Add no_std feature and hashbrown dependency

Add no_std feature as an initial step to supporting embedded platforms.

Use hashbrown for HashMap, HashSet, and hash_map replacements for their
std::collections counterparts.

Author: GeneFerneau

ci/check-compiles.sh

@@ -3,4 +3,5 @@ set -e
 set -x
 echo Testing $(git log -1 --oneline)
 cargo check
-cd fuzz && cargo check --features=stdin_fuzz
+cd fuzz && cargo check --features=stdin_fuzz && cargo check --features=no_std
+cd ../lightning && cargo check --features=no_std

fuzz/Cargo.toml

@@ -15,6 +15,7 @@ afl_fuzz = ["afl"]
 honggfuzz_fuzz = ["honggfuzz"]
 libfuzzer_fuzz = ["libfuzzer-sys"]
 stdin_fuzz = []
+no_std = ["hashbrown"]
 
 [dependencies]
 afl = { version = "0.4", optional = true }
@@ -23,6 +24,7 @@ bitcoin = { version = "0.26", features = ["fuzztarget", "secp-lowmemory"] }
 hex = "0.3"
 honggfuzz = { version = "0.5", optional = true }
 libfuzzer-sys = { git = "https://github.com/rust-fuzz/libfuzzer-sys.git", optional = true }
+hashbrown = { version = "0.9", optional = true }
 
 [patch.crates-io]
 # Rust-Secp256k1 PR 282. This patch should be dropped once that is merged.

fuzz/src/chanmon_consistency.rs

@@ -58,7 +58,10 @@ use bitcoin::secp256k1::Secp256k1;
 
 use std::mem;
 use std::cmp::Ordering;
+#[cfg(not(feature = "no_std"))]
 use std::collections::{HashSet, hash_map, HashMap};
+#[cfg(feature = "no_std")]
+use hashbrown::{HashMap, HashSet, hash_map};
 use std::sync::{Arc,Mutex};
 use std::sync::atomic;
 use std::io::Cursor;

fuzz/src/full_stack.rs

@@ -49,7 +49,10 @@ use bitcoin::secp256k1::key::{PublicKey,SecretKey};
 use bitcoin::secp256k1::Secp256k1;
 
 use std::cell::RefCell;
+#[cfg(not(feature = "no_std"))]
 use std::collections::{HashMap, hash_map};
+#[cfg(feature = "no_std")]
+use hashbrown::{HashMap, hash_map};
 use std::cmp;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicU64,AtomicUsize,Ordering};

fuzz/src/lib.rs

@@ -20,3 +20,5 @@ pub mod peer_crypt;
 pub mod router;
 
 pub mod msg_targets;
+
+#[cfg(feature = "no_std")] extern crate hashbrown;

fuzz/src/router.rs

@@ -26,7 +26,10 @@ use bitcoin::blockdata::constants::genesis_block;
 
 use utils::test_logger;
 
+#[cfg(not(feature = "no_std"))]
 use std::collections::HashSet;
+#[cfg(feature = "no_std")]
+use hashbrown::HashSet;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicUsize, Ordering};
 

lightning/Cargo.toml

@@ -21,6 +21,7 @@ max_level_error = []
 max_level_warn = []
 max_level_info = []
 max_level_debug = []
+no_std = ["hashbrown"]
 # Allow signing of local transactions that may have been revoked or will be revoked, for functional testing (e.g. justice tx handling).
 # This is unsafe to use in production because it may result in the counterparty publishing taking our funds.
 unsafe_revoked_tx_signing = []
@@ -29,6 +30,7 @@ unstable = []
 [dependencies]
 bitcoin = "0.26"
 
+hashbrown = { version = "0.9", optional = true }
 hex = { version = "0.3", optional = true }
 regex = { version = "0.1.80", optional = true }
 

lightning/src/chain/chainmonitor.rs

@@ -42,7 +42,10 @@ use util::logger::Logger;
 use util::events;
 use util::events::Event;
 
+#[cfg(not(feature = "no_std"))]
 use std::collections::{HashMap, hash_map};
+#[cfg(feature = "no_std")]
+use hashbrown::{HashMap, hash_map};
 use std::sync::RwLock;
 use std::ops::Deref;
 

lightning/src/chain/channelmonitor.rs

@@ -51,7 +51,10 @@ use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, U48};
 use util::byte_utils;
 use util::events::Event;
 
+#[cfg(not(feature = "no_std"))]
 use std::collections::{HashMap, HashSet, hash_map};
+#[cfg(feature = "no_std")]
+use hashbrown::{HashMap, HashSet, hash_map};
 use std::{cmp, mem};
 use std::io::Error;
 use std::ops::Deref;

lightning/src/chain/keysinterface.rs

@@ -36,7 +36,10 @@ use ln::chan_utils;
 use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction};
 use ln::msgs::UnsignedChannelAnnouncement;
 
+#[cfg(not(feature = "no_std"))]
 use std::collections::HashSet;
+#[cfg(feature = "no_std")]
+use hashbrown::HashSet;
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::io::Error;
 use ln::msgs::{DecodeError, MAX_VALUE_MSAT};

lightning/src/lib.rs

@@ -34,6 +34,8 @@ extern crate bitcoin;
 #[cfg(any(test, feature = "_test_utils"))] extern crate hex;
 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))] extern crate regex;
 
+#[cfg(feature = "no_std")] extern crate hashbrown;
+
 #[macro_use]
 pub mod util;
 pub mod chain;

lightning/src/ln/channelmanager.rs

@@ -56,7 +56,10 @@ use util::logger::Logger;
 use util::errors::APIError;
 
 use std::{cmp, mem};
+#[cfg(not(feature = "no_std"))]
 use std::collections::{HashMap, hash_map, HashSet};
+#[cfg(feature = "no_std")]
+use hashbrown::{HashMap, HashSet, hash_map};
 use std::io::{Cursor, Read};
 use std::sync::{Arc, Condvar, Mutex, MutexGuard, RwLock, RwLockReadGuard};
 use std::sync::atomic::{AtomicUsize, Ordering};

lightning/src/ln/functional_test_utils.rs

@@ -42,7 +42,10 @@ use std::cell::RefCell;
 use std::rc::Rc;
 use std::sync::Mutex;
 use std::mem;
+#[cfg(not(feature = "no_std"))]
 use std::collections::HashMap;
+#[cfg(feature = "no_std")]
+use hashbrown::HashMap;
 
 pub const CHAN_CONFIRM_DEPTH: u32 = 100;
 

lightning/src/ln/functional_tests.rs

@@ -47,7 +47,11 @@ use bitcoin::secp256k1::key::{PublicKey,SecretKey};
 
 use regex;
 
-use std::collections::{BTreeSet, HashMap, HashSet};
+use std::collections::BTreeSet;
+#[cfg(not(feature = "no_std"))]
+use std::collections::{HashMap, HashSet};
+#[cfg(feature = "no_std")]
+use hashbrown::{HashMap, HashSet};
 use std::default::Default;
 use std::sync::Mutex;
 use std::sync::atomic::Ordering;

lightning/src/ln/onchaintx.rs

@@ -32,7 +32,10 @@ use util::logger::Logger;
 use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter};
 use util::byte_utils;
 
+#[cfg(not(feature = "no_std"))]
 use std::collections::{HashMap, hash_map};
+#[cfg(feature = "no_std")]
+use hashbrown::{HashMap, hash_map};
 use std::cmp;
 use std::ops::Deref;
 use std::mem::replace;

lightning/src/ln/peer_handler.rs

@@ -30,7 +30,11 @@ use util::events::{MessageSendEvent, MessageSendEventsProvider};
 use util::logger::Logger;
 use routing::network_graph::NetGraphMsgHandler;
 
-use std::collections::{HashMap,hash_map,HashSet,LinkedList};
+use std::collections::LinkedList;
+#[cfg(not(feature = "no_std"))]
+use std::collections::{HashMap, HashSet, hash_map};
+#[cfg(feature = "no_std")]
+use hashbrown::{HashMap, HashSet, hash_map};
 use std::sync::{Arc, Mutex};
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::{cmp, error, hash, fmt, mem};

lightning/src/ln/reorg_tests.rs

@@ -23,7 +23,10 @@ use util::ser::{ReadableArgs, Writeable};
 use bitcoin::blockdata::block::{Block, BlockHeader};
 use bitcoin::hash_types::BlockHash;
 
+#[cfg(not(feature = "no_std"))]
 use std::collections::HashMap;
+#[cfg(feature = "no_std")]
+use hashbrown::HashMap;
 use std::mem;
 
 use ln::functional_test_utils::*;

lightning/src/routing/router.rs

@@ -22,7 +22,11 @@ use util::ser::{Writeable, Readable};
 use util::logger::Logger;
 
 use std::cmp;
-use std::collections::{HashMap, BinaryHeap};
+use std::collections::BinaryHeap;
+#[cfg(not(feature = "no_std"))]
+use std::collections::HashMap;
+#[cfg(feature = "no_std")]
+use hashbrown::HashMap;
 use std::ops::Deref;
 
 /// A hop in a route

lightning/src/util/ser.rs

@@ -11,7 +11,10 @@
 //! as ChannelsManagers and ChannelMonitors.
 
 use std::io::{Read, Write};
+#[cfg(not(feature = "no_std"))]
 use std::collections::HashMap;
+#[cfg(feature = "no_std")]
+use hashbrown::HashMap;
 use std::hash::Hash;
 use std::sync::Mutex;
 use std::cmp;

lightning/src/util/test_utils.rs

@@ -38,7 +38,10 @@ use std::time::Duration;
 use std::sync::{Mutex, Arc};
 use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
 use std::{cmp, mem};
+#[cfg(not(feature = "no_std"))]
 use std::collections::{HashMap, HashSet};
+#[cfg(feature = "no_std")]
+use hashbrown::{HashMap, HashSet};
 use chain::keysinterface::InMemorySigner;
 
 pub struct TestVecWriter(pub Vec<u8>);