Merge pull request #1442 from Lorak-mmk/prepared-statement-optimization

PreparedStatement: put id and lwt in shared state

Author: Lorak-mmk

.github/workflows/book.yml

@@ -31,6 +31,11 @@ jobs:
       with:
         # We can't use cache here, or mdbook will complain about multiple candidates for dependency.
         cache: false
+    # This is a workaround for https://github.com/actions-rust-lang/setup-rust-toolchain/issues/79
+    # and https://github.com/rust-lang/mdBook/issues/2501
+    # When either mdbook or setup-rust-toolchain fix the issue, we can remove this.
+    - name: Set default toolchain globally
+      run: rustup default stable
     - name: Install mdbook
       uses: taiki-e/install-action@v2
       with:

scylla/src/statement/prepared.rs

@@ -96,32 +96,31 @@ use crate::routing::partitioner::{Partitioner, PartitionerHasher, PartitionerNam
 pub struct PreparedStatement {
     pub(crate) config: StatementConfig,
     /// Tracing IDs of all queries used to prepare this statement.
+    // TODO(2.0): Unpub this, move this to PreparedStatementSharedData, and expose a getter.
     pub prepare_tracing_ids: Vec<Uuid>,
 
-    id: Bytes,
     shared: Arc<PreparedStatementSharedData>,
     page_size: PageSize,
     partitioner_name: PartitionerName,
-    is_confirmed_lwt: bool,
 }
 
 #[derive(Debug)]
 struct PreparedStatementSharedData {
+    id: Bytes,
     metadata: PreparedMetadata,
     result_metadata: Arc<ResultMetadata<'static>>,
     statement: String,
+    is_confirmed_lwt: bool,
 }
 
 impl Clone for PreparedStatement {
     fn clone(&self) -> Self {
         Self {
             config: self.config.clone(),
             prepare_tracing_ids: Vec::new(),
-            id: self.id.clone(),
             shared: self.shared.clone(),
             page_size: self.page_size,
             partitioner_name: self.partitioner_name.clone(),
-            is_confirmed_lwt: self.is_confirmed_lwt,
         }
     }
 }
@@ -137,23 +136,23 @@ impl PreparedStatement {
         config: StatementConfig,
     ) -> Self {
         Self {
-            id,
             shared: Arc::new(PreparedStatementSharedData {
+                id,
                 metadata,
                 result_metadata,
                 statement,
+                is_confirmed_lwt: is_lwt,
             }),
             prepare_tracing_ids: Vec::new(),
             page_size,
-            config,
             partitioner_name: Default::default(),
-            is_confirmed_lwt: is_lwt,
+            config,
         }
     }
 
     /// Retrieves the ID of this prepared statement.
     pub fn get_id(&self) -> &Bytes {
-        &self.id
+        &self.shared.id
     }
 
     /// Retrieves the statement string of this prepared statement.
@@ -200,7 +199,7 @@ impl PreparedStatement {
     /// Note: this a Scylla-specific optimisation. Therefore, the result
     /// will be always false for Cassandra.
     pub fn is_confirmed_lwt(&self) -> bool {
-        self.is_confirmed_lwt
+        self.shared.is_confirmed_lwt
     }
 
     /// Computes the partition key of the target table from given values —