Module buffer_pool 

Reusable buffer pool for decompression output buffers.

Pools Vec<u8> buffers to reduce allocator pressure during sequential and parallel decompression. Reusable buffer pool for decompression output buffers.

Eliminates per-block Vec<u8> allocations during decompression by pooling and reusing buffers of common sizes. This is especially important for the parallel decompression path where N threads hitting the global allocator concurrently causes contention.

Design

The pool is a simple Mutex<Vec<Vec<u8>>> stack. Buffers are checked out for decompression and returned after the decompressed data has been copied or converted to Bytes.

When a buffer is needed for cache insertion (converting to Bytes), the buffer is consumed and not returned to the pool. The pool naturally reaches steady state as the block cache fills up and stops triggering new decompressions.

Structs

BufferPool

A pool of reusable Vec<u8> buffers for decompression.

Constants

DEFAULT_POOL_SIZE

Default maximum number of idle buffers to retain in the pool.