests for a key, which you must enable by checking the Enable Delete-From-History checkbox in the key settings for your key in the Admin Portal.

Requires Initialization with secret key.

Method(s)

To Delete Messages from History you can use the following method(s) in the Go SDK.

pn.DeleteMessages().
    Channel(channel).
    Start(start).
    End(end).
    QueryParam(queryParam).
    Execute()

Parameter	Type	Required	Description
Channel	string	Yes	Specifies channels to delete messages from.
Start	int64	Optional	Timetoken delimiting the start of time slice (inclusive) to delete messages from.
End	int64	Optional	Timetoken delimiting the end of time slice (exclusive) to delete messages from.
QueryParam	map[string]string	Optional	QueryParam accepts a map, the keys and values of the map are passed as the query string parameters of the URL called by the API.

Basic Usage

res, status, err := pn.DeleteMessages().
        Channel("ch").
        Start(int64(15343325214676133)).
        End(int64(15343325004275466)).
        Execute()

Response

Method	Type
Error	error
Category	StatusCategory
Operation	OperationType
StatusCode	int
TLSEnabled	bool
UUID	string
AuthKey	string
Origin	string
OriginalResponse	string
Request	string
AffectedChannels	[]string
AffectedChannelGroups	[]string

Other Examples

Delete specific message from history

To delete a specific message, pass the publish timetoken (received from a successful publish) in the End parameter and timetoken +/- 1 in the Start parameter. For example, if 15526611838554310 is the publish timetoken, pass 15526611838554309 in Start and 15526611838554310 in End parameters respectively as shown in the following code snippet.

res, status, err := pn.DeleteMessages().
        Channel("ch").
        Start(int64(15526611838554309)).
        End(int64(15526611838554310)).
        Execute()

Message Counts

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Returns the number of messages published on one or more channels since a given time. The count returned is the number of messages in history with a timetoken value greater than or equal to than the passed value in the ChannelsTimetokenparameter.

Unlimited message retention

For keys with unlimited message retention enabled, this method considers only messages published in the last 30 days.

Method(s)

You can use the following method(s) in the Go SDK:

pn.MessageCounts().
    Channels(channels).
    ChannelsTimetoken(channelsTimetoken).
    QueryParam(queryParam).
    Execute()

Parameter	Type	Required	Default	Description
Channels	[]string	Yes		The channels to fetch the message count
ChannelsTimetoken	[]int64	Yes	nil	Array of timetokens, in order of the channels list. Specify a single timetoken to apply it to all channels. Otherwise, the list of timetokens must be the same length as the list of channels, or the function returns a PNStatus with an error flag.
QueryParam	map[string]string	Optional	nil	QueryParam accepts a map, the keys and values of the map are passed as the query string parameters of the URL called by the API.

Basic Usage

res, status, err := pn.MessageCounts().
        Channels([]string{"ch1", "ch2"}).
        ChannelsTimetoken([]int64{1551795013294}).
        Execute()

Returns

The MessageCounts() operation returns a MessageCountsResponse object which contains the following operations:

Method	Type	Description
Channels	map[string]int	A map of Channels with message count. Channels without messages have a count of 0. Channels with 10,000 messages or more have a count of 10000.

Status Response

Method	Type
Error	error
Category	StatusCategory
Operation	OperationType
StatusCode	int
TLSEnabled	bool
UUID	string
AuthKey	string
Origin	string
OriginalResponse	string
Request	string
AffectedChannels	[]string
AffectedChannelGroups	[]string

Other Examples

Retrieve count of messages using different timetokens for each channel

pn.MessageCounts().
        Channels([]string{ch1, ch2}).
        ChannelsTimetoken([]int64{1551795013294,155179501329433}).
        Execute()

History (deprecated)

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Alternative method

This method is deprecated. Use fetch history instead.

This function fetches historical messages of a channel.

It is possible to control how messages are returned and in what order, for example you can:

• Search for messages starting on the newest end of the timeline (default behavior - Reverse = false)
• Search for messages from the oldest end of the timeline by setting Reverse to true.
• Page through results by providing a Start OR End timetoken.
• Retrieve a slice of the time line by providing both a Start AND End timetoken.
• Limit the number of messages to a specific quantity using the Count parameter.

Start & End parameter usage clarity

If only the Start parameter is specified (without End), you will receive messages that are older than and up to that Start timetoken value. If only the End parameter is specified (without Start) you will receive messages that match that End timetoken value and newer. Specifying values for both Start and End parameters will return messages between those timetoken values (inclusive on the End value). Keep in mind that you will still receive a maximum of 100 messages even if there are more messages that meet the timetoken values. Iterative calls to history adjusting the Start timetoken is necessary to page through the full set of results if more than 100 messages meet the timetoken values.

Method(s)

To run History you can use the following method(s) in the Go SDK:

pn.History().
    Channel(string).
    Reverse(bool).
    IncludeTimetoken(bool).
    IncludeMeta(bool).
    Start(int64).
    End(int64).
    Count(int).
    QueryParam(queryParam).
    Execute()

Parameter	Type	Required	Default	Description
Channel	string	True		Specifies channel to return history messages from.
Reverse	bool	Optional	false	Setting to true will traverse the time line in reverse starting with the oldest message first.
IncludeTimetoken	bool	Optional	false	Whether event dates timetokens should be included in response or not.
IncludeMeta	bool	Optional	false	Whether meta (passed when Publishing the message) should be included in response or not.
Start	int64	Optional		Timetoken delimiting the start of time slice (exclusive) to pull messages from.
End	int64	Optional		Timetoken delimiting the end of time slice (inclusive) to pull messages from.
Count	int	Optional	100	Specifies the number of historical messages to return.
QueryParam	map[string]string	Optional	nil	QueryParam accepts a map, the keys and values of the map are passed as the query string parameters of the URL called by the API.

tip

Using the reverse parameter

Messages are always returned sorted in ascending time direction from history regardless of Reverse. The Reverse direction matters when you have more than 100 (or Count, if it's set) messages in the time interval, in which case Reverse determines the end of the time interval from which it should start retrieving the messages.

Basic Usage

Retrieve the last 100 messages on a channel:

res, status, err := pn.History().
    Channel("history_channel"). // where to fetch history from
    Count(). // how many items to fetch
    Execute()

fmt.Println(res, status, err)

Response

The History() operation returns a PNHistoryResult which contains the following operations:

Method	Type	Description
Messages	[]HistoryResponseItem	array of messages of type PNHistoryItemResult. See PNHistoryItemResult for more details.
StartTimetoken	int64	Start timetoken.
EndTimetoken	int64	End timetoken.

PNHistoryItemResult

Method	Type	Description
Timetoken	int64	Timetoken of the message.
Message	interface	The Message.
Meta	interface	The meta data (if sent, when publishing the message).

Other Examples

Use History() to retrieve the three oldest messages by retrieving from the time line in reverse

res, status, err := pn.History().
    Channel("my-ch"). // where to fetch history from
    Count(3). // how many items to fetch
    Reverse(true). // should go in reverse?
    Execute()

Response

for _, v := range res.Messages {
    fmt.Println(v.Entry) // custom JSON structure for message
}

Use History() to retrieve messages newer than a given timetoken by paging from oldest message to newest message starting at a single point in time (exclusive)

res, status, err := pn.History().
    Channel("my-ch"). // where to fetch history from
    Start(int64(13847168620721752)). // first timestamp
    Reverse(true). // should go in reverse?
    Execute()

Response

for _, v := range res.Messages {
    fmt.Println(v.Entry) // custom JSON structure for message
}

Use History() to retrieve messages until a given timetoken by paging from newest message to oldest message until a specific end point in time (inclusive)

res, status, err := pn.History().
    Channel("my-ch"). // where to fetch history from
    Count(100).
    Start(int64(-1)). // first timestamp
    End(int64(13847168819178600)). // last timestamp
    Reverse(true). // should go in reverse?
    Execute()

Response

for _, v := range res.Messages {
    fmt.Println(v.Entry) // custom JSON structure for message
}

History Paging Example

func getAllMessages(startTT int64) {
    res, _, _ := pn.History().
        Channel("history_channel").
        Count(2).
        Execute()

    msgs := res.Messages
    start := res.StartTimetoken
    end := res.EndTimetoken

    if len(msgs) > 0 {
        fmt.Println(len(msgs))
        fmt.Println("start " + strconv.Itoa(int(start)))
        fmt.Println("end " + strconv.Itoa(int(end)))
    }

show all 22 lines

Include timetoken in history response

res, status, status := pn.History().
    Channel("history_channel").
    Count(100).
    IncludeTimetoken(true).
    Execute()

fmt.Println(res, status, err)