define SmallHashMap in spacetimedb_data_structures#4136
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Shubham8287
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Jan 27, 2026
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Description of Changes
Defines
SmallHashMapinspacetimedb_data_structures.The data structure is a hybrid map that is backed by a vector and linear scan for the first
Melements.Then it falls back into a normal hash map.
For the first
Nelements, whereN < M, the vector is stored inline. That is, the vector is aSmallVec<[(K, V); N>.The structure is optimized for access patterns where the keys and values are accessed together,
therefore, keys and values are not stored separately.
API and ABI breaking changes
None, just additive.
Expected complexity level and risk
1
Testing
A comprehensive proptest suite is added for the datastructure.