Make the del/put_current and append Cursor methods unsafe
#108
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Kerollmops
changed the title
del_current, put_current, and append Cursor methods unsafedel/put_current, and append Cursor methods unsafe
Kerollmops
changed the title
del/put_current, and append Cursor methods unsafedel/put_current and append Cursor methods unsafe
irevoire
approved these changes
Jun 28, 2021
Kerollmops
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to meilisearch/milli
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this pull request
Jun 28, 2021
It is undefined behavior to keep a reference to the database while modifying it, we were keeping references in the database and also feeding the heed put_current methods with keys referenced inside the database itself. meilisearch/heed#108
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This PR emerges from a bug that we found in the milli repository, an undefined behavior due to a bad usage of LMDB. We were keeping borrowed data from an LMDB database while modifying it by using
put_currentat the same time, this is prohibited!In this PR we simply declare the
del_current,put_current, andappenditerator methods as unsafe and improved the documentation of them by introducing a Safety paragraph explaining the safe way to use these methods. The right way to use these methods is to justto_ownedthe key and value from the database before using this method.