Diff: src/MQTTCommon/MQTTSubscribeClient.c

Revision:

0:09ef59d2d0f7

Child:

22:0dbabcc6e7b2

diff -r 000000000000 -r 09ef59d2d0f7 src/MQTTCommon/MQTTSubscribeClient.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/MQTTCommon/MQTTSubscribeClient.c	Fri Oct 07 17:21:45 2016 +0000
@@ -0,0 +1,132 @@
+/*******************************************************************************
+ * Copyright (c) 2014 IBM Corp.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ *
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *   http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * Contributors:
+ *    Ian Craggs - initial API and implementation and/or initial documentation
+ *******************************************************************************/
+
+#include "MQTTPacket.h"
+
+#include <string.h>
+
+/**
+  * Determines the length of the MQTT subscribe packet that would be produced using the supplied parameters
+  * @param count the number of topic filter strings in topicFilters
+  * @param topicFilters the array of topic filter strings to be used in the publish
+  * @return the length of buffer needed to contain the serialized version of the packet
+  */
+int MQTTSerialize_subscribeLength(int count, MQTTString topicFilters[])
+{
+	int i;
+	int len = 2; /* packetid */
+
+	for (i = 0; i < count; ++i)
+		len += 2 + MQTTstrlen(topicFilters[i]) + 1; /* length + topic + req_qos */
+	return len;
+}
+
+
+/**
+  * Serializes the supplied subscribe data into the supplied buffer, ready for sending
+  * @param buf the buffer into which the packet will be serialized
+  * @param buflen the length in bytes of the supplied bufferr
+  * @param dup integer - the MQTT dup flag
+  * @param packetid integer - the MQTT packet identifier
+  * @param count - number of members in the topicFilters and reqQos arrays
+  * @param topicFilters - array of topic filter names
+  * @param requestedQoSs - array of requested QoS
+  * @return the length of the serialized data.  <= 0 indicates error
+  */
+int MQTTSerialize_subscribe(unsigned char* buf, int buflen, unsigned char dup, unsigned short packetid, int count,
+		MQTTString topicFilters[], int requestedQoSs[])
+{
+	unsigned char *ptr = buf;
+	MQTTHeader header = {0};
+	int rem_len = 0;
+	int rc = 0;
+	int i = 0;
+
+	if (MQTTPacket_len(rem_len = MQTTSerialize_subscribeLength(count, topicFilters)) > buflen)
+	{
+		rc = MQTTPACKET_BUFFER_TOO_SHORT;
+		goto exit;
+	}
+
+	header.byte = 0;
+	header.bits.type = SUBSCRIBE_MSG;
+	header.bits.dup = dup;
+	header.bits.qos = 1;
+	writeChar(&ptr, header.byte); /* write header */
+
+	ptr += MQTTPacket_encode(ptr, rem_len); /* write remaining length */;
+
+	writeInt(&ptr, packetid);
+
+	for (i = 0; i < count; ++i)
+	{
+		writeMQTTString(&ptr, topicFilters[i]);
+		writeChar(&ptr, requestedQoSs[i]);
+	}
+
+	rc = ptr - buf;
+exit:
+	return rc;
+}
+
+
+
+/**
+  * Deserializes the supplied (wire) buffer into suback data
+  * @param packetid returned integer - the MQTT packet identifier
+  * @param maxcount - the maximum number of members allowed in the grantedQoSs array
+  * @param count returned integer - number of members in the grantedQoSs array
+  * @param grantedQoSs returned array of integers - the granted qualities of service
+  * @param buf the raw buffer data, of the correct length determined by the remaining length field
+  * @param buflen the length in bytes of the data in the supplied buffer
+  * @return error code.  1 is success, 0 is failure
+  */
+int MQTTDeserialize_suback(unsigned short* packetid, int maxcount, int* count, int grantedQoSs[], unsigned char* buf, int buflen)
+{
+	MQTTHeader header = {0};
+	unsigned char* curdata = buf;
+	unsigned char* enddata = NULL;
+	int rc = 0;
+	int mylen;
+
+	header.byte = readChar(&curdata);
+	if (header.bits.type != SUBACK_MSG)
+		goto exit;
+
+	curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
+	enddata = curdata + mylen;
+	if (enddata - curdata < 2)
+		goto exit;
+
+	*packetid = readInt(&curdata);
+
+	*count = 0;
+	while (curdata < enddata)
+	{
+		if (*count > maxcount)
+		{
+			rc = -1;
+			goto exit;
+		}
+		grantedQoSs[(*count)++] = readChar(&curdata);
+	}
+
+	rc = 1;
+exit:
+	return rc;
+}
+
+