Fixes #879: memory-guarded KDTree with tiled fallback for proximity#892
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brendancol merged 1 commit intomasterfrom Feb 25, 2026
Merged
Fixes #879: memory-guarded KDTree with tiled fallback for proximity#892brendancol merged 1 commit intomasterfrom
brendancol merged 1 commit intomasterfrom
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The dask KDTree path in proximity() accumulated all target coordinates in memory before building a global cKDTree, causing OOM on dense rasters. Replace the unbounded accumulation with a two-phase approach: - Phase 0: stream chunks counting targets, cache coords within 25% budget - Memory decision: if global tree estimate < 50% available RAM, build a single cKDTree (fast, lazy via da.map_blocks); otherwise fall back to a tiled expanding-ring KDTree (eager but memory-safe) The tiled path builds local trees per output chunk, expanding the search ring until a boundary-distance validation proves correctness. A ResourceWarning is emitted when the tiled fallback activates.
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Summary
_process_dask_kdtree()with a streaming count pass that caches coords within a 25% memory budgetda.map_blockspath (functionally identical to before); otherwise → tiled expanding-ring KDTree fallback (eager, memory-safe)ResourceWarningwhen tiled fallback activatesTest plan