#ifndef MAPFILE_H
#define MAPFILE_H

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#ifdef HAVE_MMAP
#  include <sys/types.h>
#  include <sys/stat.h>
#  include <fcntl.h>
#  include <sys/mman.h>
#  include <unistd.h>
#elif defined(WIN32)
# include <windows.h>
#else
#  include <fstream>
#  include <vector>
#endif

class MapFile {
public:
  char *cur;
  MapFile(void) : data(NULL), end_of_file(NULL), size(0) {}
  ~MapFile();
  bool open(const char *file_name, long file_size=-1);
  char *begin(void) { return data; }
  char *end(void) { return end_of_file; }
  char *find_str(char *beg, const char *str, char *end=NULL); 
  operator bool () { return cur<end_of_file; }
  bool eof() { return ! *this; }
private:
  char *data;
  char *end_of_file;
  long size;
#ifdef HAVE_MMAP
  int mmap_fd;
#elif defined(WIN32)
  HANDLE hFile;
  HANDLE hFileMap;
#else
  std::vector<char> data_buffer;
#endif

  void close(void);
};

inline void MapFile::close(void)
{
  if (!data)
    return;
#ifdef HAVE_MMAP
  munmap(data, size);
  ::close(mmap_fd);
#elif defined(WIN32)
  UnmapViewOfFile(data);
  CloseHandle(hFileMap);
  CloseHandle(hFile);
#endif
  data=NULL;
}

inline bool MapFile::open(const char *file_name, long file_size)
{
  close();
  size=file_size;
#ifdef HAVE_MMAP
  if ((mmap_fd = ::open(file_name, O_RDONLY)) < 0) {
    std::cerr<<"Can not open: "<<file_name<<std::endl;
    return false;
  }
  if (-1==size) {
    struct stat stat_info;
    if (fstat(mmap_fd, &stat_info)==-1)
      return false;
    size=stat_info.st_size;
  }
  data = (char *)mmap(NULL, size, PROT_READ, MAP_SHARED, mmap_fd, 0);
  if ((void *)data == (void *)(-1))
    return false;

#elif defined(WIN32)
  hFile = CreateFile(file_name, GENERIC_READ, 0, NULL, OPEN_ALWAYS,
		     FILE_ATTRIBUTE_NORMAL, 0);
  if (-1==size)
    size=GetFileSize(hFile, NULL);
  hFileMap = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0,
			       size, NULL);
  data = (char *)MapViewOfFile(hFileMap, FILE_MAP_READ, 0, 0, size);
#  else
  std::ifstream f(file_name);
  if (!f)
    return false;
  if (-1==size) {
    if (!f.seekg(0, std::ios::end))
      return false;
    size=f.tellg();
    if (!f.seekg(0))
      return false;
  }
  data_buffer.resize(size);
  if (!f.read(&(data_buffer[0]), data_buffer.size()))
    return false;
  data=&(data_buffer[0]);
#endif
  cur=data;
  end_of_file=data+size;
  return true;
}

inline MapFile::~MapFile()
{
  close();
}

inline char *MapFile::find_str(char *beg, const char *str, char *end)
{
  const char *p;
  if (!end)
    end=MapFile::end();
  while (beg!=end) {
    p=str;
    while (beg!=end && *p && *p==*beg) ++p, ++beg;
    if (*p=='\0')
      return beg+(str-p);
    ++beg;
  }
  return end;
}

#endif/*MAPFILE_H*/