Savestate: store only live audio queue data (AudioChannel section v3) - #21989
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Arkadyzja wants to merge 1 commit into
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Savestate: store only live audio queue data (AudioChannel section v3)#21989Arkadyzja wants to merge 1 commit into
Arkadyzja wants to merge 1 commit into
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FixedSizeQueue::DoState serializes the entire fixed backing store. For the sceAudio channel queues that is 512KB per channel (32768*8 s16 samples), or ~4.6MB of mostly dead bytes in every savestate across the nine channels - the live sample count at any moment is normally a few KB. This addresses the existing TODO in DoState. Add DoStateCompact(), which stores only the live [head, head+count) region and restores it linearized at the front of storage. A wrapped live region is written as its two pieces in pop order; since the POD DoArray path writes raw bytes with no per-element or per-call header, the single linear read on load consumes them identically. The count is validated on load and a bad value fails the load cleanly via p.SetError. AudioChannel bumps its section to v3 to use the compact form; old states still load through the unchanged full-storage path. This shrinks every savestate by several MB uncompressed and cuts the copy/compress cost of each save, including the rewind feature's periodic states.
hrydgard
added
Audio
Code Cleanup
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What
Adds
FixedSizeQueue::DoStateCompact()and bumps theAudioChannelsection to v3 to use it. This addresses the existing TODO inFixedSizeQueue::DoState:Why
DoStateserializes the entire fixed backing store. EachsceAudiochannel queue isFixedSizeQueue<s16, 32768 * 8>= 512KB, and there are nine of them — ~4.6MB of almost entirely dead bytes in every savestate, while the live sample count at any moment is typically a few KB. That's wasted memcpy, wasted compression input, and wasted size in every save — manual saves, save slots, and the rewind feature's periodic in-memory states alike.How
DoStateCompact()stores only the live[head, head+count)region:DoArraypath writes raw bytes with no per-element or per-call header, so the concatenation is byte-identical to a single linear write of the logical queue contents.head = 0,tail = count % N), which is an equivalent queue state.p.SetError()instead of desyncing the stream.The old full-storage
DoState()is untouched; the two formats are not interchangeable, so callers opt in via their own section version — whichAudioChannel(the only caller changed here) does with v3.Compatibility
AudioChannelsections) load exactly as before through the full-storage path.