Struct AllocationHistogram 

pub struct AllocationHistogram { /* private fields */ }

Tracks allocation size distribution in power-of-2 buckets.

Bucket i covers the byte range [2^(i+4), 2^(i+5)), so:

• Bucket 0: [16, 32)
• Bucket 1: [32, 64)
• …
• Bucket 31: [2^35, ∞) (32 GiB and above)

Allocations smaller than 16 bytes are placed in bucket 0.

Implementations

impl AllocationHistogram

pub fn new() -> Self

Creates a new empty histogram.

pub fn bucket_index(size: usize) -> usize

Computes the bucket index for a given allocation size.

Sizes below 16 bytes map to bucket 0. The bucket index is derived from the position of the highest set bit, offset by 4 (since bucket 0 starts at 2^4 = 16).

pub fn record(&mut self, size: usize)

Records an allocation of the given size.

pub fn bucket_range(index: usize) -> (usize, usize)

Returns the (inclusive-min, exclusive-max) byte range for a bucket.

For the last bucket (index 31), the max is usize::MAX since it covers all sizes >= 2^35.

pub fn bucket_counts(&self) -> &[u64; 32]

Returns a reference to the raw bucket counts.

pub fn total_allocations(&self) -> u64

Returns the total number of allocations recorded.

pub fn percentile(&self, p: f64) -> usize

Computes the approximate allocation size at the given percentile.

p should be in the range [0.0, 100.0]. Returns the lower bound of the bucket that contains the p-th percentile allocation.

Returns 0 if no allocations have been recorded.

pub fn median(&self) -> usize

Shorthand for percentile(50.0).

Trait Implementations

impl Clone for AllocationHistogram

fn clone(&self) -> AllocationHistogram

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AllocationHistogram

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for AllocationHistogram

fn default() -> Self

Returns the “default value” for a type.