com.digi.xbee.api.models.XBeePacketsQueue Maven / Gradle / Ivy
/**
* Copyright 2017, Digi International Inc.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at http://mozilla.org/MPL/2.0/.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package com.digi.xbee.api.models;
import java.net.Inet4Address;
import java.util.LinkedList;
import com.digi.xbee.api.RemoteXBeeDevice;
import com.digi.xbee.api.packet.APIFrameType;
import com.digi.xbee.api.packet.XBeeAPIPacket;
import com.digi.xbee.api.packet.XBeePacket;
import com.digi.xbee.api.packet.common.ExplicitRxIndicatorPacket;
import com.digi.xbee.api.packet.common.ReceivePacket;
import com.digi.xbee.api.packet.common.RemoteATCommandResponsePacket;
import com.digi.xbee.api.packet.ip.RXIPv4Packet;
import com.digi.xbee.api.packet.raw.RX16IOPacket;
import com.digi.xbee.api.packet.raw.RX16Packet;
import com.digi.xbee.api.packet.raw.RX64IOPacket;
import com.digi.xbee.api.packet.raw.RX64Packet;
/**
* This class represents a queue of XBee packets used for sequential packets
* reading within the XBee Java API.
*
* The class provides some methods to get specific packet types from
* different source nodes.
*
* @see com.digi.xbee.api.packet.XBeePacket
*/
public class XBeePacketsQueue {
// Constants.
/**
* Default maximum number of packets to store in the queue
* (value: {@value}).
*/
public static final int DEFAULT_MAX_LENGTH = 50;
// Variables.
private int maxLength = DEFAULT_MAX_LENGTH;
private LinkedList packetsList;
private Object lock = new Object();
/**
* Class constructor. Instantiates a new object of type
* {@code XBeePacketsQueue}.
*/
public XBeePacketsQueue() {
this(DEFAULT_MAX_LENGTH);
}
/**
* Class constructor. Instantiates a new object of type
* {@code XBeePacketsQueue} with the given maximum length.
*
* @param maxLength Maximum length of the queue.
*
* @throws IllegalArgumentException if {@code maxLength < 1}.
*/
public XBeePacketsQueue(int maxLength) {
if (maxLength < 1)
throw new IllegalArgumentException("Queue length must be greater than 0.");
this.maxLength = maxLength;
packetsList = new LinkedList();
}
/**
* Adds the provided packet to the list of packets. If the queue is full
* the first packet will be discarded to add the given one.
*
* @param xbeePacket The XBee packet to be added to the list.
*
* @see com.digi.xbee.api.packet.XBeePacket
*/
public void addPacket(XBeePacket xbeePacket) {
synchronized (lock) {
if (packetsList.size() == maxLength)
packetsList.removeFirst();
packetsList.add(xbeePacket);
}
}
/**
* Clears the list of packets.
*/
public void clearQueue() {
synchronized (lock) {
packetsList.clear();
}
}
/**
* Returns the first packet from the queue waiting up to the specified
* timeout if necessary for an XBee packet to become available.
* {@code null }if the queue is empty.
*
* @param timeout The time in milliseconds to wait for an XBee packet to
* become available. 0 to return immediately.
* @return The first packet from the queue, {@code null} if it is empty.
*
* @see com.digi.xbee.api.packet.XBeePacket
*/
public XBeePacket getFirstPacket(int timeout) {
if (timeout > 0) {
XBeePacket xbeePacket = getFirstPacket(0);
// Wait for a timeout or until an XBee packet is read.
Long deadLine = System.currentTimeMillis() + timeout;
while (xbeePacket == null && deadLine > System.currentTimeMillis()) {
sleep(100);
xbeePacket = getFirstPacket(0);
}
return xbeePacket;
}
synchronized (lock) {
if (!packetsList.isEmpty())
return packetsList.pop();
}
return null;
}
/**
* Returns the first packet from the queue whose 64-bit source address
* matches the address of the provided remote XBee device.
*
* The methods waits up to the specified timeout if necessary for an
* XBee packet to become available. Null if the queue is empty or there is
* not any XBee packet sent by the provided remote XBee device.
*
* @param remoteXBeeDevice The remote XBee device containing the 64-bit
* address to look for in the list of packets.
* @param timeout The time in milliseconds to wait for an XBee packet from
* the specified remote XBee device to become available.
* 0 to return immediately.
*
* @return The first XBee packet whose 64-bit address matches the address
* of the provided remote XBee device. {@code null} if no packets
* from the specified XBee device are found in the queue.
*
* @see com.digi.xbee.api.RemoteXBeeDevice
* @see com.digi.xbee.api.packet.XBeePacket
*/
public XBeePacket getFirstPacketFrom(RemoteXBeeDevice remoteXBeeDevice, int timeout) {
if (timeout > 0) {
XBeePacket xbeePacket = getFirstPacketFrom(remoteXBeeDevice, 0);
// Wait for a timeout or until an XBee packet from remoteXBeeDevice is read.
Long deadLine = System.currentTimeMillis() + timeout;
while (xbeePacket == null && deadLine > System.currentTimeMillis()) {
sleep(100);
xbeePacket = getFirstPacketFrom(remoteXBeeDevice, 0);
}
return xbeePacket;
} else {
synchronized (lock) {
for (int i = 0; i < packetsList.size(); i++) {
XBeePacket xbeePacket = packetsList.get(i);
if (addressesMatch(xbeePacket, remoteXBeeDevice))
return packetsList.remove(i);
}
}
}
return null;
}
/**
* Returns the first data packet from the queue waiting up to the
* specified timeout if necessary for an XBee data packet to become
* available. {@code null} if the queue is empty or there is not any data
* packet inside.
*
* @param timeout The time in milliseconds to wait for an XBee data packet
* to become available. 0 to return immediately.
*
* @return The first data packet from the queue, {@code null} if it is
* empty or no data packets are contained in the queue.
*
* @see com.digi.xbee.api.packet.XBeePacket
*/
public XBeePacket getFirstDataPacket(int timeout) {
if (timeout > 0) {
XBeePacket xbeePacket = getFirstDataPacket(0);
// Wait for a timeout or until a data XBee packet is read.
Long deadLine = System.currentTimeMillis() + timeout;
while (xbeePacket == null && deadLine > System.currentTimeMillis()) {
sleep(100);
xbeePacket = getFirstDataPacket(0);
}
return xbeePacket;
} else {
synchronized (lock) {
for (int i = 0; i < packetsList.size(); i++) {
XBeePacket xbeePacket = packetsList.get(i);
if (isDataPacket(xbeePacket))
return packetsList.remove(i);
}
}
}
return null;
}
/**
* Returns the first data packet from the queue whose 64-bit source
* address matches the address of the provided remote XBee device.
*
* The methods waits up to the specified timeout if necessary for an
* XBee data packet to become available. {@code null} if the queue is
* empty or there is not any XBee data packet sent by the provided remote
* XBee device.
*
* @param remoteXBeeDevice The XBee device containing the 64-bit address
* to look for in the list of packets.
* @param timeout The time in milliseconds to wait for an XBee data packet
* from the specified remote XBee device to become
* available. 0 to return immediately.
*
* @return The first XBee data packet whose its 64-bit address matches the
* address of the provided remote XBee device. {@code null} if no
* data packets from the specified XBee device are found in the
* queue.
*
* @see com.digi.xbee.api.RemoteXBeeDevice
* @see com.digi.xbee.api.packet.XBeePacket
*/
public XBeePacket getFirstDataPacketFrom(RemoteXBeeDevice remoteXBeeDevice, int timeout) {
if (timeout > 0) {
XBeePacket xbeePacket = getFirstDataPacketFrom(remoteXBeeDevice, 0);
// Wait for a timeout or until an XBee packet from remoteXBeeDevice is read.
Long deadLine = System.currentTimeMillis() + timeout;
while (xbeePacket == null && deadLine > System.currentTimeMillis()) {
sleep(100);
xbeePacket = getFirstDataPacketFrom(remoteXBeeDevice, 0);
}
return xbeePacket;
} else {
synchronized (lock) {
for (int i = 0; i < packetsList.size(); i++) {
XBeePacket xbeePacket = packetsList.get(i);
if (isDataPacket(xbeePacket) && addressesMatch(xbeePacket, remoteXBeeDevice))
return packetsList.remove(i);
}
}
}
return null;
}
/**
* Returns the first explicit data packet from the queue waiting up to the
* specified timeout if necessary for an XBee explicit data packet to
* become available. {@code null} if the queue is empty or there is not
* any explicit data packet inside.
*
* @param timeout The time in milliseconds to wait for an XBee explicit
* data packet to become available. 0 to return immediately.
*
* @return The first explicit data packet from the queue, {@code null} if
* it is empty or no data packets are contained in the queue.
*
* @see com.digi.xbee.api.packet.XBeePacket
* @see com.digi.xbee.api.packet.common.ExplicitRxIndicatorPacket
*/
public XBeePacket getFirstExplicitDataPacket(int timeout) {
if (timeout > 0) {
XBeePacket xbeePacket = getFirstExplicitDataPacket(0);
// Wait for a timeout or until an explicit data XBee packet is read.
Long deadLine = System.currentTimeMillis() + timeout;
while (xbeePacket == null && deadLine > System.currentTimeMillis()) {
sleep(100);
xbeePacket = getFirstExplicitDataPacket(0);
}
return xbeePacket;
} else {
synchronized (lock) {
for (int i = 0; i < packetsList.size(); i++) {
XBeePacket xbeePacket = packetsList.get(i);
if (isExplicitDataPacket(xbeePacket))
return packetsList.remove(i);
}
}
}
return null;
}
/**
* Returns the first explicit data packet from the queue whose 64-bit
* source address matches the address of the provided remote XBee device.
*
* The methods waits up to the specified timeout if necessary for an
* XBee explicit data packet to become available. {@code null} if the
* queue is empty or there is not any XBee explicit data packet sent by
* the provided remote XBee device.
*
* @param remoteXBeeDevice The XBee device containing the 64-bit address
* to look for in the list of packets.
* @param timeout The time in milliseconds to wait for an XBee explicit
* data packet from the specified remote XBee device to
* become available. 0 to return immediately.
*
* @return The first XBee explicit data packet whose its 64-bit address
* matches the address of the provided remote XBee device.
* {@code null} if no explicit data packets from the specified
* XBee device are found in the queue.
*
* @see com.digi.xbee.api.RemoteXBeeDevice
* @see com.digi.xbee.api.packet.XBeePacket
* @see com.digi.xbee.api.packet.common.ExplicitRxIndicatorPacket
*/
public XBeePacket getFirstExplicitDataPacketFrom(RemoteXBeeDevice remoteXBeeDevice, int timeout) {
if (timeout > 0) {
XBeePacket xbeePacket = getFirstExplicitDataPacketFrom(remoteXBeeDevice, 0);
// Wait for a timeout or until an XBee explicit data packet from remoteXBeeDevice is read.
Long deadLine = System.currentTimeMillis() + timeout;
while (xbeePacket == null && deadLine > System.currentTimeMillis()) {
sleep(100);
xbeePacket = getFirstExplicitDataPacketFrom(remoteXBeeDevice, 0);
}
return xbeePacket;
} else {
synchronized (lock) {
for (int i = 0; i < packetsList.size(); i++) {
XBeePacket xbeePacket = packetsList.get(i);
if (isExplicitDataPacket(xbeePacket) && addressesMatch(xbeePacket, remoteXBeeDevice))
return packetsList.remove(i);
}
}
}
return null;
}
/**
* Returns the first IP data packet from the queue waiting up to the
* specified timeout if necessary for a IP data packet to
* become available. {@code null} if the queue is empty or there is not
* any IP data packet inside.
*
* @param timeout The time in milliseconds to wait for a IP data
* packet to become available. 0 to return immediately.
*
* @return The first IP data packet from the queue, {@code null} if
* it is empty or no IP packets are contained in the queue.
*
* @see com.digi.xbee.api.packet.XBeePacket
* @see com.digi.xbee.api.packet.ip.RXIPv4Packet
*
* @since 1.2.0
*/
public XBeePacket getFirstIPDataPacket(int timeout) {
if (timeout > 0) {
XBeePacket xbeePacket = getFirstIPDataPacket(0);
// Wait for a timeout or until a IP data packet is read.
Long deadLine = System.currentTimeMillis() + timeout;
while (xbeePacket == null && deadLine > System.currentTimeMillis()) {
sleep(100);
xbeePacket = getFirstIPDataPacket(0);
}
return xbeePacket;
} else {
synchronized (lock) {
for (int i = 0; i < packetsList.size(); i++) {
XBeePacket xbeePacket = packetsList.get(i);
if (isIPDataPacket(xbeePacket))
return packetsList.remove(i);
}
}
}
return null;
}
/**
* Returns the first IP data packet from the queue whose IP address
* matches the provided address.
*
* The methods waits up to the specified timeout if necessary for a
* IP data packet to become available. {@code null} if the
* queue is empty or there is not any IP data packet sent by
* the provided IP address.
*
* @param ipAddress The IP address to look for in the list of packets.
* @param timeout The time in milliseconds to wait for a IP data
* packet from the specified IP address to become available.
* 0 to return immediately.
*
* @return The first IP packet whose IP address matches the provided
* IP address. {@code null} if no IP data packets from the
* specified IP address are found in the queue.
*
* @see com.digi.xbee.api.packet.XBeePacket
* @see com.digi.xbee.api.packet.ip.RXIPv4Packet
* @see java.net.Inet4Address
*
* @since 1.2.0
*/
public XBeePacket getFirstIPDataPacketFrom(Inet4Address ipAddress, int timeout) {
if (timeout > 0) {
XBeePacket xbeePacket = getFirstIPDataPacketFrom(ipAddress, 0);
// Wait for a timeout or until a IP data packet with the provided IP address is read.
Long deadLine = System.currentTimeMillis() + timeout;
while (xbeePacket == null && deadLine > System.currentTimeMillis()) {
sleep(100);
xbeePacket = getFirstIPDataPacketFrom(ipAddress, 0);
}
return xbeePacket;
} else {
synchronized (lock) {
for (int i = 0; i < packetsList.size(); i++) {
XBeePacket xbeePacket = packetsList.get(i);
if (isIPDataPacket(xbeePacket) && ipAddressesMatch(xbeePacket, ipAddress))
return packetsList.remove(i);
}
}
}
return null;
}
/**
* Returns whether or not the source address of the provided XBee packet
* matches the address of the given remote XBee device.
*
* @param xbeePacket The XBee packet to compare its address with the
* remote XBee device.
* @param remoteXBeeDevice The remote XBee device to compare its address
* with the XBee packet.
*
* @return {@code true} if the source address of the provided packet (if
* it has) matches the address of the remote XBee device.
*
* @see com.digi.xbee.api.RemoteXBeeDevice
* @see com.digi.xbee.api.packet.XBeePacket
*/
private boolean addressesMatch(XBeePacket xbeePacket, RemoteXBeeDevice remoteXBeeDevice) {
if (!(xbeePacket instanceof XBeeAPIPacket))
return false;
APIFrameType packetType = ((XBeeAPIPacket)xbeePacket).getFrameType();
switch (packetType) {
case RECEIVE_PACKET:
if (remoteXBeeDevice.get64BitAddress() != null && ((ReceivePacket)xbeePacket).get64bitSourceAddress().equals(remoteXBeeDevice.get64BitAddress()))
return true;
if (remoteXBeeDevice.get16BitAddress() != null && ((ReceivePacket)xbeePacket).get16bitSourceAddress().equals(remoteXBeeDevice.get16BitAddress()))
return true;
break;
case REMOTE_AT_COMMAND_RESPONSE:
if (remoteXBeeDevice.get64BitAddress() != null && ((RemoteATCommandResponsePacket)xbeePacket).get64bitSourceAddress().equals(remoteXBeeDevice.get64BitAddress()))
return true;
if (remoteXBeeDevice.get16BitAddress() != null && ((RemoteATCommandResponsePacket)xbeePacket).get16bitSourceAddress().equals(remoteXBeeDevice.get16BitAddress()))
return true;
break;
case RX_16:
if (((RX16Packet)xbeePacket).get16bitSourceAddress().equals(remoteXBeeDevice.get16BitAddress()))
return true;
break;
case RX_64:
if (((RX64Packet)xbeePacket).get64bitSourceAddress().equals(remoteXBeeDevice.get64BitAddress()))
return true;
break;
case RX_IO_16:
if (((RX16IOPacket)xbeePacket).get16bitSourceAddress().equals(remoteXBeeDevice.get16BitAddress()))
return true;
break;
case RX_IO_64:
if (((RX64IOPacket)xbeePacket).get64bitSourceAddress().equals(remoteXBeeDevice.get64BitAddress()))
return true;
break;
case EXPLICIT_RX_INDICATOR:
if (((ExplicitRxIndicatorPacket)xbeePacket).get64BitSourceAddress().equals(remoteXBeeDevice.get64BitAddress()))
return true;
break;
default:
return false;
}
return false;
}
/**
* Returns whether or not the IP address of the XBee packet matches the
* provided one.
*
* @param xbeePacket The XBee packet to compare its IP address with the
* provided one.
* @param ipAddress The IP address to be compared with the XBee packet's one.
*
* @return {@code true} if the IP address of the XBee packet (if it has)
* matches the provided one. {@code false} otherwise.
*
* @see com.digi.xbee.api.packet.XBeePacket
* @see java.net.Inet4Address
*
* @since 1.2.0
*/
private boolean ipAddressesMatch(XBeePacket xbeePacket, Inet4Address ipAddress) {
if (xbeePacket == null || ipAddress == null
|| !(xbeePacket instanceof XBeeAPIPacket))
return false;
APIFrameType packetType = ((XBeeAPIPacket)xbeePacket).getFrameType();
switch (packetType) {
case RX_IPV4:
if (((RXIPv4Packet)xbeePacket).getSourceAddress().equals(ipAddress))
return true;
break;
default:
return false;
}
return false;
}
/**
* Returns whether or not the given XBee packet is a data packet.
*
* @param xbeePacket The XBee packet to check if is data packet.
*
* @return {@code true} if the XBee packet is a data packet, {@code false}
* otherwise.
*
* @see com.digi.xbee.api.packet.XBeePacket
*/
private boolean isDataPacket(XBeePacket xbeePacket) {
if (!(xbeePacket instanceof XBeeAPIPacket))
return false;
APIFrameType packetType = ((XBeeAPIPacket)xbeePacket).getFrameType();
switch (packetType) {
case RECEIVE_PACKET:
case RX_16:
case RX_64:
return true;
default:
return false;
}
}
/**
* Returns whether or not the given XBee packet is an explicit data packet.
*
* @param xbeePacket The XBee packet to check if is an explicit data packet.
*
* @return {@code true} if the XBee packet is an explicit data packet,
* {@code false} otherwise.
*
* @see com.digi.xbee.api.packet.XBeePacket
* @see com.digi.xbee.api.packet.common.ExplicitRxIndicatorPacket
*/
private boolean isExplicitDataPacket(XBeePacket xbeePacket) {
if (!(xbeePacket instanceof XBeeAPIPacket))
return false;
APIFrameType packetType = ((XBeeAPIPacket)xbeePacket).getFrameType();
return packetType == APIFrameType.EXPLICIT_RX_INDICATOR;
}
/**
* Returns whether or not the given XBee packet is a IP data packet.
*
* @param xbeePacket The XBee packet to check if is a IP data packet.
*
* @return {@code true} if the XBee packet is a IP data packet,
* {@code false} otherwise.
*
* @see com.digi.xbee.api.packet.XBeePacket
* @see com.digi.xbee.api.packet.ip.RXIPv4Packet
*
* @since 1.2.0
*/
private boolean isIPDataPacket(XBeePacket xbeePacket) {
if (!(xbeePacket instanceof XBeeAPIPacket))
return false;
APIFrameType packetType = ((XBeeAPIPacket)xbeePacket).getFrameType();
return packetType == APIFrameType.RX_IPV4;
}
/**
* Sleeps the thread for the given number of milliseconds.
*
* @param milliseconds The number of milliseconds that the thread should
* be sleeping.
*/
private void sleep(int milliseconds) {
try {
Thread.sleep(milliseconds);
} catch (InterruptedException e) { }
}
/**
* Returns the maximum size of the XBee packets queue.
*
* @return The maximum size of the XBee packets queue.
*/
public int getMaxSize() {
return maxLength;
}
/**
* Returns the current size of the XBee packets queue.
*
* @return The current size of the XBee packets queue.
*/
public int getCurrentSize() {
synchronized (lock) {
return packetsList.size();
}
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy