Add istream and ostream capability to Xdr

Author: loganharbour

include/utils/xdr_cxx.h

@@ -70,11 +70,22 @@ class Xdr
 public:
 
   /**
-   * Constructor.  Takes the filename and the mode.
+   * File-based constructor.  Takes the filename and the mode.
    * Valid modes are ENCODE, DECODE, READ, and WRITE.
    */
   Xdr (std::string name="", const XdrMODE m=UNKNOWN);
 
+  /**
+   * Output stream based constructor.
+   * Assumes mode WRITE.
+   */
+  Xdr (std::ostream & stream);
+  /**
+   * Input stream based constructor.
+   * Assumes mode READ.
+   */
+  Xdr (std::istream & stream);
+
   /**
    * Destructor.  Closes the file if it is open.
    */

src/utils/xdr_cxx.C

@@ -122,6 +122,42 @@ Xdr::Xdr (std::string name,
 
 
 
+Xdr::Xdr (std::ostream & stream) :
+  mode(WRITE),
+  file_name(),
+#ifdef LIBMESH_HAVE_XDR
+  fp(nullptr),
+#endif
+  in(),
+  out(std::make_unique<std::ostream>(stream.rdbuf())),
+  comm_len(xdr_MAX_STRING_LENGTH),
+  gzipped_file(false),
+  bzipped_file(false),
+  xzipped_file(false),
+  version_number(LIBMESH_VERSION_ID(LIBMESH_MAJOR_VERSION, LIBMESH_MINOR_VERSION, LIBMESH_MICRO_VERSION))
+{
+}
+
+
+
+Xdr::Xdr (std::istream & stream) :
+  mode(READ),
+  file_name(),
+#ifdef LIBMESH_HAVE_XDR
+  fp(nullptr),
+#endif
+  in(std::make_unique<std::istream>(stream.rdbuf())),
+  out(),
+  comm_len(xdr_MAX_STRING_LENGTH),
+  gzipped_file(false),
+  bzipped_file(false),
+  xzipped_file(false),
+  version_number(LIBMESH_VERSION_ID(LIBMESH_MAJOR_VERSION, LIBMESH_MINOR_VERSION, LIBMESH_MICRO_VERSION))
+{
+}
+
+
+
 Xdr::~Xdr()
 {
   this->close();