[logfmt] parse spans that are not kv-pairs

Author: tstack

src/base/intern_string.hh

@@ -586,11 +586,11 @@ struct string_fragment {
                     string_fragment{
                         this->sf_string,
                         this->sf_begin,
-                        this->sf_begin + curr,
+                        curr,
                     },
                     string_fragment{
                         this->sf_string,
-                        this->sf_begin + curr + 1,
+                        curr + 1,
                         this->sf_end,
                     });
             }
@@ -601,6 +601,35 @@ struct string_fragment {
         return std::nullopt;
     }
 
+    template<typename P>
+    split_when_result rsplit_when(P&& predicate) const
+    {
+        if (this->empty()) {
+            return std::make_pair(string_fragment{}, string_fragment{});
+        }
+
+        auto curr = this->sf_end - 1;
+        while (curr >= this->sf_begin) {
+            if (predicate(this->sf_string[curr])) {
+                return std::make_pair(
+                    string_fragment{
+                        this->sf_string,
+                        this->sf_begin,
+                        curr + 1,
+                    },
+                    string_fragment{
+                        this->sf_string,
+                        curr + 1,
+                        this->sf_end,
+                    });
+            }
+
+            curr -= 1;
+        }
+
+        return std::make_pair(string_fragment{}, *this);
+    }
+
     using split_n_result = std::pair<string_fragment, string_fragment>;
 
     split_n_result split_n(int amount) const;

src/formats/logfmt/logfmt.parser.cc

@@ -38,9 +38,9 @@
 logfmt::parser::parser(string_fragment sf) : p_next_input(sf) {}
 
 static bool
-is_not_eq(char ch)
+is_not_key(char ch)
 {
-    return ch != '=';
+    return !isalnum(ch) && ch != '_' && ch != '-' && ch != '.';
 }
 
 struct bare_value_predicate {
@@ -181,20 +181,25 @@ logfmt::parser::step()
         return end_of_input{};
     }
 
-    auto pair_opt = remaining.split_while(is_not_eq);
-
-    if (!pair_opt) {
+    auto [before, after] = remaining.split_when(string_fragment::tag1{'='});
+    if (before.empty()) {
         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 (before.sf_end == remaining.sf_end) {
+        this->p_next_input = after;
+        return before;
+    }
 
-    if (!after_eq) {
-        return error{pair_opt->second.sf_begin, "expecting '='"};
+    auto [plain, key] = before.rsplit_when(is_not_key);
+    if (!plain.empty()) {
+        this->p_next_input = key;
+        this->p_next_input.sf_end = after.sf_end;
+        return plain;
     }
 
-    auto value_start = after_eq.value();
+    auto key_frag = before;
+    auto value_start = after;
 
     if (value_start.startswith("\"")) {
         string_fragment::quoted_string_body qsb;

src/formats/logfmt/logfmt.parser.hh

@@ -32,8 +32,9 @@
 #ifndef lnav_logfmt_parser_hh
 #define lnav_logfmt_parser_hh
 
+#include <utility>
+
 #include "base/intern_string.hh"
-#include "base/result.h"
 #include "mapbox/variant.hpp"
 
 namespace logfmt {
@@ -76,6 +77,7 @@ public:
     using kvpair = std::pair<string_fragment, value_type>;
 
     using step_result = mapbox::util::variant<
+        string_fragment,
         end_of_input,
         kvpair,
         error