getAvailableDiskSpace now works on FreeBSD

Author: jercaianu

changelog/std-file-getAvailableDiskSpace.dd

@@ -4,8 +4,6 @@ $(REF getAvailableDiskSpace, std,file) receives as a parameter the path of a fil
 directory in the file system, and returns the available disk space on the mounted filesystem.
 If the given path is nonexistent, an exception is thrown.
 
-Due to inconsistent behaviour with the `statvfs` `Posix` function, FreeBSD does not support this functionality.
-
 ---
 import std.file;
 ulong size = getAvailableDiskSpace(".");

std/file.d

@@ -5122,75 +5122,85 @@ string tempDir() @trusted
 }
 
 /**
-* Returns the available space in a file system.
-*
-* On `Windows`, this function uses the result of the Windows API function
-* $(LINK2 https://msdn.microsoft.com/en-us/library/windows/desktop/aa364937(v=vs.85).aspx, $(D GetDiskFreeSpaceExW)).
-*
-* On `POSIX` platforms, it uses the $(LINK2 http://man7.org/linux/man-pages/man3/statvfs.3.html,
-* $(D statvfs)) function.
-*
-* Due to inconsistent behaviour with the `statvfs` `Posix` function,
-* `FreeBSD` does not support `getAvailableDiskSpace`.
-*
-* Params:
-*     path = a valid path to any file in the file system
-*
-* Returns:
-*    ulong which contains the available space in bytes
-*
-* Throws:
-*     $(LREF FileException) in case statvfs (`POSIX`) or GetDiskFreeSpaceExW (`Windows`) fails.
+Returns the available space in a file system.
+
+On `Windows`, this function uses the result of the Windows API function
+$(LINK2 https://msdn.microsoft.com/en-us/library/windows/desktop/aa364937(v=vs.85).aspx, $(D GetDiskFreeSpaceExW)).
+
+On `POSIX` platforms, it uses the $(LINK2 http://man7.org/linux/man-pages/man3/statvfs.3.html,
+$(D statvfs)) function. On `FreeBSD` however, it uses the $(LINK2 https://www.freebsd.org/cgi/man.cgi?query=statfs&sektion=2,
+$(D statfs)) function.
+
+Params:
+    path = a valid path to any file in the file system
+Returns:
+    Available space in bytes
+
+Throws:
+$(LREF FileException) in case of failure
 */
-ulong getAvailableDiskSpace(string path) @trusted
+ulong getAvailableDiskSpace(string path) @safe
 {
     import std.exception : enforce;
     import std.conv : text;
 
-    version (FreeBSD)
-    {
-        static assert(0, "Unsupported platform");
-    }
-    else version (Windows)
+    version (Windows)
     {
         import core.sys.windows.winbase : GetDiskFreeSpaceExW, GetLastError;
         import core.sys.windows.winnt : ULARGE_INTEGER;
         import std.internal.cstring : tempCStringW;
 
         ULARGE_INTEGER freeBytesAvailable;
-        auto err = GetDiskFreeSpaceExW(path.tempCStringW(), &freeBytesAvailable, null, null);
+        auto err = () @trusted {
+            return GetDiskFreeSpaceExW(path.tempCStringW(), &freeBytesAvailable, null, null);
+        } ();
         enforce(err != 0,
             new FileException(text("Cannot get available disk space: ", GetLastError())));
 
         return freeBytesAvailable.QuadPart;
     }
     else version (Posix)
     {
-        import core.sys.posix.sys.statvfs : statvfs, statvfs_t;
         import std.string : toStringz;
 
-        statvfs_t stats = void;
-        auto err = statvfs(path.toStringz(), &stats);
-        enforce(err == 0,
-            new FileException(text("Cannot get available disk space: ", err)));
+        version (FreeBSD)
+        {
+            import core.sys.posix.sys.statvfs : statfs, statfs_t;
 
-        return stats.f_bavail * stats.f_frsize;
+            statfs_t stats = void;
+            auto err = () @trusted {
+                return statfs(path.toStringz(), &stats);
+            } ();
+            enforce(err == 0,
+                new FileException(text("Cannot get available disk space: ", err)));
+
+            return stats.f_bavail * stats.f_bsize;
+        }
+        else
+        {
+            import core.sys.posix.sys.statvfs : statvfs, statvfs_t;
+
+            statvfs_t stats = void;
+            auto err = () @trusted {
+                return statvfs(path.toStringz(), &stats);
+            } ();
+            enforce(err == 0,
+                new FileException(text("Cannot get available disk space: ", err)));
+
+            return stats.f_bavail * stats.f_frsize;
+        }
     }
     else static assert(0, "Unsupported platform");
 }
 
-version (FreeBSD) {}
-else
+///
+@safe unittest
 {
-    ///
-    @safe unittest
-    {
-        import std.exception : assertThrown;
+    import std.exception : assertThrown;
 
-        auto space = getAvailableDiskSpace(".");
-        assert(space > 0);
+    auto space = getAvailableDiskSpace(".");
+    assert(space > 0);
 
-        assertThrown(getAvailableDiskSpace("ThisFileDoesNotExist123123"));
-    }
+    assertThrown!FileException(getAvailableDiskSpace("ThisFileDoesNotExist123123"));
 }