fixes issue 1008

include/ada_c.h

@@ -38,12 +38,21 @@ typedef struct {
 
 typedef void* ada_url;
 
+// ada_parse and ada_parse_with_base parse a URL.
 // input should be a null terminated C string (ASCII or UTF-8)
 // you must call ada_free on the returned pointer
 ada_url ada_parse(const char* input, size_t length);
 ada_url ada_parse_with_base(const char* input, size_t input_length,
                             const char* base, size_t base_length);
 
+// The ada_reparse and ada_reparse_with_base functions reparse a URL, working just like
+// ada_parse and ada_parse_with_base, except that they reuse the memory allocated for the ada_url instance.
+// This is more efficient if you want to parse many URLs.
+ada_url ada_reparse(ada_url result, const char* input, size_t length);
+ada_url ada_reparse_with_base(ada_url result, const char* input,
+                              size_t input_length, const char* base,
+                              size_t base_length);
+
 // input and base should be a null terminated C strings
 bool ada_can_parse(const char* input, size_t length);
 bool ada_can_parse_with_base(const char* input, size_t input_length,

src/ada_c.cpp

@@ -70,6 +70,13 @@ ada_url ada_parse(const char* input, size_t length) noexcept {
       ada::parse<ada::url_aggregator>(std::string_view(input, length)));
 }
 
+ada_url ada_reparse(ada_url result, const char* input, size_t length) noexcept {
+  using url_type = ada::result<ada::url_aggregator>;
+  static_cast<url_type*>(result)->~url_type();
+  return new (result) url_type(
+      ada::parse<ada::url_aggregator>(std::string_view(input, length)));
+}
+
 ada_url ada_parse_with_base(const char* input, size_t input_length,
                             const char* base, size_t base_length) noexcept {
   auto base_out =
@@ -83,6 +90,24 @@ ada_url ada_parse_with_base(const char* input, size_t input_length,
       std::string_view(input, input_length), &base_out.value()));
 }
 
+ada_url ada_reparse_with_base(ada_url result, const char* input,
+                              size_t input_length, const char* base,
+                              size_t base_length) noexcept {
+  using url_type = ada::result<ada::url_aggregator>;
+  static_cast<url_type*>(result)->~url_type();
+
+  auto base_out =
+      ada::parse<ada::url_aggregator>(std::string_view(base, base_length));
+
+  if (!base_out) {
+    return new (result) ada::result<ada::url_aggregator>(base_out);
+  }
+
+  return new (result)
+      ada::result<ada::url_aggregator>(ada::parse<ada::url_aggregator>(
+          std::string_view(input, input_length), &base_out.value()));
+}
+
 bool ada_can_parse(const char* input, size_t length) noexcept {
   return ada::can_parse(std::string_view(input, length));
 }