OW_PosixFileSystem.cpp

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* Copyright (C) 2001-2004 Vintela, Inc. All rights reserved.
*
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* modification, are permitted provided that the following conditions are met:
*
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*    this list of conditions and the following disclaimer.
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#include "OW_config.h"
#include "OW_FileSystem.hpp"
#include "OW_CryptographicRandomNumber.hpp"
#include "OW_Mutex.hpp"
#include "OW_MutexLock.hpp"
#include "OW_File.hpp"
#include "OW_String.hpp"
#include "OW_Array.hpp"
#include "OW_Format.hpp"
#include "OW_ExceptionIds.hpp"
#include "OW_Assertion.hpp"

extern "C"
{
#ifdef OW_WIN32

   #include <direct.h>
   #include <io.h>
   #include <share.h>
   
   #define _ACCESS ::_access
   #define R_OK 4
   #define F_OK 0
   #define W_OK 2
   #define _CHDIR _chdir
   #define _MKDIR(a,b)  _mkdir((a))
   #define _RMDIR _rmdir
   #define _UNLINK _unlink

#else

   #ifdef OW_HAVE_UNISTD_H
   #include <unistd.h>
   #endif
   #ifdef OW_HAVE_DIRENT_H
   #include <dirent.h>
   #endif
   
   #define _ACCESS ::access
   #define _CHDIR chdir
   #define _MKDIR(a,b) mkdir((a),(b))
   #define _RMDIR rmdir
   #define _UNLINK unlink

#ifdef OW_NETWARE
#define MAXSYMLINKS 20
#endif

#endif

#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
}

#include <cstdio> // for rename
#include <fstream>
#include <cerrno>

namespace OW_NAMESPACE
{

OW_DEFINE_EXCEPTION_WITH_ID(FileSystem);

namespace FileSystem
{

// STATIC
int
changeFileOwner(const String& filename,
   const UserId& userId)
{
#ifdef OW_WIN32
   return 0;   // File ownership on Win32?
#else
   return ::chown(filename.c_str(), userId, gid_t(-1));
#endif
}
// STATIC
File
openFile(const String& path)
{
#ifdef OW_WIN32
   HANDLE fh = ::CreateFile(path.c_str(), GENERIC_READ | GENERIC_WRITE,
      FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
      FILE_ATTRIBUTE_NORMAL, NULL);

   return (fh  != INVALID_HANDLE_VALUE) ? File(fh) : File();
#else
   return File(::open(path.c_str(), O_RDWR));
#endif
}
// STATIC
File
createFile(const String& path)
{
#ifdef OW_WIN32
   HANDLE fh = ::CreateFile(path.c_str(), GENERIC_READ | GENERIC_WRITE,
        FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, CREATE_NEW,
      FILE_ATTRIBUTE_NORMAL, NULL);
   return (fh  != INVALID_HANDLE_VALUE) ? File(fh) : File();
#else
   int fd = ::open(path.c_str(), O_CREAT | O_EXCL | O_TRUNC | O_RDWR, 0660);
   if (fd != -1)
   {
      return File(fd);
   }
   return File();
#endif

}
// STATIC
File
openOrCreateFile(const String& path)
{
#ifdef OW_WIN32
   HANDLE fh = ::CreateFile(path.c_str(), GENERIC_READ | GENERIC_WRITE,
      FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
      FILE_ATTRIBUTE_NORMAL, NULL);
   return (fh  != INVALID_HANDLE_VALUE) ? File(fh) : File();
#else
   return File(::open(path.c_str(), O_RDWR | O_CREAT, 0660));
#endif
}

bool
exists(const String& path)
{
   return _ACCESS(path.c_str(), F_OK) == 0;
}

#ifndef OW_WIN32
bool
isExecutable(const String& path)
{
   return _ACCESS(path.c_str(), X_OK) == 0;
}
#endif

bool
canRead(const String& path)
{
   return _ACCESS(path.c_str(), R_OK) == 0;
}
bool
canWrite(const String& path)
{
   return _ACCESS(path.c_str(), W_OK) == 0;
}
#ifndef OW_WIN32
bool
isLink(const String& path)
{
   struct stat st;
   if (lstat(path.c_str(), &st) != 0)
   {
      return false;
   }
   return S_ISLNK(st.st_mode);
}
#endif

bool
isDirectory(const String& path)
{
#ifdef OW_WIN32
   struct _stat st;
   if (_stat(path.c_str(), &st) != 0)
   {
      return false;
   }
   return ((st.st_mode & _S_IFDIR) != 0);
#else
   struct stat st;
   if (stat(path.c_str(), &st) != 0)
   {
      return false;
   }
   return S_ISDIR(st.st_mode);
#endif
}
bool
changeDirectory(const String& path)
{
   return _CHDIR(path.c_str()) == 0;
}
bool
makeDirectory(const String& path, int mode)
{
   return _MKDIR(path.c_str(), mode) == 0;
}
bool
getFileSize(const String& path, off_t& size)
{
#ifdef OW_WIN32
   struct _stat st;
   if (_stat(path.c_str(), &st) != 0)
   {
      return false;
   }
#else
   struct stat st;
   if (stat(path.c_str(), &st) != 0)
   {
      return false;
   }
#endif
   size = st.st_size;
   return true;
}
bool
removeDirectory(const String& path)
{
   return _RMDIR(path.c_str()) == 0;
}
bool
removeFile(const String& path)
{
   return _UNLINK(path.c_str()) == 0;
}
bool
getDirectoryContents(const String& path,
   StringArray& dirEntries)
{
   static Mutex readdirGuard;
   MutexLock lock(readdirGuard);

#ifdef OW_WIN32
   struct _finddata_t dentry;
   long hFile;
   String _path = path;

   // Find first directory entry
   if (!_path.endsWith(OW_FILENAME_SEPARATOR))
   {
      _path += OW_FILENAME_SEPARATOR;
   }
   _path += "*";
    if ((hFile = _findfirst( _path.c_str(), &dentry)) == -1L)
   {
      return false;
   }
   dirEntries.clear();
   while (_findnext(hFile, &dentry) == 0)
   {
      dirEntries.append(String(dentry.name));
   }
   _findclose(hFile);
#else
   DIR* dp(0);
   struct dirent* dentry(0);
   if ((dp = opendir(path.c_str())) == NULL)
   {
      return false;
   }
   dirEntries.clear();
   while ((dentry = readdir(dp)) != NULL)
   {
      dirEntries.append(String(dentry->d_name));
   }
   closedir(dp);
#endif
   return true;
}
bool
renameFile(const String& oldFileName,
   const String& newFileName)
{
   return ::rename(oldFileName.c_str(), newFileName.c_str()) == 0;
}
size_t
read(const FileHandle& hdl, void* bfr, size_t numberOfBytes,
   off_t offset)
{
#ifdef OW_WIN32
   OVERLAPPED ov = { 0, 0, 0, 0, NULL };
   OVERLAPPED *pov = NULL;
   if(offset != -1L)
   {
      ov.Offset = (DWORD) offset;
      pov = &ov;
   }

   DWORD bytesRead;
   size_t cc = (size_t)-1;
   if(::ReadFile(hdl, bfr, (DWORD)numberOfBytes, &bytesRead, pov))
   {
      cc = (size_t)bytesRead;
   }
      
   return cc;
#else
   if (offset != -1L)
   {
      ::lseek(hdl, offset, SEEK_SET);
   }
   return ::read(hdl, bfr, numberOfBytes);
#endif
}
size_t
write(FileHandle& hdl, const void* bfr, size_t numberOfBytes,
   off_t offset)
{
#ifdef OW_WIN32
   OVERLAPPED ov = { 0, 0, 0, 0, NULL };
   OVERLAPPED *pov = NULL;
   if(offset != -1L)
   {
      ov.Offset = (DWORD) offset;
      pov = &ov;
   }

   DWORD bytesWritten;
   size_t cc = (size_t)-1;
   if(::WriteFile(hdl, bfr, (DWORD)numberOfBytes, &bytesWritten, pov))
   {
      cc = (size_t)bytesWritten;
   }
   return cc;
#else

   if (offset != -1L)
   {
      ::lseek(hdl, offset, SEEK_SET);
   }
   return ::write(hdl, bfr, numberOfBytes);
#endif
}
off_t
seek(const FileHandle& hdl, off_t offset, int whence)
{
#ifdef OW_WIN32
   DWORD moveMethod;
   switch(whence)
   {
      case SEEK_END: moveMethod = FILE_END; break;
      case SEEK_CUR: moveMethod = FILE_CURRENT; break;
      default: moveMethod = FILE_BEGIN; break;
   }
   return (off_t) ::SetFilePointer(hdl, (LONG)offset, NULL, moveMethod);
#else
   return ::lseek(hdl, offset, whence);
#endif
}
off_t
tell(const FileHandle& hdl)
{
#ifdef OW_WIN32
   return (off_t) ::SetFilePointer(hdl, 0L, NULL, FILE_CURRENT);
#else
   return ::lseek(hdl, 0, SEEK_CUR);
#endif
}
void
rewind(const FileHandle& hdl)
{
#ifdef OW_WIN32
   ::SetFilePointer(hdl, 0L, NULL, FILE_BEGIN);
#else
   ::lseek(hdl, 0, SEEK_SET);
#endif
}
int
close(const FileHandle& hdl)
{
#ifdef OW_WIN32
   return (::CloseHandle(hdl)) ? 0 : -1;
#else
   return ::close(hdl);
#endif
}
int
flush(FileHandle& hdl)
{
#ifdef OW_WIN32
   return (::FlushFileBuffers(hdl)) ? 0 : -1;
#else
   #ifdef OW_DARWIN
      return ::fsync(hdl);
   #else
      return 0;
   #endif
#endif
}
void
initRandomFile(const String& filename)
{
#ifdef OW_WIN32
   char bfr[1024];
   CryptographicRandomNumber rnum(0, 0xFF);
   for (size_t i = 0; i < 1024; ++i)
   {
      bfr[i] = (char)rnum.getNextNumber();
   }
   HANDLE fh = ::CreateFile(filename.c_str(), GENERIC_WRITE,
      FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, CREATE_ALWAYS,
      FILE_ATTRIBUTE_NORMAL, NULL);
   if(fh == INVALID_HANDLE_VALUE)
   {
      OW_THROW(FileSystemException,
         Format("Can't open random file %1 for writing",
         filename).c_str());
   }
   DWORD bytesWritten;
   size_t cc = (size_t)-1;
   bool success = (::WriteFile(fh, bfr, (DWORD)1024, &bytesWritten, NULL) != 0);
   ::CloseHandle(fh);
   if(!success || bytesWritten < 1024)
   {
      OW_THROW(FileSystemException,
         Format("Failed writing data to random file %1", filename).c_str());
   }
#else
   int hdl = ::open(filename.c_str(), O_CREAT | O_TRUNC | O_WRONLY, 0600);
   if (hdl == -1)
   {
      OW_THROW(FileSystemException, Format("Can't open random file %1 for writing", filename).c_str());
   }
   CryptographicRandomNumber rnum(0, 0xFF);
   for (size_t i = 0; i < 1024; ++i)
   {
      char c = rnum.getNextNumber();
		::write(hdl, &c, 1);
   }
	::close(hdl);
#endif
}

String getFileContents(const String& filename)
{
   std::ifstream in(filename.c_str());
   if (!in)
   {
      OW_THROW(FileSystemException, Format("Failed to open file %1", filename).c_str());
   }
   OStringStream ss;
   ss << in.rdbuf();
   return ss.toString();
}

StringArray getFileLines(const String& filename)
{
   return getFileContents(filename).tokenize("\r\n");
}

String readSymbolicLink(const String& path)
{
#ifdef OW_WIN32
   return Path::realPath(path);
#else
   std::vector<char> buf(MAXPATHLEN);
   int rc;
   do
   {
      rc = ::readlink(path.c_str(), &buf[0], buf.size());
      if (rc >= 0)
      {
         buf.resize(rc);
         buf.push_back('\0');
         return String(&buf[0]);
      }
      buf.resize(buf.size() * 2);
   } while (rc < 0 && errno == ENAMETOOLONG);
   OW_THROW_ERRNO(FileSystemException);
#endif
}

namespace Path
{

String realPath(const String& path)
{
#ifdef OW_WIN32
   char c, *bfr, *pname;
   const char *pathcstr;
   DWORD cc;

   pathcstr = path.c_str();
   while (*pathcstr == '/' || *pathcstr == '\\')
   {
      ++pathcstr;
   }

   // if we ate some '\' or '/' chars, the back up to
   // allow for 1
   if(pathcstr != path.c_str())
   {
      --pathcstr;
   }
      
   cc = GetFullPathName(path.c_str(), 1, &c, &pname);
   if(!cc)
   {
      OW_THROW(FileSystemException, Format("Can't get full path name for path %s", path).c_str());
   }
   bfr = new char[cc];
   cc = GetFullPathName(path.c_str(), cc, bfr, &pname);
   if(!cc)
   {
      delete [] bfr;
      OW_THROW(FileSystemException, Format("Can't get full path name for path %s", path).c_str());
   }
   String rstr(bfr);
   delete [] bfr;
   return rstr;
#else
   String workingPath(path);
   String resolvedPath;
   int numLinks = 0;

   // handle relative paths.
   if (workingPath.length() > 0 && workingPath[0] != '/')
   {
      // result of getCurrentWorkingDirectory is already resolved.
      resolvedPath = getCurrentWorkingDirectory();
   }

   const char* pathCompBegin(workingPath.c_str());
   const char* pathCompEnd(pathCompBegin);
   while (*pathCompBegin != '\0')
   {
      // skip bunches of ////
      while (*pathCompBegin == '/')
      {
         ++pathCompBegin;
      }

      // find end of the path component
      pathCompEnd = pathCompBegin;
      while (*pathCompEnd != '\0' && *pathCompEnd != '/')
      {
         ++pathCompEnd;
      }

      if (pathCompEnd - pathCompBegin == 0)
      {
         break;
      }
      else if (pathCompEnd - pathCompBegin == 1 && pathCompBegin[0] == '.')
      {
         ;// don't add . to the result
      }
      else if (pathCompEnd - pathCompBegin == 2 && pathCompBegin[0] == '.' && pathCompBegin[1] == '.')
      {
         // hit .. so remove the last directory from the result
         size_t lastSlash = resolvedPath.lastIndexOf('/');
         if (lastSlash != String::npos)
         {
            resolvedPath.erase(lastSlash);
         }
      }
      else
      {
         resolvedPath += '/';
         resolvedPath += String(pathCompBegin, pathCompEnd - pathCompBegin);

         // now check the path actually exists
         struct stat pathStats;
#ifdef OW_NETWARE
         if (::stat(resolvedPath.c_str(), &pathStats) < 0)
         {
            OW_THROW_ERRNO_MSG(FileSystemException, resolvedPath);
         }
#else
         if (::lstat(resolvedPath.c_str(), &pathStats) < 0)
         {
            OW_THROW_ERRNO_MSG(FileSystemException, resolvedPath);
         }
         if (S_ISLNK(pathStats.st_mode))
         {
            ++numLinks;
            if (numLinks > MAXSYMLINKS)
            {
               errno = ELOOP;
               OW_THROW_ERRNO_MSG(FileSystemException, resolvedPath);
            }
            String linkTarget(readSymbolicLink(resolvedPath));

            if (linkTarget.length() > 0 && linkTarget[0] != '/')
            {
               // relative link. Remove the link from the resolvedPath and add the linkTarget
               OW_ASSERT(resolvedPath.lastIndexOf('/') != String::npos); // should always happen, we just added a / to the string
               resolvedPath.erase(resolvedPath.lastIndexOf('/'));

               resolvedPath += '/';
               resolvedPath += linkTarget;
            }
            else
            {
               // absolute link
               resolvedPath = linkTarget;
            }

            // now reset and start over on the new path
            resolvedPath += pathCompEnd;
            workingPath = resolvedPath;
            pathCompBegin = pathCompEnd = workingPath.c_str();
            resolvedPath.erase();
         }
#endif
      }

      // keep the loop flowing
      pathCompBegin = pathCompEnd;
   }

   if (resolvedPath.empty())
   {
      resolvedPath = "/";
   }

   return resolvedPath;
#endif
}

String dirname(const String& filename)
{
   // skip over trailing slashes
   size_t lastSlash = filename.length() - 1;
   while (lastSlash > 0 
      && filename[lastSlash] == OW_FILENAME_SEPARATOR_C)
   {
      --lastSlash;
   }
   
   lastSlash = filename.lastIndexOf(OW_FILENAME_SEPARATOR_C, lastSlash);

   if (lastSlash == String::npos)
   {
      return ".";
   }

   while (lastSlash > 0 && filename[lastSlash - 1] == OW_FILENAME_SEPARATOR_C)
   {
      --lastSlash;
   }

   if (lastSlash == 0)
   {
      return OW_FILENAME_SEPARATOR;
   }

   return filename.substring(0, lastSlash);
}

String getCurrentWorkingDirectory()
{
   std::vector<char> buf(MAXPATHLEN);
   char* p;
   do
   {
      p = ::getcwd(&buf[0], buf.size());
      if (p != 0)
      {
         return p;
      }
      buf.resize(buf.size() * 2);
   } while (p == 0 && errno == ERANGE);

   OW_THROW_ERRNO(FileSystemException);
}

} // end namespace Path
} // end namespace FileSystem
} // end namespace OW_NAMESPACE

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