Support dynamically allocated signaling payload

 - We end up allocating `MAX_SIGNALING_MESSAGE_LEN` per signaling message received.
 - Not needed, and we can chose to do this allocation dynamically.
 - For memory constrained devices, this is a huge deal. and would reduce(~couple of 100KBs of) peak memory usage.

Author: vikramdattu

samples/Common.c

@@ -1410,6 +1410,9 @@ STATUS submitPendingIceCandidate(PPendingMessageQueue pPendingMessageQueue, PSam
             if (pReceivedSignalingMessage->signalingMessage.messageType == SIGNALING_MESSAGE_TYPE_ICE_CANDIDATE) {
                 CHK_STATUS(handleRemoteCandidate(pSampleStreamingSession, &pReceivedSignalingMessage->signalingMessage));
             }
+#ifdef DYNAMIC_SIGNALING_PAYLOAD
+            SAFE_MEMFREE(pReceivedSignalingMessage->signalingMessage.payload);
+#endif
             SAFE_MEMFREE(pReceivedSignalingMessage);
         }
     } while (!noPendingSignalingMessageForClient);
@@ -1418,6 +1421,11 @@ STATUS submitPendingIceCandidate(PPendingMessageQueue pPendingMessageQueue, PSam
 
 CleanUp:
 
+#ifdef DYNAMIC_SIGNALING_PAYLOAD
+    if (pReceivedSignalingMessage) {
+        SAFE_MEMFREE(pReceivedSignalingMessage->signalingMessage.payload);
+    }
+#endif
     SAFE_MEMFREE(pReceivedSignalingMessage);
     CHK_LOG_ERR(retStatus);
     return retStatus;
@@ -1539,6 +1547,12 @@ STATUS signalingMessageReceived(UINT64 customData, PReceivedSignalingMessage pRe
 
                 *pReceivedSignalingMessageCopy = *pReceivedSignalingMessage;
 
+#ifdef DYNAMIC_SIGNALING_PAYLOAD
+                pReceivedSignalingMessageCopy->signalingMessage.payload = (PCHAR) MEMALLOC(pReceivedSignalingMessage->signalingMessage.payloadLen);
+                CHK(pReceivedSignalingMessageCopy->signalingMessage.payload != NULL, STATUS_NOT_ENOUGH_MEMORY);
+                MEMCPY(pReceivedSignalingMessageCopy->signalingMessage.payload, pReceivedSignalingMessage->signalingMessage.payload, pReceivedSignalingMessage->signalingMessage.payloadLen);
+#endif
+
                 CHK_STATUS(stackQueueEnqueue(pPendingMessageQueue->messageQueue, (UINT64) pReceivedSignalingMessageCopy));
 
                 // NULL the pointers to not free any longer
@@ -1571,6 +1585,11 @@ STATUS signalingMessageReceived(UINT64 customData, PReceivedSignalingMessage pRe
 
 CleanUp:
 
+#ifdef DYNAMIC_SIGNALING_PAYLOAD
+    if (pReceivedSignalingMessageCopy) {
+        SAFE_MEMFREE(pReceivedSignalingMessageCopy->signalingMessage.payload);
+    }
+#endif
     SAFE_MEMFREE(pReceivedSignalingMessageCopy);
     if (pPendingMessageQueue != NULL) {
         freeMessageQueue(pPendingMessageQueue);

src/include/com/amazonaws/kinesis/video/webrtcclient/Include.h

@@ -1262,6 +1262,15 @@ typedef struct {
                                                               //!<
 } RtcIceCandidateInit, *PRtcIceCandidateInit;
 
+/**
+ * @brief Define this macro to use dynamically allocated payload in SignalingMessage
+ * This can be useful for platforms with limited memory as it avoids allocating
+ * MAX_SIGNALING_MESSAGE_LEN for each message when only a small payload is needed
+ */
+#ifndef DYNAMIC_SIGNALING_PAYLOAD
+#define DYNAMIC_SIGNALING_PAYLOAD   1
+#endif
+
 /**
  * @brief Structure defining the basic signaling message
  */
@@ -1276,7 +1285,11 @@ typedef struct {
 
     UINT32 payloadLen; //!< Optional payload length. If 0, the length will be calculated
 
+#ifdef DYNAMIC_SIGNALING_PAYLOAD
+    PCHAR payload; //!< Actual signaling message payload - dynamically allocated
+#else
     CHAR payload[MAX_SIGNALING_MESSAGE_LEN + 1]; //!< Actual signaling message payload
+#endif
 } SignalingMessage, *PSignalingMessage;
 
 /**

src/source/Signaling/LwsApiCalls.c

@@ -2017,6 +2017,10 @@ STATUS receiveLwsMessage(PSignalingClient pSignalingClient, PCHAR pMessage, UINT
 
     CHK(NULL != (pSignalingMessageWrapper = (PSignalingMessageWrapper) MEMCALLOC(1, SIZEOF(SignalingMessageWrapper))), STATUS_NOT_ENOUGH_MEMORY);
 
+#ifdef DYNAMIC_SIGNALING_PAYLOAD
+    CHK(NULL != (pSignalingMessageWrapper->receivedSignalingMessage.signalingMessage.payload = (PBYTE) MEMCALLOC(1, MAX_SIGNALING_MESSAGE_LEN + 1)), STATUS_NOT_ENOUGH_MEMORY);
+#endif
+
     pSignalingMessageWrapper->receivedSignalingMessage.signalingMessage.version = SIGNALING_MESSAGE_CURRENT_VERSION;
 
     // Loop through the tokens and extract the stream description
@@ -2235,7 +2239,11 @@ STATUS receiveLwsMessage(PSignalingClient pSignalingClient, PCHAR pMessage, UINT
         if (IS_VALID_TID_VALUE(receivedTid)) {
             THREAD_CANCEL(receivedTid);
         }
-
+#ifdef DYNAMIC_SIGNALING_PAYLOAD
+        if (pSignalingMessageWrapper) {
+            SAFE_MEMFREE(pSignalingMessageWrapper->receivedSignalingMessage.signalingMessage.payload);
+        }
+#endif
         SAFE_MEMFREE(pSignalingMessageWrapper);
     }
 
@@ -2402,6 +2410,9 @@ PVOID receiveLwsMessageWrapper(PVOID args)
 CleanUp:
     CHK_LOG_ERR(retStatus);
 
+#ifdef DYNAMIC_SIGNALING_PAYLOAD
+    SAFE_MEMFREE(pSignalingMessageWrapper->receivedSignalingMessage.signalingMessage.payload);
+#endif
     SAFE_MEMFREE(pSignalingMessageWrapper);
 
     return (PVOID) (ULONG_PTR) retStatus;