Safe IO script part (#595)

* Safe IO script part

* Fix compile-check

* Apply suggestions from code review

* Fix compile-check... again...

* Apply suggestions from code review :(


* Apply suggestions from code review


* stuff :)

* :D

* Add optional failure callback

* fix :)

* he forgot

forgor

* Fix memory leak :)

* gah

* oops :)

* Use failed callback if the json file is invalid

---------

Co-authored-by: Jack <66967891+ASpoonPlaysGames@users.noreply.github.com>
Co-authored-by: uniboi <64006268+uniboi@users.noreply.github.com>

2 files changed, 87 insertions, 0 deletions

diff --git a/Northstar.Custom/mod.json b/Northstar.Custom/mod.json
index 5fcdb0fd..22f9c45f 100644
--- a/Northstar.Custom/mod.json
+++ b/Northstar.Custom/mod.json
@@ -430,6 +430,10 @@
 		{
 			"Path":  "sh_northstar_http_requests.gnut",
 			"RunOn": "CLIENT || SERVER || UI"
+		},
+		{
+			"Path": "sh_northstar_safe_io.gnut",
+			"RunOn": "CLIENT || SERVER || UI"
 		}
 	],
 
diff --git a/Northstar.Custom/mod/scripts/vscripts/sh_northstar_safe_io.gnut b/Northstar.Custom/mod/scripts/vscripts/sh_northstar_safe_io.gnut
new file mode 100644
index 00000000..f7b31cc2
--- /dev/null
+++ b/Northstar.Custom/mod/scripts/vscripts/sh_northstar_safe_io.gnut
@@ -0,0 +1,83 @@
+globalize_all_functions
+
+table< int, void functionref( string ) > pendingCallbacks
+table< int, void functionref( table ) > pendingJSONCallbacks
+table< int, void functionref() > failedCallbacks
+
+
+void function NSLoadFile( string file, void functionref( string ) onSuccess, void functionref() onFailure = null )
+{
+    int handle = NS_InternalLoadFile( file )
+
+    pendingCallbacks[handle] <- onSuccess
+    if (onFailure != null)
+        failedCallbacks[handle] <- onFailure
+}
+
+void function NSLoadJSONFile( string file, void functionref( table ) onSuccess, void functionref() onFailure = null )
+{
+    int handle = NS_InternalLoadFile( file )
+
+    pendingJSONCallbacks[handle] <- onSuccess
+    if (onFailure != null)
+        failedCallbacks[handle] <- onFailure
+}
+
+void function NSHandleLoadResult( int handle, bool success, string result )
+{
+    bool hasFailedCallback = handle in failedCallbacks
+    bool isJSONRequest = handle in pendingJSONCallbacks
+    bool isValid = isJSONRequest || handle in pendingCallbacks
+
+    if (!isValid)
+        throw "Invalid IO callback handle"
+
+    if (success)
+    {
+        if (isJSONRequest)
+        {
+            try
+            {
+                table result = DecodeJSON(result, true)
+                pendingJSONCallbacks[handle](result)
+            }
+            catch (ex)
+            {
+                print(ex)
+                // parsing failed, setting 'success' to false, since we
+                // consider this a failure.
+                success = false
+            }
+        }
+        else
+        {
+            pendingCallbacks[handle](result)
+        }
+    }
+    // don't use 'else', json might fail parsing and set 'success' to false.
+    if (!success)
+    {
+        if (hasFailedCallback)
+            failedCallbacks[handle]()
+        else
+        {
+            if (isJSONRequest)
+                pendingJSONCallbacks[handle]({})
+            else
+                pendingCallbacks[handle]("")
+        }
+    }
+
+    if (isJSONRequest)
+        delete pendingJSONCallbacks[handle]
+    else
+        delete pendingCallbacks[handle]
+
+    if (hasFailedCallback)
+        delete failedCallbacks[handle]
+}
+
+array<string> function NSGetAllFiles( string path = "" )
+{
+    return NS_InternalGetAllFiles(path)
+}