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/**
* This header file contains static functions adapted from
* Marc Lehmanns' JSON::XS, particularly because it's fast,
* doesn't seem to rely on any external structures, and because
* numeric conversions aren't my ideas of fun.
*/
#ifndef JSONXS_INLINE_H_
#define JSONXS_INLINE_H_
#include "perl-jsonsl.h"
#if __GNUC__ >= 3
# define expect(expr,value) __builtin_expect ((expr), (value))
# define INLINE static inline
#else
# define expect(expr,value) (expr)
# define INLINE static
#endif
#define ERR die
#define expect_false(expr) expect ((expr) != 0, 0)
#define expect_true(expr) expect ((expr) != 0, 1)
#define jsonxs__atof_scan1(s,a,e,p,m) jsonxs__atof_scan1_THX(aTHX_ s,a,e,p,m)
INLINE void
jsonxs__atof_scan1_THX(pTHX_ const char *s,
NV *accum, int *expo, int postdp,
int maxdepth)
{
UV uaccum = 0;
int eaccum = 0;
/* if we recurse too deep, skip all remaining digits
to avoid a stack overflow attack */
if (expect_false (--maxdepth <= 0))
while (((U8)*s - '0') < 10)
++s;
for (;;)
{
U8 dig = (U8)*s - '0';
if (expect_false (dig >= 10))
{
if (dig == (U8)((U8)'.' - (U8)'0'))
{
++s;
jsonxs__atof_scan1(s, accum, expo, 1, maxdepth);
}
else if ((dig | ' ') == 'e' - '0')
{
int exp2 = 0;
int neg = 0;
++s;
if (*s == '-')
{
++s;
neg = 1;
}
else if (*s == '+')
++s;
while ((dig = (U8)*s - '0') < 10)
exp2 = exp2 * 10 + *s++ - '0';
*expo += neg ? -exp2 : exp2;
}
break;
}
++s;
uaccum = uaccum * 10 + dig;
++eaccum;
/*
if we have too many digits, then recurse for more
we actually do this for rather few digits
*/
if (uaccum >= (UV_MAX - 9) / 10)
{
if (postdp) *expo -= eaccum;
jsonxs__atof_scan1 (s, accum, expo, postdp, maxdepth);
if (postdp) *expo += eaccum;
break;
}
}
/*
// this relies greatly on the quality of the pow ()
// implementation of the platform, but a good
// implementation is hard to beat.
// (IEEE 754 conformant ones are required to be exact)
*
*/
if (postdp) *expo -= eaccum;
*accum += uaccum * Perl_pow (10., *expo);
*expo += eaccum;
}
#define jsonxs__atof(s) jsonxs__atof_THX(aTHX_ s)
INLINE NV
jsonxs__atof_THX (pTHX_ const char *s)
{
NV accum = 0.;
int expo = 0;
int neg = 0;
if (*s == '-')
{
++s;
neg = 1;
}
/* a recursion depth of ten gives us >>500 bits */
jsonxs__atof_scan1(s, &accum, &expo, 0, 10);
return neg ? -accum : accum;
}
#define jsonxs_inline_process_number(s) jsonxs_inline_process_number_THX(aTHX_ s)
INLINE SV *
jsonxs_inline_process_number_THX(pTHX_ const char *start)
{
int is_nv = 0;
const char *c = start;
if (*c == '-')
++c;
if (*c == '0') {
++c;
if (*c >= '0' && *c <= '9') {
ERR("malformed number (leading zero must not be followed by another digit)");
}
} else if (*c < '0' || *c > '9') {
ERR("malformed number (no digits after initial minus)");
} else {
do {
++c;
} while (*c >= '0' && *c <= '9');
}
if (*c == '.') {
++c;
if (*c < '0' || *c > '9')
ERR("malformed number (no digits after decimal point)");
do {
++c;
} while (*c >= '0' && *c <= '9');
is_nv = 1;
}
if (*c == 'e' || *c == 'E') {
++c;
if (*c == '-' || *c == '+')
++c;
if (*c < '0' || *c > '9')
ERR("malformed number (no digits after exp sign)");
do {
++c;
} while (*c >= '0' && *c <= '9');
is_nv = 1;
}
if (!is_nv) {
int len = c - start;
/* special case the rather common 1..5-digit-int case */
if (*start == '-')
switch (len) {
case 2:
return newSViv (-(IV)( start [1] - '0' * 1));
case 3:
return newSViv (-(IV)( start [1] * 10 + start [2] - '0' * 11));
case 4:
return newSViv (-(IV)( start [1] * 100 + start [2] * 10 + start [3] - '0' * 111));
case 5:
return newSViv (-(IV)( start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 1111));
case 6:
return newSViv (-(IV)(start [1] * 10000 + start [2] * 1000 + start [3] * 100 + start [4] * 10 + start [5] - '0' * 11111));
}
else
switch (len) {
case 1:
return newSViv ( start [0] - '0' * 1);
case 2:
return newSViv ( start [0] * 10 + start [1] - '0' * 11);
case 3:
return newSViv ( start [0] * 100 + start [1] * 10 + start [2] - '0' * 111);
case 4:
return newSViv ( start [0] * 1000 + start [1] * 100 + start [2] * 10 + start [3] - '0' * 1111);
case 5:
return newSViv ( start [0] * 10000 + start [1] * 1000 + start [2] * 100 + start [3] * 10 + start [4] - '0' * 11111);
}
{
UV uv;
int numtype = grok_number (start, len, &uv);
if (numtype & IS_NUMBER_IN_UV
) {
if (numtype & IS_NUMBER_NEG)
{
if (uv < (UV) IV_MIN
)
return newSViv (-(IV)uv);
} else
return newSVuv (uv);
}
}
len -= *start == '-' ? 1 : 0;
/* does not fit into IV or UV, try NV */
if (len <= NV_DIG
)
/* fits into NV without loss of precision */
return newSVnv (jsonxs__atof (start));
/* everything else fails, convert it to a string */
return newSVpvn (start, c - start);
}
/* loss of precision here */
return newSVnv (jsonxs__atof (start));
}
#undef ERR
#undef expect_false
#undef expect_true
#endif /* JSONXS_INLINE_H_ */
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