Struct CodesStats 

pub struct CodesStats<const ZETA: usize = 10, const GOLOMB: usize = 10, const EXP_GOLOMB: usize = 10, const RICE: usize = 10, const PI: usize = 10> {
    pub total: u64,
    pub unary: u64,
    pub gamma: u64,
    pub delta: u64,
    pub omega: u64,
    pub vbyte: u64,
    pub zeta: [u64; ZETA],
    pub golomb: [u64; GOLOMB],
    pub exp_golomb: [u64; EXP_GOLOMB],
    pub rice: [u64; RICE],
    pub pi: [u64; PI],
}

Keeps track of the space needed to store a stream of integers using different codes.

This structure can be used to determine empirically which code provides the best compression for a given stream. You have to update the structure with the integers in the stream; at any time, you can examine the statistics or call best_code to get the best code.

The structure keeps tracks of the codes for which the module code_consts provide constants.

Fields

total: u64

The total number of elements observed.

unary: u64

The total space used to store the elements if they were stored using the unary code.

gamma: u64

The total space used to store the elements if they were stored using the gamma code.

delta: u64

The total space used to store the elements if they were stored using the delta code.

omega: u64

The total space used to store the elements if they were stored using the omega code.

vbyte: u64

The total space used to store the elements if they were stored using the variable byte code.

zeta: [u64; ZETA]

The total space used to store the elements if they were stored using a zeta code. zeta[0] represents ζ₁, zeta[1] represents ζ₂, and so on.

golomb: [u64; GOLOMB]

The total space used to store the elements if they were stored using a Golomb code. golomb[0] represents the Golomb code with modulus 1, golomb[1] represents the Golomb code with modulus 2, and so on.

exp_golomb: [u64; EXP_GOLOMB]

The total space used to store the elements if they were stored using an exponential Golomb code. exp_golomb[0] represents the exponential Golomb code with parameter 0, exp_golomb[1] with parameter 1, and so on.

rice: [u64; RICE]

The total space used to store the elements if they were stored using a Rice code. rice[0] represents the Rice code with log₂(b) = 0, rice[1] with log₂(b) = 1, and so on.

pi: [u64; PI]

The total space used to store the elements if they were stored using a pi code. pi[0] represents π₂, pi[1] represents π₃, and so on.

Implementations

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

pub fn update(&mut self, n: u64) -> u64

Update the stats with the lengths of the codes for n and return n for convenience.

pub fn update_many(&mut self, n: u64, count: u64) -> u64

Update the stats with count occurrences of n and return n for convenience.

pub fn add(&mut self, rhs: &Self)

Combines additively this stats with another one.

pub fn best_code(&self) -> (Codes, u64)

Returns the best code for the stream and its space usage.

When VByte is the best code, Codes::VByteBe is returned as the canonical representative (both variants have the same bit length).

pub fn get_codes(&self) -> Vec<(Codes, u64)>

Returns a vector of all codes and their space usage, in ascending order by space usage.

pub fn bits_for(&self, code: Codes) -> Option<u64>

Returns the number of bits used by the given code.

Trait Implementations

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> Add for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

fn add(self, rhs: Self) -> Self

Combines additively this stats with another one, creating a new one.

type Output = CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

The resulting type after applying the + operator.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> AddAssign for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

fn add_assign(&mut self, rhs: Self)

Combines additively this stats with another one.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> Clone for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

fn clone(&self) -> CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> Debug for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

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

Formats the value using the given formatter.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> Default for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

fn default() -> Self

Returns the “default value” for a type.

impl<'de, const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> Deserialize<'de> for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

Available on crate feature serde only.

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> FlatType for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

where u64: MemSize + FlatType, [u64; ZETA]: MemSize + FlatType, [u64; GOLOMB]: MemSize + FlatType, [u64; EXP_GOLOMB]: MemSize + FlatType, [u64; RICE]: MemSize + FlatType, [u64; PI]: MemSize + FlatType,

type Flat = False

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> MemDbgImpl for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

where u64: MemDbgImpl + FlatType, [u64; ZETA]: MemDbgImpl + FlatType, [u64; GOLOMB]: MemDbgImpl + FlatType, [u64; EXP_GOLOMB]: MemDbgImpl + FlatType, [u64; RICE]: MemDbgImpl + FlatType, [u64; PI]: MemDbgImpl + FlatType,

fn _mem_dbg_rec_on( &self, _memdbg_writer: &mut impl Write, _memdbg_total_size: usize, _memdbg_max_depth: usize, _memdbg_prefix: &mut String, _memdbg_is_last: bool, _memdbg_flags: DbgFlags, _memdbg_refs: &mut HashSet<usize>, ) -> Result

fn _mem_dbg_depth_on( &self, writer: &mut impl Write, total_size: usize, max_depth: usize, prefix: &mut String, field_name: Option<&str>, is_last: bool, padded_size: usize, flags: DbgFlags, dbg_refs: &mut HashSet<usize>, ) -> Result<(), Error>

fn _mem_dbg_depth_on_impl( &self, writer: &mut impl Write, total_size: usize, max_depth: usize, prefix: &mut String, field_name: Option<&str>, is_last: bool, padded_size: usize, flags: DbgFlags, dbg_refs: &mut HashSet<usize>, ref_display: RefDisplay, ) -> Result<(), Error>

Internal implementation for depth display.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> MemSize for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

where u64: MemSize + FlatType, [u64; ZETA]: MemSize + FlatType, [u64; GOLOMB]: MemSize + FlatType, [u64; EXP_GOLOMB]: MemSize + FlatType, [u64; RICE]: MemSize + FlatType, [u64; PI]: MemSize + FlatType,

fn mem_size_rec( &self, _memsize_flags: SizeFlags, _memsize_refs: &mut HashMap<usize, usize>, ) -> usize

Recursive implementation that tracks visited references for deduplication.

fn mem_size(&self, flags: SizeFlags) -> usize

Returns the (recursively computed) overall memory size of the structure in bytes.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> PartialEq for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

fn eq(&self, other: &CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> Serialize for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

Available on crate feature serde only.

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> Sum for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

Allows calling .sum() on an iterator of CodesStats.

fn sum<I: Iterator<Item = Self>>(iter: I) -> Self

Takes an iterator and generates Self from the elements by “summing up” the items.

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> Copy for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> Eq for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>

impl<const ZETA: usize, const GOLOMB: usize, const EXP_GOLOMB: usize, const RICE: usize, const PI: usize> StructuralPartialEq for CodesStats<ZETA, GOLOMB, EXP_GOLOMB, RICE, PI>