Change brings in a new signVerifyReader which provides a io.Reader
compatible reader, additionally implements Verify() function.
Verify() function validates the signature present in the incoming
request. This approach is choosen to avoid complexities involved
in using io.Pipe().
Thanks to Krishna for his inputs on this.
Fixes#2058Fixes#2054Fixes#2087
The object cache implementation is XL cache, which defaults
to 8GB worth of read cache. Currently GetObject() transparently
writes to this cache upon first client read and then subsequently
serves reads from the same cache.
Currently expiration is not implemented.
