Struct Layer

pub struct Layer<'l, Stream: Write + Read + Seek> {
    pub bounds: Option<Range<u64>>,
    pub size: u64,
    pub read_cursor: (u64, usize),
    /* private fields */
}

Represents a layer (either in the heap or disk) in the stack-db that stacks

Fields

bounds: Option<Range<u64>>

The bounds of the layer; the range of the layer

size: u64

The total size of all the writes in the layer

read_cursor: (u64, usize)

The current read cursor to speed up sequential reads

Implementations

impl<'l, Stream: Write + Read + Seek> Layer<'l, Stream>

pub fn new(stream: Stream) -> Self

pub fn load(stream: Stream) -> Result<Self, Error>

pub fn check_collisions( &mut self, range: &Range<u64>, ) -> Result<Box<[Range<u64>]>, Error>

Checks for collisions on the current layer

pub fn check_non_collisions( &self, range: &Range<u64>, collisions: &[Range<u64>], ) -> Box<[Range<u64>]>

Takes in the ordered output of the check_collisions function to find the inverse

pub fn read_unchecked( &mut self, addr: &Range<u64>, ) -> Result<(Range<usize>, Cow<'_, [u8]>), Error>

Reads from the layer unchecked and returns the section data and the desired relative range within the section.

warning: will throw out-of-bounds error (or undefined behaviour) if the read is accross two sections (each read can only be on one section of a layer)

pub fn write_unchecked( &mut self, idx: u64, data: Cow<'l, [u8]>, ) -> Result<(), Error>

Writes to the heap layer without checking for collisions

WARNING: the layer will be corrupt (due to undefined behaviour) if there are any collisions; this function is meant to be used internally

pub fn flush(&mut self) -> Result<(), Error>

Moves the layer from the heap to disk

Trait Implementations

impl<'l, Stream: Debug + Write + Read + Seek> Debug for Layer<'l, Stream>

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

Formats the value using the given formatter.