+MqttPersistable (MQTT v3 Client API) +

From cc8ace92f17c8e5aef7d68ff316e5cd038cd36b5 Mon Sep 17 00:00:00 2001 From: Nathan Lasseter Date: Wed, 22 May 2013 15:34:00 +0100 Subject: Initial Commit --- .../paho/client/mqttv3/MqttPersistable.html | 387 +++++++++++++++++++++ 1 file changed, 387 insertions(+) create mode 100644 libs/org.eclipse.paho.client.mqttv3/org/eclipse/paho/client/mqttv3/MqttPersistable.html (limited to 'libs/org.eclipse.paho.client.mqttv3/org/eclipse/paho/client/mqttv3/MqttPersistable.html') diff --git a/libs/org.eclipse.paho.client.mqttv3/org/eclipse/paho/client/mqttv3/MqttPersistable.html b/libs/org.eclipse.paho.client.mqttv3/org/eclipse/paho/client/mqttv3/MqttPersistable.html new file mode 100644 index 0000000..153e026 --- /dev/null +++ b/libs/org.eclipse.paho.client.mqttv3/org/eclipse/paho/client/mqttv3/MqttPersistable.html @@ -0,0 +1,387 @@ + + + + + + +MqttPersistable (MQTT v3 Client API) + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

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+ +org.eclipse.paho.client.mqttv3 +
+Interface MqttPersistable

public interface MqttPersistable

+ +

+Represents an object used to pass data to be persisted across the + MqttClientPersistence + interface. +

+ When data is passed across the interface the header and payload are + separated, so that unnecessary message copies may be avoided. + For example, if a 10 MB payload was published it would be inefficient + to create a byte array a few bytes larger than 10 MB and copy the + MQTT message header and payload into a contiguous byte array.

+ When the request to persist data is made a separate byte array and offset + is passed for the header and payload. Only the data between + offset and length need be persisted. + So for example, a message to be persisted consists of a header byte + array starting at offset 1 and length 4, plus a payload byte array + starting at offset 30 and length 40000. There are three ways in which + the persistence implementation may return data to the client on + recovery: +

It could return the data as it was passed in + originally, with the same byte arrays and offsets.
It could safely just persist and return the bytes from the offset + for the specified length. For example, return a header byte array with + offset 0 and length 4, plus a payload byte array with offset 0 and length + 40000
It could return the header and payload as a contiguous byte array + with the header bytes preceeding the payload. The contiguous byte array + should be set as the header byte array, with the payload byte array being + null. For example, return a single byte array with offset 0 + and length 40004. + This is useful when recovering from a file where the header and payload + could be written as a contiguous stream of bytes.

+ +

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+Method Summary
+ byte[] getHeaderBytes() + +
+          Returns the header bytes in an array. +
+ int getHeaderLength() + +
+          Returns the length of the header.
+ int getHeaderOffset() + +
+          Returns the offset of the header within the byte array returned by getHeaderBytes().
+ byte[] getPayloadBytes() + +
+          Returns the payload bytes in an array. +
+ int getPayloadLength() + +
+          Returns the length of the payload.
+ int getPayloadOffset() + +
+          Returns the offset of the payload within the byte array returned by getPayloadBytes().
+ +

+Method Summary
+ `byte[]`	`getHeaderBytes()` + + + Returns the header bytes in an array. +
+ `int`	`getHeaderLength()` + + + Returns the length of the header.
+ `int`	`getHeaderOffset()` + + + Returns the offset of the header within the byte array returned by `getHeaderBytes()`.
+ `byte[]`	`getPayloadBytes()` + + + Returns the payload bytes in an array. +
+ `int`	`getPayloadLength()` + + + Returns the length of the payload.
+ `int`	`getPayloadOffset()` + + + Returns the offset of the payload within the byte array returned by `getPayloadBytes()`.

+ + + + + + + + + + + + + + +
+Method Detail
+ +

+getHeaderBytes

+public byte[] getHeaderBytes()
+                      throws MqttPersistenceException

Returns the header bytes in an array. + The bytes start at getHeaderOffset() + and continue for getHeaderLength(). +

Returns:: the header bytes. +
Throws: +: MqttPersistenceException

+ +

+getHeaderLength

+public int getHeaderLength()
+                    throws MqttPersistenceException

Returns the length of the header. +

Returns:: the header length +
Throws: +: MqttPersistenceException

+ +

+getHeaderOffset

+public int getHeaderOffset()
+                    throws MqttPersistenceException

Returns the offset of the header within the byte array returned by getHeaderBytes(). +

Returns:: the header offset. +
Throws: +: MqttPersistenceException

+ +

+getPayloadBytes

+public byte[] getPayloadBytes()
+                       throws MqttPersistenceException

Returns the payload bytes in an array. + The bytes start at getPayloadOffset() + and continue for getPayloadLength(). +

Returns:: the payload bytes. +
Throws: +: MqttPersistenceException

+ +

+getPayloadLength

+public int getPayloadLength()
+                     throws MqttPersistenceException

Returns the length of the payload. +

Returns:: the payload length. +
Throws: +: MqttPersistenceException

+ +

+getPayloadOffset

+public int getPayloadOffset()
+                     throws MqttPersistenceException

Returns the offset of the payload within the byte array returned by getPayloadBytes(). +

Returns:: the payload offset. +
Throws: +: MqttPersistenceException

+ +

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