move header files to include/hotstuff

15 files changed, 19 insertions, 2319 deletions

diff --git a/src/client.cpp b/src/client.cpp
index f787003..482c23d 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -1,4 +1,4 @@
-#include "client.h"
+#include "hotstuff/client.h"
 
 namespace hotstuff {
 
diff --git a/src/client.h b/src/client.h
deleted file mode 100644
index dd1cfee..0000000
--- a/src/client.h
+++ /dev/null
@@ -1,66 +0,0 @@
-#ifndef _HOTSTUFF_CLIENT_H
-#define _HOTSTUFF_CLIENT_H
-
-#include "type.h"
-#include "salticidae/msg.h"
-#include "entity.h"
-
-namespace hotstuff {
-
-enum {
-    REQ_CMD = 0x4,
-    RESP_CMD = 0x5,
-    CHK_CMD = 0x6
-};
-
-class CommandDummy: public Command {
-    static uint64_t cnt;
-    uint64_t n;
-    uint256_t hash;
-
-    public:
-
-    CommandDummy() {}
-
-    ~CommandDummy() override {}
-
-    CommandDummy(uint64_t n):
-        n(n), hash(salticidae::get_hash(*this)) {}
-
-    static command_t make_cmd() {
-        return new CommandDummy(cnt++);
-    }
-
-    void serialize(DataStream &s) const override {
-        s << n;
-    }
-
-    void unserialize(DataStream &s) override {
-        s >> n;
-        hash = salticidae::get_hash(*this);
-    }
-
-    const uint256_t &get_hash() const override {
-        return hash;
-    }
-
-    bool verify() const override {
-        return true;
-    }
-};
-
-struct MsgClient: public salticidae::MsgBase<> {
-    using MsgBase::MsgBase;
-    void gen_reqcmd(const Command &cmd);
-    void parse_reqcmd(CommandDummy &cmd) const;
-
-    void gen_respcmd(const uint256_t &cmd_hash, const Finality &fin);
-    void parse_respcmd(uint256_t &cmd_hash, Finality &fin) const;
-
-    void gen_chkcmd(const uint256_t &cmd_hash);
-    void parse_chkcmd(uint256_t &cmd_hash) const;
-};
-
-}
-
-#endif
diff --git a/src/core.cpp b/src/core.cpp
index d6a4cc7..125e168 100644
--- a/src/core.cpp
+++ b/src/core.cpp
@@ -1,5 +1,5 @@
 #include <stack>
-#include "core.h"
+#include "hotstuff/core.h"
 
 using salticidae::DataStream;
 using salticidae::static_pointer_cast;
diff --git a/src/core.h b/src/core.h
deleted file mode 100644
index c7e1fe6..0000000
--- a/src/core.h
+++ /dev/null
@@ -1,631 +0,0 @@
-#ifndef _HOTSTUFF_CORE_H
-#define _HOTSTUFF_CORE_H
-
-#include <queue>
-#include <set>
-#include <unordered_map>
-#include <unordered_set>
-
-#include "salticidae/stream.h"
-#include "salticidae/util.h"
-#include "salticidae/network.h"
-#include "salticidae/msg.h"
-
-#include "promise.hpp"
-#include "util.h"
-#include "entity.h"
-#include "crypto.h"
-
-using salticidae::EventContext;
-using salticidae::Event;
-using salticidae::NetAddr;
-using salticidae::MsgNetwork;
-using salticidae::PeerNetwork;
-using salticidae::ElapsedTime;
-using salticidae::_1;
-using salticidae::_2;
-
-namespace hotstuff {
-
-const double ent_waiting_timeout = 10;
-const double double_inf = 1e10;
-
-enum {
-    PROPOSE = 0x0,
-    VOTE = 0x1,
-    QUERY_FETCH_BLK = 0x2,
-    RESP_FETCH_BLK = 0x3,
-};
-
-using promise::promise_t;
-
-struct Proposal;
-struct Vote;
-
-/** Abstraction for HotStuff protocol state machine (without network implementation). */
-class HotStuffCore {
-    block_t b0;                                  /** the genesis block */
-    /* === state variables === */
-    /** block containing the QC for the highest block having one */
-    block_t bqc;
-    block_t bexec;                            /**< last executed block */
-    uint32_t vheight;          /**< height of the block last voted for */
-    /* === auxilliary variables === */
-    privkey_bt priv_key;            /**< private key for signing votes */
-    std::set<block_t, BlockHeightCmp> tails;   /**< set of tail blocks */
-    ReplicaConfig config;                   /**< replica configuration */
-    /* === async event queues === */
-    std::unordered_map<block_t, promise_t> qc_waiting;
-    promise_t propose_waiting;
-
-    block_t sanity_check_delivered(const uint256_t &blk_hash);
-    void sanity_check_delivered(const block_t &blk);
-    void check_commit(const block_t &_bqc);
-    bool update(const uint256_t &bqc_hash);
-    void on_qc_finish(const block_t &blk);
-    void on_propose_(const block_t &blk);
-
-    protected:
-    ReplicaID id;                  /**< identity of the replica itself */
-    const int32_t parent_limit;         /**< maximum number of parents */
-
-    public:
-    BoxObj<EntityStorage> storage;
-
-    HotStuffCore(ReplicaID id,
-                privkey_bt &&priv_key,
-                int32_t parent_limit);
-    virtual ~HotStuffCore() = default;
-
-    /* Inputs of the state machine triggered by external events, should called
-     * by the class user, with proper invariants. */
-
-    /** Call to initialize the protocol, should be called once before all other
-     * functions. */
-    void on_init(uint32_t nfaulty) { config.nmajority = 2 * nfaulty + 1; }
-
-    /** Call to deliver a block.
-     * A block is only delivered if itself is fetched, the block for the
-     * contained qc is fetched and all parents are delivered. The user should
-     * always ensure this invariant. The invalid blocks will be dropped by this
-     * function.
-     * @return true if valid */
-    bool on_deliver_blk(const block_t &blk);
-
-    /** Call upon the delivery of a proposal message.
-     * The block mentioned in the message should be already delivered. */
-    void on_receive_proposal(const Proposal &prop);
-
-    /** Call upon the delivery of a vote message.
-     * The block mentioned in the message should be already delivered. */
-    void on_receive_vote(const Vote &vote);
-
-    /** Call to submit new commands to be decided (executed). */
-    void on_propose(const std::vector<command_t> &cmds);
-
-    /* Functions required to construct concrete instances for abstract classes.
-     * */
-
-    /* Outputs of the state machine triggering external events.  The virtual
-     * functions should be implemented by the user to specify the behavior upon
-     * the events. */
-    protected:
-    /** Called by HotStuffCore upon the decision being made for cmd. */
-    virtual void do_decide(const command_t &cmd) = 0;
-    /** Called by HotStuffCore upon broadcasting a new proposal.
-     * The user should send the proposal message to all replicas except for
-     * itself. */
-    virtual void do_broadcast_proposal(const Proposal &prop) = 0;
-    /** Called upon sending out a new vote to the next proposer.  The user
-     * should send the vote message to a *good* proposer to have good liveness,
-     * while safety is always guaranteed by HotStuffCore. */
-    virtual void do_vote(ReplicaID last_proposer, const Vote &vote) = 0;
-
-    /* The user plugs in the detailed instances for those
-     * polymorphic data types. */
-    public:
-    /** Create a partial certificate that proves the vote for a block. */
-    virtual part_cert_bt create_part_cert(const PrivKey &priv_key, const uint256_t &blk_hash) = 0;
-    /** Create a partial certificate from its seralized form. */
-    virtual part_cert_bt parse_part_cert(DataStream &s) = 0;
-    /** Create a quorum certificate that proves 2f+1 votes for a block. */
-    virtual quorum_cert_bt create_quorum_cert(const uint256_t &blk_hash) = 0;
-    /** Create a quorum certificate from its serialized form. */
-    virtual quorum_cert_bt parse_quorum_cert(DataStream &s) = 0;
-    /** Create a command object from its serialized form. */
-    virtual command_t parse_cmd(DataStream &s) = 0;
-
-    public:
-    /** Add a replica to the current configuration. This should only be called
-     * before running HotStuffCore protocol. */
-    void add_replica(ReplicaID rid, const NetAddr &addr, pubkey_bt &&pub_key);
-    /** Try to prune blocks lower than last committed height - staleness. */
-    void prune(uint32_t staleness);
-
-    /* PaceMaker can use these functions to monitor the core protocol state
-     * transition */
-    /** Get a promise resolved when the block gets a QC. */
-    promise_t async_qc_finish(const block_t &blk);
-    /** Get a promise resolved when a new block is proposed. */
-    promise_t async_wait_propose();
-
-    /* Other useful functions */
-    block_t get_genesis() { return b0; }
-    const ReplicaConfig &get_config() { return config; }
-    int8_t get_cmd_decision(const uint256_t &cmd_hash);
-    ReplicaID get_id() { return id; }
-    operator std::string () const;
-};
-
-/** Abstraction for proposal messages. */
-struct Proposal: public Serializable {
-    ReplicaID proposer;
-    /** hash for the block containing the highest QC */
-    uint256_t bqc_hash;
-    /** block being proposed */
-    block_t blk;
-
-    /** handle of the core object to allow polymorphism. The user should use
-     * a pointer to the object of the class derived from HotStuffCore */
-    HotStuffCore *hsc;
-
-    Proposal(HotStuffCore *hsc): blk(nullptr), hsc(hsc) {}
-    Proposal(ReplicaID proposer,
-            const uint256_t &bqc_hash,
-            block_t &blk,
-            HotStuffCore *hsc):
-        proposer(proposer),
-        bqc_hash(bqc_hash),
-        blk(blk), hsc(hsc) {}
-
-    void serialize(DataStream &s) const override {
-        s << proposer
-          << bqc_hash
-          << *blk;
-    }
-
-    void unserialize(DataStream &s) override {
-        assert(hsc != nullptr);
-        s >> proposer
-          >> bqc_hash;
-        Block _blk;
-        _blk.unserialize(s, hsc);
-        blk = hsc->storage->add_blk(std::move(_blk));
-    }
-
-    operator std::string () const {
-        DataStream s;
-        s << "<proposal "
-          << "rid=" << std::to_string(proposer) << " "
-          << "bqc=" << get_hex10(bqc_hash) << " "
-          << "blk=" << get_hex10(blk->get_hash()) << ">";
-        return std::string(std::move(s));
-    }
-};
-
-/** Abstraction for vote messages. */
-struct Vote: public Serializable {
-    ReplicaID voter;
-    /** hash for the block containing the highest QC */
-    uint256_t bqc_hash;
-    /** block being voted */
-    uint256_t blk_hash;
-    /** proof of validity for the vote (nullptr for a negative vote) */
-    part_cert_bt cert;
-    
-    /** handle of the core object to allow polymorphism */
-    HotStuffCore *hsc;
-
-    Vote(HotStuffCore *hsc): cert(nullptr), hsc(hsc) {}
-    Vote(ReplicaID voter,
-        const uint256_t &bqc_hash,
-        const uint256_t &blk_hash,
-        part_cert_bt &&cert,
-        HotStuffCore *hsc):
-        voter(voter),
-        bqc_hash(bqc_hash),
-        blk_hash(blk_hash),
-        cert(std::move(cert)), hsc(hsc) {}
-
-    Vote(const Vote &other):
-        voter(other.voter),
-        bqc_hash(other.bqc_hash),
-        blk_hash(other.blk_hash),
-        cert(other.cert->clone()),
-        hsc(other.hsc) {}
-
-    Vote(Vote &&other) = default;
-    
-    void serialize(DataStream &s) const override {
-        s << voter
-          << bqc_hash
-          << blk_hash;
-        if (cert == nullptr)
-            s << (uint8_t)0;
-        else
-            s << (uint8_t)1 << *cert;
-    }
-
-    void unserialize(DataStream &s) override {
-        assert(hsc != nullptr);
-        uint8_t has_cert;
-        s >> voter
-          >> bqc_hash
-          >> blk_hash
-          >> has_cert;
-        cert = has_cert ? hsc->parse_part_cert(s) : nullptr;
-    }
-
-    bool verify() const {
-        assert(hsc != nullptr);
-        return cert->verify(hsc->get_config().get_pubkey(voter)) &&
-                cert->get_blk_hash() == blk_hash;
-    }
-
-    operator std::string () const {
-        DataStream s;
-        s << "<vote "
-          << "rid=" << std::to_string(voter) << " "
-          << "bqc=" << get_hex10(bqc_hash) << " "
-          << "blk=" << get_hex10(blk_hash) << " "
-          << "cert=" << (cert ? "yes" : "no") << ">";
-        return std::string(std::move(s));
-    }
-};
-
-/** Abstraction for liveness gadget (oracle). */
-class PaceMaker {
-    public:
-    virtual ~PaceMaker() = default;
-    /** Get a promise resolved when the pace maker thinks it is a *good* time
-     * to issue new commands. When promise is resolved with the ID of itself,
-     * the replica should propose the command, otherwise it will forward the
-     * command to the proposer indicated by the ID. */
-    virtual promise_t beat() = 0;
-    /** Get a promise resolved when the pace maker thinks it is a *good* time
-     * to vote for a block. The promise is resolved with the next proposer's ID
-     * */
-    virtual promise_t next_proposer(ReplicaID last_proposer) = 0;
-};
-
-using pacemaker_bt = BoxObj<PaceMaker>;
-
-/** A pace maker that waits for the qc of the last proposed block. */
-class PaceMakerDummy: public PaceMaker {
-    HotStuffCore *hsc;
-    std::queue<promise_t> pending_beats;
-    block_t last_proposed;
-    bool locked;
-
-    void schedule_next() {
-        if (!pending_beats.empty() && !locked)
-        {
-            auto pm = pending_beats.front();
-            pending_beats.pop();
-            hsc->async_qc_finish(last_proposed).then(
-                    [id = hsc->get_id(), pm]() {
-                pm.resolve(id);
-            });
-            locked = true;
-        }
-    }
-
-    void update_last_proposed() {
-        hsc->async_wait_propose().then([this](block_t blk) {
-            update_last_proposed();
-            last_proposed = blk;
-            locked = false;
-            schedule_next();
-        });
-    }
-
-    public:
-    PaceMakerDummy(HotStuffCore *hsc):
-            hsc(hsc),
-            last_proposed(hsc->get_genesis()),
-            locked(false) {
-        update_last_proposed();
-    }
-
-    promise_t beat() override {
-        promise_t pm;
-        pending_beats.push(pm);
-        schedule_next();
-        return pm;
-    }
-
-    promise_t next_proposer(ReplicaID last_proposer) override {
-        return promise_t([last_proposer](promise_t &pm) {
-            pm.resolve(last_proposer);
-        });
-    }
-};
-
-/** Network message format for HotStuff. */
-struct MsgHotStuff: public salticidae::MsgBase<> {
-    using MsgBase::MsgBase;
-    void gen_propose(const Proposal &);
-    void parse_propose(Proposal &) const;
-
-    void gen_vote(const Vote &);
-    void parse_vote(Vote &) const;
-
-    void gen_qfetchblk(const std::vector<uint256_t> &blk_hashes);
-    void parse_qfetchblk(std::vector<uint256_t> &blk_hashes) const;
-
-    void gen_rfetchblk(const std::vector<block_t> &blks);
-    void parse_rfetchblk(std::vector<block_t> &blks, HotStuffCore *hsc) const;
-};
-
-using promise::promise_t;
-
-class HotStuffBase;
-
-template<EntityType ent_type>
-class FetchContext: public promise_t {
-    Event timeout;
-    HotStuffBase *hs;
-    MsgHotStuff fetch_msg;
-    const uint256_t ent_hash;
-    std::unordered_set<NetAddr> replica_ids;
-    inline void timeout_cb(evutil_socket_t, short);
-    public:
-    FetchContext(const FetchContext &) = delete;
-    FetchContext &operator=(const FetchContext &) = delete;
-    FetchContext(FetchContext &&other);
-
-    FetchContext(const uint256_t &ent_hash, HotStuffBase *hs);
-    ~FetchContext() {}
-
-    inline void send(const NetAddr &replica_id);
-    inline void reset_timeout();
-    inline void add_replica(const NetAddr &replica_id, bool fetch_now = true);
-};
-
-class BlockDeliveryContext: public promise_t {
-    public:
-    ElapsedTime elapsed;
-    BlockDeliveryContext &operator=(const BlockDeliveryContext &) = delete;
-    BlockDeliveryContext(const BlockDeliveryContext &other):
-        promise_t(static_cast<const promise_t &>(other)),
-        elapsed(other.elapsed) {}
-    BlockDeliveryContext(BlockDeliveryContext &&other):
-        promise_t(static_cast<const promise_t &>(other)),
-        elapsed(std::move(other.elapsed)) {}
-    template<typename Func>
-    BlockDeliveryContext(Func callback): promise_t(callback) {
-        elapsed.start();
-    }
-};
-
-
-/** HotStuff protocol (with network implementation). */
-class HotStuffBase: public HotStuffCore {
-    using BlockFetchContext = FetchContext<ENT_TYPE_BLK>;
-    using CmdFetchContext = FetchContext<ENT_TYPE_CMD>;
-    using conn_t = MsgNetwork<MsgHotStuff>::conn_t;
-
-    friend BlockFetchContext;
-    friend CmdFetchContext;
-
-    protected:
-    /** the binding address in replica network */
-    NetAddr listen_addr;
-    /** the block size */
-    size_t blk_size;
-    /** libevent handle */
-    EventContext eb;
-    pacemaker_bt pmaker;
-
-    private:
-    /** whether libevent handle is owned by itself */
-    bool eb_loop;
-    /** network stack */
-    PeerNetwork<MsgHotStuff> pn;
-#ifdef HOTSTUFF_ENABLE_BLK_PROFILE
-    BlockProfiler blk_profiler;
-#endif
-    /* queues for async tasks */
-    std::unordered_map<const uint256_t, BlockFetchContext> blk_fetch_waiting;
-    std::unordered_map<const uint256_t, BlockDeliveryContext> blk_delivery_waiting;
-    std::unordered_map<const uint256_t, CmdFetchContext> cmd_fetch_waiting;
-    std::unordered_map<const uint256_t, promise_t> decision_waiting;
-    std::queue<command_t> cmd_pending;
-
-    /* statistics */
-    uint64_t fetched;
-    uint64_t delivered;
-    mutable uint64_t nsent;
-    mutable uint64_t nrecv;
-
-    mutable uint32_t part_parent_size;
-    mutable uint32_t part_fetched;
-    mutable uint32_t part_delivered;
-    mutable uint32_t part_decided;
-    mutable uint32_t part_gened;
-    mutable double part_delivery_time;
-    mutable double part_delivery_time_min;
-    mutable double part_delivery_time_max;
-    mutable std::unordered_map<const NetAddr, uint32_t> part_fetched_replica;
-
-    void on_fetch_cmd(const command_t &cmd);
-    void on_fetch_blk(const block_t &blk);
-    void on_deliver_blk(const block_t &blk);
-
-    /** deliver consensus message: <propose> */
-    inline void propose_handler(const MsgHotStuff &, conn_t);
-    /** deliver consensus message: <vote> */
-    inline void vote_handler(const MsgHotStuff &, conn_t);
-    /** fetches full block data */
-    inline void query_fetch_blk_handler(const MsgHotStuff &, conn_t);
-    /** receives a block */
-    inline void resp_fetch_blk_handler(const MsgHotStuff &, conn_t);
-
-    void do_broadcast_proposal(const Proposal &) override;
-    void do_vote(ReplicaID, const Vote &) override;
-    void do_decide(const command_t &) override;
-
-    public:
-    HotStuffBase(uint32_t blk_size,
-            int32_t parent_limit,
-            ReplicaID rid,
-            privkey_bt &&priv_key,
-            NetAddr listen_addr,
-            EventContext eb = EventContext(),
-            pacemaker_bt pmaker = nullptr);
-
-    ~HotStuffBase();
-
-    /* the API for HotStuffBase */
-
-    /* Submit the command to be decided. */
-    void add_command(command_t cmd) {
-        cmd_pending.push(storage->add_cmd(cmd));
-        if (cmd_pending.size() >= blk_size)
-        {
-            std::vector<command_t> cmds;
-            for (uint32_t i = 0; i < blk_size; i++)
-            {
-                cmds.push_back(cmd_pending.front());
-                cmd_pending.pop();
-            }
-            pmaker->beat().then([this, cmds = std::move(cmds)]() {
-                on_propose(cmds);
-            });
-        }
-    }
-
-    void add_replica(ReplicaID idx, const NetAddr &addr, pubkey_bt &&pub_key);
-    void start(bool eb_loop = false);
-
-    size_t size() const { return pn.all_peers().size(); }
-    void print_stat() const;
-
-    /* Helper functions */
-    /** Returns a promise resolved (with command_t cmd) when Command is fetched. */
-    promise_t async_fetch_cmd(const uint256_t &cmd_hash, const NetAddr *replica_id, bool fetch_now = true);
-    /** Returns a promise resolved (with block_t blk) when Block is fetched. */
-    promise_t async_fetch_blk(const uint256_t &blk_hash, const NetAddr *replica_id, bool fetch_now = true);
-    /** Returns a promise resolved (with block_t blk) when Block is delivered (i.e. prefix is fetched). */
-    promise_t async_deliver_blk(const uint256_t &blk_hash,  const NetAddr &replica_id);
-    /** Returns a promise resolved (with command_t cmd) when Command is decided. */
-    promise_t async_decide(const uint256_t &cmd_hash);
-};
-
-/** HotStuff protocol (templated by cryptographic implementation). */
-template<typename PrivKeyType = PrivKeyDummy,
-        typename PubKeyType = PubKeyDummy,
-        typename PartCertType = PartCertDummy,
-        typename QuorumCertType = QuorumCertDummy>
-class HotStuff: public HotStuffBase {
-    using HotStuffBase::HotStuffBase;
-    protected:
-
-    part_cert_bt create_part_cert(const PrivKey &priv_key, const uint256_t &blk_hash) override {
-        return new PartCertType(
-                    static_cast<const PrivKeyType &>(priv_key),
-                    blk_hash);
-    }
-
-    part_cert_bt parse_part_cert(DataStream &s) override {
-        PartCert *pc = new PartCertType();
-        s >> *pc;
-        return pc;
-    }
-
-    quorum_cert_bt create_quorum_cert(const uint256_t &blk_hash) override {
-        return new QuorumCertType(get_config(), blk_hash);
-    }
-
-    quorum_cert_bt parse_quorum_cert(DataStream &s) override {
-        QuorumCert *qc = new QuorumCertType();
-        s >> *qc;
-        return qc;
-    }
-
-    public:
-    HotStuff(uint32_t blk_size,
-            int32_t parent_limit,
-            ReplicaID rid,
-            const bytearray_t &raw_privkey,
-            NetAddr listen_addr,
-            EventContext eb = nullptr):
-        HotStuffBase(blk_size,
-                    parent_limit,
-                    rid,
-                    new PrivKeyType(raw_privkey),
-                    listen_addr,
-                    eb) {}
-
-    void add_replica(ReplicaID idx, const NetAddr &addr, const bytearray_t &pubkey_raw) {
-        DataStream s(pubkey_raw);
-        HotStuffBase::add_replica(idx, addr, new PubKeyType(pubkey_raw));
-    }
-};
-
-using HotStuffNoSig = HotStuff<>;
-using HotStuffSecp256k1 = HotStuff<PrivKeySecp256k1, PubKeySecp256k1,
-                                    PartCertSecp256k1, QuorumCertSecp256k1>;
-
-template<EntityType ent_type>
-FetchContext<ent_type>::FetchContext(FetchContext && other):
-        promise_t(static_cast<const promise_t &>(other)),
-        hs(other.hs),
-        fetch_msg(std::move(other.fetch_msg)),
-        ent_hash(other.ent_hash),
-        replica_ids(std::move(other.replica_ids)) {
-    other.timeout.del();
-    timeout = Event(hs->eb, -1, 0,
-            std::bind(&FetchContext::timeout_cb, this, _1, _2));
-    reset_timeout();
-}
-
-template<>
-inline void FetchContext<ENT_TYPE_CMD>::timeout_cb(evutil_socket_t, short) {
-    HOTSTUFF_LOG_WARN("cmd fetching %.10s timeout", get_hex(ent_hash).c_str());
-    for (const auto &replica_id: replica_ids)
-        send(replica_id);
-    reset_timeout();
-}
-
-template<>
-inline void FetchContext<ENT_TYPE_BLK>::timeout_cb(evutil_socket_t, short) {
-    HOTSTUFF_LOG_WARN("block fetching %.10s timeout", get_hex(ent_hash).c_str());
-    for (const auto &replica_id: replica_ids)
-        send(replica_id);
-    reset_timeout();
-}
-
-template<EntityType ent_type>
-FetchContext<ent_type>::FetchContext(
-                                const uint256_t &ent_hash, HotStuffBase *hs):
-            promise_t([](promise_t){}),
-            hs(hs), ent_hash(ent_hash) {
-    fetch_msg.gen_qfetchblk(std::vector<uint256_t>{ent_hash});
-
-    timeout = Event(hs->eb, -1, 0,
-            std::bind(&FetchContext::timeout_cb, this, _1, _2));
-    reset_timeout();
-}
-
-template<EntityType ent_type>
-void FetchContext<ent_type>::send(const NetAddr &replica_id) {
-    hs->part_fetched_replica[replica_id]++;
-    hs->pn.send_msg(fetch_msg, replica_id);
-}
-
-template<EntityType ent_type>
-void FetchContext<ent_type>::reset_timeout() {
-    timeout.add_with_timeout(salticidae::gen_rand_timeout(ent_waiting_timeout));
-}
-
-template<EntityType ent_type>
-void FetchContext<ent_type>::add_replica(const NetAddr &replica_id, bool fetch_now) {
-    if (replica_ids.empty() && fetch_now)
-        send(replica_id);
-    replica_ids.insert(replica_id);
-}
-
-}
-
-#endif
diff --git a/src/crypto.cpp b/src/crypto.cpp
index 335a521..7450229 100644
--- a/src/crypto.cpp
+++ b/src/crypto.cpp
@@ -1,5 +1,5 @@
-#include "entity.h"
-#include "crypto.h"
+#include "hotstuff/entity.h"
+#include "hotstuff/crypto.h"
 
 namespace hotstuff {
 
diff --git a/src/crypto.h b/src/crypto.h
deleted file mode 100644
index 2fbf745..0000000
--- a/src/crypto.h
+++ /dev/null
@@ -1,386 +0,0 @@
-#ifndef _HOTSTUFF_CRYPTO_H
-#define _HOTSTUFF_CRYPTO_H
-
-#include "salticidae/crypto.h"
-#include "salticidae/ref.h"
-#include "secp256k1.h"
-#include <openssl/rand.h>
-#include "type.h"
-
-using salticidae::RcObj;
-using salticidae::BoxObj;
-
-namespace hotstuff {
-
-using salticidae::SHA256;
-
-class PubKey: public Serializable, Cloneable {
-    public:
-    virtual ~PubKey() = default;
-    virtual PubKey *clone() override = 0;
-};
-
-using pubkey_bt = BoxObj<PubKey>;
-
-class PrivKey: public Serializable {
-    public:
-    virtual ~PrivKey() = default;
-    virtual pubkey_bt get_pubkey() const = 0;
-    virtual void from_rand() = 0;
-};
-
-using privkey_bt = BoxObj<PrivKey>;
-
-class PartCert: public Serializable, public Cloneable {
-    public:
-    virtual ~PartCert() = default;
-    virtual bool verify(const PubKey &pubkey) = 0;
-    virtual const uint256_t &get_blk_hash() const = 0;
-    virtual PartCert *clone() override = 0;
-};
-
-class ReplicaConfig;
-
-class QuorumCert: public Serializable, public Cloneable {
-    public:
-    virtual ~QuorumCert() = default;
-    virtual void add_part(ReplicaID replica, const PartCert &pc) = 0;
-    virtual void compute() = 0;
-    virtual bool verify(const ReplicaConfig &config) = 0;
-    virtual const uint256_t &get_blk_hash() const = 0;
-    virtual QuorumCert *clone() override = 0;
-};
-
-using part_cert_bt = BoxObj<PartCert>;
-using quorum_cert_bt = BoxObj<QuorumCert>;
-
-class PubKeyDummy: public PubKey {
-    PubKeyDummy *clone() override { return new PubKeyDummy(*this); }
-    void serialize(DataStream &) const override {}
-    void unserialize(DataStream &) override {}
-};
-
-class PrivKeyDummy: public PrivKey {
-    pubkey_bt get_pubkey() const override { return new PubKeyDummy(); }
-    void serialize(DataStream &) const override {}
-    void unserialize(DataStream &) override {}
-    void from_rand() override {}
-};
-
-class PartCertDummy: public PartCert {
-    uint256_t blk_hash;
-    public:
-    PartCertDummy() {}
-    PartCertDummy(const uint256_t &blk_hash):
-        blk_hash(blk_hash) {}
-
-    void serialize(DataStream &s) const override {
-        s << (uint32_t)0 << blk_hash;
-    }
-
-    void unserialize(DataStream &s) override {
-        uint32_t tmp;
-        s >> tmp >> blk_hash;
-    }
-
-    PartCert *clone() override {
-        return new PartCertDummy(blk_hash);
-    }
-
-    bool verify(const PubKey &) override { return true; }
-
-    const uint256_t &get_blk_hash() const override { return blk_hash; }
-};
-
-class QuorumCertDummy: public QuorumCert {
-    uint256_t blk_hash;
-    public:
-    QuorumCertDummy() {}
-    QuorumCertDummy(const ReplicaConfig &, const uint256_t &blk_hash):
-        blk_hash(blk_hash) {}
-
-    void serialize(DataStream &s) const override {
-        s << (uint32_t)1 << blk_hash;
-    }
-
-    void unserialize(DataStream &s) override {
-        uint32_t tmp;
-        s >> tmp >> blk_hash;
-    }
-
-    QuorumCert *clone() override {
-        return new QuorumCertDummy(*this);
-    }
-
-    void add_part(ReplicaID, const PartCert &) override {}
-    void compute() override {}
-    bool verify(const ReplicaConfig &) override { return true; }
-
-    const uint256_t &get_blk_hash() const override { return blk_hash; }
-};
-
-
-class Secp256k1Context {
-    secp256k1_context *ctx;
-    friend class PubKeySecp256k1;
-    friend class SigSecp256k1;
-    public:
-    Secp256k1Context(bool sign = false):
-        ctx(secp256k1_context_create(
-            sign ? SECP256K1_CONTEXT_SIGN :
-                    SECP256K1_CONTEXT_VERIFY)) {}
-
-    Secp256k1Context(const Secp256k1Context &) = delete;
-
-    Secp256k1Context(Secp256k1Context &&other): ctx(other.ctx) {
-        other.ctx = nullptr;
-    }
-
-    ~Secp256k1Context() {
-        if (ctx) secp256k1_context_destroy(ctx);
-    }
-};
-
-using secp256k1_context_t = RcObj<Secp256k1Context>;
-
-extern secp256k1_context_t secp256k1_default_sign_ctx;
-extern secp256k1_context_t secp256k1_default_verify_ctx;
-
-class PrivKeySecp256k1;
-
-class PubKeySecp256k1: public PubKey {
-    static const auto _olen = 33;
-    friend class SigSecp256k1;
-    secp256k1_pubkey data;
-    secp256k1_context_t ctx;
-
-    public:
-    PubKeySecp256k1(const secp256k1_context_t &ctx =
-                            secp256k1_default_sign_ctx):
-        PubKey(), ctx(ctx) {}
-    
-    PubKeySecp256k1(const bytearray_t &raw_bytes,
-                    const secp256k1_context_t &ctx =
-                            secp256k1_default_sign_ctx):
-        PubKeySecp256k1(ctx) { from_bytes(raw_bytes); }
-
-    inline PubKeySecp256k1(const PrivKeySecp256k1 &priv_key,
-                            const secp256k1_context_t &ctx =
-                                    secp256k1_default_sign_ctx);
-
-    void serialize(DataStream &s) const override {
-        static uint8_t output[_olen];
-        size_t olen = _olen;
-        (void)secp256k1_ec_pubkey_serialize(
-                ctx->ctx, (unsigned char *)output,
-                &olen, &data, SECP256K1_EC_COMPRESSED);
-        s.put_data(output, output + _olen);
-    }
-
-    void unserialize(DataStream &s) override {
-        static const auto _exc = std::invalid_argument("ill-formed public key");
-        try {
-            if (!secp256k1_ec_pubkey_parse(
-                    ctx->ctx, &data, s.get_data_inplace(_olen), _olen))
-                throw _exc;
-        } catch (std::ios_base::failure &) {
-            throw _exc;
-        }
-    }
-
-    PubKeySecp256k1 *clone() override {
-        return new PubKeySecp256k1(*this);
-    }
-};
-
-class PrivKeySecp256k1: public PrivKey {
-    static const auto nbytes = 32;
-    friend class PubKeySecp256k1;
-    friend class SigSecp256k1;
-    uint8_t data[nbytes];
-    secp256k1_context_t ctx;
-
-    public:
-    PrivKeySecp256k1(const secp256k1_context_t &ctx =
-                            secp256k1_default_sign_ctx):
-        PrivKey(), ctx(ctx) {}
-
-    PrivKeySecp256k1(const bytearray_t &raw_bytes,
-                     const secp256k1_context_t &ctx =
-                            secp256k1_default_sign_ctx):
-        PrivKeySecp256k1(ctx) { from_bytes(raw_bytes); }
-
-    void serialize(DataStream &s) const override {
-        s.put_data(data, data + nbytes);
-    }
-
-    void unserialize(DataStream &s) override {
-        static const auto _exc = std::invalid_argument("ill-formed private key");
-        try {
-            memmove(data, s.get_data_inplace(nbytes), nbytes);
-        } catch (std::ios_base::failure &) {
-            throw _exc;
-        }
-    }
-
-    void from_rand() override {
-        if (!RAND_bytes(data, nbytes))
-            throw std::runtime_error("cannot get rand bytes from openssl");
-    }
-
-    inline pubkey_bt get_pubkey() const override;
-};
-
-pubkey_bt PrivKeySecp256k1::get_pubkey() const {
-    return new PubKeySecp256k1(*this, ctx);
-}
-
-PubKeySecp256k1::PubKeySecp256k1(
-        const PrivKeySecp256k1 &priv_key,
-        const secp256k1_context_t &ctx): PubKey(), ctx(ctx) {
-    if (!secp256k1_ec_pubkey_create(ctx->ctx, &data, priv_key.data))
-        throw std::invalid_argument("invalid secp256k1 private key");
-}
-
-class SigSecp256k1: public Serializable {
-    secp256k1_ecdsa_signature data;
-    secp256k1_context_t ctx;
-
-    void check_msg_length(const bytearray_t &msg) {
-        if (msg.size() != 32)
-            throw std::invalid_argument("the message should be 32-bytes");
-    }
-
-    public:
-    SigSecp256k1(const secp256k1_context_t &ctx =
-                        secp256k1_default_sign_ctx):
-        Serializable(), ctx(ctx) {}
-    SigSecp256k1(const uint256_t &digest,
-                const PrivKeySecp256k1 &priv_key,
-                secp256k1_context_t &ctx =
-                        secp256k1_default_sign_ctx):
-        Serializable(), ctx(ctx) {
-        sign(digest, priv_key);
-    }
-
-    void serialize(DataStream &s) const override {
-        static uint8_t output[64];
-        (void)secp256k1_ecdsa_signature_serialize_compact(
-            ctx->ctx, (unsigned char *)output,
-            &data);
-        s.put_data(output, output + 64);
-    }
-
-    void unserialize(DataStream &s) override {
-        static const auto _exc = std::invalid_argument("ill-formed signature");
-        try {
-            if (!secp256k1_ecdsa_signature_parse_compact(
-                    ctx->ctx, &data, s.get_data_inplace(64)))
-                throw _exc;
-        } catch (std::ios_base::failure &) {
-            throw _exc;
-        }
-    }
-
-    void sign(const bytearray_t &msg, const PrivKeySecp256k1 &priv_key) {
-        check_msg_length(msg);
-        if (!secp256k1_ecdsa_sign(
-                ctx->ctx, &data,
-                (unsigned char *)&*msg.begin(),
-                (unsigned char *)priv_key.data,
-                NULL, // default nonce function
-                NULL))
-            throw std::invalid_argument("failed to create secp256k1 signature");
-    }
-
-    bool verify(const bytearray_t &msg, const PubKeySecp256k1 &pub_key,
-                const secp256k1_context_t &_ctx) {
-        check_msg_length(msg);
-        return secp256k1_ecdsa_verify(
-                _ctx->ctx, &data,
-                (unsigned char *)&*msg.begin(),
-                &pub_key.data) == 1;
-    }
-
-    bool verify(const bytearray_t &msg, const PubKeySecp256k1 &pub_key) {
-        return verify(msg, pub_key, ctx);
-    }
-};
-
-class PartCertSecp256k1: public SigSecp256k1, public PartCert {
-    uint256_t blk_hash;
-
-    public:
-    PartCertSecp256k1() = default;
-    PartCertSecp256k1(const PrivKeySecp256k1 &priv_key, const uint256_t &blk_hash):
-        SigSecp256k1(blk_hash, priv_key),
-        PartCert(),
-        blk_hash(blk_hash) {}
-
-    bool verify(const PubKey &pub_key) override {
-        return SigSecp256k1::verify(blk_hash,
-                                    static_cast<const PubKeySecp256k1 &>(pub_key),
-                                    secp256k1_default_verify_ctx);
-    }
-
-    const uint256_t &get_blk_hash() const override { return blk_hash; }
-
-    PartCertSecp256k1 *clone() override {
-        return new PartCertSecp256k1(*this);
-    }
-
-    void serialize(DataStream &s) const override {
-        s << blk_hash;
-        this->SigSecp256k1::serialize(s);
-    }
-
-    void unserialize(DataStream &s) override {
-        s >> blk_hash;
-        this->SigSecp256k1::unserialize(s);
-    }
-};
-
-class QuorumCertSecp256k1: public QuorumCert {
-    uint256_t blk_hash;
-    salticidae::Bits rids;
-    std::vector<SigSecp256k1> sigs;
-
-    public:
-    QuorumCertSecp256k1() = default;
-    QuorumCertSecp256k1(const ReplicaConfig &config, const uint256_t &blk_hash);
-
-    void add_part(ReplicaID rid, const PartCert &pc) override {
-        if (pc.get_blk_hash() != blk_hash)
-            throw std::invalid_argument("PartCert does match the block hash");
-        if (!rids.get(rid))
-        {
-            rids.set(rid);
-            sigs.push_back(static_cast<const PartCertSecp256k1 &>(pc));
-        }
-    }
-
-    void compute() override {}
-
-    bool verify(const ReplicaConfig &config) override;
-
-    const uint256_t &get_blk_hash() const override { return blk_hash; }
-
-    QuorumCertSecp256k1 *clone() override {
-        return new QuorumCertSecp256k1(*this);
-    }
-
-    void serialize(DataStream &s) const override {
-        s << blk_hash << rids;
-        for (const auto &sig: sigs) s << sig;
-    }
-
-    void unserialize(DataStream &s) override {
-        s >> blk_hash >> rids;
-        sigs.resize(rids.size());
-        for (auto &sig: sigs) s >> sig;
-    }
-};
-
-}
-
-#endif
diff --git a/src/entity.cpp b/src/entity.cpp
index 1294484..1d2e926 100644
--- a/src/entity.cpp
+++ b/src/entity.cpp
@@ -1,5 +1,5 @@
-#include "entity.h"
-#include "core.h"
+#include "hotstuff/entity.h"
+#include "hotstuff/core.h"
 
 namespace hotstuff {
 
diff --git a/src/entity.h b/src/entity.h
deleted file mode 100644
index b3a0df4..0000000
--- a/src/entity.h
+++ /dev/null
@@ -1,309 +0,0 @@
-#ifndef _HOTSTUFF_ENT_H
-#define _HOTSTUFF_ENT_H
-
-#include <vector>
-#include <unordered_map>
-#include <unordered_set>
-#include <string>
-#include <cstddef>
-#include <ios>
-
-#include "salticidae/netaddr.h"
-#include "salticidae/ref.h"
-#include "type.h"
-#include "util.h"
-#include "crypto.h"
-
-namespace hotstuff {
-
-enum EntityType {
-    ENT_TYPE_CMD = 0x0,
-    ENT_TYPE_BLK = 0x1
-};
-
-struct ReplicaInfo {
-    ReplicaID id;
-    salticidae::NetAddr addr;
-    pubkey_bt pubkey;
-
-    ReplicaInfo(ReplicaID id,
-                const salticidae::NetAddr &addr,
-                pubkey_bt &&pubkey):
-        id(id), addr(addr), pubkey(std::move(pubkey)) {}
-
-    ReplicaInfo(const ReplicaInfo &other):
-        id(other.id), addr(other.addr),
-        pubkey(other.pubkey->clone()) {}
-
-    ReplicaInfo(ReplicaInfo &&other):
-        id(other.id), addr(other.addr),
-        pubkey(std::move(other.pubkey)) {}
-};
-
-class ReplicaConfig {
-    std::unordered_map<ReplicaID, ReplicaInfo> replica_map;
-
-    public:
-    size_t nmajority;
-
-    void add_replica(ReplicaID rid, const ReplicaInfo &info) {
-        replica_map.insert(std::make_pair(rid, info));
-    }
-
-    const ReplicaInfo &get_info(ReplicaID rid) const {
-        auto it = replica_map.find(rid);
-        if (it == replica_map.end())
-            throw HotStuffError("rid %s not found",
-                    get_hex(rid).c_str());
-        return it->second;
-    }
-
-    const PubKey &get_pubkey(ReplicaID rid) const {
-        return *(get_info(rid).pubkey);
-    }
-
-    const salticidae::NetAddr &get_addr(ReplicaID rid) const {
-        return get_info(rid).addr;
-    }
-};
-
-class Block;
-class HotStuffCore;
-
-using block_t = salticidae::RcObj<Block>;
-using block_weak_t = salticidae::WeakObj<Block>;
-
-struct Finality: public Serializable {
-    int8_t decision;
-    uint256_t blk_hash;
-    
-    public:
-    Finality(): decision(0) {}
-    Finality(int8_t decision, uint256_t blk_hash):
-        decision(decision), blk_hash(blk_hash) {}
-
-    void serialize(DataStream &s) const override {
-        s << decision;
-        if (decision == 1) s << blk_hash;
-    }
-
-    void unserialize(DataStream &s) override {
-        s >> decision;
-        if (decision == 1) s >> blk_hash;
-    }
-};
-
-class Command: public Serializable {
-    friend HotStuffCore;
-    block_weak_t container;
-    public:
-    virtual ~Command() = default;
-    virtual const uint256_t &get_hash() const = 0;
-    virtual bool verify() const = 0;
-    inline int8_t get_decision() const;
-    inline Finality get_finality() const;
-    block_t get_container() const {
-        return container;
-    }
-};
-
-using command_t = RcObj<Command>;
-
-template<typename Hashable>
-inline static std::vector<uint256_t>
-get_hashes(const std::vector<Hashable> &plist) {
-    std::vector<uint256_t> hashes;
-    for (const auto &p: plist)
-        hashes.push_back(p->get_hash());
-    return std::move(hashes);
-}
-
-class Block {
-    friend HotStuffCore;
-    std::vector<uint256_t> parent_hashes;
-    std::vector<command_t> cmds;
-    quorum_cert_bt qc;
-    uint256_t hash;
-
-    std::vector<block_t> parents;
-    block_t qc_ref;
-    quorum_cert_bt self_qc;
-    uint32_t height;
-    bool delivered;
-    int8_t decision;
-
-    std::unordered_set<ReplicaID> voted;
-
-    public:
-    Block():
-        qc(nullptr),
-        qc_ref(nullptr),
-        self_qc(nullptr), height(0),
-        delivered(false), decision(0) {}
-
-    Block(bool delivered, int8_t decision):
-        qc(nullptr),
-        hash(salticidae::get_hash(*this)),
-        qc_ref(nullptr),
-        self_qc(nullptr), height(0),
-        delivered(delivered), decision(decision) {}
-
-    Block(const std::vector<block_t> &parents,
-        const std::vector<command_t> &cmds,
-        uint32_t height,
-        quorum_cert_bt &&qc,
-        const block_t &qc_ref,
-        quorum_cert_bt &&self_qc,
-        int8_t decision = 0):
-            parent_hashes(get_hashes(parents)),
-            cmds(cmds),
-            qc(std::move(qc)),
-            hash(salticidae::get_hash(*this)),
-            parents(parents),
-            qc_ref(qc_ref),
-            self_qc(std::move(self_qc)),
-            height(height),
-            delivered(0),
-            decision(decision) {}
-
-    void serialize(DataStream &s) const;
-
-    void unserialize(DataStream &s, HotStuffCore *hsc);
-
-    const std::vector<command_t> &get_cmds() const {
-        return cmds;
-    }
-
-    const std::vector<block_t> &get_parents() const {
-        return parents;
-    }
-
-    const std::vector<uint256_t> &get_parent_hashes() const {
-        return parent_hashes;
-    }
-
-    const uint256_t &get_hash() const { return hash; }
-
-    bool verify(const ReplicaConfig &config) const {
-        if (qc && !qc->verify(config)) return false;
-        for (auto cmd: cmds)
-            if (!cmd->verify()) return false;
-        return true;
-    }
-
-    int8_t get_decision() const { return decision; }
-
-    bool is_delivered() const { return delivered; }
-
-    uint32_t get_height() const { return height; }
-
-    const quorum_cert_bt &get_qc() const { return qc; }
-
-    operator std::string () const {
-        DataStream s;
-        s << "<block "
-          << "id="  << get_hex10(hash) << " "
-          << "height=" << std::to_string(height) << " "
-          << "parent=" << get_hex10(parent_hashes[0]) << ">";
-        return std::string(std::move(s));
-    }
-};
-
-struct BlockHeightCmp {
-    bool operator()(const block_t &a, const block_t &b) const {
-        return a->get_height() < b->get_height();
-    }
-};
-
-int8_t Command::get_decision() const {
-    block_t cptr = container;
-    return cptr ? cptr->get_decision() : 0;
-}
-
-Finality Command::get_finality() const {
-    block_t blk = get_container();
-    return Finality(get_decision(),
-                    blk ? blk->get_hash() : uint256_t());
-}
-
-class EntityStorage {
-    std::unordered_map<const uint256_t, block_t> blk_cache;
-    std::unordered_map<const uint256_t, command_t> cmd_cache;
-    public:
-    bool is_blk_delivered(const uint256_t &blk_hash) {
-        auto it = blk_cache.find(blk_hash);
-        if (it == blk_cache.end()) return false;
-        return it->second->is_delivered();
-    }
-
-    bool is_blk_fetched(const uint256_t &blk_hash) {
-        return blk_cache.count(blk_hash);
-    }
-
-    const block_t &add_blk(Block &&_blk) {
-        block_t blk = new Block(std::move(_blk));
-        return blk_cache.insert(std::make_pair(blk->get_hash(), blk)).first->second;
-    }
-
-    const block_t &add_blk(const block_t &blk) {
-        return blk_cache.insert(std::make_pair(blk->get_hash(), blk)).first->second;
-    }
-
-    block_t find_blk(const uint256_t &blk_hash) {
-        auto it = blk_cache.find(blk_hash);
-        return it == blk_cache.end() ? nullptr : it->second;
-    }
-
-    bool is_cmd_fetched(const uint256_t &cmd_hash) {
-        return cmd_cache.count(cmd_hash);
-    }
-
-    const command_t &add_cmd(const command_t &cmd) {
-        return cmd_cache.insert(std::make_pair(cmd->get_hash(), cmd)).first->second;
-    }
-
-    command_t find_cmd(const uint256_t &cmd_hash) {
-        auto it = cmd_cache.find(cmd_hash);
-        return it == cmd_cache.end() ? nullptr: it->second;
-    }
-
-    size_t get_cmd_cache_size() {
-        return cmd_cache.size();
-    }
-    size_t get_blk_cache_size() {
-        return blk_cache.size();
-    }
-
-    bool try_release_cmd(const command_t &cmd) {
-        if (cmd.get_cnt() == 2) /* only referred by cmd and the storage */
-        {
-            const auto &cmd_hash = cmd->get_hash();
-            cmd_cache.erase(cmd_hash);
-            return true;
-        }
-        return false;
-    }
-
-    bool try_release_blk(const block_t &blk) {
-        if (blk.get_cnt() == 2) /* only referred by blk and the storage */
-        {
-            const auto &blk_hash = blk->get_hash();
-#ifdef HOTSTUFF_ENABLE_LOG_PROTO
-            HOTSTUFF_LOG_INFO("releasing blk %.10s", get_hex(blk_hash).c_str());
-#endif
-            for (const auto &cmd: blk->get_cmds())
-                try_release_cmd(cmd);
-            blk_cache.erase(blk_hash);
-            return true;
-        }
-#ifdef HOTSTUFF_ENABLE_LOG_PROTO
-        else
-            HOTSTUFF_LOG_INFO("cannot release (%lu)", blk.get_cnt());
-#endif
-        return false;
-    }
-};
-
-}
-
-#endif
diff --git a/src/hotstuff.cpp b/src/hotstuff.cpp
index b10f103..74d2f04 100644
--- a/src/hotstuff.cpp
+++ b/src/hotstuff.cpp
@@ -11,12 +11,13 @@
 #include "salticidae/util.h"
 #include "salticidae/network.h"
 #include "salticidae/msg.h"
-#include "promise.hpp"
-#include "type.h"
-#include "core.h"
-#include "entity.h"
-#include "util.h"
-#include "client.h"
+
+#include "hotstuff/promise.hpp"
+#include "hotstuff/type.h"
+#include "hotstuff/core.h"
+#include "hotstuff/entity.h"
+#include "hotstuff/util.h"
+#include "hotstuff/client.h"
 
 using promise::promise_t;
 using salticidae::NetAddr;
diff --git a/src/hotstuff_client.cpp b/src/hotstuff_client.cpp
index 5c04e5f..6b26c9c 100644
--- a/src/hotstuff_client.cpp
+++ b/src/hotstuff_client.cpp
@@ -3,9 +3,10 @@
 #include "salticidae/netaddr.h"
 #include "salticidae/network.h"
 #include "salticidae/util.h"
-#include "util.h"
-#include "type.h"
-#include "client.h"
+
+#include "hotstuff/util.h"
+#include "hotstuff/type.h"
+#include "hotstuff/client.h"
 
 using salticidae::NetAddr;
 using salticidae::Config;
diff --git a/src/hotstuff_keygen.cpp b/src/hotstuff_keygen.cpp
index 7a7e615..100cb01 100644
--- a/src/hotstuff_keygen.cpp
+++ b/src/hotstuff_keygen.cpp
@@ -1,6 +1,6 @@
 #include <error.h>
 #include "salticidae/util.h"
-#include "crypto.h"
+#include "hotstuff/crypto.h"
 
 using salticidae::Config;
 using hotstuff::privkey_bt;
diff --git a/src/promise.hpp b/src/promise.hpp
deleted file mode 100644
index 593d5c1..0000000
--- a/src/promise.hpp
+++ /dev/null
@@ -1,745 +0,0 @@
-#ifndef _CPPROMISE_HPP
-#define _CPPROMISE_HPP
-
-/**
- * MIT License
- * Copyright (c) 2018 Ted Yin <[email protected]>
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-#include <stack>
-#include <vector>
-#include <memory>
-#include <functional>
-#include <type_traits>
-
-#if __cplusplus >= 201703L
-#ifdef __has_include
-#   if __has_include(<any>)
-#       include <any>
-#       ifdef __cpp_lib_any
-#           define _CPPROMISE_STD_ANY
-#       endif
-#   endif
-#endif
-#endif
-
-#ifndef _CPPROMISE_STD_ANY
-#include <boost/any.hpp>
-#endif
-
-/**
- * Implement type-safe Promise primitives similar to the ones specified by
- * Javascript Promise/A+.
- */
-namespace promise {
-#ifdef _CPPROMISE_STD_ANY
-    using pm_any_t = std::any;
-    template<typename T>
-    constexpr auto any_cast = static_cast<T(*)(const std::any&)>(std::any_cast<T>);
-    using bad_any_cast = std::bad_any_cast;
-#else
-#   warning "using boost::any"
-#   pragma message "using boost::any"
-    using pm_any_t = boost::any;
-    template<typename T>
-    constexpr auto any_cast = static_cast<T(*)(const boost::any&)>(boost::any_cast<T>);
-    using bad_any_cast = boost::bad_any_cast;
-#endif
-    using callback_t = std::function<void()>;
-    using values_t = std::vector<pm_any_t>;
-
-    /* match lambdas */
-    template<typename T>
-    struct function_traits:
-        public function_traits<decltype(&T::operator())> {};
- 
-    template<typename ReturnType>
-    struct function_traits<ReturnType()> {
-        using ret_type = ReturnType;
-        using arg_type = void;
-        using empty_arg = void;
-    };
-   
-    /* match plain functions */
-    template<typename ReturnType, typename ArgType>
-    struct function_traits<ReturnType(ArgType)> {
-        using ret_type = ReturnType;
-        using arg_type = ArgType;
-        using non_empty_arg = void;
-    };
- 
-    /* match function pointers */
-    template<typename ReturnType, typename... ArgType>
-    struct function_traits<ReturnType(*)(ArgType...)>:
-        public function_traits<ReturnType(ArgType...)> {};
-
-    /* match const member functions */
-    template<typename ClassType, typename ReturnType, typename... ArgType>
-    struct function_traits<ReturnType(ClassType::*)(ArgType...) const>:
-        public function_traits<ReturnType(ArgType...)> {};
-
-    /* match member functions */
-    template<typename ClassType, typename ReturnType, typename... ArgType>
-    struct function_traits<ReturnType(ClassType::*)(ArgType...)>:
-        public function_traits<ReturnType(ArgType...)> {};
-
-    template<typename Func, typename ReturnType>
-    using enable_if_return = typename std::enable_if<
-            std::is_same<typename function_traits<Func>::ret_type,
-                         ReturnType>::value>;
-
-    template<typename Func, typename ReturnType>
-    using disable_if_return = typename std::enable_if<
-            !std::is_same<typename function_traits<Func>::ret_type,
-                         ReturnType>::value>;
-
-    template<typename Func, typename ArgType>
-    using enable_if_arg = typename std::enable_if<
-            std::is_same<typename function_traits<Func>::arg_type,
-                         ArgType>::value>;
-
-    template<typename Func, typename ArgType>
-    using disable_if_arg = typename std::enable_if<
-            !std::is_same<typename function_traits<Func>::arg_type,
-                         ArgType>::value>;
-
-    class Promise;
-    //class promise_t: public std::shared_ptr<Promise> {
-    class promise_t {
-        Promise *pm;
-        size_t *ref_cnt;
-        public:
-        friend Promise;
-        template<typename PList> friend promise_t all(const PList &promise_list);
-        template<typename PList> friend promise_t race(const PList &promise_list);
-
-        inline promise_t();
-        inline ~promise_t();
-        template<typename Func> inline promise_t(Func callback);
-
-        void swap(promise_t &other) {
-            std::swap(pm, other.pm);
-            std::swap(ref_cnt, other.ref_cnt);
-        }
-
-        promise_t &operator=(const promise_t &other) {
-            if (this != &other)
-            {
-                promise_t tmp(other);
-                tmp.swap(*this);
-            }
-            return *this;
-        }
-
-        promise_t &operator=(promise_t &&other) {
-            if (this != &other)
-            {
-                promise_t tmp(std::move(other));
-                tmp.swap(*this);
-            }
-            return *this;
-        }
-
-        promise_t(const promise_t &other):
-            pm(other.pm),
-            ref_cnt(other.ref_cnt) {
-            ++*ref_cnt;
-        }
-
-        promise_t(promise_t &&other):
-            pm(other.pm),
-            ref_cnt(other.ref_cnt) {
-            other.pm = nullptr;
-        }
-
-        Promise *operator->() const {
-            return pm;
-        }
-
-        template<typename T> inline void resolve(T result) const;
-        template<typename T> inline void reject(T reason) const;
-        inline void resolve() const;
-        inline void reject() const;
-
-        template<typename FuncFulfilled>
-        inline promise_t then(FuncFulfilled on_fulfilled) const;
-
-        template<typename FuncFulfilled, typename FuncRejected>
-        inline promise_t then(FuncFulfilled on_fulfilled,
-                            FuncRejected on_rejected) const;
-
-        template<typename FuncRejected>
-        inline promise_t fail(FuncRejected on_rejected) const;
-    };
-
-#define PROMISE_ERR_INVALID_STATE do {throw std::runtime_error("invalid promise state");} while (0)
-#define PROMISE_ERR_MISMATCH_TYPE do {throw std::runtime_error("mismatching promise value types");} while (0)
-    
-    class Promise {
-        template<typename PList> friend promise_t all(const PList &promise_list);
-        template<typename PList> friend promise_t race(const PList &promise_list);
-        std::vector<callback_t> fulfilled_callbacks;
-        std::vector<callback_t> rejected_callbacks;
-#ifdef CPPROMISE_USE_STACK_FREE
-        std::vector<Promise *> fulfilled_pms;
-        std::vector<Promise *> rejected_pms;
-#endif
-        enum class State {
-            Pending,
-#ifdef CPPROMISE_USE_STACK_FREE
-            PreFulfilled,
-            PreRejected,
-#endif
-            Fulfilled,
-            Rejected,
-        } state;
-        pm_any_t result;
-        pm_any_t reason;
-
-        void add_on_fulfilled(callback_t &&cb) {
-            fulfilled_callbacks.push_back(std::move(cb));
-        }
-
-        void add_on_rejected(callback_t &&cb) {
-            rejected_callbacks.push_back(std::move(cb));
-        }
-
-        template<typename Func,
-            typename function_traits<Func>::non_empty_arg * = nullptr>
-        static constexpr auto cps_transform(
-                Func f, const pm_any_t &result, const promise_t &npm) {
-            return [&result, npm, f = std::forward<Func>(f)]() mutable {
-#ifndef CPPROMISE_USE_STACK_FREE
-                f(result)->then(
-                    [npm] (pm_any_t result) {npm->resolve(result);},
-                    [npm] (pm_any_t reason) {npm->reject(reason);});
-#else
-                promise_t rpm{f(result)};
-                rpm->then(
-                    [rpm, npm] (pm_any_t result) {
-                        npm->_resolve(result);
-                    },
-                    [rpm, npm] (pm_any_t reason) {
-                        npm->_reject(reason);
-                    });
-                rpm->_dep_resolve(npm);
-                rpm->_dep_reject(npm);
-#endif
-            };
-        }
-
-        template<typename Func,
-            typename function_traits<Func>::empty_arg * = nullptr>
-        static constexpr auto cps_transform(
-                Func f, const pm_any_t &, const promise_t &npm) {
-            return [npm, f = std::forward<Func>(f)]() mutable {
-#ifndef CPPROMISE_USE_STACK_FREE
-                f()->then(
-                    [npm] (pm_any_t result) {npm->resolve(result);},
-                    [npm] (pm_any_t reason) {npm->reject(reason);});
-#else
-                promise_t rpm{f()};
-                rpm->then(
-                    [rpm, npm] (pm_any_t result) {
-                        npm->_resolve(result);
-                    },
-                    [rpm, npm] (pm_any_t reason) {
-                        npm->_reject(reason);
-                    });
-                rpm->_dep_resolve(npm);
-                rpm->_dep_reject(npm);
-#endif
-            };
-        }
-
-        template<typename Func,
-            typename enable_if_return<Func, promise_t>::type * = nullptr>
-        constexpr auto gen_on_fulfilled(Func on_fulfilled, const promise_t &npm) {
-            return cps_transform(std::forward<Func>(on_fulfilled), this->result, npm);
-        }
-
-        template<typename Func,
-            typename enable_if_return<Func, promise_t>::type * = nullptr>
-        constexpr auto gen_on_rejected(Func on_rejected, const promise_t &npm) {
-            return cps_transform(std::forward<Func>(on_rejected), this->reason, npm);
-        }
-
-
-        template<typename Func,
-            typename enable_if_return<Func, void>::type * = nullptr,
-            typename function_traits<Func>::non_empty_arg * = nullptr>
-        constexpr auto gen_on_fulfilled(Func on_fulfilled, const promise_t &npm) {
-            return [this, npm,
-                    on_fulfilled = std::forward<Func>(on_fulfilled)]() mutable {
-                on_fulfilled(result);
-                npm->_resolve();
-            };
-        }
-
-        template<typename Func,
-            typename enable_if_return<Func, void>::type * = nullptr,
-            typename function_traits<Func>::empty_arg * = nullptr>
-        constexpr auto gen_on_fulfilled(Func on_fulfilled, const promise_t &npm) {
-            return [on_fulfilled = std::forward<Func>(on_fulfilled), npm]() mutable {
-                on_fulfilled();
-                npm->_resolve();
-            };
-        }
-
-        template<typename Func,
-            typename enable_if_return<Func, void>::type * = nullptr,
-            typename function_traits<Func>::non_empty_arg * = nullptr>
-        constexpr auto gen_on_rejected(Func on_rejected, const promise_t &npm) {
-            return [this, npm,
-                    on_rejected = std::forward<Func>(on_rejected)]() mutable {
-                on_rejected(reason);
-                npm->_reject();
-            };
-        }
-
-        template<typename Func,
-            typename enable_if_return<Func, void>::type * = nullptr,
-            typename function_traits<Func>::empty_arg * = nullptr>
-        constexpr auto gen_on_rejected(Func on_rejected, const promise_t &npm) {
-            return [npm,
-                    on_rejected = std::forward<Func>(on_rejected)]() mutable {
-                on_rejected();
-                npm->_reject();
-            };
-        }
-
-        template<typename Func,
-            typename enable_if_return<Func, pm_any_t>::type * = nullptr,
-            typename function_traits<Func>::non_empty_arg * = nullptr>
-        constexpr auto gen_on_fulfilled(Func on_fulfilled, const promise_t &npm) {
-            return [this, npm,
-                    on_fulfilled = std::forward<Func>(on_fulfilled)]() mutable {
-                npm->_resolve(on_fulfilled(result));
-            };
-        }
-
-        template<typename Func,
-            typename enable_if_return<Func, pm_any_t>::type * = nullptr,
-            typename function_traits<Func>::empty_arg * = nullptr>
-        constexpr auto gen_on_fulfilled(Func on_fulfilled, const promise_t &npm) {
-            return [npm, on_fulfilled = std::forward<Func>(on_fulfilled)]() mutable {
-                npm->_resolve(on_fulfilled());
-            };
-        }
-
-        template<typename Func,
-            typename enable_if_return<Func, pm_any_t>::type * = nullptr,
-            typename function_traits<Func>::non_empty_arg * = nullptr>
-        constexpr auto gen_on_rejected(Func on_rejected, const promise_t &npm) {
-            return [this, npm, on_rejected = std::forward<Func>(on_rejected)]() mutable {
-                npm->_reject(on_rejected(reason));
-            };
-        }
-
-        template<typename Func,
-            typename enable_if_return<Func, pm_any_t>::type * = nullptr,
-            typename function_traits<Func>::empty_arg * = nullptr>
-        constexpr auto gen_on_rejected(Func on_rejected, const promise_t &npm) {
-            return [npm, on_rejected = std::forward<Func>(on_rejected)]() mutable {
-                npm->_reject(on_rejected());
-            };
-        }
-
-#ifdef CPPROMISE_USE_STACK_FREE
-        void _trigger() {
-            std::stack<std::tuple<
-                std::vector<Promise *>::const_iterator,
-                std::vector<Promise *> *,
-                Promise *>> s;
-            auto push_frame = [&s](Promise *pm) {
-                if (pm->state == State::PreFulfilled)
-                {
-                    pm->state = State::Fulfilled;
-                    for (auto &cb: pm->fulfilled_callbacks) cb();
-                    s.push(std::make_tuple(pm->fulfilled_pms.begin(),
-                                          &pm->fulfilled_pms,
-                                          pm));
-                }
-                else if (pm->state == State::PreRejected)
-                {
-                    pm->state = State::Rejected;
-                    for (auto &cb: pm->rejected_callbacks) cb();
-                    s.push(std::make_tuple(pm->rejected_pms.begin(),
-                                          &pm->rejected_pms,
-                                          pm));
-                }
-            };
-            push_frame(this);
-            while (!s.empty())
-            {
-                auto &u = s.top();
-                auto &it = std::get<0>(u);
-                auto vec = std::get<1>(u);
-                auto pm = std::get<2>(u);
-                if (it == vec->end())
-                {
-                    s.pop();
-                    vec->clear();
-                    pm->fulfilled_callbacks.clear();
-                    pm->rejected_callbacks.clear();
-                    continue;
-                }
-                push_frame(*it++);
-            }
-        }
-
-        void trigger_fulfill() {
-            state = State::PreFulfilled;
-            _trigger();
-        }
-
-        void trigger_reject() {
-            state = State::PreRejected;
-            _trigger();
-        }
-
-        void _resolve() {
-            if (state == State::Pending) state = State::PreFulfilled;
-        }
-
-        void _reject() {
-            if (state == State::Pending) state = State::PreRejected;
-        }
-
-        void _dep_resolve(const promise_t &npm) {
-            if (state == State::Pending)
-                fulfilled_pms.push_back(npm.pm);
-            else
-                npm->_trigger();
-        }
-
-        void _dep_reject(const promise_t &npm) {
-            if (state == State::Pending)
-                rejected_pms.push_back(npm.pm);
-            else
-                npm->_trigger();
-        }
-
-        void _resolve(pm_any_t _result) {
-            if (state == State::Pending)
-            {
-                result = _result;
-                state = State::PreFulfilled;
-            }
-        }
-
-        void _reject(pm_any_t _reason) {
-            if (state == State::Pending)
-            {
-                reason = _reason;
-                state = State::PreRejected;
-            }
-        }
-#else
-        void _resolve() { resolve(); }
-        void _reject() { reject(); }
-        void _resolve(pm_any_t result) { resolve(result); }
-        void _reject(pm_any_t reason) { reject(reason); }
-
-        void trigger_fulfill() {
-            state = State::Fulfilled;
-            for (const auto &cb: fulfilled_callbacks) cb();
-            fulfilled_callbacks.clear();
-        }
-
-        void trigger_reject() {
-            state = State::Rejected;
-            for (const auto &cb: rejected_callbacks) cb();
-            rejected_callbacks.clear();
-        }
-#endif
-        public:
-
-        Promise(): state(State::Pending) {}
-        ~Promise() {}
-
-        template<typename FuncFulfilled, typename FuncRejected>
-        promise_t then(FuncFulfilled on_fulfilled,
-                      FuncRejected on_rejected) {
-            switch (state)
-            {
-                case State::Pending:
-                return promise_t([this,
-                                on_fulfilled = std::forward<FuncFulfilled>(on_fulfilled),
-                                on_rejected = std::forward<FuncRejected>(on_rejected)
-                                ](promise_t &npm) {
-                    add_on_fulfilled(gen_on_fulfilled(std::move(on_fulfilled), npm));
-                    add_on_rejected(gen_on_rejected(std::move(on_rejected), npm));
-#ifdef CPPROMISE_USE_STACK_FREE
-                    _dep_resolve(npm);
-                    _dep_reject(npm);
-#endif
-                });
-                case State::Fulfilled:
-                return promise_t([this,
-                                on_fulfilled = std::forward<FuncFulfilled>(on_fulfilled)
-                                ](promise_t &npm) {
-                    gen_on_fulfilled(std::move(on_fulfilled), npm)();
-                });
-                case State::Rejected:
-                return promise_t([this,
-                                on_rejected = std::forward<FuncRejected>(on_rejected)
-                                ](promise_t &npm) {
-                    gen_on_rejected(std::move(on_rejected), npm)();
-                });
-                default: PROMISE_ERR_INVALID_STATE;
-            }
-        }
-
-        template<typename FuncFulfilled>
-        promise_t then(FuncFulfilled &&on_fulfilled) {
-            switch (state)
-            {
-                case State::Pending:
-                return promise_t([this,
-                                on_fulfilled = std::forward<FuncFulfilled>(on_fulfilled)
-                                ](promise_t &npm) {
-                    add_on_fulfilled(gen_on_fulfilled(std::move(on_fulfilled), npm));
-                    add_on_rejected([this, npm]() {npm->_reject(reason);});
-#ifdef CPPROMISE_USE_STACK_FREE
-                    _dep_resolve(npm);
-                    _dep_reject(npm);
-#endif
-                });
-                case State::Fulfilled:
-                return promise_t([this,
-                                on_fulfilled = std::forward<FuncFulfilled>(on_fulfilled)
-                                ](promise_t &npm) {
-                    gen_on_fulfilled(std::move(on_fulfilled), npm)();
-                });
-                case State::Rejected:
-                return promise_t([this](promise_t &npm) {npm->_reject(reason);});
-                default: PROMISE_ERR_INVALID_STATE;
-            }
-        }
- 
-        template<typename FuncRejected>
-        promise_t fail(FuncRejected &&on_rejected) {
-            switch (state)
-            {
-                case State::Pending:
-                return promise_t([this,
-                                on_rejected = std::forward<FuncRejected>(on_rejected)
-                                ](promise_t &npm) {
-                    callback_t ret;
-                    add_on_rejected(gen_on_rejected(std::move(on_rejected), npm));
-                    add_on_fulfilled([this, npm]() {npm->_resolve(result);});
-#ifdef CPPROMISE_USE_STACK_FREE
-                    _dep_resolve(npm);
-                    _dep_reject(npm);
-#endif
-                });
-                case State::Fulfilled:
-                return promise_t([this](promise_t &npm) {npm->_resolve(result);});
-                case State::Rejected:
-                return promise_t([this,
-                                on_rejected = std::forward<FuncRejected>(on_rejected)
-                                ](promise_t &npm) {
-                    gen_on_rejected(std::move(on_rejected), npm)();
-                });
-                default: PROMISE_ERR_INVALID_STATE;
-            }
-        }
-  
-        void resolve() {
-            if (state == State::Pending) trigger_fulfill();
-        }
-
-        void reject() {
-            if (state == State::Pending) trigger_reject();
-        }
-
-        void resolve(pm_any_t _result) {
-            if (state == State::Pending)
-            {
-                result = _result;
-                trigger_fulfill();
-            }
-        }
-
-        void reject(pm_any_t _reason) {
-            if (state == State::Pending)
-            {
-                reason = _reason;
-                trigger_reject();
-            }
-        }
-    };
-        
-    template<typename PList> promise_t all(const PList &promise_list) {
-        return promise_t([&promise_list] (promise_t &npm) {
-            auto size = std::make_shared<size_t>(promise_list.size());
-            auto results = std::make_shared<values_t>();
-            if (!*size) PROMISE_ERR_MISMATCH_TYPE;
-            results->resize(*size);
-            size_t idx = 0;
-            for (const auto &pm: promise_list) {
-                pm->then(
-                    [results, size, idx, npm](pm_any_t result) {
-                        (*results)[idx] = result;
-                        if (!--(*size))
-                            npm->_resolve(*results);
-                    },
-                    [npm](pm_any_t reason) {npm->_reject(reason);});
-#ifdef CPPROMISE_USE_STACK_FREE
-                pm->_dep_resolve(npm);
-                pm->_dep_reject(npm);
-#endif
-                idx++;
-            }
-        });
-    }
-
-    template<typename PList> promise_t race(const PList &promise_list) {
-        return promise_t([&promise_list] (promise_t &npm) {
-            for (const auto &pm: promise_list) {
-                pm->then([npm](pm_any_t result) {npm->_resolve(result);},
-                        [npm](pm_any_t reason) {npm->_reject(reason);});
-#ifdef CPPROMISE_USE_STACK_FREE
-                pm->_dep_resolve(npm);
-                pm->_dep_reject(npm);
-#endif
-            }
-        });
-    }
-
-    template<typename Func>
-    inline promise_t::promise_t(Func callback):
-            pm(new Promise()),
-        ref_cnt(new size_t(1)) {
-        callback(*this);
-    }
-
-    inline promise_t::promise_t():
-        pm(new Promise()),
-        ref_cnt(new size_t(1)) {}
-
-    inline promise_t::~promise_t() {
-        if (pm)
-        {
-            if (--*ref_cnt) return;
-            delete pm;
-            delete ref_cnt;
-        }
-    }
-
-    template<typename T>
-    inline void promise_t::resolve(T result) const { (*this)->resolve(result); }
-
-    template<typename T>
-    inline void promise_t::reject(T reason) const { (*this)->reject(reason); }
-
-    inline void promise_t::resolve() const { (*this)->resolve(); }
-    inline void promise_t::reject() const { (*this)->reject(); }
-
-    template<typename T>
-    struct callback_types {
-        using arg_type = typename function_traits<T>::arg_type;
-        using ret_type = typename std::conditional<
-            std::is_same<typename function_traits<T>::ret_type, promise_t>::value,
-            promise_t, pm_any_t>::type;
-    };
-
-    template<typename Func,
-        typename disable_if_arg<Func, pm_any_t>::type * = nullptr,
-        typename enable_if_return<Func, void>::type * = nullptr,
-        typename function_traits<Func>::non_empty_arg * = nullptr>
-    constexpr auto gen_any_callback(Func f) {
-        using func_t = callback_types<Func>;
-        return [f = std::forward<Func>(f)](pm_any_t v) mutable {
-            try {
-                f(any_cast<typename func_t::arg_type>(v));
-            } catch (bad_any_cast &e) { PROMISE_ERR_MISMATCH_TYPE; }
-        };
-    }
-
-    template<typename Func,
-        typename enable_if_arg<Func, pm_any_t>::type * = nullptr,
-        typename enable_if_return<Func, void>::type * = nullptr,
-        typename function_traits<Func>::non_empty_arg * = nullptr>
-    constexpr auto gen_any_callback(Func f) {
-        return [f = std::forward<Func>(f)](pm_any_t v) mutable {f(v);};
-    }
-
-    template<typename Func,
-        typename enable_if_return<Func, void>::type * = nullptr,
-        typename function_traits<Func>::empty_arg * = nullptr>
-    constexpr auto gen_any_callback(Func f) { return std::forward<Func>(f); }
-
-    template<typename Func,
-        typename enable_if_arg<Func, pm_any_t>::type * = nullptr,
-        typename disable_if_return<Func, void>::type * = nullptr,
-        typename function_traits<Func>::non_empty_arg * = nullptr>
-    constexpr auto gen_any_callback(Func f) {
-        using func_t = callback_types<Func>;
-        return [f = std::forward<Func>(f)](pm_any_t v) mutable {
-            return typename func_t::ret_type(f(v));
-        };
-    }
-
-    template<typename Func,
-        typename disable_if_arg<Func, pm_any_t>::type * = nullptr,
-        typename disable_if_return<Func, void>::type * = nullptr,
-        typename function_traits<Func>::non_empty_arg * = nullptr>
-    constexpr auto gen_any_callback(Func f) {
-        using func_t = callback_types<Func>;
-        return [f = std::forward<Func>(f)](pm_any_t v) mutable {
-            try {
-                return typename func_t::ret_type(
-                    f(any_cast<typename func_t::arg_type>(v)));
-            } catch (bad_any_cast &e) { PROMISE_ERR_MISMATCH_TYPE; }
-        };
-    }
-
-    template<typename Func,
-        typename disable_if_return<Func, void>::type * = nullptr,
-        typename function_traits<Func>::empty_arg * = nullptr>
-    constexpr auto gen_any_callback(Func f) {
-        using func_t = callback_types<Func>;
-        return [f = std::forward<Func>(f)]() mutable {
-            return typename func_t::ret_type(f());
-        };
-    }
-
-    template<typename FuncFulfilled>
-    inline promise_t promise_t::then(FuncFulfilled on_fulfilled) const {
-        return (*this)->then(gen_any_callback(std::forward<FuncFulfilled>(on_fulfilled)));
-    }
-
-    template<typename FuncFulfilled, typename FuncRejected>
-    inline promise_t promise_t::then(FuncFulfilled on_fulfilled,
-                                    FuncRejected on_rejected) const {
-        return (*this)->then(gen_any_callback(std::forward<FuncFulfilled>(on_fulfilled)),
-                            gen_any_callback(std::forward<FuncRejected>(on_rejected)));
-    }
-
-    template<typename FuncRejected>
-    inline promise_t promise_t::fail(FuncRejected on_rejected) const {
-        return (*this)->fail(gen_any_callback(std::forward<FuncRejected>(on_rejected)));
-    }
-}
-
-#endif
diff --git a/src/type.h b/src/type.h
deleted file mode 100644
index 4665979..0000000
--- a/src/type.h
+++ /dev/null
@@ -1,46 +0,0 @@
-#ifndef _HOTSTUFF_TYPE_H
-#define _HOTSTUFF_TYPE_H
-
-#include "salticidae/stream.h"
-#include "salticidae/type.h"
-#include "salticidae/util.h"
-
-namespace hotstuff {
-
-using salticidae::uint256_t;
-using salticidae::DataStream;
-using salticidae::htole;
-using salticidae::letoh;
-using salticidae::get_hex;
-using salticidae::from_hex;
-using salticidae::bytearray_t;
-
-inline std::string get_hex10(const uint256_t &x) {
-    return get_hex(x).substr(0, 10);
-}
-
-class HotStuffError: public salticidae::SalticidaeError {
-    public:
-    template<typename... Args>
-    HotStuffError(Args... args): salticidae::SalticidaeError(args...) {}
-};
-
-class HotStuffInvalidEntity: public HotStuffError {
-    public:
-    template<typename... Args>
-    HotStuffInvalidEntity(Args... args): HotStuffError(args...) {}
-};
-
-using salticidae::Serializable;
-
-class Cloneable {
-    public:
-    virtual ~Cloneable() = default;
-    virtual Cloneable *clone() = 0;
-};
-
-using ReplicaID = uint16_t;
-
-}
-
-#endif
diff --git a/src/util.cpp b/src/util.cpp
index dc509f1..bed6e5a 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -1,4 +1,4 @@
-#include "util.h"
+#include "hotstuff/util.h"
 
 namespace hotstuff {
 
diff --git a/src/util.h b/src/util.h
deleted file mode 100644
index 42c0135..0000000
--- a/src/util.h
+++ /dev/null
@@ -1,119 +0,0 @@
-#ifndef _HOTSTUFF_UTIL_H
-#define _HOTSTUFF_UTIL_H
-
-#include "salticidae/util.h"
-
-namespace hotstuff {
-
-class Logger: public salticidae::Logger {
-    public:
-    using salticidae::Logger::Logger;
-};
-
-extern Logger logger;
-
-#ifdef HOTSTUFF_DEBUG_LOG
-#define HOTSTUFF_NORMAL_LOG
-#define HOTSTUFF_ENABLE_LOG_DEBUG
-#endif
-
-#ifdef HOTSTUFF_NORMAL_LOG
-#define HOTSTUFF_ENABLE_LOG_INFO
-#define HOTSTUFF_ENABLE_LOG_WARN
-#endif
-
-#ifdef HOTSTUFF_ENABLE_LOG_INFO
-#define HOTSTUFF_LOG_INFO(...) hotstuff::logger.info(__VA_ARGS__)
-#else
-#define HOTSTUFF_LOG_INFO(...) ((void)0)
-#endif
-
-#ifdef HOTSTUFF_ENABLE_LOG_DEBUG
-#define HOTSTUFF_LOG_DEBUG(...) hotstuff::logger.debug(__VA_ARGS__)
-#else
-#define HOTSTUFF_LOG_DEBUG(...) ((void)0)
-#endif
-
-#ifdef HOTSTUFF_ENABLE_LOG_WARN
-#define HOTSTUFF_LOG_WARN(...) hotstuff::logger.warning(__VA_ARGS__)
-#else
-#define HOTSTUFF_LOG_WARN(...) ((void)0)
-#endif
-
-#define HOTSTUFF_LOG_ERROR(...) hotstuff::logger.error(__VA_ARGS__)
-
-#ifdef HOTSTUFF_ENABLE_BLK_PROFILE
-class BlockProfiler {
-    enum BlockState {
-        BLK_SEEN,
-        BLK_FETCH,
-        BLK_CC
-    };
-
-    struct BlockProfile {
-        bool is_local;          /* is the block proposed by the replica itself? */
-        BlockState state;
-        double hash_seen_time;  /* the first time to see block hash */
-        double full_fetch_time; /* the first time to get full block content */
-        double cc_time;         /* the time when it receives cc */
-        double commit_time;     /* the time when it commits */
-    };
-
-    std::unordered_map<const uint256, BlockProfile> blocks;
-    ElapsedTime timer;
-
-    public:
-    BlockProfiler() { timer.start(); }
-
-    auto rec_blk(const uint256 &blk_hash, bool is_local) {
-        auto it = blocks.find(blk_hash);
-        assert(it == blocks.end());
-        timer.stop(false);
-        return blocks.insert(std::make_pair(blk_hash,
-            BlockProfile{is_local, BLK_SEEN, timer.elapsed_sec, 0, 0, 0})).first;
-    }
-
-    void get_blk(const uint256 &blk_hash) {
-        auto it = blocks.find(blk_hash);
-        if (it == blocks.end())
-            it = rec_blk(blk_hash, false);
-        BlockProfile &blkp = it->second;
-        assert(blkp.state == BLK_SEEN);
-        timer.stop(false);
-        blkp.full_fetch_time = timer.elapsed_sec;
-        blkp.state = BLK_FETCH;
-    }
-
-    void have_cc(const uint256 &blk_hash) {
-        auto it = blocks.find(blk_hash);
-        assert(it != blocks.end());
-        BlockProfile &blkp = it->second;
-        assert(blkp.state == BLK_FETCH);
-        timer.stop(false);
-        blkp.polling_start_time = timer.elapsed_sec;
-        blkp.state = BLK_CC;
-    }
-
-    const char *decide_blk(const uint256 &blk_hash) {
-        static char buff[1024];
-        auto it = blocks.find(blk_hash);
-        assert(it != blocks.end());
-        BlockProfile &blkp = it->second;
-        assert(blkp.state == BLK_CC);
-        timer.stop(false);
-        blkp.commit_time = timer.elapsed_sec;
-        snprintf(buff, sizeof buff, "(%d,%.4f,%.4f,%.4f,%.4f,%.4f)",
-                blkp.is_local,
-                blkp.hash_seen_time, blkp.full_fetch_time,
-                blkp.polling_start_time, blkp.polling_end_time,
-                blkp.commit_time);
-        blocks.erase(it);
-        return buff;
-    }
-};
-
-#endif
-
-}
-
-#endif