The Slice compilers can optionally generate checksums of Slice definitions. For slice2rb
, the --checksum
option causes the compiler to generate code that adds checksums to the hash collection Ice::SliceChecksums
. The checksums are installed automatically when the Ruby code is first parsed; no action is required by the application.
In order to verify a server's checksums, a client could simply compare the two hash objects using a comparison operator. However, this is not feasible if it is possible that the server might return a superset of the client's checksums. A more general solution is to iterate over the local checksums as demonstrated below:
{zcode:rb} serverChecksums = ... for i in Ice::SliceChecksums.keys if not serverChecksums.has_key?(i) # No match found for type id! elif Ice::SliceChecksums[i] != serverChecksums[i] # Checksum mismatch! end end {zcode} |
In this example, the client first verifies that the server's dictionary contains an entry for each Slice type ID, and then it proceeds to compare the checksums.