1 files changed, 70 insertions, 0 deletions
diff --git a/decoder/filelib.h b/decoder/filelib.h
new file mode 100644
index 00000000..03c22b0d
--- /dev/null
+++ b/decoder/filelib.h
@@ -0,0 +1,70 @@
+#ifndef _FILELIB_H_
+#define _FILELIB_H_
+
+#include <cassert>
+#include <string>
+#include <iostream>
+#include <cstdlib>
+#include "gzstream.h"
+
+bool FileExists(const std::string& file_name);
+bool DirectoryExists(const std::string& dir_name);
+
+// reads from standard in if filename is -
+// uncompresses if file ends with .gz
+// otherwise, reads from a normal file
+class ReadFile {
+ public:
+  ReadFile(const std::string& filename) :
+    no_delete_on_exit_(filename == "-"),
+    in_(no_delete_on_exit_ ? static_cast<std::istream*>(&std::cin) :
+      (EndsWith(filename, ".gz") ?
+        static_cast<std::istream*>(new igzstream(filename.c_str())) :
+        static_cast<std::istream*>(new std::ifstream(filename.c_str())))) {
+    if (!no_delete_on_exit_ && !FileExists(filename)) {
+      std::cerr << "File does not exist: " << filename << std::endl;
+      abort();
+    }
+    if (!*in_) {
+      std::cerr << "Failed to open " << filename << std::endl;
+      abort();
+    }
+  }
+  ~ReadFile() {
+    if (!no_delete_on_exit_) delete in_;
+  }
+
+  inline std::istream* stream() { return in_; }
+  
+ private:
+  static bool EndsWith(const std::string& f, const std::string& suf) {
+    return (f.size() > suf.size()) && (f.rfind(suf) == f.size() - suf.size());
+  }
+  const bool no_delete_on_exit_;
+  std::istream* const in_;
+};
+
+class WriteFile {
+ public:
+  WriteFile(const std::string& filename) :
+    no_delete_on_exit_(filename == "-"),
+    out_(no_delete_on_exit_ ? static_cast<std::ostream*>(&std::cout) :
+      (EndsWith(filename, ".gz") ?
+        static_cast<std::ostream*>(new ogzstream(filename.c_str())) :
+        static_cast<std::ostream*>(new std::ofstream(filename.c_str())))) {}
+  ~WriteFile() {
+    (*out_) << std::flush;
+    if (!no_delete_on_exit_) delete out_;
+  }
+
+  inline std::ostream* stream() { return out_; }
+  
+ private:
+  static bool EndsWith(const std::string& f, const std::string& suf) {
+    return (f.size() > suf.size()) && (f.rfind(suf) == f.size() - suf.size());
+  }
+  const bool no_delete_on_exit_;
+  std::ostream* const out_;
+};
+
+#endif