perf(buffer): capacity-reuse in VulkanBuffer::Resize (#63) #96

Merged

catbot merged 1 commit from claude/issue-63 into master

2026-06-16 20:22:38 +02:00

catbot commented

2026-06-16 20:22:34 +02:00

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Problem

VulkanBuffer::Resize always destroyed + reallocated, even when the existing buffer already had room. Per-frame refit paths deliberately skip Resize (UPDATE mode), so this was never a steady-state cost — but capacity-reuse is the safer direction.

Fix

Reuse the existing allocation in place when all of the following hold:

the new request fits within the created capacity,
the requested usage flags equal the flags the buffer was created with (usage flags are immutable after vkCreateBuffer),
the memory type already chosen still satisfies the required property flags ((memoryPropertyFlagsChosen & required) == required).

preferredPropertyFlags is a best-effort perf hint and does not affect correctness, so it is intentionally not part of the guard. On reuse the buffer handle, device address, and mapped pointer are all preserved; only size shrinks to the new logical extent. Any mismatch falls back to the original destroy + recreate path.

VulkanBufferBase now tracks capacity and usageFlagsCreated, set in Create and carried through the move constructor.

Tests

Adds VulkanBufferResizeReuse, a device-free regression test that stamps a fake handle + capacity/flags and drives the reuse guard directly, asserting the in-place path issues no Vulkan call (a real reallocate would fault with no device). Full suite: 14 passed (crafter-build test --jobs=1).

Resolves #63

🤖 Generated with Claude Code

## Problem `VulkanBuffer::Resize` always destroyed + reallocated, even when the existing buffer already had room. Per-frame refit paths deliberately skip Resize (UPDATE mode), so this was never a steady-state cost — but capacity-reuse is the safer direction. ## Fix Reuse the existing allocation in place when **all** of the following hold: - the new request fits within the created `capacity`, - the requested usage flags equal the flags the buffer was created with (usage flags are immutable after `vkCreateBuffer`), - the memory type already chosen still satisfies the required property flags (`(memoryPropertyFlagsChosen & required) == required`). `preferredPropertyFlags` is a best-effort perf hint and does not affect correctness, so it is intentionally not part of the guard. On reuse the buffer handle, device address, and mapped pointer are all preserved; only `size` shrinks to the new logical extent. Any mismatch falls back to the original destroy + recreate path. `VulkanBufferBase` now tracks `capacity` and `usageFlagsCreated`, set in `Create` and carried through the move constructor. ## Tests Adds `VulkanBufferResizeReuse`, a device-free regression test that stamps a fake handle + capacity/flags and drives the reuse guard directly, asserting the in-place path issues no Vulkan call (a real reallocate would fault with no device). Full suite: 14 passed (`crafter-build test --jobs=1`). Resolves #63 🤖 Generated with [Claude Code](https://claude.com/claude-code)

catbot added 1 commit

2026-06-16 20:22:34 +02:00

perf(buffer): capacity-reuse in VulkanBuffer::Resize (#63 ) b6d0ec5cae

Resize previously always destroyed + reallocated. It now reuses the
existing allocation in place when the new request still fits the created
capacity and the immutable-at-create properties match: usage flags are
fixed at create, and the chosen memory type must still satisfy the
required property flags. preferredPropertyFlags is a best-effort perf
hint and is intentionally not part of the guard. On reuse the buffer
handle, device address and mapped pointer are preserved; only `size`
shrinks to the new logical extent.

Tracks capacity and the created usage flags on VulkanBufferBase, set at
Create and carried through the move constructor.

Adds VulkanBufferResizeReuse, a device-free regression test that drives
the reuse guard directly and asserts the in-place path issues no Vulkan
call.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

catbot merged commit b7500e1fd0 into master

2026-06-16 20:22:38 +02:00

catbot deleted branch claude/issue-63

2026-06-16 20:22:38 +02:00

catbot referenced this pull request from a commit

2026-06-16 20:22:40 +02:00

Merge pull request 'perf(buffer): capacity-reuse in VulkanBuffer::Resize (#63)' (#96) from claude/issue-63 into master