refactor: remove tr_url_query_view (#8049)

replace bespoke struct with std:: container

libtransmission/magnet-metainfo.cc

@@ -235,7 +235,7 @@ bool tr_magnet_metainfo::parseMagnet(std::string_view magnet_link, tr_error* err
     }
 
     bool got_hash = false;
-    for (auto const& [key, value] : tr_url_query_view{ parsed->query })
+    for (auto const& [key, value] : parsed->query_entries())
     {
         if (key == "dn"sv)
         {

libtransmission/web-utils.cc

@@ -434,19 +434,18 @@ std::string tr_urlTrackerLogName(std::string_view url)
     return std::string{ url };
 }
 
-tr_url_query_view::iterator& tr_url_query_view::iterator::operator++()
+std::vector<std::pair<std::string_view, std::string_view>> tr_url_parsed_t::query_entries() const
 {
-    auto pair = tr_strv_sep(&remain, '&');
-    keyval.first = tr_strv_sep(&pair, '=');
-    keyval.second = pair;
-    return *this;
-}
-
-tr_url_query_view::iterator tr_url_query_view::begin() const
-{
-    auto it = iterator{};
-    it.remain = query;
-    return ++it;
+    auto tmp = query;
+    auto ret = std::vector<std::pair<std::string_view, std::string_view>>{};
+    ret.reserve(std::count(std::begin(tmp), std::end(tmp), '&') + 1U);
+    while (!std::empty(tmp))
+    {
+        auto val = tr_strv_sep(&tmp, '&');
+        auto key = tr_strv_sep(&val, '=');
+        ret.emplace_back(key, val);
+    }
+    return ret;
 }
 
 std::string tr_urlPercentDecode(std::string_view in)

libtransmission/web-utils.h

@@ -10,6 +10,7 @@
 #include <string>
 #include <string_view>
 #include <utility>
+#include <vector>
 
 #include <fmt/format.h>
 
@@ -38,6 +39,10 @@ struct tr_url_parsed_t
     std::string_view fragment; // "nose"
     std::string_view full; // "http://example.com:80/over/there?name=ferret#nose"
     uint16_t port = 0;
+
+    // returns a vector of key,val pairs, e.g.
+    // `first=hello&second=world` -> [<"first","hello">,<"second","world">]
+    [[nodiscard]] std::vector<std::pair<std::string_view, std::string_view>> query_entries() const;
 };
 
 [[nodiscard]] std::optional<tr_url_parsed_t> tr_urlParse(std::string_view url);
@@ -50,52 +55,6 @@ struct tr_url_parsed_t
 // This is to avoid logging sensitive info, e.g. a personal announcer id in the URL.
 [[nodiscard]] std::string tr_urlTrackerLogName(std::string_view url);
 
-// example use: `for (auto const [key, val] : tr_url_query_view{ querystr })`
-struct tr_url_query_view
-{
-    std::string_view const query;
-
-    explicit tr_url_query_view(std::string_view query_in)
-        : query{ query_in }
-    {
-    }
-
-    struct iterator
-    {
-        std::pair<std::string_view, std::string_view> keyval;
-        std::string_view remain;
-
-        iterator& operator++();
-
-        [[nodiscard]] constexpr auto const& operator*() const
-        {
-            return keyval;
-        }
-
-        [[nodiscard]] constexpr auto const* operator->() const
-        {
-            return &keyval;
-        }
-
-        [[nodiscard]] constexpr bool operator==(iterator const& that) const
-        {
-            return this->remain == that.remain && this->keyval == that.keyval;
-        }
-
-        [[nodiscard]] constexpr bool operator!=(iterator const& that) const
-        {
-            return !(*this == that);
-        }
-    };
-
-    [[nodiscard]] iterator begin() const;
-
-    [[nodiscard]] static constexpr iterator end()
-    {
-        return iterator{};
-    }
-};
-
 template<typename BackInsertIter>
 constexpr void tr_urlPercentEncode(BackInsertIter out, std::string_view input, bool escape_reserved = true)
 {

tests/libtransmission/web-utils-test.cc

@@ -160,13 +160,15 @@ TEST_F(WebUtilsTest, urlParseFuzz)
     }
 }
 
-TEST_F(WebUtilsTest, urlNextQueryPair)
+TEST_F(WebUtilsTest, urlQueryEntries)
 {
-    auto constexpr Query = "a=1&b=two&c=si&d_has_no_val&e=&f&g=gee"sv;
-    auto const query_view = tr_url_query_view{ Query };
-    auto const end = std::end(query_view);
+    auto parsed = tr_url_parsed_t{};
+    parsed.query = "a=1&b=two&c=si&d_has_no_val&e=&f&g=gee"sv;
 
-    auto it = std::begin(query_view);
+    auto const keyvals = parsed.query_entries();
+    auto const end = std::cend(keyvals);
+
+    auto it = std::cbegin(keyvals);
     EXPECT_NE(end, it);
     EXPECT_EQ("a"sv, it->first);
     EXPECT_EQ("1"sv, it->second);