Enum ValueStorage

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#[repr(C)]pub enum ValueStorage {
    Inline {
        len: u8,
        data: [u8; 56],
    },
    Heap(Box<[u8]>),
    Tombstone,
}

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Expand description

Optimized value storage with inline allocation for small values

For typical database workloads, 80%+ of values are < 56 bytes. Storing these inline eliminates heap allocation and pointer chasing.

§Cache Analysis

Current path: DashMap lookup → Version ptr → Value ptr (Vec data) Cache misses: 2-3 (worst case)

Inline path: DashMap lookup → Version with inline value Cache misses: 1

Expected speedup: 2-2.5× for reads on small values

Variants§

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Inline

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Value stored inline (most common case for small values)

Fields

§len: u8

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

§data: [u8; 56]

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

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Heap(Box<[u8]>)

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Value stored on heap (for large values > 56 bytes)

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Tombstone

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Tombstone marker (key was deleted)

Implementations§

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impl ValueStorage

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pub fn new(value: Option<&[u8]>) -> Self

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Create new value storage, preferring inline when possible

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pub fn as_bytes(&self) -> Option<&[u8]>

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Get value as byte slice

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pub fn is_tombstone(&self) -> bool

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Check if this is a tombstone

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pub fn is_inline(&self) -> bool

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Check if value is stored inline

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pub fn len(&self) -> usize

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Get the size of the stored value

Source

pub fn is_empty(&self) -> bool

👎Deprecated:

Unused duplicate memtable; live memtables are lscs::ColumnarMemtable + durable_storage::MvccMemTable. Scheduled for removal (Task 2 consolidation).

Check if the stored value is empty

Trait Implementations§

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impl Debug for ValueStorage

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

Formats the value using the given formatter. Read more

Auto Trait Implementations§

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impl UnwindSafe for ValueStorage

Blanket Implementations§

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impl<T> Allocation for T
where T: RefUnwindSafe + Send + Sync,

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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impl<ST, DT> CastableFrom<ST, Initialized, Initialized> for DT
where ST: ?Sized, DT: ?Sized,

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impl<ST, DT> CastableFrom<ST, Uninit, Uninit> for DT
where ST: ?Sized, DT: ?Sized,

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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

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impl<T, U> Into for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoEither for T

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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more

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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more

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