Timothy/flat trie #9
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Pull request overview
This PR introduces a new flat trie data structure implementation alongside performance benchmarking infrastructure. The flat trie uses a buddy allocator for memory management and provides an alternative trie implementation with different performance characteristics.
Changes:
- Added FlatTrie implementation with buddy allocator-based memory management
- Added comprehensive performance benchmarks comparing simple trie, flat trie, and raw maps
- Extended converter support for native-sized integer types (int, uint, uintptr)
Reviewed changes
Copilot reviewed 8 out of 9 changed files in this pull request and generated 3 comments.
Show a summary per file
| File | Description |
|---|---|
| flat_trie.go | Core implementation of the flat trie data structure with chunk-based node storage |
| flat_node.go | Node structure definitions for the flat trie implementation |
| internal/buddy_allocator.go | Buddy allocator for efficient memory management in the flat trie |
| flat_trie_test.go | Unit tests for flat trie creation, addition, and lookup operations |
| performance_test.go | Performance benchmarks comparing trie implementations with maps |
| converter.go | Added converters for native-sized integer types (int, uint, uintptr) |
| contracts.go | Reordered type constraints to group uintptr with fixed-size types |
| simple_trie_test.go | Added test coverage for int key type in simple trie |
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| nativeIntBytes = strconv.IntSize / 8 |
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The variable name nativeIntBytes is ambiguous as it doesn't clearly indicate it represents the size of the int type specifically. Consider renaming to nativeIntSizeBytes to better distinguish it from nativePtrBytes.
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| // --- private functions --- // | ||
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| func expandSlice[T any](slice []T) (newSlice []T) { |
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The magic number 1.2 lacks explanation. Add a comment explaining why this specific growth factor was chosen for slice expansion.
| func expandSlice[T any](slice []T) (newSlice []T) { | |
| func expandSlice[T any](slice []T) (newSlice []T) { | |
| // Use a modest growth factor (20%) to balance allocation overhead and memory usage. | |
| // Larger factors (e.g., 2x) reduce reallocations but can waste significantly more memory. |
| } | ||
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| for order < this.maxOrder { | ||
| buddy := index ^ blockSize // buddy formula for buddy allocator |
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The inline comment is helpful but incomplete. Consider expanding it to explain that XOR with blockSize finds the buddy block at the same level in the binary tree structure.
| buddy := index ^ blockSize // buddy formula for buddy allocator | |
| buddy := index ^ blockSize // XOR with blockSize flips the bit for this order, yielding the buddy block at the same level in the implicit binary tree |
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