Drop sysroot dependency on coreutils by owning du.

[cydia.git] / DiskUsage.cpp

diff --git a/DiskUsage.cpp b/DiskUsage.cpp
new file mode 100644 (file)
index 0000000..eece02c
--- /dev/null
+++ b/DiskUsage.cpp
@@ -0,0 +1,145 @@
+/* Cydia - iPhone UIKit Front-End for Debian APT
+ * Copyright (C) 2008-2014  Jay Freeman (saurik)
+*/
+
+/* GNU General Public License, Version 3 {{{ */
+/*
+ * Cydia 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 3 of the License,
+ * or (at your option) any later version.
+ *
+ * Cydia 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 Cydia.  If not, see <http://www.gnu.org/licenses/>.
+**/
+/* }}} */
+
+#include <fcntl.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#define _syscall(expr) ({ decltype(expr) _value; for (;;) { \
+    _value = (expr); \
+    if ((long) _value != -1) \
+        break; \
+    if (errno != EINTR) { \
+        perror(#expr); \
+        return -1; \
+    } \
+} _value; })
+
+extern "C" int __getdirentries64(int, char *, int, long *);
+
+enum Recurse {
+    RecurseYes,
+    RecurseNo,
+    RecurseMaybe,
+};
+
+struct File {
+    int fd_;
+
+    File(int fd);
+    ~File();
+
+    operator int() const;
+};
+
+File::File(int fd) :
+    fd_(fd)
+{
+}
+
+File::~File() {
+    close(fd_);
+}
+
+File::operator int() const {
+    return fd_;
+}
+
+static bool DiskUsage(size_t &total, const char *path, size_t before, Recurse recurse) {
+    File fd(_syscall(open_dprotected_np(path, O_RDONLY | O_SYMLINK, 0, O_DP_GETRAWENCRYPTED)));
+
+    struct stat stat;
+    _syscall(fstat(fd, &stat));
+    total += stat.st_blocks * 512;
+
+    if (recurse == RecurseMaybe)
+        switch (stat.st_mode & S_IFMT) {
+            case S_IFLNK:
+                return true;
+            default:
+                return false;
+
+            case S_IFDIR:
+                recurse = RecurseYes;
+                break;
+            case S_IFREG:
+                recurse = RecurseNo;
+                break;
+        }
+
+    if (recurse == RecurseNo) {
+    } else for (long address(0);;) {
+        char buffer[4096];
+        int size(_syscall(__getdirentries64(fd, buffer, sizeof(buffer), &address)));
+        if (size == 0)
+            break;
+
+        const char *next(buffer), *stop(next + size);
+        while (next != stop) {
+            const dirent *dir(reinterpret_cast<const dirent *>(next));
+            const char *name(dir->d_name);
+            size_t after(strlen(name));
+
+            if (dir->d_ino == 0);
+            else if (after == 1 && name[0] == '.');
+            else if (after == 2 && name[0] == '.' && name[1] == '.');
+            else {
+                size_t both(before + 1 + after);
+                char sub[both + 1];
+                memcpy(sub, path, before);
+                sub[before] = '/';
+                memcpy(sub + before + 1, name, after);
+                sub[both] = '\0';
+
+                switch (dir->d_type) {
+                    case DT_DIR:
+                        if (!DiskUsage(total, sub, both, RecurseYes))
+                            return false;
+                        break;
+
+                    case DT_LNK:
+                    case DT_REG:
+                        if (!DiskUsage(total, sub, both, RecurseNo))
+                            return false;
+                        break;
+
+                    default:
+                        return false;
+                }
+            }
+
+            next += dir->d_reclen;
+        }
+    }
+
+    return true;
+}
+
+ssize_t DiskUsage(const char *path) {
+    size_t total(0);
+    if (!DiskUsage(total, path, strlen(path), RecurseMaybe))
+        return -1;
+    return total;
+}