A Bucketizer
uses distinct allocators for handling allocations of sizes in the intervals [min, min + step - 1]
, [min + step, min + 2 * step - 1]
, [min + 2 * step, min + 3 * step - 1]
, ...
, [max - step + 1, max]
.
Bucketizer
holds a fixed-size array of allocators and dispatches calls to them appropriately. The size of the array is (max + 1 - min) / step
, which must be an exact division.
Allocations for sizes smaller than min
or larger than max
are illegal for Bucketizer
. To handle them separately, Segregator
may be of use.
import std.algorithm.comparison : max; import std.experimental.allocator.building_blocks.allocator_list : AllocatorList; import std.experimental.allocator.building_blocks.free_list : FreeList; import std.experimental.allocator.building_blocks.region : Region; import std.experimental.allocator.common : unbounded; import std.experimental.allocator.mallocator : Mallocator; import std.typecons : Ternary; Bucketizer!( FreeList!( AllocatorList!( (size_t n) => Region!Mallocator(max(n, 1024 * 1024))), 0, unbounded), 65, 512, 64) a; auto b = a.allocate(400); writeln(b.length); // 400 writeln(a.owns(b)); // Ternary.yes a.deallocate(b);
The array of allocators is publicly available for e.g. initialization and inspection.
The alignment offered is the same as Allocator.alignment
.
Rounds up to the maximum size of the bucket in which bytes
falls.
Directs the call to either one of the buckets
allocators.
Allocates the requested bytes
of memory with specified alignment
. Directs the call to either one of the buckets
allocators. Defined only if Allocator
defines alignedAllocate
.
This method allows expansion within the respective bucket range. It succeeds if both b.length
and b.length + delta
fall in a range of the form [min + k * step, min + (k + 1) * step - 1]
.
This method allows reallocation within the respective bucket range. If both b.length
and size
fall in a range of the form [min + k * step, min + (k + 1) * step - 1]
, then reallocation is in place. Otherwise, reallocation with moving is attempted.
Similar to reallocate
, with alignment. Defined only if Allocator
defines alignedReallocate
.
Defined only if Allocator
defines owns
. Finds the owner of b
and forwards the call to it.
This method is only defined if Allocator
defines deallocate
.
This method is only defined if all allocators involved define deallocateAll
, and calls it for each bucket in turn. Returns true
if all allocators could deallocate all.
This method is only defined if all allocators involved define resolveInternalPointer
, and tries it for each bucket in turn.
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Licensed under the Boost License 1.0.
https://dlang.org/phobos/std_experimental_allocator_building_blocks_bucketizer.html