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//! Hikari AFS B-Tree
const efi = @import("../../efi/efi.zig");
const shared_afs = @import("../../../shared/fs/afs/afs.zig");
const block_io = @import("block_io.zig");
const EfiBlockContext = block_io.EfiBlockContext;
// Import shared types
const BTreeNodeDescriptor = shared_afs.BTreeNodeDescriptor;
const BTreeHeaderRecord = shared_afs.BTreeHeaderRecord;
const IndexKey = shared_afs.types.IndexKey;
const StackRecord = shared_afs.StackRecord;
const UnitRecord = shared_afs.UnitRecord;
const ThreadRecord = shared_afs.types.ThreadRecord;
const SpanDescriptor = shared_afs.SpanDescriptor;
// Import shared B-tree operations
const btree_ops = shared_afs.btree;
const constants = shared_afs.constants;
pub const BTreeError = error{
ReadFailed,
InvalidNode,
InvalidHeader,
KeyNotFound,
TreeEmpty,
AllocationFailed,
};
pub const BTree = struct {
block_io: *efi.protocols.BlockIoProtocol,
boot_services: *efi.services.BootServices,
partition_start_lba: u64,
cell_size: u32,
base_span: SpanDescriptor,
node_size: u32,
root_node: u32,
first_leaf: u32,
last_leaf: u32,
depth: u16,
node_buffer: [*]u8,
pub fn initialize(
block_io_proto: *efi.protocols.BlockIoProtocol,
boot_services: *efi.services.BootServices,
partition_start_lba: u64,
cell_size: u32,
base_span: SpanDescriptor,
header: *const BTreeHeaderRecord,
) BTreeError!BTree {
var node_buffer: [*]align(8) u8 = undefined;
const alloc_status = boot_services.allocate_pool(
.loader_data,
header.node_size,
&node_buffer,
);
if (efi.types.is_error(alloc_status)) {
return BTreeError.AllocationFailed;
}
return BTree{
.block_io = block_io_proto,
.boot_services = boot_services,
.partition_start_lba = partition_start_lba,
.cell_size = cell_size,
.base_span = base_span,
.node_size = header.node_size,
.root_node = header.root_node,
.first_leaf = header.first_leaf_node,
.last_leaf = header.last_leaf_node,
.depth = header.depth,
.node_buffer = node_buffer,
};
}
pub fn read_node(self: *BTree, node_number: u32) BTreeError!*BTreeNodeDescriptor {
const cell_offset = btree_ops.get_node_cell(node_number, self.cell_size, self.node_size);
const node_offset_in_cell = btree_ops.get_node_offset_in_cell(node_number, self.cell_size, self.node_size);
const cell_lba = self.partition_start_lba +
((self.base_span.start_cell + cell_offset) * self.cell_size / self.block_io.media.block_size);
var cell_buffer: [*]align(8) u8 = undefined;
const alloc_status = self.boot_services.allocate_pool(
.loader_data,
self.cell_size,
&cell_buffer,
);
if (efi.types.is_error(alloc_status)) {
return BTreeError.AllocationFailed;
}
const read_status = self.block_io.read_blocks(
self.block_io,
self.block_io.media.media_id,
cell_lba,
self.cell_size,
cell_buffer,
);
if (efi.types.is_error(read_status)) {
return BTreeError.ReadFailed;
}
const node_ptr = cell_buffer + node_offset_in_cell;
var i: u32 = 0;
while (i < self.node_size) : (i += 1) {
self.node_buffer[i] = node_ptr[i];
}
_ = self.boot_services.free_pool(cell_buffer);
return @ptrCast(@alignCast(self.node_buffer));
}
pub fn get_record_offset(self: *BTree, record_index: u16) u16 {
return btree_ops.get_record_offset(self.node_buffer, self.node_size, record_index);
}
pub fn get_record_ptr(self: *BTree, record_index: u16) [*]u8 {
return btree_ops.get_record_ptr(self.node_buffer, self.node_size, record_index);
}
pub fn search_index(
self: *BTree,
parent_node_id: u32,
identity: []const u16,
) BTreeError!?*const UnitRecord {
if (self.depth == 0) {
return BTreeError.TreeEmpty;
}
var current_node = self.root_node;
var current_depth: u16 = self.depth;
while (current_depth > 0) {
const node_desc = try self.read_node(current_node);
if (node_desc.is_leaf()) {
return btree_ops.search_leaf_for_unit(
self.node_buffer,
self.node_size,
node_desc.record_count,
parent_node_id,
identity,
);
}
const next_node = btree_ops.search_index_node(
self.node_buffer,
self.node_size,
node_desc.record_count,
parent_node_id,
identity,
);
if (next_node) |node| {
current_node = node;
current_depth -= 1;
} else {
return null;
}
}
return null;
}
pub fn search_index_for_stack(
self: *BTree,
parent_node_id: u32,
identity: []const u16,
) BTreeError!?*const StackRecord {
if (self.depth == 0) {
return BTreeError.TreeEmpty;
}
var current_node = self.root_node;
var current_depth: u16 = self.depth;
while (current_depth > 0) {
const node_desc = try self.read_node(current_node);
if (node_desc.is_leaf()) {
return btree_ops.search_leaf_for_stack(
self.node_buffer,
self.node_size,
node_desc.record_count,
parent_node_id,
identity,
);
}
const next_node = btree_ops.search_index_node(
self.node_buffer,
self.node_size,
node_desc.record_count,
parent_node_id,
identity,
);
if (next_node) |node| {
current_node = node;
current_depth -= 1;
} else {
return null;
}
}
return null;
}
pub fn get_thread_record(
self: *BTree,
node_id: u32,
) BTreeError!?*const ThreadRecord {
var empty_identity: [0]u16 = undefined;
return self.search_thread(node_id, &empty_identity);
}
fn search_thread(
self: *BTree,
node_id: u32,
identity: []const u16,
) BTreeError!?*const ThreadRecord {
if (self.depth == 0) {
return BTreeError.TreeEmpty;
}
var current_node = self.root_node;
var current_depth: u16 = self.depth;
while (current_depth > 0) {
const node_desc = try self.read_node(current_node);
if (node_desc.is_leaf()) {
return btree_ops.search_leaf_for_thread(
self.node_buffer,
self.node_size,
node_desc.record_count,
node_id,
identity,
);
}
const next_node = btree_ops.search_index_node(
self.node_buffer,
self.node_size,
node_desc.record_count,
node_id,
identity,
);
if (next_node) |node| {
current_node = node;
current_depth -= 1;
} else {
return null;
}
}
return null;
}
};
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