From 5f0d3a1edcad43a4342cfd1390bd6596859aae35 Mon Sep 17 00:00:00 2001
From: bbgan <2893129936@qq.com>
Date: Wed, 31 Jan 2024 22:08:44 +0800
Subject: [PATCH] support escape and unescape[xml]

---
 iguana/util.hpp       |  88 +++++++++++++++++++--------------
 iguana/xml_reader.hpp |   7 ++-
 iguana/xml_util.hpp   | 111 ++++++++++++++++++++++++++++++++++++++++++
 iguana/xml_writer.hpp |  31 +++++++++++-
 test/test_xml.cpp     |  29 +++++++++++
 5 files changed, 228 insertions(+), 38 deletions(-)

diff --git a/iguana/util.hpp b/iguana/util.hpp
index 5d622712..f4ecd675 100644
--- a/iguana/util.hpp
+++ b/iguana/util.hpp
@@ -215,10 +215,59 @@ inline constexpr auto has_qoute = [](uint64_t chunk) IGUANA__INLINE_LAMBDA {
       0b0010001000100010001000100010001000100010001000100010001000100010);
 };
 
+template <bool is_xml_serialization = false, typename Stream, typename Ch>
+IGUANA_INLINE void write_unicode_to_string(Ch& it, Stream& ss) {
+  static const char hexDigits[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
+                                     '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+  unsigned codepoint = 0;
+  if (!decode_utf8(it, codepoint))
+    IGUANA_UNLIKELY { throw std::runtime_error("illegal unicode character"); }
+  if constexpr (is_xml_serialization) {
+    ss.append("&#x");
+  }
+  else {
+    ss.push_back('\\');
+    ss.push_back('u');
+  }
+
+  if (codepoint <= 0xD7FF || (codepoint >= 0xE000 && codepoint <= 0xFFFF)) {
+    ss.push_back(hexDigits[(codepoint >> 12) & 15]);
+    ss.push_back(hexDigits[(codepoint >> 8) & 15]);
+    ss.push_back(hexDigits[(codepoint >> 4) & 15]);
+    ss.push_back(hexDigits[(codepoint)&15]);
+  }
+  else {
+    if (codepoint < 0x010000 || codepoint > 0x10FFFF)
+      IGUANA_UNLIKELY { throw std::runtime_error("illegal codepoint"); }
+    // Surrogate pair
+    unsigned s = codepoint - 0x010000;
+    unsigned lead = (s >> 10) + 0xD800;
+    unsigned trail = (s & 0x3FF) + 0xDC00;
+    ss.push_back(hexDigits[(lead >> 12) & 15]);
+    ss.push_back(hexDigits[(lead >> 8) & 15]);
+    ss.push_back(hexDigits[(lead >> 4) & 15]);
+    ss.push_back(hexDigits[(lead)&15]);
+    if constexpr (is_xml_serialization) {
+      ss.append(";&#x");
+    }
+    else {
+      ss.push_back('\\');
+      ss.push_back('u');
+    }
+    ss.push_back(hexDigits[(trail >> 12) & 15]);
+    ss.push_back(hexDigits[(trail >> 8) & 15]);
+    ss.push_back(hexDigits[(trail >> 4) & 15]);
+    ss.push_back(hexDigits[(trail)&15]);
+  }
+  if constexpr (is_xml_serialization) {
+    ss.push_back(';');
+  }
+}
+
 // https://github.com/Tencent/rapidjson/blob/master/include/rapidjson/writer.h
 template <typename Ch, typename SizeType, typename Stream>
-inline void write_string_with_escape(const Ch* it, SizeType length,
-                                     Stream& ss) {
+IGUANA_INLINE void write_string_with_escape(const Ch* it, SizeType length,
+                                            Stream& ss) {
   static const char hexDigits[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
                                      '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
   static const char escape[256] = {
@@ -241,40 +290,7 @@ inline void write_string_with_escape(const Ch* it, SizeType length,
   std::advance(end, length);
   while (it < end) {
     if (static_cast<unsigned>(*it) >= 0x80)
-      IGUANA_UNLIKELY {
-        unsigned codepoint = 0;
-        if (!decode_utf8(it, codepoint))
-          IGUANA_UNLIKELY {
-            throw std::runtime_error("illegal unicode character");
-          }
-        ss.push_back('\\');
-        ss.push_back('u');
-        if (codepoint <= 0xD7FF ||
-            (codepoint >= 0xE000 && codepoint <= 0xFFFF)) {
-          ss.push_back(hexDigits[(codepoint >> 12) & 15]);
-          ss.push_back(hexDigits[(codepoint >> 8) & 15]);
-          ss.push_back(hexDigits[(codepoint >> 4) & 15]);
-          ss.push_back(hexDigits[(codepoint)&15]);
-        }
-        else {
-          if (codepoint < 0x010000 || codepoint > 0x10FFFF)
-            IGUANA_UNLIKELY { throw std::runtime_error("illegal codepoint"); }
-          // Surrogate pair
-          unsigned s = codepoint - 0x010000;
-          unsigned lead = (s >> 10) + 0xD800;
-          unsigned trail = (s & 0x3FF) + 0xDC00;
-          ss.push_back(hexDigits[(lead >> 12) & 15]);
-          ss.push_back(hexDigits[(lead >> 8) & 15]);
-          ss.push_back(hexDigits[(lead >> 4) & 15]);
-          ss.push_back(hexDigits[(lead)&15]);
-          ss.push_back('\\');
-          ss.push_back('u');
-          ss.push_back(hexDigits[(trail >> 12) & 15]);
-          ss.push_back(hexDigits[(trail >> 8) & 15]);
-          ss.push_back(hexDigits[(trail >> 4) & 15]);
-          ss.push_back(hexDigits[(trail)&15]);
-        }
-      }
+      IGUANA_UNLIKELY { write_unicode_to_string(it, ss); }
     else if (escape[static_cast<unsigned char>(*it)])
       IGUANA_UNLIKELY {
         ss.push_back('\\');
diff --git a/iguana/xml_reader.hpp b/iguana/xml_reader.hpp
index 829a2705..6da30fab 100644
--- a/iguana/xml_reader.hpp
+++ b/iguana/xml_reader.hpp
@@ -28,7 +28,12 @@ template <typename U, typename It, std::enable_if_t<plain_v<U>, int> = 0>
 IGUANA_INLINE void parse_value(U &&value, It &&begin, It &&end) {
   using T = std::decay_t<U>;
   if constexpr (string_container_v<T>) {
-    value = T(&*begin, static_cast<size_t>(std::distance(begin, end)));
+    if constexpr (string_view_v<T>) {
+      value = T(&*begin, static_cast<size_t>(std::distance(begin, end)));
+    }
+    else {
+      parse_escape_xml(value, begin, end);
+    }
   }
   else if constexpr (num_v<T>) {
     auto size = std::distance(begin, end);
diff --git a/iguana/xml_util.hpp b/iguana/xml_util.hpp
index cd2df709..fb1dff6a 100644
--- a/iguana/xml_util.hpp
+++ b/iguana/xml_util.hpp
@@ -186,4 +186,115 @@ IGUANA_INLINE auto skip_pass(It &&it, It &&end) {
   return res + 1;
 }
 
+template <char... C, typename It>
+IGUANA_INLINE bool is_match(It &&it, const It &end) {
+  const auto n = static_cast<size_t>(std::distance(it, end));
+  if ((n < sizeof...(C)) || (... || (*it++ != C))) {
+    return false;
+  }
+  return true;
+}
+
+// loose policy: allow '&'
+template <typename U, typename It, std::enable_if_t<string_v<U>, int> = 0>
+IGUANA_INLINE void parse_escape_xml(U &value, It &&it, It &&end) {
+  static const unsigned char lookup_digits[256] = {
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 0,   1,   2,   3,   4,   5,   6,   7,   8,   9,   255, 255,
+      255, 255, 255, 255, 255, 10,  11,  12,  13,  14,  15,  255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 10,  11,  12,  13,  14,  15,  255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+      255};
+  while (it < end) {
+    if (*it == '&')
+      IGUANA_UNLIKELY {
+        switch (*(it + 1)) {
+          // &amp; &apos;
+          case 'a':
+            if (is_match<'m', 'p', ';'>(it + 2, end)) {
+              value.push_back('&');
+              it += 5;
+              continue;
+            }
+            if (is_match<'p', 'o', 's', ';'>(it + 2, end)) {
+              value.push_back('\'');
+              it += 6;
+              continue;
+            }
+            break;
+          // &quot;
+          case 'q':
+            if (is_match<'u', 'o', 't', ';'>(it + 2, end)) {
+              value.push_back('\"');
+              it += 6;
+              continue;
+            }
+            break;
+          // &gt;
+          case 'g':
+            if (is_match<'t', ';'>(it + 2, end)) {
+              value.push_back('>');
+              it += 4;
+              continue;
+            }
+            break;
+          // &lt;
+          case 'l':
+            if (is_match<'t', ';'>(it + 2, end)) {
+              value.push_back('<');
+              it += 4;
+              continue;
+            }
+            break;
+          case '#':
+            if (*(it + 2) == 'x') {
+              // &#x
+              unsigned long codepoint = 0;
+              it += 3;
+              while (true) {
+                auto digit = lookup_digits[static_cast<unsigned char>(*it)];
+                if (digit == 0xFF)
+                  break;
+                codepoint = codepoint * 16 + digit;
+                ++it;
+              }
+              encode_utf8(value, codepoint);
+            }
+            else {
+              unsigned long codepoint = 0;
+              it += 2;
+              while (true) {
+                auto digit = lookup_digits[static_cast<unsigned char>(*it)];
+                if (digit == 0xFF)
+                  break;
+                codepoint = codepoint * 10 + digit;
+                ++it;
+              }
+              encode_utf8(value, codepoint);
+            }
+            match<';'>(it, end);
+            continue;
+          default:
+            break;
+        }
+        value.push_back(*(it++));
+      }
+    else {
+      value.push_back(*(it++));
+    }
+  }
+}
+
 }  // namespace iguana
diff --git a/iguana/xml_writer.hpp b/iguana/xml_writer.hpp
index b83a2c8b..21d2ed41 100644
--- a/iguana/xml_writer.hpp
+++ b/iguana/xml_writer.hpp
@@ -6,6 +6,35 @@
 
 namespace iguana {
 
+template <typename Ch, typename SizeType, typename Stream>
+IGUANA_INLINE void render_string_with_escape_xml(const Ch *it, SizeType length,
+                                                 Stream &ss) {
+  auto end = it;
+  std::advance(end, length);
+  while (it < end) {
+    if (static_cast<unsigned>(*it) >= 0x80)
+      IGUANA_UNLIKELY {
+        write_unicode_to_string<true>(it, ss);
+        continue;
+        ss.push_back(*it);
+      }
+    else if (*it == '\'')
+      IGUANA_UNLIKELY { ss.append("&apos;"); }
+    else if (*it == '"')
+      IGUANA_UNLIKELY { ss.append("&quot;"); }
+    else if (*it == '&')
+      IGUANA_UNLIKELY { ss.append("&amp;"); }
+    else if (*it == '>')
+      IGUANA_UNLIKELY { ss.append("&gt;"); }
+    else if (*it == '<')
+      IGUANA_UNLIKELY { ss.append("&lt;"); }
+    else {
+      ss.push_back(*it);
+    }
+    ++it;
+  }
+}
+
 template <bool pretty, size_t spaces, typename Stream, typename T,
           std::enable_if_t<sequence_container_v<T>, int> = 0>
 IGUANA_INLINE void render_xml_value(Stream &ss, const T &value,
@@ -42,7 +71,7 @@ IGUANA_INLINE void render_head(Stream &ss, std::string_view str) {
 template <typename Stream, typename T, std::enable_if_t<plain_v<T>, int> = 0>
 IGUANA_INLINE void render_value(Stream &ss, const T &value) {
   if constexpr (string_container_v<T>) {
-    ss.append(value.data(), value.size());
+    render_string_with_escape_xml(value.data(), value.size(), ss);
   }
   else if constexpr (num_v<T>) {
     char temp[65];
diff --git a/test/test_xml.cpp b/test/test_xml.cpp
index a7796bc9..f6697088 100644
--- a/test/test_xml.cpp
+++ b/test/test_xml.cpp
@@ -18,6 +18,35 @@ struct Owner_t {
   }
 };
 REFLECTION(Owner_t, ID, DisplayName);
+TEST_CASE("test escape") {
+  {
+    std::string str = R"(
+    <Owner_t description="&lt;&#x5c0f;&#24378;&gt;">
+      <ID>&apos;&amp;&quot;&lt;&gt;</ID>
+      <DisplayName>&#x5c0f;&#24378;</DisplayName>
+    </Owner_t>
+    )";
+    using Owner_attr_t =
+        iguana::xml_attr_t<Owner_t, std::map<std::string_view, std::string>>;
+    auto validator = [](const Owner_attr_t &Owner) {
+      auto Ow = Owner.value();
+      auto attr = Owner.attr();
+      CHECK(attr["description"] == "<小强>");
+      CHECK(Ow.ID == R"('&"<>)");
+      CHECK(Ow.DisplayName == "小强");
+    };
+    Owner_attr_t Owner;
+    iguana::from_xml(Owner, str);
+    validator(Owner);
+
+    std::string ss;
+    iguana::to_xml(Owner, ss);
+    std::cout << ss << std::endl;
+    Owner_attr_t Owner1;
+    iguana::from_xml(Owner1, ss);
+    validator(Owner1);
+  }
+}
 
 struct Contents {
   std::string Key;