DiskUsage.cpp

   1 /* Cydia - iPhone UIKit Front-End for Debian APT
   2  * Copyright (C) 2008-2015  Jay Freeman (saurik)
   3 */
   4
   5 /* GNU General Public License, Version 3 {{{ */
   6 /*
   7  * Cydia is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation, either version 3 of the License,
  10  * or (at your option) any later version.
  11  *
  12  * Cydia is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with Cydia.  If not, see <http://www.gnu.org/licenses/>.
  19 **/
  20 /* }}} */
  21
  22 #include <fcntl.h>
  23 #include <dirent.h>
  24 #include <unistd.h>
  25 #include <stdio.h>
  26 #include <errno.h>
  27 #include <string.h>
  28 #include <sys/stat.h>
  29
  30 #define _syscall(expr) ({ decltype(expr) _value; for (;;) { \
  31     _value = (expr); \
  32     if ((long) _value != -1) \
  33         break; \
  34     if (errno != EINTR) { \
  35         perror(#expr); \
  36         return -1; \
  37     } \
  38 } _value; })
  39
  40 extern "C" int __getdirentries64(int, char *, int, long *);
  41
  42 enum Recurse {
  43     RecurseYes,
  44     RecurseNo,
  45     RecurseMaybe,
  46 };
  47
  48 struct File {
  49     int fd_;
  50
  51     File(int fd);
  52     ~File();
  53
  54     operator int() const;
  55 };
  56
  57 File::File(int fd) :
  58     fd_(fd)
  59 {
  60 }
  61
  62 File::~File() {
  63     close(fd_);
  64 }
  65
  66 File::operator int() const {
  67     return fd_;
  68 }
  69
  70 static bool DiskUsage(size_t &total, const char *path, size_t before, Recurse recurse) {
  71     File fd(_syscall(open_dprotected_np(path, O_RDONLY | O_SYMLINK, 0, O_DP_GETRAWENCRYPTED)));
  72
  73     struct stat stat;
  74     _syscall(fstat(fd, &stat));
  75     total += stat.st_blocks * 512;
  76
  77     if (recurse == RecurseMaybe)
  78         switch (stat.st_mode & S_IFMT) {
  79             case S_IFLNK:
  80                 return true;
  81             default:
  82                 return false;
  83
  84             case S_IFDIR:
  85                 recurse = RecurseYes;
  86                 break;
  87             case S_IFREG:
  88                 recurse = RecurseNo;
  89                 break;
  90         }
  91
  92     if (recurse == RecurseNo) {
  93     } else for (long address(0);;) {
  94         char buffer[4096];
  95         int size(_syscall(__getdirentries64(fd, buffer, sizeof(buffer), &address)));
  96         if (size == 0)
  97             break;
  98
  99         const char *next(buffer), *stop(next + size);
 100         while (next != stop) {
 101             const dirent *dir(reinterpret_cast<const dirent *>(next));
 102             const char *name(dir->d_name);
 103             size_t after(strlen(name));
 104
 105             if (dir->d_ino == 0);
 106             else if (after == 1 && name[0] == '.');
 107             else if (after == 2 && name[0] == '.' && name[1] == '.');
 108             else {
 109                 size_t both(before + 1 + after);
 110                 char sub[both + 1];
 111                 memcpy(sub, path, before);
 112                 sub[before] = '/';
 113                 memcpy(sub + before + 1, name, after);
 114                 sub[both] = '\0';
 115
 116                 switch (dir->d_type) {
 117                     case DT_DIR:
 118                         if (!DiskUsage(total, sub, both, RecurseYes))
 119                             return false;
 120                         break;
 121
 122                     case DT_LNK:
 123                     case DT_REG:
 124                         if (!DiskUsage(total, sub, both, RecurseNo))
 125                             return false;
 126                         break;
 127
 128                     default:
 129                         return false;
 130                 }
 131             }
 132
 133             next += dir->d_reclen;
 134         }
 135     }
 136
 137     return true;
 138 }
 139
 140 ssize_t DiskUsage(const char *path) {
 141     size_t total(0);
 142     if (!DiskUsage(total, path, strlen(path), RecurseMaybe))
 143         return -1;
 144     return total;
 145 }