Struct tidb_query_datatype::codec::mysql::decimal::Decimal

#[repr(C)]pub struct Decimal {
    int_cnt: u8,
    frac_cnt: u8,
    result_frac_cnt: u8,
    negative: bool,
    word_buf: [u32; 9],
}

Decimal represents a decimal value.

Fields

int_cnt: u8

The number of decimal digits before the point.

frac_cnt: u8

The number of decimal digits after the point.

result_frac_cnt: u8

The number of calculated or printed result fraction digits.

negative: bool

word_buf: [u32; 9]

An array of u32 words. A word is an u32 value can hold 9 digits.(0 <= word < wordBase)

Implementations

impl Decimal

pub fn abs(self) -> Res<Decimal>

abs the Decimal into a new Decimal.

pub fn ceil(&self) -> Res<Decimal>

ceil the Decimal into a new Decimal.

pub fn floor(&self) -> Res<Decimal>

floor the Decimal into a new Decimal.

fn new(int_cnt: u8, frac_cnt: u8, negative: bool) -> Decimal

create a new decimal for internal usage.

pub fn is_negative(&self) -> bool

pub fn zero() -> Decimal

Creates a new decimal which is zero.

fn remove_leading_zeroes(&self, prec: u8) -> (usize, u8)

Given a precision count ‘prec’, get:

1. the index of first non-zero word in self.word_buf to hold the leading ‘prec’ number of digits
2. the number of remained digits if we remove all leading zeros for the leading ‘prec’ number of digits

fn prepare_buf(&self) -> (Vec<u8>, usize, u8, u8, u8)

Prepare a buf for string output.

pub fn prec_and_frac(&self) -> (u8, u8)

Get the least precision and fraction count to encode this decimal completely.

fn digit_bounds(&self) -> (u8, u8)

digit_bounds returns bounds of decimal digits in the number.

fn do_mini_left_shift(self, shift: u8, beg: u8, end: u8) -> Decimal

do_mini_left_shift does left shift for alignment of data in buffer.

Result fitting in the buffer should be garanted. ‘shift’ have to be from 1 to DIGITS_PER_WORD - 1 (inclusive)

fn do_mini_right_shift(self, shift: u8, beg: u8, end: u8) -> Decimal

do_mini_right_shift does right shift for alignment of data in buffer.

Result fitting in the buffer should be garanted. ‘shift’ have to be from 1 to DIGITS_PER_WORD - 1 (inclusive)

pub fn convert_to(
    self,
    ctx: &mut EvalContext,
    flen: u8,
    decimal: u8
) -> Result<Decimal>

convert_to(ProduceDecWithSpecifiedTp in tidb) produces a new decimal according to flen and decimal.

pub fn round(self, frac: i8, round_mode: RoundMode) -> Res<Decimal>

Round rounds the decimal to “frac” digits.

NOTES scale can be negative ! one TRUNCATED error (line XXX below) isn’t treated very logical :(

fn round_with_word_buf_len(
    self,
    frac: i8,
    word_buf_len: u8,
    round_mode: RoundMode
) -> Res<Decimal>

fn handle_incr(
    res: Res<Decimal>,
    int_word_cnt: u8,
    frac_words_to: i8,
    frac: i8,
    frac_word_cnt: u8,
    word_buf_len: u8,
    round_mode: RoundMode
) -> Res<Decimal>

fn handle_carry(
    dec: Res<Decimal>,
    to_idx: usize,
    frac: i8,
    frac_word_to: i8,
    int_word_cnt: u8,
    word_buf_len: u8
) -> Res<Decimal>

pub fn shift(self, shift: isize) -> Res<Decimal>

shift shifts decimal digits in given number (with rounding if it need), shift > 0 means shift to left shift, shift < 0 means right shift.

In fact it is multiplying on 10^shift.

fn shift_with_word_buf_len(self, shift: isize, word_buf_len: u8) -> Res<Decimal>

pub fn as_i64(&self) -> Res<i64>

as_i64 returns int part of the decimal.

pub fn as_i64_with_ctx(&self, ctx: &mut EvalContext) -> Result<i64>

as_i64_with_ctx returns int part of the decimal.

pub fn as_u64(&self) -> Res<u64>

as_u64 returns int part of the decimal

pub fn from_f64(val: f64) -> Result<Decimal>

pub fn from_bytes(s: &[u8]) -> Result<Res<Decimal>>

Returns a Decimal from a given bytes slice

Notes

An error will be returned if the given input is as follows:

1. empty string
2. string which cannot be converted to decimal

fn from_bytes_with_word_buf(s: &[u8], word_buf_len: u8) -> Result<Res<Decimal>>

Returns a Decimal from a given bytes slice buffer and specified buffer length

Notes

An error will be returned if the given input is as follows:

1. an empty string
2. a string which cannot be converted to decimal

pub fn approximate_encoded_size(&self) -> usize

Get the approximate needed capacity to encode this decimal.

see also encode_decimal.

fn div(&self, rhs: &Decimal, frac_incr: u8) -> Option<Res<Decimal>>

pub fn is_zero(&self) -> bool

Trait Implementations

impl<'a, 'b> Add<&'a Decimal> for &'b Decimal

type Output = Res<Decimal>

The resulting type after applying the + operator.

fn add(self, rhs: &'a Decimal) -> Res<Decimal>

Performs the + operation.

impl AsMySQLBool for Decimal

fn as_mysql_bool(&self, _ctx: &mut EvalContext) -> Result<bool>

Evaluates into a MySQL logic value.

impl Clone for Decimal

fn clone(&self) -> Decimal

Returns a copy of the value.

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

Performs copy-assignment from source.

impl ConvertTo<Decimal> for i64

fn convert(&self, _: &mut EvalContext) -> Result<Decimal>

Converts the given value to T value

impl ConvertTo<Decimal> for u64

fn convert(&self, _: &mut EvalContext) -> Result<Decimal>

Converts the given value to T value

impl ConvertTo<Decimal> for Time

fn convert(&self, _: &mut EvalContext) -> Result<Decimal>

Converts the given value to T value

impl ConvertTo<Decimal> for f64

fn convert(&self, _: &mut EvalContext) -> Result<Decimal>

Convert a float number to decimal.

This function will use float’s canonical string representation rather than the accurate value the float represent.

impl ConvertTo<Decimal> for Real

fn convert(&self, ctx: &mut EvalContext) -> Result<Decimal>

Converts the given value to T value

impl ConvertTo<Decimal> for &[u8]

fn convert(&self, ctx: &mut EvalContext) -> Result<Decimal>

Converts the given value to T value

impl ConvertTo<Decimal> for Cow<'_, [u8]>

fn convert(&self, ctx: &mut EvalContext) -> Result<Decimal>

Converts the given value to T value

impl ConvertTo<Decimal> for Bytes

fn convert(&self, ctx: &mut EvalContext) -> Result<Decimal>

Converts the given value to T value

impl ConvertTo<Decimal> for Json

fn convert(&self, ctx: &mut EvalContext) -> Result<Decimal>

Port from TiDB’s types.ConvertJSONToDecimal

impl<'a> ConvertTo<Decimal> for JsonRef<'a>

fn convert(&self, ctx: &mut EvalContext) -> Result<Decimal>

Port from TiDB’s types.ConvertJSONToDecimal

impl ConvertTo<Decimal> for Duration

fn convert(&self, _: &mut EvalContext) -> Result<Decimal>

This function should not return err, if it return err, then the err is because of bug.

Port from TiDB’ Duration::ToNumber

impl ConvertTo<Json> for Decimal

fn convert(&self, ctx: &mut EvalContext) -> Result<Json>

Converts the given value to T value

impl ConvertTo<f64> for Decimal

fn convert(&self, _: &mut EvalContext) -> Result<f64>

This function should not return err, if it return err, then the err because of bug.

Port from TiDB’s MyDecimal::ToFloat64.

impl Copy for Decimal

impl Debug for Decimal

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

Formats the value using the given formatter.

impl Display for Decimal

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

Formats the value using the given formatter.

impl<'a, 'b> Div<&'a Decimal> for &'b Decimal

type Output = Option<Res<Decimal>>

The resulting type after applying the / operator.

fn div(self, rhs: &'a Decimal) -> Self::Output

Performs the / operation.

impl Eq for Decimal

impl Evaluable for Decimal

const EVAL_TYPE: EvalType

fn borrow_scalar_value(v: &ScalarValue) -> Option<&Self>

Borrows this concrete type from a ScalarValue in the same type; panics if the varient mismatches.

fn borrow_scalar_value_ref<'a>(v: ScalarValueRef<'a>) -> Option<&'a Self>

Borrows this concrete type from a ScalarValueRef in the same type; panics if the varient mismatches.

fn borrow_vector_value(v: &VectorValue) -> &ChunkedVecSized<Decimal>

Borrows a slice of this concrete type from a VectorValue in the same type; panics if the varient mismatches.

impl EvaluableRet for Decimal

const EVAL_TYPE: EvalType

type ChunkedType = ChunkedVecSized<Self>

fn cast_chunk_into_vector_value(vec: ChunkedVecSized<Self>) -> VectorValue

Converts a vector of this concrete type into a VectorValue in the same type; panics if the varient mismatches.

impl From<Decimal> for ScalarValue

fn from(s: Decimal) -> ScalarValue

Performs the conversion.

impl From<Decimal> for Datum

fn from(data: Decimal) -> Datum

Performs the conversion.

impl From<i16> for Decimal

fn from(t: i16) -> Decimal

Performs the conversion.

impl From<i32> for Decimal

fn from(t: i32) -> Decimal

Performs the conversion.

impl From<i64> for Decimal

fn from(i: i64) -> Decimal

Performs the conversion.

impl From<i8> for Decimal

fn from(t: i8) -> Decimal

Performs the conversion.

impl From<isize> for Decimal

fn from(t: isize) -> Decimal

Performs the conversion.

impl From<u16> for Decimal

fn from(t: u16) -> Decimal

Performs the conversion.

impl From<u32> for Decimal

fn from(t: u32) -> Decimal

Performs the conversion.

impl From<u64> for Decimal

fn from(u: u64) -> Decimal

Performs the conversion.

impl From<u8> for Decimal

fn from(t: u8) -> Decimal

Performs the conversion.

impl From<usize> for Decimal

fn from(t: usize) -> Decimal

Performs the conversion.

impl FromStr for Decimal

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Decimal>

Parses a string s to return a value of this type.

impl Hash for Decimal

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

pub fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<'a, 'b> Mul<&'a Decimal> for &'b Decimal

type Output = Res<Decimal>

The resulting type after applying the * operator.

fn mul(self, rhs: &'a Decimal) -> Res<Decimal>

Performs the * operation.

impl Neg for Decimal

type Output = Decimal

The resulting type after applying the - operator.

fn neg(self) -> Decimal

Performs the unary - operation.

impl Ord for Decimal

fn cmp(&self, right: &Decimal) -> Ordering

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Decimal> for Decimal

fn eq(&self, right: &Decimal) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialOrd<Decimal> for Decimal

fn partial_cmp(&self, right: &Decimal) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]pub fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]pub fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> RawDatumDecoder<Decimal> for &'a [u8]

fn decode(
    self,
    _field_type: &FieldType,
    _ctx: &mut EvalContext
) -> Result<Option<Decimal>>

impl<'a, 'b> Rem<&'a Decimal> for &'b Decimal

type Output = Option<Res<Decimal>>

The resulting type after applying the % operator.

fn rem(self, rhs: &'a Decimal) -> Self::Output

Performs the % operation.

impl Rem<Decimal> for Decimal

type Output = Option<Res<Decimal>>

The resulting type after applying the % operator.

fn rem(self, rhs: Decimal) -> Option<Res<Decimal>>

Performs the % operation.

impl<'a, 'b> Sub<&'a Decimal> for &'b Decimal

type Output = Res<Decimal>

The resulting type after applying the - operator.

fn sub(self, rhs: &'a Decimal) -> Res<Decimal>

Performs the - operation.

impl ToInt for Decimal

fn to_int(&self, ctx: &mut EvalContext, tp: FieldTypeTp) -> Result<i64>

Converts the given value to an i64

fn to_uint(&self, ctx: &mut EvalContext, tp: FieldTypeTp) -> Result<u64>

Converts the given value to an u64

impl ToString for Decimal

fn to_string(&self) -> String

Converts the given value to a String.

impl VectorValueExt<Decimal> for VectorValue

fn push(&mut self, v: Option<Decimal>)

The generic version for VectorValue::push_xxx().