add StructMapper.setChars, getChars

src/data/StructMapper.cpp

@@ -103,6 +103,18 @@ void StructMapping::setNumber(
     }
 }
 
+void StructMapping::setChars(
+    ubyte* dst, std::string_view value, const std::string& name
+) {
+    const auto& field = requreField(name);
+    if (field.type != FieldType::CHAR) {
+        throw std::runtime_error("'char' field type required");
+    }
+    auto ptr = reinterpret_cast<char*>(dst + field.offset);
+    std::memcpy(ptr, value.data(), 
+        std::min(value.size(), static_cast<std::size_t>(field.elements)));
+}
+
 template<typename T>
 static T get_int(const ubyte* src) {
     return dataio::le2h(*reinterpret_cast<const T*>(src));
@@ -160,3 +172,14 @@ number_t StructMapping::getNumber(
     }
     throw std::runtime_error("type error");
 }
+
+std::string_view StructMapping::getChars(
+    const ubyte* src, const std::string& name
+) const {
+    const auto& field = requreField(name);
+    if (field.type != FieldType::CHAR) {
+        throw std::runtime_error("'char' field type required");
+    }
+    auto ptr = src + field.offset;
+    return std::string_view(reinterpret_cast<const char*>(ptr), field.elements);
+}

src/data/StructMapper.hpp

@@ -57,9 +57,11 @@ namespace data {
 
         integer_t getInteger(const ubyte* src, const std::string& name, int index=0) const;
         number_t getNumber(const ubyte* src, const std::string& name, int index=0) const;
+        std::string_view getChars(const ubyte* src, const std::string& name) const;
 
         void setInteger(ubyte* dst, integer_t value, const std::string& name, int index=0);
         void setNumber(ubyte* dst, number_t value, const std::string& name, int index=0);
+        void setChars(ubyte* dst, std::string_view value, const std::string& name);
 
         int size() const {
             return totalSize;

test/data/StructMapper.cpp

@@ -9,7 +9,7 @@ TEST(StructMapper, ReadWrite) {
 
     std::vector<Field> fields {
         Field {FieldType::I8, "a", 1},
-        Field {FieldType::I32, "b", 1},
+        Field {FieldType::CHAR, "s", 4},
         Field {FieldType::F32, "f", 1},
     };
     auto mapping = StructMapping::create(fields);
@@ -20,4 +20,7 @@ TEST(StructMapper, ReadWrite) {
 
     mapping.setNumber(buffer, 3.141592f, "f");
     EXPECT_FLOAT_EQ(mapping.getNumber(buffer, "f"), 3.141592f);
+
+    mapping.setChars(buffer, "hello", "s");
+    EXPECT_EQ(mapping.getChars(buffer, "s"), "hell");
 }