fixed general purpose allocator
This commit is contained in:
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a147865048
commit
ffcc848b0f
@ -76,7 +76,8 @@ impl FilePointer<FreeListBlock> {
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impl GeneralPurposeAllocator {
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const SIZE_MASK: u8 = 0b1000_0000;
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const MIN_ALLOCATION_SIZE: u64 = size_of::<FreeListBlock>() as u64 - size_of::<U64>() as u64;
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pub const MIN_ALLOCATION_SIZE: u64 =
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size_of::<FreeListBlock>() as u64 - size_of::<U64>() as u64;
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pub fn size<R>(db: &Db<R>, head: FilePointer<FreeListBlock>) -> u64 {
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// println!("get size({head:?})");
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@ -152,7 +153,9 @@ impl GeneralPurposeAllocator {
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// we need space to store the free list entry
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let needed_size = expected_size.max(Self::MIN_ALLOCATION_SIZE);
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// while this pointet doesn't technically point to a `FreeListBlock` (it points to the head pointer)
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// dbg!(needed_size);
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// while this pointer doesn't technically point to a `FreeListBlock` (it points to the head pointer)
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// as long as it's at most in the `prev` position it will never be allocated and only ever be
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// written to to set the pointer to the first element. We use `empty_list` to make sure we never
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// write into it incorrectly.
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@ -163,7 +166,10 @@ impl GeneralPurposeAllocator {
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let mut prev = head;
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let mut next: FilePointer<FreeListBlock> = unsafe { db.read(head.next_ptr()) };
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// println!("next: {next:?} | prev: {prev:?} | prevprev: {prevprev:?}");
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let empty_list = next.is_null();
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// dbg!(empty_list);
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while !next.is_null() && !Self::can_allocate_into(needed_size, Self::size(db, next)) {
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prevprev = prev;
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@ -171,6 +177,13 @@ impl GeneralPurposeAllocator {
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next = unsafe { db.read(next.next_ptr()) };
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}
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let prev_is_head = prevprev.is_null();
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// dbg!(Self::size(db, next));
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// dbg!(prev_is_head);
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// println!("next: {next:?} | prev: {prev:?} | prevprev: {prevprev:?}");
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// dbg!(next, Self::size(db, next));
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let start = if next.is_null() {
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@ -202,7 +215,9 @@ impl GeneralPurposeAllocator {
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let n_pages = Self::needed_pages(still_needed);
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assert_ne!(n_pages, 0);
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let page_start = db.add_pages(n_pages).start();
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let page = db.add_pages(n_pages);
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let page_start = page.start();
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// println!("allocate_general_pages({n_pages}, size={expected_size}) -> {}..{}", page.0.get(), page.0.get() + n_pages as u32);
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// dbg!(n_pages, page_start);
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@ -231,7 +246,7 @@ impl GeneralPurposeAllocator {
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let extra_space = Self::size(db, start) - needed_size;
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// dbg!(prev, nextnext, extra_space);
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// dbg!(start, prev, nextnext, extra_space);
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if extra_space != 0 {
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let remainder = FilePointer::<FreeListBlock>::new(start.into_raw() + needed_size);
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@ -245,7 +260,8 @@ impl GeneralPurposeAllocator {
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db.write(remainder.next_ptr(), nextnext);
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}
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// println!("{:x?}", unsafe { db.read::<[u8; 9 + 8]>(remainder) });
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// println!("{:x?}", unsafe { db.read(prev.cast::<[u8; 8]>()) });
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// println!("{:x?}", unsafe { db.read(remainder.cast::<[u8; 9 + 8]>()) });
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} else {
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unsafe { db.write(prev.next_ptr(), nextnext) };
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}
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@ -253,9 +269,7 @@ impl GeneralPurposeAllocator {
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start
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};
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let start = Self::clear(db, start);
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start.range(expected_size)
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start.into_raw().range(expected_size)
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}
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pub fn free<R>(self, db: &mut Db<R>, range: FileRange) {
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@ -420,7 +434,7 @@ impl SlabListPointer {
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}
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pub fn add_slab<R>(self, db: &mut Db<R>, slab_size: u32) -> SlabPointer {
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println!("add_slab({slab_size})");
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// println!("add_slab({slab_size})");
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let this = self.read_header(db);
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@ -469,7 +483,7 @@ pub struct RelativeFreeListHeader {
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impl RelativeFreeListHeader {
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const DATA_SIZE: u32 = PAGE_SIZE as u32 - size_of::<Self>() as u32;
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fn capacity(size: u32) -> u32 {
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pub fn capacity(size: u32) -> u32 {
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debug_assert_eq!(SlabKind::for_size(size), SlabKind::RelativeFreeList);
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Self::DATA_SIZE / size
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}
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@ -518,7 +532,7 @@ impl SlabPointer {
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first.get(),
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));
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let next: U16 = unsafe { db.read(ptr) };
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let next = unsafe { db.read(ptr) };
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let header = unsafe { db.modify::<RelativeFreeListHeader>(start) };
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@ -593,22 +607,21 @@ impl SlabPointer {
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pub fn allocate_page<R>(&self, db: &mut Db<R>) -> RawFilePointer {
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let Slab { head, size } = self.read(db);
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let page = db.add_pages(1);
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println!("allocate_slab_page({size})");
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// println!("allocate_slab_page({size}) -> {}", page.0.get());
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let size = size.get();
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match SlabKind::for_size(size) {
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SlabKind::SingleBytes => todo!("single byte slabs"),
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SlabKind::RelativeFreeList => {
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let page = db.add_pages(1);
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let (next_page, offset) = head.page_offset();
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assert_eq!(offset, 0);
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let capacity = RelativeFreeListHeader::capacity(size);
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let data_offset = size_of::<Self>() as u16;
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let data_offset = size_of::<RelativeFreeListHeader>() as u16;
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unsafe {
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db.write(
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@ -620,18 +633,20 @@ impl SlabPointer {
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)
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};
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let mut offset = 0;
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let mut prev = 0;
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for i in (0..capacity).rev() {
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let next = data_offset + (i * size) as u16;
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let next = data_offset
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.checked_add(u16::try_from(i * size).unwrap())
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.unwrap();
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unsafe {
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db.write(
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FilePointer::new(RawFilePointer::from_page_and_offset(page, next)),
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U16::from(offset),
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U16::from(prev),
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)
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};
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offset = next;
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prev = next;
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}
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self.set_head(db, page.start());
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@ -641,8 +656,6 @@ impl SlabPointer {
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SlabKind::AbsoluteFreeList => {
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let n = PAGE_SIZE / size as u64;
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let page = db.add_pages(1);
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let mut next = head;
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for i in (0..n).rev() {
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let current = page.start() + i * size as u64;
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679
src/lib.rs
679
src/lib.rs
@ -31,6 +31,9 @@ mod atomic_arc;
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mod mapped;
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mod transaction;
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#[cfg(test)]
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mod tests;
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use allocator::{AllocatorState, GeneralPurposeAllocator, SlabListPointer, SlabPointer};
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use atomic_arc::AtomicArc;
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use memmap::{Mmap, MmapMut};
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@ -167,7 +170,7 @@ impl RawFilePointer {
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fn from_page_and_offset(page: PagePointer, offset: u16) -> Self {
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debug_assert!(
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offset < PAGE_SIZE as u16,
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"offset 0x{offset:x} out for page bounds (0..0x{PAGE_SIZE:x})"
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"offset 0x{offset:x} out of page bounds (0..0x{PAGE_SIZE:x})"
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);
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page.start() + offset as u64
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}
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@ -183,6 +186,18 @@ impl RawFilePointer {
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#[repr(transparent)]
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pub struct PagePointer(U32);
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impl PartialOrd for PagePointer {
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fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
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self.0.get().partial_cmp(&other.0.get())
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}
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}
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impl Ord for PagePointer {
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fn cmp(&self, other: &Self) -> std::cmp::Ordering {
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self.0.get().cmp(&other.0.get())
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}
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}
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impl PagePointer {
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fn start(self) -> RawFilePointer {
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RawFilePointer((self.0.get() as u64 * PAGE_SIZE).into())
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@ -434,7 +449,7 @@ impl<R> Db<R> {
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#[track_caller]
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unsafe fn copy_nonoverlapping(&mut self, from: FileRange, to: FileRange) {
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let len = from.len();
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println!("copy from {from:?} to {to:?} ({len})",);
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// println!("copy from {from:?} to {to:?} ({len})",);
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// intervals must be non-overlapping and of the same size
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assert!(!from.as_range().contains(&(to.start().0.get() as usize)));
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@ -621,7 +636,6 @@ impl<R> Db<R> {
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// TODO: scrap the PAGE-wise allocation and make slab allocations allocations of the general allocator.
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pub fn allocate(&mut self, size: u64) -> FileRange {
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// println!("allocate({size})");
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if size == 0 {
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return RawFilePointer::null().range(0);
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}
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@ -643,662 +657,3 @@ impl<R> Db<R> {
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}
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}
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}
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#[cfg(test)]
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mod tests {
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use crate::allocator::{div_round_up, RelativeFreeListHeader, SlabKind};
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use super::*;
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use mapped::ReaderTrait;
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use std::io::Write;
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use std::ops::Shl;
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use std::process::Stdio;
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#[derive(Debug, Clone, Copy)]
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enum Operation {
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Allocate { size: u64 },
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Free { index: usize },
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}
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fn causes_fragmentation(sequence: &[Operation], print: bool) -> bool {
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let mut db = Db::<()>::create(tempfile::tempfile().unwrap(), &[]);
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let allocator = Db::<()>::general_purpose_allocator();
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let mut ranges = Vec::new();
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for &operation in sequence {
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match operation {
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Operation::Allocate { size } => ranges.push(allocator.allocate(&mut db, size)),
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Operation::Free { index } => {
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if ranges.get(index).is_some() {
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allocator.free(&mut db, ranges.remove(index))
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}
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}
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}
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}
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for range in ranges.drain(..) {
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allocator.free(&mut db, range);
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}
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fragmentation(&mut db, print) > 1
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}
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fn fragmentation<R>(db: &mut Db<R>, print: bool) -> usize {
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let allocator = Db::<()>::general_purpose_allocator();
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let mut next = unsafe { db.read(allocator.head_ptr) };
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let mut n = 0;
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while !next.is_null() {
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let size = GeneralPurposeAllocator::size(db, next);
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if print {
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println!("\x1b[34m[{n}]\x1b[m {:?}", next.into_raw().range(size));
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}
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next = unsafe { db.read(next.next_ptr()) };
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n += 1;
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}
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n
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}
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#[test]
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fn debug_fragmentation() {
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use Operation::*;
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#[rustfmt::skip]
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let mut sequence = vec![Allocate { size: 1946 }, Allocate { size: 3252 }, Free { index: 0 }, Allocate { size: 7391 }, Allocate { size: 394 }, Allocate { size: 3726 }, Allocate { size: 1429 }, Allocate { size: 3188 }, Allocate { size: 6375 }, Allocate { size: 4453 }, Allocate { size: 2514 }, Allocate { size: 4754 }, Allocate { size: 6785 }, Allocate { size: 2751 }, Allocate { size: 4107 }, Allocate { size: 3509 }, Allocate { size: 5897 }, Allocate { size: 7081 }, Allocate { size: 2419 }, Allocate { size: 5400 }, Allocate { size: 7135 }, Free { index: 14 }, Allocate { size: 2130 }, Free { index: 18 }, Allocate { size: 3450 }, Allocate { size: 1296 }, Allocate { size: 8091 }, Allocate { size: 4646 }, Allocate { size: 3891 }, Free { index: 0 }, Allocate { size: 1087 }, Allocate { size: 101 }, Allocate { size: 5353 }, Allocate { size: 3381 }, Allocate { size: 6869 }, Free { index: 1 }, Allocate { size: 3750 }, Allocate { size: 1398 }, Free { index: 22 }, Allocate { size: 18 }, Free { index: 25 }, Allocate { size: 642 }, Free { index: 4 }, Allocate { size: 4 }, Allocate { size: 1898 }, Allocate { size: 5259 }, Free { index: 26 }, Allocate { size: 3151 }, Allocate { size: 4989 }, Allocate { size: 6493 }, Allocate { size: 551 }, Allocate { size: 706 }, Allocate { size: 4161 }, Free { index: 16 }, Allocate { size: 3422 }, Allocate { size: 3011 }, Allocate { size: 5149 }, Allocate { size: 4687 }, Allocate { size: 5 }, Free { index: 34 }, Allocate { size: 191 }, Allocate { size: 2851 }, Allocate { size: 3597 }, Free { index: 28 }, Allocate { size: 7037 }, Allocate { size: 4660 }, Allocate { size: 194 }, Allocate { size: 5537 }, Allocate { size: 3242 }, Allocate { size: 6298 }, Allocate { size: 1239 }, Allocate { size: 7025 }, Allocate { size: 3563 }, Allocate { size: 5039 }, Free { index: 40 }, Allocate { size: 4549 }, Allocate { size: 5362 }, Allocate { size: 3510 }, Free { index: 31 }, Allocate { size: 226 }, Allocate { size: 6904 }, Allocate { size: 4150 }, Allocate { size: 4914 }, Allocate { size: 2330 }, Allocate { size: 2499 }, Allocate { size: 6677 }, Allocate { size: 95 }, Allocate { size: 3726 }, Allocate { size: 3258 }, Free { index: 2 }, Allocate { size: 2129 }, Allocate { size: 3674 }, Allocate { size: 1542 }, Allocate { size: 2210 }, Free { index: 21 }, Allocate { size: 3914 }, Allocate { size: 3108 }, Allocate { size: 1979 }, Allocate { size: 2677 }, Allocate { size: 8140 }, Allocate { size: 7573 }, Allocate { size: 121 }, Free { index: 59 }, Allocate { size: 6467 }, Allocate { size: 262 }, Allocate { size: 7711 }, Allocate { size: 2450 }, Allocate { size: 4351 }, Allocate { size: 4282 }, Free { index: 39 }, Allocate { size: 4050 }, Allocate { size: 67 }, Allocate { size: 5560 }, Free { index: 51 }, Allocate { size: 6038 }, Allocate { size: 555 }, Allocate { size: 1852 }, Free { index: 78 }, Allocate { size: 698 }];
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let mut prev_sequence = sequence.clone();
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while causes_fragmentation(&sequence, false) {
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prev_sequence = sequence.clone();
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sequence.pop();
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}
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println!("{prev_sequence:?}");
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let mut sequence = prev_sequence.clone();
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loop {
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let mut removed_something = false;
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let mut i = 0;
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while i < sequence.len() {
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let mut new_sequence = sequence.clone();
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new_sequence.remove(i);
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if causes_fragmentation(&new_sequence, false) {
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removed_something = true;
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println!("removed {i} ({:?})", sequence[i]);
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sequence = new_sequence;
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} else {
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for item in &mut new_sequence {
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if let Operation::Free { index } = item {
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if *index > i {
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*index -= 1;
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}
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}
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}
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if causes_fragmentation(&new_sequence, false) {
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removed_something = true;
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println!("removed {i} ({:?}) after adjusting frees", sequence[i]);
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sequence = new_sequence;
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}
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}
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i += 1;
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}
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if !removed_something {
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break;
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}
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}
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loop {
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let mut merged_something = false;
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let mut i = 0;
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while i < sequence.len() {
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let mut new_sequence = sequence.clone();
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let removed = new_sequence.remove(i);
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if let Operation::Allocate { size: removed_size } = removed {
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if let Some(Operation::Allocate { size }) = new_sequence.get_mut(i) {
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*size += removed_size;
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}
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}
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if causes_fragmentation(&new_sequence, false) {
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merged_something = true;
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println!(
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"merged {} and {} ({:?} and {:?})",
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i,
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i + 1,
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sequence[i],
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sequence[i + 1]
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);
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sequence = new_sequence;
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} else {
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for item in &mut new_sequence {
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if let Operation::Free { index } = item {
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if *index > i {
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*index -= 1;
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}
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}
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}
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if causes_fragmentation(&new_sequence, false) {
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merged_something = true;
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println!(
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"merged {} and {} ({:?} and {:?}) after adjusting frees",
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i,
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i + 1,
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sequence[i],
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sequence[i + 1]
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);
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sequence = new_sequence;
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}
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}
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i += 1;
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}
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if !merged_something {
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break;
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}
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}
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println!("{sequence:?}");
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dbg!(causes_fragmentation(&sequence, true));
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}
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#[test]
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fn allocator() {
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let mut db = Db::<()>::create(tempfile::tempfile().unwrap(), &[4, 7, 16]);
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let mut ranges = Vec::new();
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for i in 0..10000 {
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ranges.push(db.allocate(i % 32));
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}
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let n = ranges.len();
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for range in ranges.drain(n / 4..n * 3 / 4) {
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db.free(range);
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}
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for i in 0..10000 {
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ranges.push(db.allocate((4 * i) % 32));
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}
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for range in ranges.drain(..) {
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db.free(range);
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}
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// hexdump(db.map.as_bytes());
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}
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#[test]
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fn transactions_work() {
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#[derive(Clone, Copy, FromBytes, FromZeroes, AsBytes, Unaligned)]
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#[repr(C)]
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struct DataHeader {
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generation: U64,
|
||||
list: FilePointer<DataList>,
|
||||
}
|
||||
|
||||
#[derive(Clone, Copy, FromBytes, FromZeroes, AsBytes, Unaligned)]
|
||||
#[repr(C)]
|
||||
struct DataList {
|
||||
next: FilePointer<DataList>,
|
||||
data: U64,
|
||||
}
|
||||
|
||||
let mut db = Db::<DataHeader>::create(
|
||||
tempfile::tempfile().unwrap(),
|
||||
&[size_of::<DataHeader>() as u32, size_of::<DataList>() as u32],
|
||||
);
|
||||
|
||||
let mut snapshots = VecDeque::new();
|
||||
|
||||
for i in 0..20 {
|
||||
db.transaction(|transaction| {
|
||||
let root = transaction.root();
|
||||
|
||||
let root = if !root.is_null() {
|
||||
root
|
||||
} else {
|
||||
let (root, data) = transaction.allocate::<DataHeader>();
|
||||
|
||||
*data = DataHeader {
|
||||
generation: 0.into(),
|
||||
list: FilePointer::null(),
|
||||
};
|
||||
|
||||
root
|
||||
};
|
||||
|
||||
let &data = transaction.read(root);
|
||||
|
||||
assert_eq!(data.generation.get(), i);
|
||||
|
||||
let n = {
|
||||
let mut next = data.list;
|
||||
let mut n = 0;
|
||||
while !next.is_null() {
|
||||
next = transaction.read(next).next;
|
||||
n += 1;
|
||||
}
|
||||
n
|
||||
};
|
||||
|
||||
let next = if n >= 5 {
|
||||
let next = transaction.read(data.list).next;
|
||||
transaction.free(data.list);
|
||||
next
|
||||
} else {
|
||||
data.list
|
||||
};
|
||||
|
||||
let (elem_ptr, element) = transaction.allocate::<DataList>();
|
||||
|
||||
element.next = next;
|
||||
element.data = i.into();
|
||||
|
||||
let (root, data) = transaction.modify(root);
|
||||
data.list = elem_ptr;
|
||||
data.generation = (i + 1).into();
|
||||
|
||||
root
|
||||
});
|
||||
|
||||
snapshots.push_back(db.create_reader().state.get());
|
||||
if snapshots.len() > 10 {
|
||||
drop(snapshots.pop_front());
|
||||
db.free_old_epochs()
|
||||
}
|
||||
|
||||
validate_db(&db, |snaphot, coverage| {
|
||||
coverage.set_allocated(snaphot.root.range());
|
||||
let data = snaphot.read(snaphot.root);
|
||||
|
||||
let mut next = data.list;
|
||||
while !next.is_null() {
|
||||
coverage.set_allocated(next.range());
|
||||
next = snaphot.read(next).next;
|
||||
}
|
||||
});
|
||||
}
|
||||
|
||||
// TODO: allocate some variably sized strings
|
||||
|
||||
for (i, snapshot) in snapshots.iter().enumerate() {
|
||||
let root = snapshot.read(snapshot.root);
|
||||
|
||||
assert_eq!(root.generation.get(), 1 + 10 + i as u64);
|
||||
|
||||
let mut items = Vec::new();
|
||||
|
||||
let mut ptr = root.list;
|
||||
|
||||
while !ptr.is_null() {
|
||||
let element = snapshot.read(ptr);
|
||||
|
||||
items.push(element.data.get());
|
||||
ptr = element.next;
|
||||
}
|
||||
|
||||
assert_eq!(items.len(), 5);
|
||||
assert_eq!(items[0], 10 + i as u64);
|
||||
|
||||
for (expected, &is) in items.iter().skip(1).rev().enumerate() {
|
||||
assert_eq!(expected as u64, is);
|
||||
}
|
||||
}
|
||||
|
||||
drop(snapshots);
|
||||
|
||||
// hexdump(db.map.as_bytes());
|
||||
|
||||
db.free_old_epochs();
|
||||
|
||||
// hexdump(db.map.as_bytes());
|
||||
}
|
||||
|
||||
#[repr(u8)]
|
||||
#[derive(Clone, Copy)]
|
||||
#[rustfmt::skip]
|
||||
enum CoverageKind {
|
||||
Unaccounted = 0b000,
|
||||
Allocated = 0b001,
|
||||
Free = 0b010,
|
||||
Retired = 0b011,
|
||||
SlabMetadata = 0b100,
|
||||
FileMetadata = 0b101,
|
||||
}
|
||||
|
||||
impl CoverageKind {
|
||||
fn color(self) -> &'static str {
|
||||
match self {
|
||||
CoverageKind::Unaccounted => "31",
|
||||
CoverageKind::Allocated => "32",
|
||||
CoverageKind::Free => "34",
|
||||
CoverageKind::Retired => "36",
|
||||
CoverageKind::SlabMetadata => "35",
|
||||
CoverageKind::FileMetadata => "93",
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl CoverageKind {
|
||||
#[rustfmt::skip]
|
||||
fn from_bits(a: bool, b: bool, c: bool) -> Self {
|
||||
let res = match (a, b, c) {
|
||||
(false, false, false) => Self::Unaccounted,
|
||||
(false, false, true) => Self::Allocated,
|
||||
(false, true, false) => Self::Free,
|
||||
(false, true, true) => Self::Retired,
|
||||
( true, false, false) => Self::SlabMetadata,
|
||||
( true, false, true) => Self::FileMetadata,
|
||||
_ => panic!(),
|
||||
};
|
||||
assert_eq!(res as u8, ((a as u8) << 2) + ((b as u8) << 1) + c as u8);
|
||||
res
|
||||
}
|
||||
|
||||
fn to_bits(self) -> (bool, bool, bool) {
|
||||
(
|
||||
self as u8 & 0b100 != 0,
|
||||
self as u8 & 0b010 != 0,
|
||||
self as u8 & 0b001 != 0,
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
struct CoverageMap {
|
||||
data_0: Vec<u8>,
|
||||
data_1: Vec<u8>,
|
||||
data_2: Vec<u8>,
|
||||
empty_bits: u8,
|
||||
}
|
||||
|
||||
impl CoverageMap {
|
||||
fn new(len: usize) -> Self {
|
||||
let bits = div_round_up(len as u64, 8) as usize;
|
||||
Self {
|
||||
data_0: vec![0; bits],
|
||||
data_1: vec![0; bits],
|
||||
data_2: vec![0; bits],
|
||||
empty_bits: (8 - len % 8) as u8,
|
||||
}
|
||||
}
|
||||
|
||||
#[must_use]
|
||||
fn set(&mut self, i: usize, kind: CoverageKind) -> bool {
|
||||
let i_byte = i / 8;
|
||||
let i_bit = i % 8;
|
||||
let mask = 1 << i_bit;
|
||||
|
||||
let (set_0, set_1, set_2) = kind.to_bits();
|
||||
|
||||
if i_byte >= self.data_0.len() {
|
||||
return false;
|
||||
}
|
||||
|
||||
let byte = self.data_0[i_byte] | self.data_1[i_byte] | self.data_2[i_byte];
|
||||
|
||||
if byte & mask != 0 {
|
||||
return false;
|
||||
}
|
||||
|
||||
self.data_0[i_byte] |= mask * set_0 as u8;
|
||||
self.data_1[i_byte] |= mask * set_1 as u8;
|
||||
self.data_2[i_byte] |= mask * set_2 as u8;
|
||||
|
||||
true
|
||||
}
|
||||
|
||||
#[must_use]
|
||||
fn try_set_range(&mut self, range: FileRange, kind: CoverageKind) -> bool {
|
||||
range.as_range().all(|i| self.set(i, kind))
|
||||
}
|
||||
|
||||
fn set_allocated(&mut self, range: FileRange) {
|
||||
self.set_range(range, CoverageKind::Allocated);
|
||||
}
|
||||
|
||||
fn set_range(&mut self, range: FileRange, kind: CoverageKind) {
|
||||
assert!(
|
||||
self.try_set_range(range, kind),
|
||||
"possible allocator corruption"
|
||||
)
|
||||
}
|
||||
|
||||
fn all_covered(&self) -> bool {
|
||||
let len = self.data_0.len();
|
||||
for (i, ((&byte_0, &byte_1), &byte_2)) in self
|
||||
.data_0
|
||||
.iter()
|
||||
.zip(self.data_1.iter())
|
||||
.zip(self.data_2.iter())
|
||||
.enumerate()
|
||||
{
|
||||
let byte = byte_0 | byte_1 | byte_2;
|
||||
if i == len - 1 {
|
||||
if byte != u8::MAX.overflowing_shl(self.empty_bits as u32).0 {
|
||||
return false;
|
||||
}
|
||||
} else if byte != u8::MAX {
|
||||
return false;
|
||||
}
|
||||
}
|
||||
true
|
||||
}
|
||||
|
||||
fn set_color(res: &mut String, color: &str) {
|
||||
res.push_str("\x1b[");
|
||||
res.push_str(color);
|
||||
res.push('m');
|
||||
}
|
||||
|
||||
fn print(&self) -> String {
|
||||
let mut res = String::new();
|
||||
|
||||
let mut prev = "";
|
||||
for (i, ((&byte_0, &byte_1), &byte_2)) in self
|
||||
.data_0
|
||||
.iter()
|
||||
.zip(self.data_1.iter())
|
||||
.zip(self.data_2.iter())
|
||||
.enumerate()
|
||||
{
|
||||
let byte = byte_0 | byte_1 | byte_2;
|
||||
|
||||
fn all_equal(bits: u8) -> bool {
|
||||
bits == 0 || bits == u8::MAX
|
||||
}
|
||||
|
||||
let kind = if all_equal(byte_0) && all_equal(byte_1) && all_equal(byte_2) {
|
||||
Some(CoverageKind::from_bits(
|
||||
byte_0 & 1 == 1,
|
||||
byte_1 & 1 == 1,
|
||||
byte_2 & 1 == 1,
|
||||
))
|
||||
} else {
|
||||
None
|
||||
};
|
||||
|
||||
if i != 0 {
|
||||
if i as u64 % (PAGE_SIZE / 8 / 8) == 0 {
|
||||
Self::set_color(&mut res, "");
|
||||
res.push('\n');
|
||||
Self::set_color(&mut res, prev);
|
||||
}
|
||||
if i as u64 % (PAGE_SIZE / 8) == 0 {
|
||||
Self::set_color(&mut res, "");
|
||||
prev = "";
|
||||
res.push_str(&"-".repeat((PAGE_SIZE / 8 / 8) as usize));
|
||||
res.push('\n');
|
||||
}
|
||||
}
|
||||
|
||||
let color = kind.map(CoverageKind::color).unwrap_or("33");
|
||||
if color != prev {
|
||||
Self::set_color(&mut res, color);
|
||||
}
|
||||
prev = color;
|
||||
|
||||
res.push(char::from_u32(0x2800 + byte as u32).unwrap());
|
||||
}
|
||||
|
||||
Self::set_color(&mut res, "");
|
||||
|
||||
res.push('\n');
|
||||
|
||||
res
|
||||
}
|
||||
|
||||
fn assert_covered(&self) {
|
||||
if !self.all_covered() {
|
||||
panic!("Space in the file was lost\n{}", self.print());
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn coverage_map_works() {
|
||||
let mut coverage = CoverageMap::new(40);
|
||||
assert!(!coverage.all_covered());
|
||||
assert!(
|
||||
coverage.try_set_range(RawFilePointer::null().range(20), CoverageKind::FileMetadata)
|
||||
);
|
||||
assert!(!coverage.all_covered());
|
||||
assert!(coverage.try_set_range((RawFilePointer::null() + 20).range(20), CoverageKind::Free));
|
||||
assert!(coverage.all_covered());
|
||||
assert!(!coverage.try_set_range(
|
||||
(RawFilePointer::null() + 40).range(8),
|
||||
CoverageKind::Allocated
|
||||
));
|
||||
assert!(!coverage.try_set_range(
|
||||
(RawFilePointer::null() + 50).range(10),
|
||||
CoverageKind::Allocated
|
||||
));
|
||||
}
|
||||
|
||||
fn validate_db<R>(db: &Db<R>, f: impl FnOnce(&Snapshot<R>, &mut CoverageMap)) {
|
||||
let mut coverage = CoverageMap::new(db.map.len());
|
||||
|
||||
let snapshot = &*db.state.get();
|
||||
|
||||
coverage.set_range(Db::<R>::header_ptr().range(), CoverageKind::FileMetadata);
|
||||
|
||||
// general purpose
|
||||
{
|
||||
let head = Db::<R>::header_ptr().allocator_state_ptr().general_ptr();
|
||||
let mut next = *snapshot.read(head);
|
||||
while !next.is_null() {
|
||||
let size = GeneralPurposeAllocator::size(db, next);
|
||||
coverage.set_range(next.into_raw().range(size), CoverageKind::Free);
|
||||
next = *snapshot.read(next.next_ptr());
|
||||
}
|
||||
}
|
||||
|
||||
// slabs
|
||||
{
|
||||
let slabs = *snapshot.read(Db::<R>::header_ptr().allocator_state_ptr().slabs_ptr());
|
||||
|
||||
let mut next = Some(slabs);
|
||||
while let Some(slabs) = next {
|
||||
coverage.set_range(
|
||||
slabs
|
||||
.0
|
||||
.into_raw()
|
||||
.range(slabs.read_header(db).size() as u64),
|
||||
CoverageKind::SlabMetadata,
|
||||
);
|
||||
next = slabs.next(db);
|
||||
|
||||
for slab in slabs.iter(db) {
|
||||
let size = slab.size(db);
|
||||
let head = slab.head(db);
|
||||
|
||||
match SlabKind::for_size(size) {
|
||||
SlabKind::SingleBytes => todo!(),
|
||||
SlabKind::RelativeFreeList => {
|
||||
let (mut page, offset) = head.page_offset();
|
||||
|
||||
while !page.is_null() {
|
||||
let header =
|
||||
FilePointer::<RelativeFreeListHeader>::new(page.start());
|
||||
|
||||
coverage.set_range(header.range(), CoverageKind::SlabMetadata);
|
||||
|
||||
let header = snapshot.read(header);
|
||||
|
||||
page = header.next_page;
|
||||
|
||||
let mut next = header.first.get();
|
||||
while next != 0 {
|
||||
let next_ptr = FilePointer::<U16>::new(
|
||||
RawFilePointer::from_page_and_offset(page, next),
|
||||
);
|
||||
coverage.set_range(
|
||||
next_ptr.into_raw().range(size as u64),
|
||||
CoverageKind::Free,
|
||||
);
|
||||
next = snapshot.read(next_ptr).get();
|
||||
}
|
||||
}
|
||||
|
||||
todo!();
|
||||
}
|
||||
SlabKind::AbsoluteFreeList => {
|
||||
let mut next = head;
|
||||
while !next.is_null() {
|
||||
let next_ptr = FilePointer::<RawFilePointer>::new(next);
|
||||
coverage.set_range(
|
||||
next_ptr.into_raw().range(size as u64),
|
||||
CoverageKind::Free,
|
||||
);
|
||||
next = *snapshot.read(next_ptr);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// retired objects
|
||||
{
|
||||
for SnapshotAndFreeList { to_free, .. } in &db.snapshots {
|
||||
for &range in to_free {
|
||||
coverage.set_range(range, CoverageKind::Retired);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
f(snapshot, &mut coverage);
|
||||
|
||||
if !coverage.all_covered() {
|
||||
print!("{}", coverage.print());
|
||||
panic!("space in the file was lost...");
|
||||
}
|
||||
}
|
||||
|
||||
fn hexdump(bytes: &[u8]) {
|
||||
let mut child = std::process::Command::new("hexdump")
|
||||
.arg("-C")
|
||||
.stdin(Stdio::piped())
|
||||
.stdout(Stdio::inherit())
|
||||
.spawn()
|
||||
.unwrap();
|
||||
|
||||
let mut stdin = child.stdin.take().expect("failed to get stdin");
|
||||
|
||||
stdin.write_all(bytes).unwrap();
|
||||
|
||||
std::mem::drop(stdin);
|
||||
|
||||
child.wait().unwrap();
|
||||
}
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user