optimeize unescape slash path (envoyproxy#34934)

---------

Signed-off-by: chenylh <chenyuliang@jd.com>
Signed-off-by: Martin Duke <martin.h.duke@gmail.com>

source/common/http/path_utility.cc

@@ -1,9 +1,9 @@
 #include "source/common/http/path_utility.h"
 
 #include "source/common/common/logger.h"
-#include "source/common/runtime/runtime_features.h"
 
 #include "absl/strings/str_join.h"
+#include "absl/strings/str_replace.h"
 #include "absl/strings/str_split.h"
 #include "absl/types/optional.h"
 #include "url/url_canon.h"
@@ -24,16 +24,6 @@ absl::optional<std::string> canonicalizePath(absl::string_view original_path) {
  output.Complete();
  return absl::make_optional(std::move(canonical_path));
 }
-
-void unescapeInPath(std::string& path, absl::string_view escape_sequence,
- absl::string_view substitution) {
- std::vector<absl::string_view> split = absl::StrSplit(path, escape_sequence);
- if (split.size() == 1) {
- return;
- }
- path = absl::StrJoin(split, substitution);
-}
-
 } // namespace
 
 /* static */
@@ -92,13 +82,14 @@ PathUtil::UnescapeSlashesResult PathUtil::unescapeSlashes(RequestHeaderMap& head
  }
  const absl::string_view query = absl::ClippedSubstr(original_path, query_start);
 
- // TODO(yanavlasov): optimize this by adding case insensitive matcher
- std::string decoded_path{path};
- unescapeInPath(decoded_path, "%2F", "/");
- unescapeInPath(decoded_path, "%2f", "/");
- unescapeInPath(decoded_path, "%5C", "\\");
- unescapeInPath(decoded_path, "%5c", "\\");
- headers.setPath(absl::StrCat(decoded_path, query));
+ static const std::vector<std::pair<absl::string_view, absl::string_view>> replacements{
+ {"%2F", "/"},
+ {"%2f", "/"},
+ {"%5C", "\\"},
+ {"%5c", "\\"},
+ };
+ headers.setPath(absl::StrCat(absl::StrReplaceAll(path, replacements), query));
+
  // Path length will not match if there were unescaped %2f or %5c
  return headers.getPathValue().length() != original_length
  ? UnescapeSlashesResult::FoundAndUnescaped