pdu_stream can read/write fixed length strings

acn/pdu-stream.cpp

@@ -40,6 +40,37 @@ pdu_stream::pdu_stream(uint8_t * p, std::streamsize l)
 }
 
 
+/**
+ * @brief pdu_stream::readString
+ * @param str std::string to which the read string will be appended.
+ * @param length this many bytes will be read from the stream.
+ */
+void pdu_stream::readString(std::string &str, const int length)
+{
+  uint8_t buffer[length];
+  read(buffer, sizeof(buffer));
+  if (gcount() != length)
+    return setstate(std::ios_base::failbit);
+  str += std::string(reinterpret_cast<char*>(buffer));
+}
+
+
+/**
+ * @brief pdu_stream::writeString
+ * @param str
+ * @param fixed_length write this length to the stream, padding with null if
+ * str is shorter than fixed_length.  If 0 will write only the contents of str.
+ */
+void pdu_stream::writeString(const std::string &str, const int fixed_length)
+{
+  for (size_t i = 0; i < (fixed_length > 0 ? fixed_length : str.size()); i++)
+    if (i < str.size())
+      writeType<char>(str.at(i));
+    else
+      writeType<uint8_t>(0);
+}
+
+
 /**
  * @brief pdu_stream::operator >>
  * @param val

acn/pdu-stream.h

@@ -50,6 +50,7 @@ public:
   pdu_stream& operator>> (uint64_t& val);
   pdu_stream& operator>> (UUID::uuid& uuid);
 
+  void readString(std::string& str, const int length);
 
   template<typename T> T readType()
   {
@@ -74,6 +75,9 @@ public:
   pdu_stream& operator<< (const uint32_t& val);
   pdu_stream& operator<< (const uint64_t& val);
   pdu_stream& operator<< (const UUID::uuid& uuid);
+
+  void writeString(const std::string& str, const int fixed_length = 0);
+
   template<typename T> void writeType (const T& val)
   {
     auto data = reinterpret_cast<const uint8_t*>(&val);