Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Optimize JSON encoding of numbers #458

Merged
merged 1 commit into from
Jun 28, 2023
Merged

Optimize JSON encoding of numbers #458

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
23 changes: 6 additions & 17 deletions msgspec/_core.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@
#include "structmember.h"

#include "common.h"
#include "itoa.h"
#include "ryu.h"
#include "atof.h"

Expand Down Expand Up @@ -11181,30 +11182,18 @@ json_encode_long_fallback(EncoderState *self, PyObject *obj) {
static MS_NOINLINE int
json_encode_long(EncoderState *self, PyObject *obj) {
char buf[20];
char *p = &buf[20];
char *p = buf;
uint64_t x;
bool neg, overflow;
overflow = fast_long_extract_parts(obj, &neg, &x);
if (MS_UNLIKELY(overflow)) {
return json_encode_long_fallback(self, obj);
}
while (x >= 100) {
uint64_t const old = x;
p -= 2;
x /= 100;
memcpy(p, DIGIT_TABLE + ((old - (x * 100)) << 1), 2);
}
if (x >= 10) {
p -= 2;
memcpy(p, DIGIT_TABLE + (x << 1), 2);
}
else {
*--p = x + '0';
}
if (neg) {
*--p = '-';
*p++ = '-';
}
return ms_write(self, p, &buf[20] - p);
int n = write_u64(x, p);
return ms_write(self, buf, n + neg);
}

static int
Expand All @@ -11218,7 +11207,7 @@ static MS_NOINLINE int
json_encode_float(EncoderState *self, PyObject *obj) {
char buf[24];
double x = PyFloat_AS_DOUBLE(obj);
int n = format_double(x, buf);
int n = write_f64(x, buf);
return ms_write(self, buf, n);
}

Expand Down
173 changes: 173 additions & 0 deletions msgspec/itoa.h
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,173 @@
/* This code is a modified and condensed version of the int -> str routines
* found in yyjson (https://github.com/ibireme/yyjson). The yyjson license
* is copied below:
*
* Copyright (c) 2020 YaoYuan <[email protected]>

* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/

#ifndef MS_ITOA_H
#define MS_ITOA_H

#include <stdlib.h>

#include "common.h"

static const char DIGIT_TABLE[200] = {
'0','0','0','1','0','2','0','3','0','4','0','5','0','6','0','7','0','8','0','9',
'1','0','1','1','1','2','1','3','1','4','1','5','1','6','1','7','1','8','1','9',
'2','0','2','1','2','2','2','3','2','4','2','5','2','6','2','7','2','8','2','9',
'3','0','3','1','3','2','3','3','3','4','3','5','3','6','3','7','3','8','3','9',
'4','0','4','1','4','2','4','3','4','4','4','5','4','6','4','7','4','8','4','9',
'5','0','5','1','5','2','5','3','5','4','5','5','5','6','5','7','5','8','5','9',
'6','0','6','1','6','2','6','3','6','4','6','5','6','6','6','7','6','8','6','9',
'7','0','7','1','7','2','7','3','7','4','7','5','7','6','7','7','7','8','7','9',
'8','0','8','1','8','2','8','3','8','4','8','5','8','6','8','7','8','8','8','9',
'9','0','9','1','9','2','9','3','9','4','9','5','9','6','9','7','9','8','9','9'
};

static MS_INLINE void
write_u32_8_digits(uint32_t x, char *buf) {
uint32_t aabb, ccdd, aa, bb, cc, dd;
aabb = (uint32_t)(((uint64_t)x * 109951163) >> 40); /* (x / 10000) */
ccdd = x - aabb * 10000; /* (x % 10000) */
aa = (aabb * 5243) >> 19; /* (aabb / 100) */
bb = aabb - aa * 100; /* (aabb % 100) */
cc = (ccdd * 5243) >> 19; /* (ccdd / 100) */
dd = ccdd - cc * 100; /* (ccdd % 100) */
memcpy(buf + 0, DIGIT_TABLE + aa * 2, 2);
memcpy(buf + 2, DIGIT_TABLE + bb * 2, 2);
memcpy(buf + 4, DIGIT_TABLE + cc * 2, 2);
memcpy(buf + 6, DIGIT_TABLE + dd * 2, 2);
}

static MS_INLINE void
write_u32_4_digits(uint32_t x, char *buf) {
uint32_t aa, bb;
aa = (x * 5243) >> 19; /* (x / 100) */
bb = x - aa * 100; /* (x % 100) */
memcpy(buf + 0, DIGIT_TABLE + aa * 2, 2);
memcpy(buf + 2, DIGIT_TABLE + bb * 2, 2);
}

static MS_INLINE char *
write_u32_1_to_8_digits(uint32_t x, char *buf) {
uint32_t aa, bb, cc, dd, aabb, bbcc, ccdd, lz;

if (x < 100) { /* 1-2 digits */
lz = x < 10;
memcpy(buf + 0, DIGIT_TABLE + x * 2 + lz, 2);
buf -= lz;
return buf + 2;
} else if (x < 10000) { /* 3-4 digits */
aa = (x * 5243) >> 19; /* (x / 100) */
bb = x - aa * 100; /* (x % 100) */
lz = aa < 10;
memcpy(buf + 0, DIGIT_TABLE + aa * 2 + lz, 2);
buf -= lz;
memcpy(buf + 2, DIGIT_TABLE + bb * 2, 2);
return buf + 4;
} else if (x < 1000000) { /* 5-6 digits */
aa = (uint32_t)(((uint64_t)x * 429497) >> 32); /* (x / 10000) */
bbcc = x - aa * 10000; /* (x % 10000) */
bb = (bbcc * 5243) >> 19; /* (bbcc / 100) */
cc = bbcc - bb * 100; /* (bbcc % 100) */
lz = aa < 10;
memcpy(buf + 0, DIGIT_TABLE + aa * 2 + lz, 2);
buf -= lz;
memcpy(buf + 2, DIGIT_TABLE + bb * 2, 2);
memcpy(buf + 4, DIGIT_TABLE + cc * 2, 2);
return buf + 6;
} else { /* 7-8 digits */
aabb = (uint32_t)(((uint64_t)x * 109951163) >> 40); /* (x / 10000) */
ccdd = x - aabb * 10000; /* (x % 10000) */
aa = (aabb * 5243) >> 19; /* (aabb / 100) */
bb = aabb - aa * 100; /* (aabb % 100) */
cc = (ccdd * 5243) >> 19; /* (ccdd / 100) */
dd = ccdd - cc * 100; /* (ccdd % 100) */
lz = aa < 10;
memcpy(buf + 0, DIGIT_TABLE + aa * 2 + lz, 2);
buf -= lz;
memcpy(buf + 2, DIGIT_TABLE + bb * 2, 2);
memcpy(buf + 4, DIGIT_TABLE + cc * 2, 2);
memcpy(buf + 6, DIGIT_TABLE + dd * 2, 2);
return buf + 8;
}
}

static MS_INLINE char *
write_u64_5_to_8_digits(uint32_t x, char *buf) {
uint32_t aa, bb, cc, dd, aabb, bbcc, ccdd, lz;

if (x < 1000000) { /* 5-6 digits */
aa = (uint32_t)(((uint64_t)x * 429497) >> 32); /* (x / 10000) */
bbcc = x - aa * 10000; /* (x % 10000) */
bb = (bbcc * 5243) >> 19; /* (bbcc / 100) */
cc = bbcc - bb * 100; /* (bbcc % 100) */
lz = aa < 10;
memcpy(buf + 0, DIGIT_TABLE + aa * 2 + lz, 2);
buf -= lz;
memcpy(buf + 2, DIGIT_TABLE + bb * 2, 2);
memcpy(buf + 4, DIGIT_TABLE + cc * 2, 2);
return buf + 6;
} else { /* 7-8 digits */
aabb = (uint32_t)(((uint64_t)x * 109951163) >> 40); /* (x / 10000) */
ccdd = x - aabb * 10000; /* (x % 10000) */
aa = (aabb * 5243) >> 19; /* (aabb / 100) */
bb = aabb - aa * 100; /* (aabb % 100) */
cc = (ccdd * 5243) >> 19; /* (ccdd / 100) */
dd = ccdd - cc * 100; /* (ccdd % 100) */
lz = aa < 10;
memcpy(buf + 0, DIGIT_TABLE + aa * 2 + lz, 2);
buf -= lz;
memcpy(buf + 2, DIGIT_TABLE + bb * 2, 2);
memcpy(buf + 4, DIGIT_TABLE + cc * 2, 2);
memcpy(buf + 6, DIGIT_TABLE + dd * 2, 2);
return buf + 8;
}
}

/* Write a uint64 to buf, requires 20 bytes of space */
static inline int
write_u64(uint64_t x, char *buf) {
uint64_t tmp, hgh;
uint32_t mid, low;

if (x < 100000000) { /* 1-8 digits */
return write_u32_1_to_8_digits((uint32_t)x, buf) - buf;
} else if (x < (uint64_t)100000000 * 100000000) { /* 9-16 digits */
hgh = x / 100000000; /* (x / 100000000) */
low = (uint32_t)(x - hgh * 100000000); /* (x % 100000000) */
char *cur = write_u32_1_to_8_digits((uint32_t)hgh, buf);
write_u32_8_digits(low, cur);
return cur + 8 - buf;
} else { /* 17-20 digits */
tmp = x / 100000000; /* (x / 100000000) */
low = (uint32_t)(x - tmp * 100000000); /* (x % 100000000) */
hgh = (uint32_t)(tmp / 10000); /* (tmp / 10000) */
mid = (uint32_t)(tmp - hgh * 10000); /* (tmp % 10000) */
char *cur = write_u64_5_to_8_digits((uint32_t)hgh, buf);
write_u32_4_digits(mid, cur);
write_u32_8_digits(low, cur + 4);
return cur + 12 - buf;
}
}

#endif // MS_ITOA_H
Loading
Loading