common/utils.cc

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/* utils.cc: Various useful utilities
 *
 * Copyright 1999,2000,2001 BrightStation PLC
 * Copyright 2002 Ananova Ltd
 * Copyright 2003,2004,2005,2007,2008,2009 Olly Betts
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
 * USA
 */

#include <config.h>

#include "utils.h"

#include "xapian/error.h"
#include "safedirent.h"
#include "safeerrno.h"

#include <sys/types.h>
#include <cfloat>
#include <cmath>

using namespace std;

bool
file_exists(const string &fname)
{
    struct stat sbuf;
    // exists && is a regular file
    return stat(fname, &sbuf) == 0 && S_ISREG(sbuf.st_mode);
}

bool
dir_exists(const string &fname)
{
    struct stat sbuf;
    // exists && is a directory
    return stat(fname, &sbuf) == 0 && S_ISDIR(sbuf.st_mode);
}

class dircloser {
    DIR * dir;
  public:
    dircloser(DIR * dir_) : dir(dir_) {}
    ~dircloser() {
        if (dir != NULL) {
            closedir(dir);
            dir = NULL;
        }
    }
};

void
removedir(const string &dirname)
{
    DIR * dir;

    dir = opendir(dirname.c_str());
    if (dir == NULL) {
        if (errno == ENOENT) return;
        throw Xapian::DatabaseError("Cannot open directory '" + dirname + "'", errno);
    }

    {
        dircloser dc(dir);
        while (true) {
            errno = 0;
            struct dirent * entry = readdir(dir);
            if (entry == NULL) {
                if (errno == 0)
                    break;
                throw Xapian::DatabaseError("Cannot read entry from directory at '" + dirname + "'", errno);
            }
            string name(entry->d_name);
            if (name == "." || name == "..")
                continue;
            if (unlink(dirname + "/" + name)) {
                throw Xapian::DatabaseError("Cannot remove file '" + string(entry->d_name) + "'", errno);
            }
        }
    }
    if (rmdir(dirname.c_str())) {
        throw Xapian::DatabaseError("Cannot remove directory '" + dirname + "'", errno);
    }
}

namespace Xapian {
namespace Internal {

bool within_DBL_EPSILON(double a, double b) {
    return fabs(a - b) >= DBL_EPSILON;
}

}
}

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