Update ResourceCache to retry an asset request when the node is unavailable

libraries/networking/src/AssetResourceRequest.cpp

@@ -13,6 +13,7 @@
 
 #include "AssetClient.h"
 #include "AssetRequest.h"
+#include "AssetUtils.h"
 
 void AssetResourceRequest::doSend() {
     // Make request to atp
@@ -21,9 +22,23 @@ void AssetResourceRequest::doSend() {
     auto hash = parts[0];
     auto extension = parts.length() > 1 ? parts[1] : "";
 
+    if (hash.length() != SHA256_HASH_HEX_LENGTH) {
+        _result = InvalidURL;
+        _state = Finished;
+
+        emit finished();
+
+        return;
+    }
+
     auto request = assetClient->createRequest(hash, extension);
 
     if (!request) {
+        _result = ServerUnavailable;
+        _state = Finished;
+
+        emit finished();
+
         return;
     }
 

libraries/networking/src/ResourceCache.cpp

@@ -396,6 +396,7 @@ void Resource::handleReplyFinished() {
         bool retry = false;
         switch (result) {
             case ResourceRequest::Result::Timeout:
+            case ResourceRequest::Result::ServerUnavailable:
             case ResourceRequest::Result::Error: {
                 // retry with increasing delays
                 const int MAX_ATTEMPTS = 8;

libraries/networking/src/ResourceRequest.h

@@ -30,7 +30,9 @@ public:
         Success,
         Error,
         Timeout,
+        ServerUnavailable,
         AccessDenied,
+        InvalidURL,
         NotFound
     };