feat(transactions): add single-node transaction support with session-aware reads, commits, aborts, and transaction metrics

rust/crates/rustdb-commands/src/handlers/delete_handler.rs

@@ -7,6 +7,7 @@ use tracing::debug;
 
 use crate::context::CommandContext;
 use crate::error::{CommandError, CommandResult};
+use crate::transactions;
 
 /// Handle the `delete` command.
 pub async fn handle(
@@ -36,6 +37,7 @@ pub async fn handle(
     );
 
     let ns_key = format!("{}.{}", db, coll);
+    let txn_id = transactions::active_transaction_id(ctx, cmd);
     let mut total_deleted: i32 = 0;
     let mut write_errors: Vec<Document> = Vec::new();
 
@@ -69,7 +71,7 @@ pub async fn handle(
             _ => 0, // default: delete all matches
         };
 
-        match delete_matching(db, coll, &ns_key, &filter, limit, ctx).await {
+        match delete_matching(db, coll, &ns_key, &filter, limit, ctx, txn_id.as_deref()).await {
             Ok(count) => {
                 total_deleted += count;
             }
@@ -114,7 +116,24 @@ async fn delete_matching(
     filter: &Document,
     limit: i32,
     ctx: &CommandContext,
+    txn_id: Option<&str>,
 ) -> Result<i32, CommandError> {
+    if let Some(txn_id) = txn_id {
+        let docs = transactions::load_transaction_docs(ctx, txn_id, db, coll).await?;
+        let matched = QueryMatcher::filter(&docs, filter);
+        let to_delete: &[Document] = if limit == 1 && !matched.is_empty() {
+            &matched[..1]
+        } else {
+            &matched
+        };
+
+        for doc in to_delete {
+            transactions::record_delete(ctx, txn_id, db, coll, doc.clone()).await?;
+        }
+
+        return Ok(to_delete.len() as i32);
+    }
+
     // Check if the collection exists; if not, nothing to delete.
     match ctx.storage.collection_exists(db, coll).await {
         Ok(false) => return Ok(0),