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Diffstat (limited to 'src/formats/logfmt/logfmt.parser.cc')
| -rw-r--r-- | src/formats/logfmt/logfmt.parser.cc | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/src/formats/logfmt/logfmt.parser.cc b/src/formats/logfmt/logfmt.parser.cc new file mode 100644 index 0000000..20c7252 --- /dev/null +++ b/src/formats/logfmt/logfmt.parser.cc @@ -0,0 +1,266 @@ +/** + * Copyright (c) 2021, Timothy Stack + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * * Neither the name of Timothy Stack nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * @file logfmt.parser.cc + */ + +#include "logfmt.parser.hh" + +#include "base/intern_string.hh" +#include "config.h" +#include "scn/scn.h" + +logfmt::parser::parser(string_fragment sf) : p_next_input(sf) {} + +static bool +is_not_eq(char ch) +{ + return ch != '='; +} + +struct bare_value_predicate { + enum class int_state_t { + INIT, + NEED_DIGIT, + DIGITS, + INVALID, + }; + + enum class float_state_t { + INIT, + NEED_DIGIT, + DIGITS, + FRACTION_DIGIT, + EXPONENT_INIT, + EXPONENT_NEED_DIGIT, + EXPONENT_DIGIT, + INVALID, + }; + + int_state_t bvp_int_state{int_state_t::INIT}; + float_state_t bvp_float_state{float_state_t::INIT}; + size_t bvp_index{0}; + + bool is_integer() const + { + return this->bvp_int_state == int_state_t::DIGITS; + } + + bool is_float() const + { + switch (this->bvp_float_state) { + case float_state_t::DIGITS: + case float_state_t::FRACTION_DIGIT: + case float_state_t::EXPONENT_DIGIT: + return true; + default: + return false; + } + } + + bool operator()(char ch) + { + if (ch == ' ') { + return false; + } + + bool got_digit = isdigit(ch); + switch (this->bvp_int_state) { + case int_state_t::INIT: + if (got_digit) { + this->bvp_int_state = int_state_t::DIGITS; + } else if (ch == '-') { + this->bvp_int_state = int_state_t::NEED_DIGIT; + } else { + this->bvp_int_state = int_state_t::INVALID; + } + break; + case int_state_t::DIGITS: + case int_state_t::NEED_DIGIT: + if (got_digit) { + this->bvp_int_state = int_state_t::DIGITS; + } else { + this->bvp_int_state = int_state_t::INVALID; + } + break; + case int_state_t::INVALID: + break; + } + + switch (this->bvp_float_state) { + case float_state_t::INIT: + if (got_digit) { + this->bvp_float_state = float_state_t::DIGITS; + } else if (ch == '-') { + this->bvp_float_state = float_state_t::NEED_DIGIT; + } else { + this->bvp_float_state = float_state_t::INVALID; + } + break; + case float_state_t::DIGITS: + case float_state_t::NEED_DIGIT: + if (got_digit) { + this->bvp_float_state = float_state_t::DIGITS; + } else if (ch == '.') { + this->bvp_float_state = float_state_t::FRACTION_DIGIT; + } else if (ch == 'e' || ch == 'E') { + this->bvp_float_state = float_state_t::EXPONENT_INIT; + } else { + this->bvp_float_state = float_state_t::INVALID; + } + break; + case float_state_t::FRACTION_DIGIT: + if (got_digit) { + this->bvp_float_state = float_state_t::FRACTION_DIGIT; + } else if (ch == 'e' || ch == 'E') { + this->bvp_float_state = float_state_t::EXPONENT_INIT; + } else { + this->bvp_float_state = float_state_t::INVALID; + } + break; + case float_state_t::EXPONENT_INIT: + if (got_digit) { + this->bvp_float_state = float_state_t::EXPONENT_DIGIT; + } else if (ch == '-' || ch == '+') { + this->bvp_float_state = float_state_t::EXPONENT_NEED_DIGIT; + } else { + this->bvp_float_state = float_state_t::INVALID; + } + break; + case float_state_t::EXPONENT_NEED_DIGIT: + case float_state_t::EXPONENT_DIGIT: + if (got_digit) { + this->bvp_float_state = float_state_t::EXPONENT_DIGIT; + } else { + this->bvp_float_state = float_state_t::INVALID; + } + break; + case float_state_t::INVALID: + break; + } + + this->bvp_index += 1; + + return true; + } +}; + +logfmt::parser::step_result +logfmt::parser::step() +{ + const static auto IS_DQ = string_fragment::tag1{'"'}; + + auto remaining = this->p_next_input.skip(isspace); + + if (remaining.empty()) { + return end_of_input{}; + } + + auto pair_opt = remaining.split_while(is_not_eq); + + if (!pair_opt) { + return error{remaining.sf_begin, "expecting key followed by '='"}; + } + + auto key_frag = pair_opt->first; + auto after_eq = pair_opt->second.consume(string_fragment::tag1{'='}); + + if (!after_eq) { + return error{pair_opt->second.sf_begin, "expecting '='"}; + } + + auto value_start = after_eq.value(); + + if (value_start.startswith("\"")) { + string_fragment::quoted_string_body qsb; + auto quoted_pair = value_start.consume_n(1)->split_while(qsb); + + if (!quoted_pair) { + return error{value_start.sf_begin + 1, "string body missing"}; + } + + auto after_quote = quoted_pair->second.consume(IS_DQ); + + if (!after_quote) { + return error{quoted_pair->second.sf_begin, "non-terminated string"}; + } + + this->p_next_input = after_quote.value(); + return std::make_pair( + key_frag, + quoted_value{string_fragment{quoted_pair->first.sf_string, + quoted_pair->first.sf_begin - 1, + quoted_pair->first.sf_end + 1}}); + } + + bare_value_predicate bvp; + auto value_pair = value_start.split_while(bvp); + + if (value_pair) { + static const auto TRUE_FRAG = string_fragment::from_const("true"); + static const auto FALSE_FRAG = string_fragment::from_const("false"); + + this->p_next_input = value_pair->second; + if (bvp.is_integer()) { + int_value retval; + + auto int_scan_res + = scn::scan_value<int64_t>(value_pair->first.to_string_view()); + if (int_scan_res) { + retval.iv_value = int_scan_res.value(); + } + retval.iv_str_value = value_pair->first; + + return std::make_pair(key_frag, retval); + } + if (bvp.is_float()) { + float_value retval; + + auto float_scan_res + = scn::scan_value<double>(value_pair->first.to_string_view()); + if (float_scan_res) { + retval.fv_value = float_scan_res.value(); + } + retval.fv_str_value = value_pair->first; + + return std::make_pair(key_frag, retval); + } + if (value_pair->first.iequal(TRUE_FRAG)) { + return std::make_pair(key_frag, + bool_value{true, value_pair->first}); + } + if (value_pair->first.iequal(FALSE_FRAG)) { + return std::make_pair(key_frag, + bool_value{false, value_pair->first}); + } + return std::make_pair(key_frag, unquoted_value{value_pair->first}); + } + + this->p_next_input = value_start; + return std::make_pair(key_frag, unquoted_value{string_fragment{}}); +} |