I have been doing some testing on the bridge to see how the current implementation stands up.
For large data going to native, the highest single time impact is the conversion of the string rawArgs to a JSONArray. Currently Echo, FileUtils, FileTransfer are likely to be impacted by this. The plugin execute is called by the bridge with String rawArgs, and the signature of these plugins (and others) calls for JSONArray args. This causes a non-obvious invocation of JSONArray(string) that isn't particularly fast. Testing on a Nexus 7 for a 1MB echo call (total round trip 580ms) 58% - conversion from json string to JSONArray (in Native) 28% - js preparation (Process any ArrayBuffers in the args into a string.) more to follow...
