Implement basic stream_writer methods

3 files changed, 26 insertions, 3 deletions

diff --git a/include/io/stream_writer.h b/include/io/stream_writer.h
index ea3dcd1c58..78d02cb2cc 100644
--- a/include/io/stream_writer.h
+++ b/include/io/stream_writer.h
@@ -42,17 +42,22 @@ class output_error : public std::runtime_error
 class stream_writer
 {
 public:
+    ///Maximum length of an NBT string (65535)
+    static constexpr size_t max_string_len = UINT16_MAX;
+
     /**
      * @param os the stream to write to
      * @param e the byte order of the written data. The Java edition
      * of Minecraft uses Big Endian, the Pocket edition uses Little Endian
      */
-    explicit stream_writer(std::ostream& os, endian::endian e = endian::big) noexcept;
+    explicit stream_writer(std::ostream& os, endian::endian e = endian::big) noexcept:
+        os(os), endian(e)
+    {}
 
     ///Returns the stream
-    std::ostream& get_ostr() const;
+    std::ostream& get_ostr() const { return os; }
     ///Returns the byte order
-    endian::endian get_endian() const;
+    endian::endian get_endian() const { return endian; }
 
     /**
      * @brief Writes a tag type to the stream
@@ -70,6 +75,7 @@ public:
      *
      * An NBT string consists of two bytes indicating the length, followed by
      * the characters encoded in modified UTF-8.
+     * @throw std::length_error if the string is too long for NBT
      */
     void write_string(const std::string& str);
 
diff --git a/src/io/stream_writer.cpp b/src/io/stream_writer.cpp
index dd90c83322..26a6a7eb65 100644
--- a/src/io/stream_writer.cpp
+++ b/src/io/stream_writer.cpp
@@ -18,13 +18,29 @@
  * along with libnbt++.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include "io/stream_writer.h"
+#include <sstream>
 
 namespace nbt
 {
 namespace io
 {
 
+void stream_writer::write_type(tag_type tt)
+{
+    write_num(static_cast<int8_t>(tt));
+}
 
+void stream_writer::write_string(const std::string& str)
+{
+    if(str.size() > max_string_len)
+    {
+        std::ostringstream sstr;
+        sstr << "String is too long for NBT (" << str.size() << " > " << max_string_len << ")";
+        throw std::length_error(sstr.str());
+    }
+    write_num(static_cast<uint16_t>(str.size()));
+    os.write(str.data(), str.size());
+}
 
 }
 }
diff --git a/test/write_test.cpp b/test/write_test.cpp
index 5c5cab055b..3f9327b978 100644
--- a/test/write_test.cpp
+++ b/test/write_test.cpp
@@ -51,6 +51,7 @@ void test_stream_writer_big()
         0x00, 0x06, //string length in Big Endian
         'f', 'o', 'o', 'b', 'a', 'r'
     };
+    std::string s = os.str();
     ASSERT(os.str() == expected);
     std::clog << "test_stream_writer_big passed" << std::endl;
 }