Use HashMap instead of BTreeMap

This reduces the file size from 87KiB to 79KiB.

Cargo.lock

@@ -18,6 +18,7 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 name = "bootstrap"
 version = "0.0.0"
 dependencies = [
+ "hashbrown",
  "linked_list_allocator",
  "redox-exec",
  "redox-initfs",
@@ -35,6 +36,12 @@ dependencies = [
  "scroll",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.14.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "290f1a1d9242c78d09ce40a5e87e7554ee637af1351968159f4952f028f75604"
+
 [[package]]
 name = "linked_list_allocator"
 version = "0.10.5"

Cargo.toml

@@ -10,6 +10,7 @@ name = "bootstrap"
 crate-type = ["staticlib"]
 
 [dependencies]
+hashbrown = { version = "0.14", default-features = false, features = ["inline-more"] }
 linked_list_allocator = "0.10"
 redox-initfs = { git = "https://gitlab.redox-os.org/redox-os/redox-initfs.git", features = ["kernel"], default-features = false }
 redox-exec = { git = "https://gitlab.redox-os.org/redox-os/relibc.git" }

src/initfs.rs

@@ -1,9 +1,11 @@
 use core::convert::TryFrom;
+#[allow(deprecated)]
+use core::hash::{BuildHasherDefault, SipHasher};
 use core::str;
 
-use alloc::collections::BTreeMap;
 use alloc::string::String;
 
+use hashbrown::HashMap;
 use redox_initfs::{InitFs, InodeStruct, Inode, InodeDir, InodeKind, types::Timespec};
 
 use syscall::data::{Packet, Stat};
@@ -19,14 +21,15 @@ struct Handle {
     filename: String,
 }
 pub struct InitFsScheme {
-    handles: BTreeMap<usize, Handle>,
+    #[allow(deprecated)]
+    handles: HashMap<usize, Handle, BuildHasherDefault<SipHasher>>,
     next_id: usize,
     fs: InitFs<'static>,
 }
 impl InitFsScheme {
     pub fn new(bytes: &'static [u8]) -> Self {
         Self {
-            handles: BTreeMap::new(),
+            handles: HashMap::default(),
             next_id: 0,
             fs: InitFs::new(bytes).expect("failed to parse initfs"),
         }