[Draft] feat: adding copy #4038
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Signed-off-by: Sanath <[email protected]>
| @@ -786,6 +786,49 @@ OpStatus OpMove(const OpArgs& op_args, string_view key, DbIndex target_db) { | |||
| return OpStatus::OK; | |||
| } | |||
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| // OpMove touches multiple databases (op_args.db_idx, target_db), so it assumes it runs | |||
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Didn't spend time on docs as this was just a draft
| // OpMove touches multiple databases (op_args.db_idx, target_db), so it assumes it runs | ||
| // as a global transaction. | ||
| // TODO: Allow running OpMove without a global transaction. | ||
| OpStatus OpCopy(const OpArgs& op_args, string_view key, DbIndex target_db) { |
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Copy is actually a non-trivial operation that requires very good understanding of Dragonfly architecture.
This code won't work when keys reside on different thread shards. If you wish to learn more about dragonfly architecture and its transactional framework, please read the docs under docs/ folder.
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I'll go through the docs and share an one-pager for this feature. Do you recommend any other resources/docs i can look at in general to understand this better?
Do you have any timeline in mind for this feature? I'm new to this domain, so will take a few weeks to deliver this.
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do you have any suggested order for reading files in the docs folder?
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df-share-nothing.md and transaction.md are good candidates
@romange Can you explain an example where this would break so i can reproduct it. This implementation works when copying the key from one database to another database. With some modifications it should also work for moving data from one key to another. Do you have any references for 2 hop transaction? I will spend some time to understand it better before implementing further. |
it's not very hard to find out where it breaks. part of our responsibility is to write tests and challenge our code. once you add unit tests to generic_family_test, I am sure you will see where it breaks. |
Creating a scratch pull request to get some early directional feedback.
For testing i tried moving a string and list form one database to another and it worked. Haven't written any unit tests yet as source code is still work in progress.
Once you confirm this is in the right direction i will add more functionality
Not sure how to connect a pull request to a Issue so i'm just linking it in the description: #3878