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-rw-r--r--absl/time/duration.cc149
1 files changed, 90 insertions, 59 deletions
diff --git a/absl/time/duration.cc b/absl/time/duration.cc
index b1af8406..952cc093 100644
--- a/absl/time/duration.cc
+++ b/absl/time/duration.cc
@@ -67,7 +67,10 @@
#include <string>
#include "absl/base/casts.h"
+#include "absl/base/macros.h"
#include "absl/numeric/int128.h"
+#include "absl/strings/string_view.h"
+#include "absl/strings/strip.h"
#include "absl/time/time.h"
namespace absl {
@@ -708,16 +711,17 @@ char* Format64(char* ep, int width, int64_t v) {
// fractional digits, because it is in the noise of what a Duration can
// represent.
struct DisplayUnit {
- const char* abbr;
+ absl::string_view abbr;
int prec;
double pow10;
};
-const DisplayUnit kDisplayNano = {"ns", 2, 1e2};
-const DisplayUnit kDisplayMicro = {"us", 5, 1e5};
-const DisplayUnit kDisplayMilli = {"ms", 8, 1e8};
-const DisplayUnit kDisplaySec = {"s", 11, 1e11};
-const DisplayUnit kDisplayMin = {"m", -1, 0.0}; // prec ignored
-const DisplayUnit kDisplayHour = {"h", -1, 0.0}; // prec ignored
+ABSL_CONST_INIT const DisplayUnit kDisplayNano = {"ns", 2, 1e2};
+ABSL_CONST_INIT const DisplayUnit kDisplayMicro = {"us", 5, 1e5};
+ABSL_CONST_INIT const DisplayUnit kDisplayMilli = {"ms", 8, 1e8};
+ABSL_CONST_INIT const DisplayUnit kDisplaySec = {"s", 11, 1e11};
+ABSL_CONST_INIT const DisplayUnit kDisplayMin = {"m", -1, 0.0}; // prec ignored
+ABSL_CONST_INIT const DisplayUnit kDisplayHour = {"h", -1,
+ 0.0}; // prec ignored
void AppendNumberUnit(std::string* out, int64_t n, DisplayUnit unit) {
char buf[sizeof("2562047788015216")]; // hours in max duration
@@ -725,16 +729,16 @@ void AppendNumberUnit(std::string* out, int64_t n, DisplayUnit unit) {
char* bp = Format64(ep, 0, n);
if (*bp != '0' || bp + 1 != ep) {
out->append(bp, ep - bp);
- out->append(unit.abbr);
+ out->append(unit.abbr.data(), unit.abbr.size());
}
}
// Note: unit.prec is limited to double's digits10 value (typically 15) so it
// always fits in buf[].
void AppendNumberUnit(std::string* out, double n, DisplayUnit unit) {
- const int buf_size = std::numeric_limits<double>::digits10;
- const int prec = std::min(buf_size, unit.prec);
- char buf[buf_size]; // also large enough to hold integer part
+ constexpr int kBufferSize = std::numeric_limits<double>::digits10;
+ const int prec = std::min(kBufferSize, unit.prec);
+ char buf[kBufferSize]; // also large enough to hold integer part
char* ep = buf + sizeof(buf);
double d = 0;
int64_t frac_part = Round(std::modf(n, &d) * unit.pow10);
@@ -748,7 +752,7 @@ void AppendNumberUnit(std::string* out, double n, DisplayUnit unit) {
while (ep[-1] == '0') --ep;
out->append(bp, ep - bp);
}
- out->append(unit.abbr);
+ out->append(unit.abbr.data(), unit.abbr.size());
}
}
@@ -800,23 +804,27 @@ namespace {
// A helper for ParseDuration() that parses a leading number from the given
// string and stores the result in *int_part/*frac_part/*frac_scale. The
// given string pointer is modified to point to the first unconsumed char.
-bool ConsumeDurationNumber(const char** dpp, int64_t* int_part,
+bool ConsumeDurationNumber(const char** dpp, const char* ep, int64_t* int_part,
int64_t* frac_part, int64_t* frac_scale) {
*int_part = 0;
*frac_part = 0;
*frac_scale = 1; // invariant: *frac_part < *frac_scale
const char* start = *dpp;
- for (; std::isdigit(**dpp); *dpp += 1) {
+ for (; *dpp != ep; *dpp += 1) {
const int d = **dpp - '0'; // contiguous digits
+ if (d < 0 || 10 <= d) break;
+
if (*int_part > kint64max / 10) return false;
*int_part *= 10;
if (*int_part > kint64max - d) return false;
*int_part += d;
}
const bool int_part_empty = (*dpp == start);
- if (**dpp != '.') return !int_part_empty;
- for (*dpp += 1; std::isdigit(**dpp); *dpp += 1) {
+ if (*dpp == ep || **dpp != '.') return !int_part_empty;
+
+ for (*dpp += 1; *dpp != ep; *dpp += 1) {
const int d = **dpp - '0'; // contiguous digits
+ if (d < 0 || 10 <= d) break;
if (*frac_scale <= kint64max / 10) {
*frac_part *= 10;
*frac_part += d;
@@ -830,32 +838,56 @@ bool ConsumeDurationNumber(const char** dpp, int64_t* int_part,
// ns, us, ms, s, m, h) from the given string and stores the resulting unit
// in "*unit". The given string pointer is modified to point to the first
// unconsumed char.
-bool ConsumeDurationUnit(const char** start, Duration* unit) {
- const char *s = *start;
- bool ok = true;
- if (strncmp(s, "ns", 2) == 0) {
- s += 2;
- *unit = Nanoseconds(1);
- } else if (strncmp(s, "us", 2) == 0) {
- s += 2;
- *unit = Microseconds(1);
- } else if (strncmp(s, "ms", 2) == 0) {
- s += 2;
- *unit = Milliseconds(1);
- } else if (strncmp(s, "s", 1) == 0) {
- s += 1;
- *unit = Seconds(1);
- } else if (strncmp(s, "m", 1) == 0) {
- s += 1;
- *unit = Minutes(1);
- } else if (strncmp(s, "h", 1) == 0) {
- s += 1;
- *unit = Hours(1);
- } else {
- ok = false;
+bool ConsumeDurationUnit(const char** start, const char* end, Duration* unit) {
+ size_t size = end - *start;
+ switch (size) {
+ case 0:
+ return false;
+ default:
+ switch (**start) {
+ case 'n':
+ if (*(*start + 1) == 's') {
+ *start += 2;
+ *unit = Nanoseconds(1);
+ return true;
+ }
+ break;
+ case 'u':
+ if (*(*start + 1) == 's') {
+ *start += 2;
+ *unit = Microseconds(1);
+ return true;
+ }
+ break;
+ case 'm':
+ if (*(*start + 1) == 's') {
+ *start += 2;
+ *unit = Milliseconds(1);
+ return true;
+ }
+ break;
+ default:
+ break;
+ }
+ ABSL_FALLTHROUGH_INTENDED;
+ case 1:
+ switch (**start) {
+ case 's':
+ *unit = Seconds(1);
+ *start += 1;
+ return true;
+ case 'm':
+ *unit = Minutes(1);
+ *start += 1;
+ return true;
+ case 'h':
+ *unit = Hours(1);
+ *start += 1;
+ return true;
+ default:
+ return false;
+ }
}
- *start = s;
- return ok;
}
} // namespace
@@ -865,39 +897,38 @@ bool ConsumeDurationUnit(const char** start, Duration* unit) {
// a possibly signed sequence of decimal numbers, each with optional
// fraction and a unit suffix, such as "300ms", "-1.5h" or "2h45m".
// Valid time units are "ns", "us" "ms", "s", "m", "h".
-bool ParseDuration(const std::string& dur_string, Duration* d) {
- const char* start = dur_string.c_str();
+bool ParseDuration(absl::string_view dur_sv, Duration* d) {
int sign = 1;
-
- if (*start == '-' || *start == '+') {
- sign = *start == '-' ? -1 : 1;
- ++start;
- }
-
- // Can't parse a duration from an empty std::string.
- if (*start == '\0') {
- return false;
+ if (absl::ConsumePrefix(&dur_sv, "-")) {
+ sign = -1;
+ } else {
+ absl::ConsumePrefix(&dur_sv, "+");
}
+ if (dur_sv.empty()) return false;
- // Special case for a std::string of "0".
- if (*start == '0' && *(start + 1) == '\0') {
+ // Special case for a string of "0".
+ if (dur_sv == "0") {
*d = ZeroDuration();
return true;
}
- if (strcmp(start, "inf") == 0) {
+ if (dur_sv == "inf") {
*d = sign * InfiniteDuration();
return true;
}
+ const char* start = dur_sv.data();
+ const char* end = start + dur_sv.size();
+
Duration dur;
- while (*start != '\0') {
+ while (start != end) {
int64_t int_part;
int64_t frac_part;
int64_t frac_scale;
Duration unit;
- if (!ConsumeDurationNumber(&start, &int_part, &frac_part, &frac_scale) ||
- !ConsumeDurationUnit(&start, &unit)) {
+ if (!ConsumeDurationNumber(&start, end, &int_part, &frac_part,
+ &frac_scale) ||
+ !ConsumeDurationUnit(&start, end, &unit)) {
return false;
}
if (int_part != 0) dur += sign * int_part * unit;
@@ -908,7 +939,7 @@ bool ParseDuration(const std::string& dur_string, Duration* d) {
}
bool AbslParseFlag(absl::string_view text, Duration* dst, std::string*) {
- return ParseDuration(std::string(text), dst);
+ return ParseDuration(text, dst);
}
std::string AbslUnparseFlag(Duration d) { return FormatDuration(d); }
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-04 17:33:58 +0000