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use std::mem;
use diskformat::*;
#[ derive (Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd) ]
pub struct BtrfsDirItem <'a> {
header: & 'a BtrfsLeafItemHeader,
data_bytes: & 'a [u8],
}
#[ repr (C, packed) ]
#[ derive (Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd) ]
pub struct BtrfsDirItemData {
child_key: BtrfsKey,
transaction_id: u64,
data_size: u16,
name_size: u16,
child_type: u8,
}
impl <'a> BtrfsDirItem <'a> {
pub fn from_bytes (
header: & 'a BtrfsLeafItemHeader,
data_bytes: & 'a [u8],
) -> Result <BtrfsDirItem <'a>, String> {
if data_bytes.len () < mem::size_of::<BtrfsDirItemData> () {
return Err (
format! (
"Must be at least 0x{:x} bytes",
mem::size_of::<BtrfsDirItemData> ()));
}
let dir_item = BtrfsDirItem {
header: header,
data_bytes: data_bytes,
};
if data_bytes.len () != (
mem::size_of::<BtrfsDirItemData> ()
+ dir_item.data_size () as usize
+ dir_item.name_size () as usize
) {
return Err (
format! (
"Must be at least 0x{:x} bytes",
mem::size_of::<BtrfsDirItemData> ()
+ dir_item.data_size () as usize
+ dir_item.name_size () as usize));
}
Ok (dir_item)
}
pub fn header (& self) -> & BtrfsLeafItemHeader {
self.header
}
pub fn key (& self) -> BtrfsKey {
self.header.key ()
}
pub fn object_id (& self) -> u64 {
self.header.object_id ()
}
pub fn data (& self) -> & BtrfsDirItemData {
unsafe {
& * (
self.data_bytes.as_ptr ()
as * const BtrfsDirItemData
)
}
}
pub fn child_key (& self) -> BtrfsKey {
self.data ().child_key
}
pub fn child_object_id (& self) -> u64 {
self.data ().child_key.object_id ()
}
pub fn transaction_id (& self) -> u64 {
self.data ().transaction_id
}
pub fn name_size (& self) -> u16 {
self.data ().name_size
}
pub fn data_size (& self) -> u16 {
self.data ().data_size
}
pub fn child_type (& self) -> u8 {
self.data ().child_type
}
pub fn name (
& 'a self,
) -> & 'a [u8] {
& self.data_bytes [
mem::size_of::<BtrfsDirItemData> ()
..
mem::size_of::<BtrfsDirItemData> ()
+ self.name_size () as usize
]
}
}