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-rw-r--r--fluent-bit/lib/jemalloc-5.3.0/src/fxp.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/fluent-bit/lib/jemalloc-5.3.0/src/fxp.c b/fluent-bit/lib/jemalloc-5.3.0/src/fxp.c
new file mode 100644
index 000000000..96585f0a6
--- /dev/null
+++ b/fluent-bit/lib/jemalloc-5.3.0/src/fxp.c
@@ -0,0 +1,124 @@
+#include "jemalloc/internal/jemalloc_preamble.h"
+#include "jemalloc/internal/jemalloc_internal_includes.h"
+
+#include "jemalloc/internal/fxp.h"
+
+static bool
+fxp_isdigit(char c) {
+ return '0' <= c && c <= '9';
+}
+
+bool
+fxp_parse(fxp_t *result, const char *str, char **end) {
+ /*
+ * Using malloc_strtoumax in this method isn't as handy as you might
+ * expect (I tried). In the fractional part, significant leading zeros
+ * mean that you still need to do your own parsing, now with trickier
+ * math. In the integer part, the casting (uintmax_t to uint32_t)
+ * forces more reasoning about bounds than just checking for overflow as
+ * we parse.
+ */
+ uint32_t integer_part = 0;
+
+ const char *cur = str;
+
+ /* The string must start with a digit or a decimal point. */
+ if (*cur != '.' && !fxp_isdigit(*cur)) {
+ return true;
+ }
+
+ while ('0' <= *cur && *cur <= '9') {
+ integer_part *= 10;
+ integer_part += *cur - '0';
+ if (integer_part >= (1U << 16)) {
+ return true;
+ }
+ cur++;
+ }
+
+ /*
+ * We've parsed all digits at the beginning of the string, without
+ * overflow. Either we're done, or there's a fractional part.
+ */
+ if (*cur != '.') {
+ *result = (integer_part << 16);
+ if (end != NULL) {
+ *end = (char *)cur;
+ }
+ return false;
+ }
+
+ /* There's a fractional part. */
+ cur++;
+ if (!fxp_isdigit(*cur)) {
+ /* Shouldn't end on the decimal point. */
+ return true;
+ }
+
+ /*
+ * We use a lot of precision for the fractional part, even though we'll
+ * discard most of it; this lets us get exact values for the important
+ * special case where the denominator is a small power of 2 (for
+ * instance, 1/512 == 0.001953125 is exactly representable even with
+ * only 16 bits of fractional precision). We need to left-shift by 16
+ * before dividing so we pick the number of digits to be
+ * floor(log(2**48)) = 14.
+ */
+ uint64_t fractional_part = 0;
+ uint64_t frac_div = 1;
+ for (int i = 0; i < FXP_FRACTIONAL_PART_DIGITS; i++) {
+ fractional_part *= 10;
+ frac_div *= 10;
+ if (fxp_isdigit(*cur)) {
+ fractional_part += *cur - '0';
+ cur++;
+ }
+ }
+ /*
+ * We only parse the first maxdigits characters, but we can still ignore
+ * any digits after that.
+ */
+ while (fxp_isdigit(*cur)) {
+ cur++;
+ }
+
+ assert(fractional_part < frac_div);
+ uint32_t fractional_repr = (uint32_t)(
+ (fractional_part << 16) / frac_div);
+
+ /* Success! */
+ *result = (integer_part << 16) + fractional_repr;
+ if (end != NULL) {
+ *end = (char *)cur;
+ }
+ return false;
+}
+
+void
+fxp_print(fxp_t a, char buf[FXP_BUF_SIZE]) {
+ uint32_t integer_part = fxp_round_down(a);
+ uint32_t fractional_part = (a & ((1U << 16) - 1));
+
+ int leading_fraction_zeros = 0;
+ uint64_t fraction_digits = fractional_part;
+ for (int i = 0; i < FXP_FRACTIONAL_PART_DIGITS; i++) {
+ if (fraction_digits < (1U << 16)
+ && fraction_digits * 10 >= (1U << 16)) {
+ leading_fraction_zeros = i;
+ }
+ fraction_digits *= 10;
+ }
+ fraction_digits >>= 16;
+ while (fraction_digits > 0 && fraction_digits % 10 == 0) {
+ fraction_digits /= 10;
+ }
+
+ size_t printed = malloc_snprintf(buf, FXP_BUF_SIZE, "%"FMTu32".",
+ integer_part);
+ for (int i = 0; i < leading_fraction_zeros; i++) {
+ buf[printed] = '0';
+ printed++;
+ }
+ malloc_snprintf(&buf[printed], FXP_BUF_SIZE - printed, "%"FMTu64,
+ fraction_digits);
+}