Version 0.8

raft/node.h

@@ -0,0 +1,146 @@
+#ifndef NODE_INCLUDED
+#define NODE_INCLUDED
+
+#include <lib/tcp.h>
+#include <lib/basic.h>
+#include <lib/message.h>
+
+#include "wal.h"
+#include "config.h"
+
+enum {
+    MESSAGE_TYPE_REQUEST_VOTE,
+    MESSAGE_TYPE_VOTED,
+    MESSAGE_TYPE_APPEND_ENTRIES,
+    MESSAGE_TYPE_APPENDED,
+    MESSAGE_TYPE_REQUEST,
+    MESSAGE_TYPE_REPLY,
+    MESSAGE_TYPE_REDIRECT,
+};
+
+typedef struct {
+    MessageHeader base;
+    uint64_t term;
+    int      sender_idx;
+    int      last_log_index;
+    uint64_t last_log_term;
+} RequestVoteMessage;
+
+typedef struct {
+    MessageHeader base;
+    uint64_t term;
+    uint8_t  value;
+} VotedMessage;
+
+typedef struct {
+    MessageHeader base;
+    uint64_t term;
+    int      leader_idx;
+    int      prev_log_index;
+    uint64_t prev_log_term;
+    int      leader_commit;
+    int      entry_count;
+    // Followed by: LogEntry entries[entry_count]
+} AppendEntriesMessage;
+
+typedef struct {
+    MessageHeader base;
+    int      sender_idx;
+    uint64_t term;
+    uint8_t  success;
+    int      match_index;
+} AppendedMessage;
+
+typedef struct {
+    MessageHeader base;
+    Operation oper;
+    uint64_t client_id;
+    uint64_t request_id;
+} RequestMessage;
+
+typedef struct {
+    MessageHeader base;
+    OperationResult result;
+} ReplyMessage;
+
+typedef struct {
+    MessageHeader base;
+    int leader_idx;
+} RedirectMessage;
+
+typedef struct {
+    uint64_t        client_id;
+    uint64_t        last_request_id;
+    OperationResult last_result;
+    bool            pending;
+    int             conn_tag;
+} ClientTableEntry;
+
+typedef struct {
+    int count;
+    int capacity;
+    ClientTableEntry *entries;
+} ClientTable;
+
+typedef enum {
+    ROLE_FOLLOWER,
+    ROLE_CANDIDATE,
+    ROLE_LEADER,
+} Role;
+
+typedef struct {
+
+    TCP tcp;
+    WAL wal;
+
+    Address self_addr;
+    Address node_addrs[NODE_LIMIT];
+    int     num_nodes;
+
+    Role role;
+
+    uint64_t term;
+    int      voted_for;
+    Handle   term_and_vote_handle;
+
+    // Index of the current leader
+    int leader_idx;
+
+    int commit_index;
+    int last_applied;
+
+    // When CANDIDATE
+    int votes_received;
+
+    // When LEADER
+    int next_indices[NODE_LIMIT];
+    int match_indices[NODE_LIMIT];
+
+    // Relative timeout in nanoseconds
+    uint64_t election_timeout;
+
+    // Last heartbeat time
+    uint64_t watchdog;
+
+    // Keep track of client request order to enforce
+    // linearizability
+    ClientTable client_table;
+    int next_client_tag;
+
+    // The state machine to be replicated
+    StateMachine state_machine;
+
+} NodeState;
+
+struct pollfd;
+
+int node_init(void *state, int argc, char **argv,
+    void **ctxs, struct pollfd *pdata, int pcap, int *pnum,
+    int *timeout);
+
+int node_tick(void *state, void **ctxs,
+    struct pollfd *pdata, int pcap, int *pnum, int *timeout);
+
+int node_free(void *state);
+
+#endif // NODE_INCLUDED