# Copyright (C) 2016-present the asyncpg authors and contributors
# <see AUTHORS file>
#
# This module is part of asyncpg and is released under
# the Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0
from libc.math cimport abs, log10
from libc.stdio cimport snprintf
import decimal
# defined in postgresql/src/backend/utils/adt/numeric.c
DEF DEC_DIGITS = 4
DEF MAX_DSCALE = 0x3FFF
DEF NUMERIC_POS = 0x0000
DEF NUMERIC_NEG = 0x4000
DEF NUMERIC_NAN = 0xC000
DEF NUMERIC_PINF = 0xD000
DEF NUMERIC_NINF = 0xF000
_Dec = decimal.Decimal
cdef numeric_encode_text(CodecContext settings, WriteBuffer buf, obj):
text_encode(settings, buf, str(obj))
cdef numeric_decode_text(CodecContext settings, FRBuffer *buf):
return _Dec(text_decode(settings, buf))
cdef numeric_encode_binary(CodecContext settings, WriteBuffer buf, obj):
cdef:
object dec
object dt
int64_t exponent
int64_t i
int64_t j
tuple pydigits
int64_t num_pydigits
int16_t pgdigit
int64_t num_pgdigits
int16_t dscale
int64_t dweight
int64_t weight
uint16_t sign
int64_t padding_size = 0
if isinstance(obj, _Dec):
dec = obj
else:
dec = _Dec(obj)
dt = dec.as_tuple()
if dt.exponent == 'n' or dt.exponent == 'N':
# NaN
sign = NUMERIC_NAN
num_pgdigits = 0
weight = 0
dscale = 0
elif dt.exponent == 'F':
# Infinity
if dt.sign:
sign = NUMERIC_NINF
else:
sign = NUMERIC_PINF
num_pgdigits = 0
weight = 0
dscale = 0
else:
exponent = dt.exponent
if exponent < 0 and -exponent > MAX_DSCALE:
raise ValueError(
'cannot encode Decimal value into numeric: '
'exponent is too small')
if dt.sign:
sign = NUMERIC_NEG
else:
sign = NUMERIC_POS
pydigits = dt.digits
num_pydigits = len(pydigits)
dweight = num_pydigits + exponent - 1
if dweight >= 0:
weight = (dweight + DEC_DIGITS) // DEC_DIGITS - 1
else:
weight = -((-dweight - 1) // DEC_DIGITS + 1)
if weight > 2 ** 16 - 1:
raise ValueError(
'cannot encode Decimal value into numeric: '
'exponent is too large')
padding_size = \
(weight + 1) * DEC_DIGITS - (dweight + 1)
num_pgdigits = \
(num_pydigits + padding_size + DEC_DIGITS - 1) // DEC_DIGITS
if num_pgdigits > 2 ** 16 - 1:
raise ValueError(
'cannot encode Decimal value into numeric: '
'number of digits is too large')
# Pad decimal digits to provide room for correct Postgres
# digit alignment in the digit computation loop.
pydigits = (0,) * DEC_DIGITS + pydigits + (0,) * DEC_DIGITS
if exponent < 0:
if -exponent > MAX_DSCALE:
raise ValueError(
'cannot encode Decimal value into numeric: '
'exponent is too small')
dscale = <int16_t>-exponent
else:
dscale = 0
buf.write_int32(2 + 2 + 2 + 2 + 2 * <uint16_t>num_pgdigits)
buf.write_int16(<int16_t>num_pgdigits)
buf.write_int16(<int16_t>weight)
buf.write_int16(<int16_t>sign)
buf.write_int16(dscale)
j = DEC_DIGITS - padding_size
for i in range(num_pgdigits):
pgdigit = (pydigits[j] * 1000 + pydigits[j + 1] * 100 +
pydigits[j + 2] * 10 + pydigits[j + 3])
j += DEC_DIGITS
buf.write_int16(pgdigit)
# The decoding strategy here is to form a string representation of
# the numeric var, as it is faster than passing an iterable of digits.
# For this reason the below code is pure overhead and is ~25% slower
# than the simple text decoder above. That said, we need the binary
# decoder to support binary COPY with numeric values.
cdef numeric_decode_binary_ex(
CodecContext settings,
FRBuffer *buf,
bint trail_fract_zero,
):
cdef:
uint16_t num_pgdigits = <uint16_t>hton.unpack_int16(frb_read(buf, 2))
int16_t weight = hton.unpack_int16(frb_read(buf, 2))
uint16_t sign = <uint16_t>hton.unpack_int16(frb_read(buf, 2))
uint16_t dscale = <uint16_t>hton.unpack_int16(frb_read(buf, 2))
int16_t pgdigit0
ssize_t i
int16_t pgdigit
object pydigits
ssize_t num_pydigits
ssize_t actual_num_pydigits
ssize_t buf_size
int64_t exponent
int64_t abs_exponent
ssize_t exponent_chars
ssize_t front_padding = 0
ssize_t num_fract_digits
ssize_t trailing_fract_zeros_adj
char smallbuf[_NUMERIC_DECODER_SMALLBUF_SIZE]
char *charbuf
char *bufptr
bint buf_allocated = False
if sign == NUMERIC_NAN:
# Not-a-number
return _Dec('NaN')
elif sign == NUMERIC_PINF:
# +Infinity
return _Dec('Infinity')
elif sign == NUMERIC_NINF:
# -Infinity
return _Dec('-Infinity')
if num_pgdigits == 0:
# Zero
return _Dec('0e-' + str(dscale))
pgdigit0 = hton.unpack_int16(frb_read(buf, 2))
if weight >= 0:
if pgdigit0 < 10:
front_padding = 3
elif pgdigit0 < 100:
front_padding = 2
elif pgdigit0 < 1000:
front_padding = 1
# The number of fractional decimal digits actually encoded in
# base-DEC_DEIGITS digits sent by Postgres.
num_fract_digits = (num_pgdigits - weight - 1) * DEC_DIGITS
# The trailing zero adjustment necessary to obtain exactly
# dscale number of fractional digits in output. May be negative,
# which indicates that trailing zeros in the last input digit
# should be discarded.
trailing_fract_zeros_adj = dscale - num_fract_digits
# Maximum possible number of decimal digits in base 10.
# The actual number might be up to 3 digits smaller due to
# leading zeros in first input digit.
num_pydigits = num_pgdigits * DEC_DIGITS
if trailing_fract_zeros_adj > 0:
num_pydigits += trailing_fract_zeros_adj
# Exponent.
exponent = (weight + 1) * DEC_DIGITS - front_padding
abs_exponent = abs(exponent)
if abs_exponent != 0:
# Number of characters required to render absolute exponent value
# in decimal.
exponent_chars = <ssize_t>log10(<double>abs_exponent) + 1
else:
exponent_chars = 0
# Output buffer size.
buf_size = (
1 + # sign
1 + # leading zero
1 + # decimal dot
num_pydigits + # digits
1 + # possible trailing zero padding
2 + # exponent indicator (E-,E+)
exponent_chars + # exponent
1 # null terminator char
)
if buf_size > _NUMERIC_DECODER_SMALLBUF_SIZE:
charbuf = <char *>cpython.PyMem_Malloc(<size_t>buf_size)
buf_allocated = True
else:
charbuf = smallbuf
try:
bufptr = charbuf
if sign == NUMERIC_NEG:
bufptr[0] = b'-'
bufptr += 1
bufptr[0] = b'0'
bufptr[1] = b'.'
bufptr += 2
if weight >= 0:
bufptr = _unpack_digit_stripping_lzeros(bufptr, pgdigit0)
else:
bufptr = _unpack_digit(bufptr, pgdigit0)
for i in range(1, num_pgdigits):
pgdigit = hton.unpack_int16(frb_read(buf, 2))
bufptr = _unpack_digit(bufptr, pgdigit)
if dscale:
if trailing_fract_zeros_adj > 0:
for i in range(trailing_fract_zeros_adj):
bufptr[i] = <char>b'0'
# If display scale is _less_ than the number of rendered digits,
# trailing_fract_zeros_adj will be negative and this will strip
# the excess trailing zeros.
bufptr += trailing_fract_zeros_adj
if trail_fract_zero:
# Check if the number of rendered digits matches the exponent,
# and if so, add another trailing zero, so the result always
# appears with a decimal point.
actual_num_pydigits = bufptr - charbuf - 2
if sign == NUMERIC_NEG:
actual_num_pydigits -= 1
if actual_num_pydigits == abs_exponent:
bufptr[0] = <char>b'0'
bufptr += 1
if exponent != 0:
bufptr[0] = b'E'
if exponent < 0:
bufptr[1] = b'-'
else:
bufptr[1] = b'+'
bufptr += 2
snprintf(bufptr, <size_t>exponent_chars + 1, '%d',
<int>abs_exponent)
bufptr += exponent_chars
bufptr[0] = 0
pydigits = cpythonx.PyUnicode_FromString(charbuf)
return _Dec(pydigits)
finally:
if buf_allocated:
cpython.PyMem_Free(charbuf)
cdef numeric_decode_binary(CodecContext settings, FRBuffer *buf):
return numeric_decode_binary_ex(settings, buf, False)
cdef inline char *_unpack_digit_stripping_lzeros(char *buf, int64_t pgdigit):
cdef:
int64_t d
bint significant
d = pgdigit // 1000
significant = (d > 0)
if significant:
pgdigit -= d * 1000
buf[0] = <char>(d + <int32_t>b'0')
buf += 1
d = pgdigit // 100
significant |= (d > 0)
if significant:
pgdigit -= d * 100
buf[0] = <char>(d + <int32_t>b'0')
buf += 1
d = pgdigit // 10
significant |= (d > 0)
if significant:
pgdigit -= d * 10
buf[0] = <char>(d + <int32_t>b'0')
buf += 1
buf[0] = <char>(pgdigit + <int32_t>b'0')
buf += 1
return buf
cdef inline char *_unpack_digit(char *buf, int64_t pgdigit):
cdef:
int64_t d
d = pgdigit // 1000
pgdigit -= d * 1000
buf[0] = <char>(d + <int32_t>b'0')
d = pgdigit // 100
pgdigit -= d * 100
buf[1] = <char>(d + <int32_t>b'0')
d = pgdigit // 10
pgdigit -= d * 10
buf[2] = <char>(d + <int32_t>b'0')
buf[3] = <char>(pgdigit + <int32_t>b'0')
buf += 4
return buf
