stella/src/unix/FSNodePOSIX.cxx

322 lines
9.0 KiB
C++

//============================================================================
//
// SSSS tt lll lll
// SS SS tt ll ll
// SS tttttt eeee ll ll aaaa
// SSSS tt ee ee ll ll aa
// SS tt eeeeee ll ll aaaaa -- "An Atari 2600 VCS Emulator"
// SS SS tt ee ll ll aa aa
// SSSS ttt eeeee llll llll aaaaa
//
// Copyright (c) 1995-2010 by Bradford W. Mott, Stephen Anthony
// and the Stella Team
//
// See the file "License.txt" for information on usage and redistribution of
// this file, and for a DISCLAIMER OF ALL WARRANTIES.
//
// $Id$
//
// Based on code from ScummVM - Scumm Interpreter
// Copyright (C) 2002-2004 The ScummVM project
//============================================================================
#include "FSNode.hxx"
#ifdef MACOSX
#include <sys/types.h>
#endif
#include <sys/param.h>
#include <sys/stat.h>
#include <dirent.h>
#include <cassert>
#include <cstdio>
#include <cstring>
#include <unistd.h>
#include <sstream>
/*
* Implementation of the Stella file system API based on POSIX (for Linux and OSX)
*
* Parts of this class are documented in the base interface class, AbstractFilesystemNode.
*/
class POSIXFilesystemNode : public AbstractFilesystemNode
{
public:
/**
* Creates a POSIXFilesystemNode with the root node as path.
*/
POSIXFilesystemNode();
/**
* Creates a POSIXFilesystemNode for a given path.
*
* @param path String with the path the new node should point to.
* @param verify true if the isValid and isDirectory flags should be verified during the construction.
*/
POSIXFilesystemNode(const string& path, bool verify);
virtual bool exists() const { return access(_path.c_str(), F_OK) == 0; }
virtual string getDisplayName() const { return _displayName; }
virtual string getName() const { return _displayName; }
virtual string getPath() const { return _path; }
virtual string getRelativePath() const;
virtual bool isDirectory() const { return _isDirectory; }
virtual bool isReadable() const { return access(_path.c_str(), R_OK) == 0; }
virtual bool isWritable() const { return access(_path.c_str(), W_OK) == 0; }
virtual bool getChildren(AbstractFSList& list, ListMode mode, bool hidden) const;
virtual AbstractFilesystemNode* getParent() const;
protected:
string _displayName;
string _path;
bool _isDirectory;
bool _isValid;
private:
/**
* Tests and sets the _isValid and _isDirectory flags, using the stat() function.
*/
virtual void setFlags();
};
/**
* Returns the last component of a given path.
*
* Examples:
* /foo/bar.txt would return /bar.txt
* /foo/bar/ would return /bar/
*
* @param str String containing the path.
* @return Pointer to the first char of the last component inside str.
*/
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
const char* lastPathComponent(const string& str)
{
if(str.empty())
return "";
const char *start = str.c_str();
const char *cur = start + str.size() - 2;
while (cur >= start && *cur != '/')
--cur;
return cur + 1;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void POSIXFilesystemNode::setFlags()
{
struct stat st;
_isValid = (0 == stat(_path.c_str(), &st));
_isDirectory = _isValid ? S_ISDIR(st.st_mode) : false;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
POSIXFilesystemNode::POSIXFilesystemNode()
{
// The root dir.
_path = "/";
_displayName = _path;
_isValid = true;
_isDirectory = true;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
POSIXFilesystemNode::POSIXFilesystemNode(const string& p, bool verify)
{
// Expand "~/" to the value of the HOME env variable
if ( p.length() >= 2 && p[0] == '~' && p[1] == '/')
{
const char *home = getenv("HOME");
if (home != NULL && strlen(home) < MAXPATHLEN)
{
_path = home;
// Skip over the tilde. We know that p contains at least
// two chars, so this is safe:
_path += p.c_str() + 1;
}
}
// Expand "./" to the current directory
else if ( p.length() >= 2 && p[0] == '.' && p[1] == '/')
{
char buf[MAXPATHLEN];
char* ret = getcwd(buf, MAXPATHLEN);
if (ret == buf)
{
_path = buf;
// Skip over the tilda. We know that p contains at least
// two chars, so this is safe:
_path += p.c_str() + 1;
}
}
else
_path = p;
_displayName = lastPathComponent(_path);
if (verify)
{
setFlags();
// Add a trailing slash, if necessary
if (_isDirectory && _path.length() > 0 && _path[_path.length()-1] != '/')
_path += '/';
}
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
string POSIXFilesystemNode::getRelativePath() const
{
// If the path starts with the home directory, replace it with '~'
const char* home = getenv("HOME");
if(home != NULL)
{
int len = strlen(home);
if(strncmp(_path.c_str(), home, len) == 0)
{
string path = "~";
const char* offset = _path.c_str() + len;
if(*offset != '/') path += "/";
path += offset;
return path;
}
}
return _path;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool POSIXFilesystemNode::getChildren(AbstractFSList& myList, ListMode mode,
bool hidden) const
{
assert(_isDirectory);
DIR *dirp = opendir(_path.c_str());
struct dirent *dp;
if (dirp == NULL)
return false;
// loop over dir entries using readdir
while ((dp = readdir(dirp)) != NULL)
{
// Skip 'invisible' files if necessary
if (dp->d_name[0] == '.' && !hidden)
continue;
// Skip '.' and '..' to avoid cycles
if ((dp->d_name[0] == '.' && dp->d_name[1] == 0) || (dp->d_name[0] == '.' && dp->d_name[1] == '.'))
continue;
string newPath(_path);
if (newPath.length() > 0 && newPath[newPath.length()-1] != '/')
newPath += '/';
newPath += dp->d_name;
POSIXFilesystemNode entry(newPath, false);
#if defined(SYSTEM_NOT_SUPPORTING_D_TYPE)
/* TODO: d_type is not part of POSIX, so it might not be supported
* on some of our targets. For those systems where it isn't supported,
* add this #elif case, which tries to use stat() instead.
*
* The d_type method is used to avoid costly recurrent stat() calls in big
* directories.
*/
entry.setFlags();
#else
if (dp->d_type == DT_UNKNOWN)
{
// Fall back to stat()
entry.setFlags();
}
else
{
entry._isValid = (dp->d_type == DT_DIR) || (dp->d_type == DT_REG) || (dp->d_type == DT_LNK);
if (dp->d_type == DT_LNK)
{
struct stat st;
if (stat(entry._path.c_str(), &st) == 0)
entry._isDirectory = S_ISDIR(st.st_mode);
else
entry._isDirectory = false;
}
else
entry._isDirectory = (dp->d_type == DT_DIR);
}
#endif
// Skip files that are invalid for some reason (e.g. because we couldn't
// properly stat them).
if (!entry._isValid)
continue;
// Honor the chosen mode
if ((mode == FilesystemNode::kListFilesOnly && entry._isDirectory) ||
(mode == FilesystemNode::kListDirectoriesOnly && !entry._isDirectory))
continue;
if (entry._isDirectory)
entry._path += "/";
myList.push_back(new POSIXFilesystemNode(entry));
}
closedir(dirp);
return true;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
AbstractFilesystemNode* POSIXFilesystemNode::getParent() const
{
if (_path == "/")
return 0;
const char *start = _path.c_str();
const char *end = lastPathComponent(_path);
return new POSIXFilesystemNode(string(start, end - start), true);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
AbstractFilesystemNode* AbstractFilesystemNode::makeRootFileNode()
{
return new POSIXFilesystemNode();
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
AbstractFilesystemNode* AbstractFilesystemNode::makeCurrentDirectoryFileNode()
{
return new POSIXFilesystemNode("./", true);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
AbstractFilesystemNode* AbstractFilesystemNode::makeHomeDirectoryFileNode()
{
return new POSIXFilesystemNode("~/", true);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
AbstractFilesystemNode* AbstractFilesystemNode::makeFileNodePath(const string& path)
{
return new POSIXFilesystemNode(path, true);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool AbstractFilesystemNode::makeDir(const string& path)
{
return mkdir(path.c_str(), 0777) == 0;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool AbstractFilesystemNode::renameFile(const string& oldfile,
const string& newfile)
{
return rename(oldfile.c_str(), newfile.c_str()) == 0;
}