1 files changed, 68 insertions, 0 deletions
diff --git a/include/gudhi_laplacian/misc.hpp b/include/gudhi_laplacian/misc.hpp
new file mode 100644
index 0000000..614f30f
--- /dev/null
+++ b/include/gudhi_laplacian/misc.hpp
@@ -0,0 +1,68 @@
+#pragma once
+
+#include <cstdint>
+#include <istream>
+#include <ostream>
+#include <string>
+
+#include <glob.h>
+
+namespace Gudhi_laplacian
+{ 
+  // FIXME: Read from PETSc headers.
+  static const int32_t PETSC_MAT_FILE_CLASSID = 1211216;
+  static const int32_t PETSC_VEC_FILE_CLASSID = 1211214;
+
+  bool preexisting_files(const std::string & prefix, const std::string & postfix)
+  {
+    glob_t globbuf;
+    std::string pattern = prefix + std::string(".*.") + postfix;
+    bool ret = (glob(pattern.c_str(), GLOB_ERR | GLOB_NOSORT, NULL, &globbuf) != GLOB_NOMATCH);
+    globfree(&globbuf);
+    return ret;
+  }
+
+
+  template <typename T> inline void reverse_endianness(T & x)
+  {
+    uint8_t * p = reinterpret_cast<uint8_t *>(&x);
+    std::reverse(p, p + sizeof(T));
+  }
+  
+  template <typename T> inline T read_le(std::istream & s)
+  {
+    T result;
+    s.read(reinterpret_cast<char *>(&result), sizeof(T));
+    #ifdef BIGENDIAN
+    reverse_endianness(result);
+    #endif
+    return result;
+  }
+
+  template <typename T> inline void write_le(std::ostream & s, T value)
+  {
+    #ifdef BIGENDIAN
+    reverse_endianness(value);
+    #endif
+    s.write(reinterpret_cast<char *>(&value), sizeof(T));
+  }
+
+  template <typename T> inline T read_be(std::istream & s)
+  {
+    T result;
+    s.read(reinterpret_cast<char *>(&result), sizeof(T));
+    #ifndef BIGENDIAN
+    reverse_endianness(result);
+    #endif
+    return result;
+  }
+
+  template <typename T> inline void write_be(std::ostream & s, T value)
+  {
+    #ifndef BIGENDIAN
+    reverse_endianness(value);
+    #endif
+    s.write(reinterpret_cast<char *>(&value), sizeof(T));
+  }   
+}
+