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CCBC-1384: update parser for golang duration
Now it follows golang behaviour more closely Change-Id: I964e89710b40375a37497a07854008bfc3c19e51 Reviewed-on: http://review.couchbase.org/c/libcouchbase/+/155445 Tested-by: Build Bot <build@couchbase.com> Reviewed-by: Brett Lawson <brett19@gmail.com>
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,199 @@ | ||
| /* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */ | ||
| /* | ||
| * Copyright 2016-2021 Couchbase, Inc. | ||
| * | ||
| * Licensed under the Apache License, Version 2.0 (the "License"); | ||
| * you may not use this file except in compliance with the License. | ||
| * You may obtain a copy of the License at | ||
| * | ||
| * http://www.apache.org/licenses/LICENSE-2.0 | ||
| * | ||
| * Unless required by applicable law or agreed to in writing, software | ||
| * distributed under the License is distributed on an "AS IS" BASIS, | ||
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| * See the License for the specific language governing permissions and | ||
| * limitations under the License. | ||
| */ | ||
|
|
||
| #include "query_utils.hh" | ||
|
|
||
| /** | ||
| * leading_int consumes the leading [0-9]* from s. | ||
| */ | ||
| static bool leading_int(std::string &s, std::int64_t &v) | ||
| { | ||
| v = 0; | ||
| std::size_t i = 0; | ||
| for (; i < s.size(); ++i) { | ||
| auto c = s[i]; | ||
|
|
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| if (c < '0' || c > '9') { | ||
| break; | ||
| } | ||
|
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| if (v > std::int64_t((1LLU << 63U) - 1LLU) / 10) { | ||
| return false; | ||
| } | ||
|
|
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| v = v * 10 + std::int64_t(c) - '0'; | ||
|
|
||
| if (v < 0) { | ||
| return false; | ||
| } | ||
| } | ||
| s = s.substr(i); | ||
| return true; | ||
| } | ||
|
|
||
| /** | ||
| * leading_fraction consumes the leading [0-9]* from s. | ||
| * | ||
| * It is used only for fractions, so does not return an error on overflow, | ||
| * it just stops accumulating precision. | ||
| */ | ||
|
|
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| static void leading_fraction(std::string &s, std::int64_t &x, std::uint32_t &scale) | ||
| { | ||
| std::size_t i = 0; | ||
| scale = 1; | ||
|
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| bool overflow = false; | ||
|
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| for (; i < s.size(); ++i) { | ||
| auto c = s[i]; | ||
|
|
||
| if (c < '0' || c > '9') { | ||
| break; | ||
| } | ||
|
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| if (overflow) { | ||
| continue; | ||
| } | ||
|
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| if (x > std::int64_t((1LLU << 63LLU) - 1LLU) / 10) { | ||
| // It's possible for overflow to give a positive number, so take care. | ||
| overflow = true; | ||
| continue; | ||
| } | ||
|
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| auto y = x * 10 + std::int64_t(c) - '0'; | ||
| if (y < 0) { | ||
| overflow = true; | ||
| continue; | ||
| } | ||
|
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| x = y; | ||
| scale *= 10; | ||
| } | ||
|
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| s = s.substr(i); | ||
| } | ||
|
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| /** | ||
| * Parses a duration string. | ||
| * A duration string is 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" (or "µs"), "ms", "s", "m", "h". | ||
| */ | ||
| std::chrono::nanoseconds lcb_parse_golang_duration(const std::string &text) | ||
| { | ||
| // [-+]?([0-9]*(\.[0-9]*)?[a-z]+)+ | ||
| std::string s = text; | ||
| std::chrono::nanoseconds d{0}; | ||
| bool neg{false}; | ||
|
|
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| // Consume [-+]? | ||
| if (!s.empty()) { | ||
| auto c = s[0]; | ||
|
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| if (c == '-' || c == '+') { | ||
| neg = c == '-'; | ||
| s = s.substr(1); | ||
| } | ||
| } | ||
| if (neg) { | ||
| throw lcb_duration_parse_error("negative durations are not supported: " + text); | ||
| } | ||
|
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| // Special case: if all that is left is "0", this is zero. | ||
| if (s == "0") { | ||
| return std::chrono::nanoseconds::zero(); | ||
| } | ||
|
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| if (s.empty()) { | ||
| throw lcb_duration_parse_error("invalid duration: " + text); | ||
| } | ||
|
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| while (!s.empty()) { | ||
| // The next character must be [0-9.] | ||
| if (!(s[0] == '.' || ('0' <= s[0] && s[0] <= '9'))) { | ||
| throw lcb_duration_parse_error("invalid duration: " + text); | ||
| } | ||
|
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| // Consume [0-9]* | ||
| auto pl = s.size(); | ||
|
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| std::int64_t v{0}; // integer before decimal point | ||
| if (!leading_int(s, v)) { | ||
| throw lcb_duration_parse_error("invalid duration (leading_int overflow): " + text); | ||
| } | ||
|
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| bool pre = pl != s.size(); // whether we consumed anything before a period | ||
|
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| std::int64_t f{0}; // integer after decimal point | ||
| std::uint32_t scale{1}; // value = v + f/scale | ||
|
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| // Consume (\.[0-9]*)? | ||
| bool post = false; | ||
| if (!s.empty() && s[0] == '.') { | ||
| s = s.substr(1); | ||
| pl = s.size(); | ||
| leading_fraction(s, f, scale); | ||
| post = pl != s.size(); | ||
| } | ||
|
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||
| if (!pre && !post) { | ||
| // no digits (e.g. ".s" or "-.s") | ||
| throw lcb_duration_parse_error("invalid duration: " + text); | ||
| } | ||
|
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||
| // Consume unit. | ||
| std::size_t i = 0; | ||
| for (; i < s.size(); ++i) { | ||
| auto c = s[i]; | ||
| if (c == '.' || ('0' <= c && c <= '9')) { | ||
| break; | ||
| } | ||
| } | ||
| if (i == 0) { | ||
| throw lcb_duration_parse_error("missing unit in duration: " + text); | ||
| } | ||
|
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| auto u = s.substr(0, i); | ||
| s = s.substr(i); | ||
|
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| if (u == "ns") { | ||
| d += std::chrono::nanoseconds(v); /* no sub-nanoseconds, ignore 'f' */ | ||
| } else if (u == "us" || u == "µs" /* U+00B5 = micro symbol */ || u == "μs" /* U+03BC = Greek letter mu */) { | ||
| d += std::chrono::microseconds(v) + | ||
| std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::microseconds(f)) / scale; | ||
| } else if (u == "ms") { | ||
| d += std::chrono::milliseconds(v) + | ||
| std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::milliseconds(f)) / scale; | ||
| } else if (u == "s") { | ||
| d += std::chrono::seconds(v) + | ||
| std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::seconds(f)) / scale; | ||
| } else if (u == "m") { | ||
| d += std::chrono::minutes(v) + | ||
| std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::minutes(f)) / scale; | ||
| } else if (u == "h") { | ||
| d += std::chrono::hours(v) + | ||
| std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::hours(f)) / scale; | ||
| } else { | ||
| throw lcb_duration_parse_error(std::string("unknown unit ").append(u).append(" in duration ").append(text)); | ||
| } | ||
| } | ||
|
|
||
| return d; | ||
| } |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,41 @@ | ||
| /* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */ | ||
| /* | ||
| * Copyright 2016-2021 Couchbase, Inc. | ||
| * | ||
| * Licensed under the Apache License, Version 2.0 (the "License"); | ||
| * you may not use this file except in compliance with the License. | ||
| * You may obtain a copy of the License at | ||
| * | ||
| * http://www.apache.org/licenses/LICENSE-2.0 | ||
| * | ||
| * Unless required by applicable law or agreed to in writing, software | ||
| * distributed under the License is distributed on an "AS IS" BASIS, | ||
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| * See the License for the specific language governing permissions and | ||
| * limitations under the License. | ||
| */ | ||
|
|
||
| #ifndef LIBCOUCHBASE_N1QL_QUERY_UTILS_HH | ||
| #define LIBCOUCHBASE_N1QL_QUERY_UTILS_HH | ||
|
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| #include <cstddef> | ||
| #include <cstdint> | ||
| #include <chrono> | ||
| #include <string> | ||
| #include <stdexcept> | ||
|
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| /** | ||
| * @private | ||
| */ | ||
| class lcb_duration_parse_error : public std::runtime_error | ||
| { | ||
| public: | ||
| explicit lcb_duration_parse_error(const std::string &msg) : std::runtime_error(msg) {} | ||
| }; | ||
|
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| /** | ||
| * @private | ||
| */ | ||
| std::chrono::nanoseconds lcb_parse_golang_duration(const std::string &text); | ||
|
|
||
| #endif // LIBCOUCHBASE_N1QL_QUERY_UTILS_HH |
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