Add wdm update server support

-- add wdm update request processing and update response generation
mechanism
-- add TraitUpdatableDataSource

Author: yunhanw-google

src/lib/core/WeaveDMConfig.h

@@ -293,6 +293,18 @@
 #define WDM_ENABLE_SUBSCRIPTIONLESS_NOTIFICATION 1
 #endif // WDM_ENABLE_SUBSCRIPTIONLESS_NOTIFICATION
 
+/**
+ *  @def WDM_ENABLE_PUBLISHER_UPDATE_SERVER_SUPPORT
+ *
+ *  @brief
+ *    Enable (1) or disable (0) sending/handling update response
+ *    in Weave Data Management Next profile.
+ *
+ */
+#ifndef WDM_ENABLE_PUBLISHER_UPDATE_SERVER_SUPPORT
+#define WDM_ENABLE_PUBLISHER_UPDATE_SERVER_SUPPORT 1
+#endif // WDM_ENABLE_PUBLISHER_UPDATE_SERVER_SUPPORT
+
 /**
  *  @def WDM_PUBLISHER_ENABLE_VIEW
  *
@@ -572,6 +584,29 @@
 #define WDM_MIN_UPDATE_SIZE 1024
 #endif /* WDM_MIN_UPDATE_SIZE */
 
+/**
+ * @def WDM_MAX_UPDATE_RESPONSE_SIZE
+ *
+ * @brief
+ *   Specify the maximum size (in bytes) of a WDM update response
+ *   payload. Note that the WDM update payload is also limited
+ *   by the size of `nl::Weave::System::PacketBuffer`
+ */
+#ifndef WDM_MAX_UPDATE_RESPONSE_SIZE
+#define WDM_MAX_UPDATE_RESPONSE_SIZE 2048
+#endif /* WDM_MAX_UPDATE_SIZE */
+
+/**
+ * @def WDM_MIN_UPDATE_RESPONSE_SIZE
+ *
+ * @brief
+ *   Specify the minimum size (in bytes) of a WDM update response
+ *   payload.
+ */
+#ifndef WDM_MIN_UPDATE_RESPONSE_SIZE
+#define WDM_MIN_UPDATE_RESPONSE_SIZE 1024
+#endif /* WDM_MIN_UPDATE_SIZE */
+
 /**
  *  @def TDM_DISABLE_STRICT_SCHEMA_COMPLIANCE
  *

src/lib/profiles/common/WeaveMessage.cpp

@@ -851,14 +851,15 @@ bool ReferencedTLVData::isFree(void)
  * @brief Pack a ReferencedTLVData object using a TLVWriter.
  *
  * @param [in] i An iterator over the message being packed.
+ * @param [in] maxLen The maximum number of bytes that should be written to the output buffer.
  *
  * @return a WEAVE_ERROR - WEAVE_NO_ERROR if all goes well, otherwise
  * an error reflecting an inability of the writer to write the
  * relevant bytes. Note that the write callback is not allowed to
  * return an error and so fails silently.
  */
 
-WEAVE_ERROR ReferencedTLVData::pack(MessageIterator &i)
+WEAVE_ERROR ReferencedTLVData::pack(MessageIterator &i, uint32_t maxLen)
 {
     WEAVE_ERROR err = WEAVE_NO_ERROR;
     System::PacketBuffer *theBuffer = i.GetBuffer();
@@ -868,7 +869,7 @@ WEAVE_ERROR ReferencedTLVData::pack(MessageIterator &i)
     if (theWriteCallback != NULL)
     {
         theData = i.thePoint;
-        writer.Init(theBuffer);
+        writer.Init(theBuffer, maxLen);
         theWriteCallback(writer, theAppState);
         theLength = theBuffer->DataLength() - oldDataLength;
         i.thePoint += theLength;

src/lib/profiles/common/WeaveMessage.h

@@ -289,7 +289,7 @@ namespace Profiles {
         return pack(i);
     };
 
-    WEAVE_ERROR pack(MessageIterator&i);
+    WEAVE_ERROR pack(MessageIterator&i, uint32_t maxLen = 0xFFFFFFFFUL);
 
     /**
      * Return the data length assuming that the object has been packed