Claude
34af6063b6
Several bugs found via deterministic simulation testing (500 seeds, 30s each): WAL format: Store full WALEntry on disk (including votes and checksum) instead of a separate WALEntryDisk. This eliminates the need to reconstruct transient vote bits after restart, and adds wal_update_entry() for persisting in-place vote modifications. Crash recovery: Restore 3-case startup logic (empty=normal, corrupt=recovery, clean=replay). Fix last_normal_view initialization on clean restart. Call adopt_view() after replay to reinitialize leader vote bits that may be stale if a crash interrupted wal_replace before the atomic rename. View change ordering: Move wal_replace before persist_state in process_begin_view so the on-disk log is always at least as recent as the persisted metadata. Reset votes on view_change_log entries before wal_replace in complete_view_change_and_become_primary and complete_recovery. View adoption: Add adopt_view() helper called from process_prepare and process_prepare_ok when a NORMAL node learns of a higher view. Updates last_normal_view and initializes leader vote bits. Invariant checker: Track node liveness across ticks (prev_alive[]) so min_commit monotonicity is correctly relaxed for nodes that just restarted. https://claude.ai/code/session_01X2b5VRntA7LM32kdN9tPAM
78 lines
2.5 KiB
C
78 lines
2.5 KiB
C
#ifndef WAL_INCLUDED
|
|
#define WAL_INCLUDED
|
|
|
|
#include "metadata.h"
|
|
#include "file_system.h"
|
|
#include "config.h"
|
|
|
|
typedef struct {
|
|
MetaOper oper;
|
|
uint32_t votes;
|
|
int view_number;
|
|
uint64_t client_id;
|
|
uint64_t request_id;
|
|
uint32_t checksum; // FNV-1a over all preceding fields
|
|
} WALEntry;
|
|
|
|
_Static_assert(NODE_LIMIT <= 32, "");
|
|
|
|
typedef struct {
|
|
int count;
|
|
int capacity;
|
|
WALEntry *entries;
|
|
Handle handle; // file handle to the WAL (0 = memory-only)
|
|
} WAL;
|
|
|
|
// Initialize an empty, memory-only WAL (no file backing).
|
|
void wal_init(WAL *wal);
|
|
|
|
// Initialize a WAL from an on-disk file. Recovers valid entries,
|
|
// discards partial/corrupted trailing entries. If was_truncated is
|
|
// non-NULL, *was_truncated is set to true when entries were discarded
|
|
// due to corruption (not just a partial trailing write).
|
|
int wal_init_from_file(WAL *wal, string file, bool *was_truncated);
|
|
|
|
// Initialize a WAL from network data (memory-only, no file).
|
|
int wal_init_from_network(WAL *wal, void *src, int num);
|
|
|
|
void wal_free(WAL *wal);
|
|
|
|
// Move ownership from src to dst. If dst is file-backed, the file
|
|
// is NOT affected; use wal_replace for atomic file replacement.
|
|
void wal_move(WAL *dst, WAL *src);
|
|
|
|
// Append an entry. If the WAL is file-backed, writes to disk and
|
|
// fsyncs before updating the in-memory buffer.
|
|
int wal_append(WAL *wal, WALEntry entry);
|
|
|
|
// Write a modified in-memory entry back to disk (recomputes checksum).
|
|
int wal_update_entry(WAL *wal, int idx);
|
|
|
|
// Truncate the WAL to new_count entries.
|
|
int wal_truncate(WAL *wal, int new_count);
|
|
|
|
// Atomically replace the WAL file contents with the given entries.
|
|
// Writes to a temporary file, fsyncs, then renames over the WAL.
|
|
// Updates the in-memory buffer and reopens the file handle.
|
|
int wal_replace(WAL *wal, WALEntry *entries, int count);
|
|
|
|
int wal_entry_count(WAL *wal);
|
|
WALEntry *wal_peek_entry(WAL *wal, int idx);
|
|
|
|
// Persistent view_number, last_normal_view and commit_index,
|
|
// analogous to raft's TermAndVote. Backed by a small file
|
|
// ("vsr.state") with a checksum for integrity.
|
|
typedef struct {
|
|
uint64_t view_number;
|
|
uint64_t last_normal_view;
|
|
int commit_index;
|
|
Handle handle;
|
|
} ViewAndCommit;
|
|
|
|
int view_and_commit_init(ViewAndCommit *vc, string file);
|
|
void view_and_commit_free(ViewAndCommit *vc);
|
|
int set_view_and_commit(ViewAndCommit *vc, uint64_t view_number,
|
|
uint64_t last_normal_view, int commit_index);
|
|
|
|
#endif // WAL_INCLUDED
|