h.inner.(marshalable).UnmarshalBinary(h.ipad); err != nil { panic(err) } return } h.inner.Reset() h.inner.Write(h.ipad) // If the underlying hash is marshalable, we can save some time by saving a // copy of the hash state now, and restoring it on future calls to Reset and // Sum instead of writing ipad/opad every time. // // We do this on Reset to avoid slowing down the common single-use case. // // This is allowed by FIPS 198-1, Section 6: "Conceptually, the intermediate // results of the compression...

     * changing any bin. The operations must not take any action that could even momentarily
     * cause a concurrent read operation to see inconsistent data. This is made easier by the
     * nature of the read operations in Map. For example, no operation can reveal that the table
     * has grown but the threshold has not yet been updated, so there are no atomicity requirements
     * for this with respect to reads.