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765 lines
24 KiB
C++
765 lines
24 KiB
C++
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/*
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* Copyright 2016 Facebook, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <folly/Conv.h>
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#include <array>
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namespace folly {
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namespace detail {
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namespace {
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/**
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* Finds the first non-digit in a string. The number of digits
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* searched depends on the precision of the Tgt integral. Assumes the
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* string starts with NO whitespace and NO sign.
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*
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* The semantics of the routine is:
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* for (;; ++b) {
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* if (b >= e || !isdigit(*b)) return b;
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* }
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*
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* Complete unrolling marks bottom-line (i.e. entire conversion)
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* improvements of 20%.
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*/
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inline const char* findFirstNonDigit(const char* b, const char* e) {
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for (; b < e; ++b) {
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auto const c = static_cast<unsigned>(*b) - '0';
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if (c >= 10) {
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break;
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}
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}
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return b;
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}
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// Maximum value of number when represented as a string
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template <class T>
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struct MaxString {
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static const char* const value;
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};
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template <> const char *const MaxString<uint8_t>::value = "255";
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template <> const char *const MaxString<uint16_t>::value = "65535";
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template <> const char *const MaxString<uint32_t>::value = "4294967295";
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#if __SIZEOF_LONG__ == 4
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template <> const char *const MaxString<unsigned long>::value =
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"4294967295";
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#else
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template <> const char *const MaxString<unsigned long>::value =
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"18446744073709551615";
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#endif
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static_assert(sizeof(unsigned long) >= 4,
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"Wrong value for MaxString<unsigned long>::value,"
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" please update.");
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template <> const char *const MaxString<unsigned long long>::value =
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"18446744073709551615";
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static_assert(sizeof(unsigned long long) >= 8,
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"Wrong value for MaxString<unsigned long long>::value"
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", please update.");
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#if FOLLY_HAVE_INT128_T
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template <> const char *const MaxString<__uint128_t>::value =
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"340282366920938463463374607431768211455";
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#endif
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/*
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* Lookup tables that converts from a decimal character value to an integral
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* binary value, shifted by a decimal "shift" multiplier.
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* For all character values in the range '0'..'9', the table at those
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* index locations returns the actual decimal value shifted by the multiplier.
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* For all other values, the lookup table returns an invalid OOR value.
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*/
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// Out-of-range flag value, larger than the largest value that can fit in
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// four decimal bytes (9999), but four of these added up together should
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// still not overflow uint16_t.
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constexpr int32_t OOR = 10000;
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FOLLY_ALIGNED(16) constexpr uint16_t shift1[] = {
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 0-9
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 10
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 20
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 30
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, 0, // 40
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1, 2, 3, 4, 5, 6, 7, 8, 9, OOR, OOR,
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 60
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 70
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 80
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 90
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 100
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 110
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 120
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 130
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 140
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 150
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 160
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 170
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 180
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 190
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 200
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 210
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 220
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 230
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 240
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OOR, OOR, OOR, OOR, OOR, OOR // 250
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};
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FOLLY_ALIGNED(16) constexpr uint16_t shift10[] = {
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 0-9
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 10
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 20
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 30
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, 0, // 40
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10, 20, 30, 40, 50, 60, 70, 80, 90, OOR, OOR,
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 60
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 70
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 80
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 90
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 100
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 110
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 120
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 130
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 140
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 150
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 160
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 170
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 180
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 190
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 200
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 210
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 220
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 230
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 240
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OOR, OOR, OOR, OOR, OOR, OOR // 250
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};
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FOLLY_ALIGNED(16) constexpr uint16_t shift100[] = {
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 0-9
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 10
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 20
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 30
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, 0, // 40
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100, 200, 300, 400, 500, 600, 700, 800, 900, OOR, OOR,
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 60
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 70
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 80
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 90
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 100
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 110
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 120
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 130
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 140
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 150
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 160
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 170
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 180
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 190
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 200
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 210
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 220
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 230
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 240
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OOR, OOR, OOR, OOR, OOR, OOR // 250
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};
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FOLLY_ALIGNED(16) constexpr uint16_t shift1000[] = {
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 0-9
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 10
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 20
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 30
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, 0, // 40
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1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, OOR, OOR,
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 60
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 70
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 80
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 90
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 100
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 110
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 120
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 130
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 140
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 150
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 160
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 170
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 180
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 190
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 200
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 210
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 220
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 230
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OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, OOR, // 240
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OOR, OOR, OOR, OOR, OOR, OOR // 250
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};
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struct ErrorString {
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const char* string;
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bool quote;
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};
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// Keep this in sync with ConversionCode in Conv.h
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constexpr const std::array<
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ErrorString,
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static_cast<std::size_t>(ConversionCode::NUM_ERROR_CODES)>
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kErrorStrings{{
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{"Success", true},
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{"Empty input string", true},
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{"No digits found in input string", true},
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{"Integer overflow when parsing bool (must be 0 or 1)", true},
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{"Invalid value for bool", true},
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{"Non-digit character found", true},
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{"Invalid leading character", true},
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{"Overflow during conversion", true},
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{"Negative overflow during conversion", true},
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{"Unable to convert string to floating point value", true},
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{"Non-whitespace character found after end of conversion", true},
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{"Overflow during arithmetic conversion", false},
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{"Negative overflow during arithmetic conversion", false},
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{"Loss of precision during arithmetic conversion", false},
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}};
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// Check if ASCII is really ASCII
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using IsAscii = std::
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integral_constant<bool, 'A' == 65 && 'Z' == 90 && 'a' == 97 && 'z' == 122>;
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// The code in this file that uses tolower() really only cares about
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// 7-bit ASCII characters, so we can take a nice shortcut here.
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inline char tolower_ascii(char in) {
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return IsAscii::value ? in | 0x20 : std::tolower(in);
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}
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inline bool bool_str_cmp(const char** b, size_t len, const char* value) {
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// Can't use strncasecmp, since we want to ensure that the full value matches
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const char* p = *b;
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const char* e = *b + len;
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const char* v = value;
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while (*v != '\0') {
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if (p == e || tolower_ascii(*p) != *v) { // value is already lowercase
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return false;
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}
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++p;
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++v;
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}
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*b = p;
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return true;
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}
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} // anonymous namespace
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Expected<bool, ConversionCode> str_to_bool(StringPiece* src) noexcept {
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auto b = src->begin(), e = src->end();
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for (;; ++b) {
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if (b >= e) {
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return makeUnexpected(ConversionCode::EMPTY_INPUT_STRING);
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}
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if (!std::isspace(*b)) {
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break;
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}
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}
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bool result;
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size_t len = e - b;
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switch (*b) {
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case '0':
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case '1': {
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result = false;
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for (; b < e && isdigit(*b); ++b) {
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if (result || (*b != '0' && *b != '1')) {
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return makeUnexpected(ConversionCode::BOOL_OVERFLOW);
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}
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result = (*b == '1');
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}
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break;
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}
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case 'y':
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case 'Y':
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result = true;
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if (!bool_str_cmp(&b, len, "yes")) {
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++b; // accept the single 'y' character
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}
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break;
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case 'n':
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case 'N':
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result = false;
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if (!bool_str_cmp(&b, len, "no")) {
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++b;
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}
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break;
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case 't':
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case 'T':
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result = true;
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if (!bool_str_cmp(&b, len, "true")) {
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++b;
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}
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break;
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case 'f':
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case 'F':
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result = false;
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||
|
if (!bool_str_cmp(&b, len, "false")) {
|
||
|
++b;
|
||
|
}
|
||
|
break;
|
||
|
case 'o':
|
||
|
case 'O':
|
||
|
if (bool_str_cmp(&b, len, "on")) {
|
||
|
result = true;
|
||
|
} else if (bool_str_cmp(&b, len, "off")) {
|
||
|
result = false;
|
||
|
} else {
|
||
|
return makeUnexpected(ConversionCode::BOOL_INVALID_VALUE);
|
||
|
}
|
||
|
break;
|
||
|
default:
|
||
|
return makeUnexpected(ConversionCode::BOOL_INVALID_VALUE);
|
||
|
}
|
||
|
|
||
|
src->assign(b, e);
|
||
|
|
||
|
return result;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* StringPiece to double, with progress information. Alters the
|
||
|
* StringPiece parameter to munch the already-parsed characters.
|
||
|
*/
|
||
|
template <class Tgt>
|
||
|
Expected<Tgt, ConversionCode> str_to_floating(StringPiece* src) noexcept {
|
||
|
using namespace double_conversion;
|
||
|
static StringToDoubleConverter
|
||
|
conv(StringToDoubleConverter::ALLOW_TRAILING_JUNK
|
||
|
| StringToDoubleConverter::ALLOW_LEADING_SPACES,
|
||
|
0.0,
|
||
|
// return this for junk input string
|
||
|
std::numeric_limits<double>::quiet_NaN(),
|
||
|
nullptr, nullptr);
|
||
|
|
||
|
if (src->empty()) {
|
||
|
return makeUnexpected(ConversionCode::EMPTY_INPUT_STRING);
|
||
|
}
|
||
|
|
||
|
int length;
|
||
|
auto result = conv.StringToDouble(src->data(),
|
||
|
static_cast<int>(src->size()),
|
||
|
&length); // processed char count
|
||
|
|
||
|
if (!std::isnan(result)) {
|
||
|
// If we get here with length = 0, the input string is empty.
|
||
|
// If we get here with result = 0.0, it's either because the string
|
||
|
// contained only whitespace, or because we had an actual zero value
|
||
|
// (with potential trailing junk). If it was only whitespace, we
|
||
|
// want to raise an error; length will point past the last character
|
||
|
// that was processed, so we need to check if that character was
|
||
|
// whitespace or not.
|
||
|
if (length == 0 || (result == 0.0 && std::isspace((*src)[length - 1]))) {
|
||
|
return makeUnexpected(ConversionCode::EMPTY_INPUT_STRING);
|
||
|
}
|
||
|
src->advance(length);
|
||
|
return result;
|
||
|
}
|
||
|
|
||
|
auto* e = src->end();
|
||
|
auto* b =
|
||
|
std::find_if_not(src->begin(), e, [](char c) { return std::isspace(c); });
|
||
|
|
||
|
// There must be non-whitespace, otherwise we would have caught this above
|
||
|
assert(b < e);
|
||
|
size_t size = e - b;
|
||
|
|
||
|
bool negative = false;
|
||
|
if (*b == '-') {
|
||
|
negative = true;
|
||
|
++b;
|
||
|
--size;
|
||
|
}
|
||
|
|
||
|
result = 0.0;
|
||
|
|
||
|
switch (tolower_ascii(*b)) {
|
||
|
case 'i':
|
||
|
if (size >= 3 && tolower_ascii(b[1]) == 'n' &&
|
||
|
tolower_ascii(b[2]) == 'f') {
|
||
|
if (size >= 8 && tolower_ascii(b[3]) == 'i' &&
|
||
|
tolower_ascii(b[4]) == 'n' && tolower_ascii(b[5]) == 'i' &&
|
||
|
tolower_ascii(b[6]) == 't' && tolower_ascii(b[7]) == 'y') {
|
||
|
b += 8;
|
||
|
} else {
|
||
|
b += 3;
|
||
|
}
|
||
|
result = std::numeric_limits<Tgt>::infinity();
|
||
|
}
|
||
|
break;
|
||
|
|
||
|
case 'n':
|
||
|
if (size >= 3 && tolower_ascii(b[1]) == 'a' &&
|
||
|
tolower_ascii(b[2]) == 'n') {
|
||
|
b += 3;
|
||
|
result = std::numeric_limits<Tgt>::quiet_NaN();
|
||
|
}
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
if (result == 0.0) {
|
||
|
// All bets are off
|
||
|
return makeUnexpected(ConversionCode::STRING_TO_FLOAT_ERROR);
|
||
|
}
|
||
|
|
||
|
if (negative) {
|
||
|
result = -result;
|
||
|
}
|
||
|
|
||
|
src->assign(b, e);
|
||
|
|
||
|
return result;
|
||
|
}
|
||
|
|
||
|
template Expected<float, ConversionCode> str_to_floating<float>(
|
||
|
StringPiece* src) noexcept;
|
||
|
template Expected<double, ConversionCode> str_to_floating<double>(
|
||
|
StringPiece* src) noexcept;
|
||
|
|
||
|
/**
|
||
|
* This class takes care of additional processing needed for signed values,
|
||
|
* like leading sign character and overflow checks.
|
||
|
*/
|
||
|
template <typename T, bool IsSigned = std::is_signed<T>::value>
|
||
|
class SignedValueHandler;
|
||
|
|
||
|
template <typename T>
|
||
|
class SignedValueHandler<T, true> {
|
||
|
public:
|
||
|
ConversionCode init(const char*& b) {
|
||
|
negative_ = false;
|
||
|
if (!std::isdigit(*b)) {
|
||
|
if (*b == '-') {
|
||
|
negative_ = true;
|
||
|
} else if (UNLIKELY(*b != '+')) {
|
||
|
return ConversionCode::INVALID_LEADING_CHAR;
|
||
|
}
|
||
|
++b;
|
||
|
}
|
||
|
return ConversionCode::SUCCESS;
|
||
|
}
|
||
|
|
||
|
ConversionCode overflow() {
|
||
|
return negative_ ? ConversionCode::NEGATIVE_OVERFLOW
|
||
|
: ConversionCode::POSITIVE_OVERFLOW;
|
||
|
}
|
||
|
|
||
|
template <typename U>
|
||
|
Expected<T, ConversionCode> finalize(U value) {
|
||
|
T rv;
|
||
|
if (negative_) {
|
||
|
rv = -value;
|
||
|
if (UNLIKELY(rv > 0)) {
|
||
|
return makeUnexpected(ConversionCode::NEGATIVE_OVERFLOW);
|
||
|
}
|
||
|
} else {
|
||
|
rv = value;
|
||
|
if (UNLIKELY(rv < 0)) {
|
||
|
return makeUnexpected(ConversionCode::POSITIVE_OVERFLOW);
|
||
|
}
|
||
|
}
|
||
|
return rv;
|
||
|
}
|
||
|
|
||
|
private:
|
||
|
bool negative_;
|
||
|
};
|
||
|
|
||
|
// For unsigned types, we don't need any extra processing
|
||
|
template <typename T>
|
||
|
class SignedValueHandler<T, false> {
|
||
|
public:
|
||
|
ConversionCode init(const char*&) {
|
||
|
return ConversionCode::SUCCESS;
|
||
|
}
|
||
|
|
||
|
ConversionCode overflow() {
|
||
|
return ConversionCode::POSITIVE_OVERFLOW;
|
||
|
}
|
||
|
|
||
|
Expected<T, ConversionCode> finalize(T value) {
|
||
|
return value;
|
||
|
}
|
||
|
};
|
||
|
|
||
|
/**
|
||
|
* String represented as a pair of pointers to char to signed/unsigned
|
||
|
* integrals. Assumes NO whitespace before or after, and also that the
|
||
|
* string is composed entirely of digits (and an optional sign only for
|
||
|
* signed types). String may be empty, in which case digits_to returns
|
||
|
* an appropriate error.
|
||
|
*/
|
||
|
template <class Tgt>
|
||
|
inline Expected<Tgt, ConversionCode> digits_to(
|
||
|
const char* b,
|
||
|
const char* const e) noexcept {
|
||
|
using UT = typename std::make_unsigned<Tgt>::type;
|
||
|
assert(b <= e);
|
||
|
|
||
|
SignedValueHandler<Tgt> sgn;
|
||
|
|
||
|
auto err = sgn.init(b);
|
||
|
if (UNLIKELY(err != ConversionCode::SUCCESS)) {
|
||
|
return makeUnexpected(err);
|
||
|
}
|
||
|
|
||
|
size_t size = e - b;
|
||
|
|
||
|
/* Although the string is entirely made of digits, we still need to
|
||
|
* check for overflow.
|
||
|
*/
|
||
|
if (size > std::numeric_limits<UT>::digits10) {
|
||
|
// Leading zeros?
|
||
|
if (b < e && *b == '0') {
|
||
|
for (++b;; ++b) {
|
||
|
if (b == e) {
|
||
|
return Tgt(0); // just zeros, e.g. "0000"
|
||
|
}
|
||
|
if (*b != '0') {
|
||
|
size = e - b;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
if (size > std::numeric_limits<UT>::digits10 &&
|
||
|
(size != std::numeric_limits<UT>::digits10 + 1 ||
|
||
|
strncmp(b, MaxString<UT>::value, size) > 0)) {
|
||
|
return makeUnexpected(sgn.overflow());
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// Here we know that the number won't overflow when
|
||
|
// converted. Proceed without checks.
|
||
|
|
||
|
UT result = 0;
|
||
|
|
||
|
for (; e - b >= 4; b += 4) {
|
||
|
result *= 10000;
|
||
|
const int32_t r0 = shift1000[static_cast<size_t>(b[0])];
|
||
|
const int32_t r1 = shift100[static_cast<size_t>(b[1])];
|
||
|
const int32_t r2 = shift10[static_cast<size_t>(b[2])];
|
||
|
const int32_t r3 = shift1[static_cast<size_t>(b[3])];
|
||
|
const auto sum = r0 + r1 + r2 + r3;
|
||
|
if (sum >= OOR) {
|
||
|
goto outOfRange;
|
||
|
}
|
||
|
result += sum;
|
||
|
}
|
||
|
|
||
|
switch (e - b) {
|
||
|
case 3: {
|
||
|
const int32_t r0 = shift100[static_cast<size_t>(b[0])];
|
||
|
const int32_t r1 = shift10[static_cast<size_t>(b[1])];
|
||
|
const int32_t r2 = shift1[static_cast<size_t>(b[2])];
|
||
|
const auto sum = r0 + r1 + r2;
|
||
|
if (sum >= OOR) {
|
||
|
goto outOfRange;
|
||
|
}
|
||
|
result = 1000 * result + sum;
|
||
|
break;
|
||
|
}
|
||
|
case 2: {
|
||
|
const int32_t r0 = shift10[static_cast<size_t>(b[0])];
|
||
|
const int32_t r1 = shift1[static_cast<size_t>(b[1])];
|
||
|
const auto sum = r0 + r1;
|
||
|
if (sum >= OOR) {
|
||
|
goto outOfRange;
|
||
|
}
|
||
|
result = 100 * result + sum;
|
||
|
break;
|
||
|
}
|
||
|
case 1: {
|
||
|
const int32_t sum = shift1[static_cast<size_t>(b[0])];
|
||
|
if (sum >= OOR) {
|
||
|
goto outOfRange;
|
||
|
}
|
||
|
result = 10 * result + sum;
|
||
|
break;
|
||
|
}
|
||
|
default:
|
||
|
assert(b == e);
|
||
|
if (size == 0) {
|
||
|
return makeUnexpected(ConversionCode::NO_DIGITS);
|
||
|
}
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
return sgn.finalize(result);
|
||
|
|
||
|
outOfRange:
|
||
|
return makeUnexpected(ConversionCode::NON_DIGIT_CHAR);
|
||
|
}
|
||
|
|
||
|
template Expected<char, ConversionCode> digits_to<char>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
template Expected<signed char, ConversionCode> digits_to<signed char>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
template Expected<unsigned char, ConversionCode> digits_to<unsigned char>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
|
||
|
template Expected<short, ConversionCode> digits_to<short>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
template Expected<unsigned short, ConversionCode> digits_to<unsigned short>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
|
||
|
template Expected<int, ConversionCode> digits_to<int>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
template Expected<unsigned int, ConversionCode> digits_to<unsigned int>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
|
||
|
template Expected<long, ConversionCode> digits_to<long>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
template Expected<unsigned long, ConversionCode> digits_to<unsigned long>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
|
||
|
template Expected<long long, ConversionCode> digits_to<long long>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
template Expected<unsigned long long, ConversionCode>
|
||
|
digits_to<unsigned long long>(const char*, const char*) noexcept;
|
||
|
|
||
|
#if FOLLY_HAVE_INT128_T
|
||
|
template Expected<__int128, ConversionCode> digits_to<__int128>(
|
||
|
const char*,
|
||
|
const char*) noexcept;
|
||
|
template Expected<unsigned __int128, ConversionCode>
|
||
|
digits_to<unsigned __int128>(const char*, const char*) noexcept;
|
||
|
#endif
|
||
|
|
||
|
/**
|
||
|
* StringPiece to integrals, with progress information. Alters the
|
||
|
* StringPiece parameter to munch the already-parsed characters.
|
||
|
*/
|
||
|
template <class Tgt>
|
||
|
Expected<Tgt, ConversionCode> str_to_integral(StringPiece* src) noexcept {
|
||
|
using UT = typename std::make_unsigned<Tgt>::type;
|
||
|
|
||
|
auto b = src->data(), past = src->data() + src->size();
|
||
|
|
||
|
for (;; ++b) {
|
||
|
if (UNLIKELY(b >= past)) {
|
||
|
return makeUnexpected(ConversionCode::EMPTY_INPUT_STRING);
|
||
|
}
|
||
|
if (!std::isspace(*b)) {
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
SignedValueHandler<Tgt> sgn;
|
||
|
auto err = sgn.init(b);
|
||
|
|
||
|
if (UNLIKELY(err != ConversionCode::SUCCESS)) {
|
||
|
return makeUnexpected(err);
|
||
|
}
|
||
|
if (std::is_signed<Tgt>::value && UNLIKELY(b >= past)) {
|
||
|
return makeUnexpected(ConversionCode::NO_DIGITS);
|
||
|
}
|
||
|
if (UNLIKELY(!isdigit(*b))) {
|
||
|
return makeUnexpected(ConversionCode::NON_DIGIT_CHAR);
|
||
|
}
|
||
|
|
||
|
auto m = findFirstNonDigit(b + 1, past);
|
||
|
|
||
|
auto tmp = digits_to<UT>(b, m);
|
||
|
|
||
|
if (UNLIKELY(!tmp.hasValue())) {
|
||
|
return makeUnexpected(
|
||
|
tmp.error() == ConversionCode::POSITIVE_OVERFLOW ? sgn.overflow()
|
||
|
: tmp.error());
|
||
|
}
|
||
|
|
||
|
auto res = sgn.finalize(tmp.value());
|
||
|
|
||
|
if (res.hasValue()) {
|
||
|
src->advance(m - src->data());
|
||
|
}
|
||
|
|
||
|
return res;
|
||
|
}
|
||
|
|
||
|
template Expected<char, ConversionCode> str_to_integral<char>(
|
||
|
StringPiece* src) noexcept;
|
||
|
template Expected<signed char, ConversionCode> str_to_integral<signed char>(
|
||
|
StringPiece* src) noexcept;
|
||
|
template Expected<unsigned char, ConversionCode> str_to_integral<unsigned char>(
|
||
|
StringPiece* src) noexcept;
|
||
|
|
||
|
template Expected<short, ConversionCode> str_to_integral<short>(
|
||
|
StringPiece* src) noexcept;
|
||
|
template Expected<unsigned short, ConversionCode>
|
||
|
str_to_integral<unsigned short>(StringPiece* src) noexcept;
|
||
|
|
||
|
template Expected<int, ConversionCode> str_to_integral<int>(
|
||
|
StringPiece* src) noexcept;
|
||
|
template Expected<unsigned int, ConversionCode> str_to_integral<unsigned int>(
|
||
|
StringPiece* src) noexcept;
|
||
|
|
||
|
template Expected<long, ConversionCode> str_to_integral<long>(
|
||
|
StringPiece* src) noexcept;
|
||
|
template Expected<unsigned long, ConversionCode> str_to_integral<unsigned long>(
|
||
|
StringPiece* src) noexcept;
|
||
|
|
||
|
template Expected<long long, ConversionCode> str_to_integral<long long>(
|
||
|
StringPiece* src) noexcept;
|
||
|
template Expected<unsigned long long, ConversionCode>
|
||
|
str_to_integral<unsigned long long>(StringPiece* src) noexcept;
|
||
|
|
||
|
#if FOLLY_HAVE_INT128_T
|
||
|
template Expected<__int128, ConversionCode> str_to_integral<__int128>(
|
||
|
StringPiece* src) noexcept;
|
||
|
template Expected<unsigned __int128, ConversionCode>
|
||
|
str_to_integral<unsigned __int128>(StringPiece* src) noexcept;
|
||
|
#endif
|
||
|
|
||
|
} // namespace detail
|
||
|
|
||
|
ConversionError makeConversionError(ConversionCode code, StringPiece input) {
|
||
|
using namespace detail;
|
||
|
static_assert(
|
||
|
std::is_unsigned<std::underlying_type<ConversionCode>::type>::value,
|
||
|
"ConversionCode should be unsigned");
|
||
|
assert((std::size_t)code < kErrorStrings.size());
|
||
|
const ErrorString& err = kErrorStrings[(std::size_t)code];
|
||
|
if (code == ConversionCode::EMPTY_INPUT_STRING && input.empty()) {
|
||
|
return {err.string, code};
|
||
|
}
|
||
|
std::string tmp(err.string);
|
||
|
tmp.append(": ");
|
||
|
if (err.quote) {
|
||
|
tmp.append(1, '"');
|
||
|
}
|
||
|
if (input.size() > 0) {
|
||
|
tmp.append(input.data(), input.size());
|
||
|
}
|
||
|
if (err.quote) {
|
||
|
tmp.append(1, '"');
|
||
|
}
|
||
|
return {tmp, code};
|
||
|
}
|
||
|
|
||
|
} // namespace folly
|