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use std::mem;
use diskformat::*;
#[ derive (Clone, Debug) ]
pub enum BtrfsLeafItem <'a> {
ChunkItem (BtrfsChunkItem <'a>),
DirIndex (BtrfsDirIndex <'a>),
DirItem (BtrfsDirItem <'a>),
ExtentData (BtrfsExtentData <'a>),
ExtentItem (BtrfsExtentItem <'a>),
InodeItem (BtrfsInodeItem <'a>),
Invalid (BtrfsInvalidItem <'a>),
Unknown (BtrfsUnknownItem <'a>),
}
#[ repr (C, packed) ]
#[ derive (Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd) ]
pub struct BtrfsLeafItemHeader {
key: BtrfsKey,
data_offset: u32,
data_size: u32,
}
impl <'a> BtrfsLeafItem <'a> {
pub fn from_bytes (
header: & 'a BtrfsLeafItemHeader,
data_bytes: & 'a [u8],
) -> BtrfsLeafItem <'a> {
match header.key.item_type () {
BTRFS_INODE_ITEM_TYPE =>
BtrfsInodeItem::from_bytes (
header,
data_bytes,
).map (
|inode_item|
BtrfsLeafItem::InodeItem (
inode_item)
),
BTRFS_DIR_ITEM_TYPE =>
BtrfsDirItem::from_bytes (
header,
data_bytes,
).map (
|dir_item|
BtrfsLeafItem::DirItem (
dir_item)
),
BTRFS_DIR_INDEX_TYPE =>
BtrfsDirIndex::from_bytes (
header,
data_bytes,
).map (
|dir_index|
BtrfsLeafItem::DirIndex (
dir_index)
),
BTRFS_EXTENT_DATA_TYPE =>
BtrfsExtentData::from_bytes (
header,
data_bytes,
).map (
|extent_data|
BtrfsLeafItem::ExtentData (
extent_data)
),
BTRFS_EXTENT_ITEM_TYPE =>
BtrfsExtentItem::from_bytes (
header,
data_bytes,
).map (
|extent_item|
BtrfsLeafItem::ExtentItem (
extent_item)
),
BTRFS_CHUNK_ITEM_TYPE =>
BtrfsChunkItem::from_bytes (
header,
data_bytes,
).map (
|chunk_item|
BtrfsLeafItem::ChunkItem (
chunk_item)
),
_ =>
Ok (
BtrfsLeafItem::Unknown (
BtrfsUnknownItem::new (
header,
data_bytes,
)
)
),
}.unwrap_or_else (
|error|
BtrfsLeafItem::Invalid (
BtrfsInvalidItem::new (
header,
data_bytes,
error,
)
)
)
}
pub fn header (& self) -> & BtrfsLeafItemHeader {
match self {
& BtrfsLeafItem::ChunkItem (ref chunk_item) =>
chunk_item.header (),
& BtrfsLeafItem::DirIndex (ref dir_index) =>
dir_index.header (),
& BtrfsLeafItem::DirItem (ref dir_item) =>
dir_item.header (),
& BtrfsLeafItem::ExtentData (ref extent_data) =>
extent_data.header (),
& BtrfsLeafItem::ExtentItem (ref extent_item) =>
extent_item.header (),
& BtrfsLeafItem::InodeItem (ref inode_item) =>
inode_item.header (),
& BtrfsLeafItem::Unknown (ref unknown_item) =>
unknown_item.header (),
& BtrfsLeafItem::Invalid (ref invalid_item) =>
invalid_item.header (),
}
}
pub fn key (& self) -> BtrfsKey {
self.header ().key
}
}
impl BtrfsLeafItemHeader {
pub fn from_bytes (
bytes: & [u8],
) -> Result <& BtrfsLeafItemHeader, String> {
if bytes.len () != mem::size_of::<BtrfsLeafItemHeader> () {
return Err (
format! (
"Must be exactly 0x{:x} bytes",
mem::size_of::<BtrfsLeafItemHeader> ()));
}
Ok (
unsafe {
& * (bytes.as_ptr () as * const BtrfsLeafItemHeader)
}
)
}
pub fn key (& self) -> BtrfsKey {
self.key
}
pub fn object_id (& self) -> u64 {
self.key.object_id ()
}
pub fn item_type (& self) -> u8 {
self.key.item_type ()
}
pub fn offset (& self) -> u64 {
self.key.offset ()
}
pub fn data_offset (& self) -> u32 {
self.data_offset
}
pub fn data_size (& self) -> u32 {
self.data_size
}
}
pub const BTRFS_INODE_ITEM_TYPE: u8 = 0x01;
pub const BTRFS_DIR_ITEM_TYPE: u8 = 0x54;
pub const BTRFS_DIR_INDEX_TYPE: u8 = 0x60;
pub const BTRFS_EXTENT_DATA_TYPE: u8 = 0x6c;
pub const BTRFS_EXTENT_ITEM_TYPE: u8 = 0xa8;
pub const BTRFS_CHUNK_ITEM_TYPE: u8 = 0xe4;