Ignore snapshot log if it matches current snapshot v1 APPLIED

Michael Bonfils: 1
 Ignore snapshot log if it matches current snapshot

 3 files changed, 19 insertions(+), 4 deletions(-)

[PATCH] Ignore snapshot log if it matches current snapshot Export this patch

Signed-off-by: Michael Bonfils <mbonfils@scaleway.com>
---
 internal.h | 11 ++++++++++-
 log.c      |  4 ++--
 snapshot.c |  8 +++++++-
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/internal.h b/internal.h
index 4815bef..d01147e 100644
--- a/internal.h
+++ b/internal.h
@@ -66,7 +66,16 @@ void libfloat_send_append_entries(libfloat_ctx_t *ctx, libfloat_node_t *node, bo
  */
 void libfloat_send_append_entries_to_all(libfloat_ctx_t *ctx);
 
-void libfloat_internal_snapshot_begin(libfloat_ctx_t *ctx);
+/*!
+ * \brief Start a snapshot
+ *
+ * \param[in] ctx libfloat context
+ * \param[in] id ID of log that trigger snapshot
+ * \param[in] term term of log
+ *
+ * \note snapshot will be ignored if current snapshot matches trigger log
+ */
+void libfloat_internal_snapshot_begin(libfloat_ctx_t *ctx, libfloat_entry_id_t id, libfloat_term_t term);
 
 #define DEBUG(c, s, ...) do {                      \
         if (c->debug != NULL)                      \
diff --git a/log.c b/log.c
index abd7cb1..bed02da 100644
--- a/log.c
+++ b/log.c
@@ -105,7 +105,7 @@ bool libfloat_add_log(libfloat_ctx_t *ctx, libfloat_commit_type_t commit_type, l
         ctx->snapshot_to_commit = entry->id;
 
         if (entry->data->type == LIBFLOAT_SNAPSHOT_LOG)
-            libfloat_internal_snapshot_begin(ctx);
+            libfloat_internal_snapshot_begin(ctx, entry->id, entry->term);
         return true;
     }
 
@@ -535,7 +535,7 @@ response:
             log->data->buf = ctx->malloc(log->data->len);
             memcpy(log->data->buf, req->entries[i]->data->buf, log->data->len);
 
-            libfloat_internal_snapshot_begin(ctx);
+            libfloat_internal_snapshot_begin(ctx, log->id, log->term);
         }
         else if (!ctx->is_snapshotting)
         {
diff --git a/snapshot.c b/snapshot.c
index dbc3859..4034018 100644
--- a/snapshot.c
+++ b/snapshot.c
@@ -108,7 +108,7 @@ static void libfloat_internal_snapshot_apply_log(libfloat_ctx_t *ctx)
     }
 }
 
-void libfloat_internal_snapshot_begin(libfloat_ctx_t *ctx)
+void libfloat_internal_snapshot_begin(libfloat_ctx_t *ctx, libfloat_entry_id_t id, libfloat_term_t term)
 {
     if (ctx->snapshot == NULL)
     {
@@ -118,6 +118,12 @@ void libfloat_internal_snapshot_begin(libfloat_ctx_t *ctx)
         return;
     }
 
+    if (id == ctx->persistent.snapshot.index + 1 && term == ctx->persistent.snapshot.term)
+    {
+        DEBUG(ctx, "libfloat_internal_snapshot_begin: A snapshot already exists with previous commit id, skip it");
+        return;
+    }
+
     /* First, let's block all writes and init variables */
     ctx->is_snapshotting = true;
     if (ctx->snapshot_to_commit < ctx->persistent.commit_index)
-- 
2.25.1

Louis Solofrizzo <louis@ne02ptzero.me>

4 months ago

LGTM

-- 
Louis Solofrizzo
> If you stick a stock of liquor in your locker,
> It is slick to stick a lock upon your stock.
> Or some joker who is slicker,
> Will trick you of your liquor,
> If you fail to lock your liquor with a lock.