On Wed, May 6, 2009 at 12:49 PM, Zulq Alam
<[hidden email]> wrote:
When deserializing Dictionary objects, it looks like they are being rehashed. Where and why is this happening?
I'm sorry I don't know where, but the why is because a deserialized Dictionary (or Set, or any hashed collection) will, if non-empty, contain newly created/deserialized objects whose identity hashes will differ from those of the serialized ones. Since Object>>#= defaults to #== and Object>>#hash defaults to #identityHash an equality-hashed collection still needs to be rehashed when deserialized since #= hashes can depend on identityHash.
dict1 := Dictionary new.
1 to: 1000 do: [:e | dict1 at: e put: e].
rep1 := ReferenceStream streamedRepresentationOf: dict1.
dict2 := ReferenceStream unStream: rep1.
rep2 := ReferenceStream streamedRepresentationOf: dict2.
dict1 = dict2. " true "
rep1 = rep2. " false "
dict1 array size. " 2560 "
dict2 array size. " 1334 "
dict1 rehash.
dict1 array size. " 1334 "
I'm using ReferenceStreams to store object graphs in a relational database as a BLOB using Glorp. Glorp determines whether to do an updated by comparing the serialized form of objects with their last state. This causes spurious UPDATEs.
Any ideas?
Thanks.
Zulq.
Locked
