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use std::collections::BTreeMap;
use std::collections::HashMap;
use diskformat::*;
pub type BtrfsChunkItemsByOffset <'a> =
BTreeMap <u64, BtrfsChunkItem <'a>>;
pub struct BtrfsChunkTree <'a> {
chunk_items_by_offset: BtrfsChunkItemsByOffset <'a>,
}
impl <'a> BtrfsChunkTree <'a> {
pub fn new (
devices: & 'a BtrfsDeviceMap,
superblock: & BtrfsSuperblock,
) -> Result <BtrfsChunkTree <'a>, String> {
let extent_tree_items =
Self::read_system_extent_tree (
devices,
superblock,
) ?;
let mut chunk_items_by_offset =
BtrfsChunkItemsByOffset::new ();
for extent_tree_item in extent_tree_items.values () {
match extent_tree_item {
& BtrfsLeafItem::ChunkItem (chunk_item) => {
chunk_items_by_offset.insert (
chunk_item.key ().offset (),
chunk_item);
},
_ => (),
}
}
Ok (
BtrfsChunkTree {
chunk_items_by_offset: chunk_items_by_offset,
}
)
}
fn read_system_extent_tree (
devices: & 'a BtrfsDeviceMap,
superblock: & BtrfsSuperblock,
) -> Result <HashMap <BtrfsKey, BtrfsLeafItem <'a>>, String> {
let mut extent_tree_items: HashMap <BtrfsKey, BtrfsLeafItem> =
HashMap::new ();
Self::read_system_extent_tree_recurse (
devices,
superblock,
superblock.chunk_tree_logical_address (),
& mut extent_tree_items,
) ?;
Ok (extent_tree_items)
}
fn read_system_extent_tree_recurse (
devices: & 'a BtrfsDeviceMap,
superblock: & BtrfsSuperblock,
logical_address: u64,
extent_tree_items: & mut HashMap <BtrfsKey, BtrfsLeafItem <'a>>,
) -> Result <(), String> {
let (device_id, device_address) =
superblock.system_logical_to_physical (
logical_address,
).expect ("Lookup logical address");
let device =
devices.get (
& device_id,
).expect ("Lookup device");
let node_bytes =
device.slice_at (
device_address as usize,
superblock.node_size () as usize);
let node =
BtrfsNode::from_bytes (
node_bytes,
) ?;
match node {
BtrfsNode::Internal (internal_node) => {
for item in internal_node.items () {
Self::read_system_extent_tree_recurse (
devices,
superblock,
item.key ().offset (),
extent_tree_items,
) ?;
}
},
BtrfsNode::Leaf (leaf_node) => {
for item in leaf_node.items () {
extent_tree_items.insert (
item.key (),
item,
);
}
},
}
Ok (())
}
pub fn logical_to_physical_address (
& self,
logical_address: u64,
) -> Option <(u64, u64)> {
for (ref chunk_item_offset, ref chunk_item)
in self.chunk_items_by_offset.iter () {
let chunk_item_offset =
** chunk_item_offset;
if logical_address >= chunk_item_offset
&& logical_address < (
chunk_item_offset +
chunk_item.data ().chunk_size ()
) {
let chunk_item_stripe =
chunk_item.stripes () [0];
return Some (
(
chunk_item_stripe.device_id (),
logical_address
- chunk_item_offset
+ chunk_item_stripe.offset (),
)
);
}
}
None
}
}