Line data    Source code

       1             : #pragma once
       2             : 
       3             : #include <string>
       4             : 
       5             : #include "envoy/matcher/matcher.h"
       6             : 
       7             : namespace Envoy {
       8             : namespace Matcher {
       9             : 
      10             : /**
      11             :  * Implementation of a map matcher which performs matches against the data provided by DataType.
      12             :  * If the match could not be completed, {MatchState::UnableToMatch, {}} will be returned. If the
      13             :  * match result was determined, {MatchState::MatchComplete, OnMatch} will be returned. If a match
      14             :  * result was determined to be no match, {MatchState::MatchComplete, {}} will be returned.
      15             :  */
      16             : template <class DataType>
      17             : class MapMatcher : public MatchTree<DataType>, Logger::Loggable<Logger::Id::matcher> {
      18             : public:
      19             :   MapMatcher(DataInputPtr<DataType>&& data_input, absl::optional<OnMatch<DataType>> on_no_match)
      20           0 :       : data_input_(std::move(data_input)), on_no_match_(std::move(on_no_match)) {
      21           0 :     auto input_type = data_input_->dataInputType();
      22           0 :     if (input_type != DefaultMatchingDataType) {
      23           0 :       throwEnvoyExceptionOrPanic(
      24           0 :           absl::StrCat("Unsupported data input type: ", input_type,
      25           0 :                        ", currently only string type is supported in map matcher"));
      26           0 :     }
      27           0 :   }
      28             : 
      29             :   // Adds a child to the map.
      30             :   virtual void addChild(std::string value, OnMatch<DataType>&& on_match) PURE;
      31             : 
      32           0 :   typename MatchTree<DataType>::MatchResult match(const DataType& data) override {
      33           0 :     const auto input = data_input_->get(data);
      34           0 :     ENVOY_LOG(trace, "Attempting to match {}", input);
      35           0 :     if (input.data_availability_ == DataInputGetResult::DataAvailability::NotAvailable) {
      36           0 :       return {MatchState::UnableToMatch, absl::nullopt};
      37           0 :     }
      38             : 
      39             :     // Returns `on_no_match` when input data is empty. (i.e., is absl::monostate).
      40           0 :     if (absl::holds_alternative<absl::monostate>(input.data_)) {
      41           0 :       return {MatchState::MatchComplete, on_no_match_};
      42           0 :     }
      43             : 
      44           0 :     const auto result = doMatch(absl::get<std::string>(input.data_));
      45           0 :     if (result) {
      46           0 :       if (result->matcher_) {
      47           0 :         return result->matcher_->match(data);
      48           0 :       } else {
      49           0 :         return {MatchState::MatchComplete, OnMatch<DataType>{result->action_cb_, nullptr}};
      50           0 :       }
      51           0 :     } else if (input.data_availability_ ==
      52           0 :                DataInputGetResult::DataAvailability::MoreDataMightBeAvailable) {
      53             :       // It's possible that we were attempting a lookup with a partial value, so delay matching
      54             :       // until we know that we actually failed.
      55           0 :       return {MatchState::UnableToMatch, absl::nullopt};
      56           0 :     }
      57             : 
      58           0 :     return {MatchState::MatchComplete, on_no_match_};
      59           0 :   }
      60             : 
      61             : protected:
      62             :   const DataInputPtr<DataType> data_input_;
      63             :   const absl::optional<OnMatch<DataType>> on_no_match_;
      64             : 
      65             :   // The inner match method. Attempts to match against the resulting data string. If the match
      66             :   // result was determined, the OnMatch will be returned. If a match result was determined to be no
      67             :   // match, {} will be returned.
      68             :   virtual absl::optional<OnMatch<DataType>> doMatch(const std::string& data) PURE;
      69             : };
      70             : 
      71             : } // namespace Matcher
      72             : } // namespace Envoy