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

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

@@ -2,8 +2,9 @@ use bson::{doc, Bson, Document};
 use rustdb_index::IndexEngine;
 use tracing::debug;
 
-use crate::context::{CommandContext, CursorState};
+use crate::context::{CommandContext, ConnectionState, CursorState};
 use crate::error::{CommandError, CommandResult};
+use crate::transactions;
 
 /// Handle various admin / diagnostic / session / auth commands.
 pub async fn handle(
@@ -11,6 +12,7 @@ pub async fn handle(
     db: &str,
     ctx: &CommandContext,
     command_name: &str,
+    connection: &ConnectionState,
 ) -> CommandResult<Document> {
     match command_name {
         "ping" => Ok(doc! { "ok": 1.0 }),
@@ -24,13 +26,7 @@ pub async fn handle(
             "ok": 1.0,
         }),
 
-        "serverStatus" => Ok(doc! {
-            "host": "localhost",
-            "version": "7.0.0",
-            "process": "rustdb",
-            "uptime": ctx.start_time.elapsed().as_secs() as i64,
-            "ok": 1.0,
-        }),
+        "serverStatus" => handle_server_status(ctx),
 
         "hostInfo" => Ok(doc! {
             "system": {
@@ -90,13 +86,7 @@ pub async fn handle(
             "codeName": "CommandNotFound",
         }),
 
-        "connectionStatus" => Ok(doc! {
-            "authInfo": {
-                "authenticatedUsers": [],
-                "authenticatedUserRoles": [],
-            },
-            "ok": 1.0,
-        }),
+        "connectionStatus" => Ok(handle_connection_status(connection)),
 
         "createUser" => handle_create_user(cmd, db, ctx).await,
 
@@ -156,9 +146,9 @@ pub async fn handle(
             Ok(doc! { "ok": 1.0 })
         }
 
-        "commitTransaction" | "abortTransaction" => Err(CommandError::IllegalOperation(
-            "Transaction numbers are only allowed on a replica set member or mongos".into(),
-        )),
+        "commitTransaction" => transactions::commit_transaction_command(cmd, ctx).await,
+
+        "abortTransaction" => transactions::abort_transaction_command(cmd, ctx),
 
         // Auth stubs - accept silently.
         "saslStart" => Ok(doc! {
@@ -195,6 +185,72 @@ pub async fn handle(
     }
 }
 
+fn handle_server_status(ctx: &CommandContext) -> CommandResult<Document> {
+    let oplog_stats = ctx.oplog.stats();
+    Ok(doc! {
+        "host": "localhost",
+        "version": "7.0.0",
+        "process": "rustdb",
+        "uptime": ctx.start_time.elapsed().as_secs() as i64,
+        "connections": {
+            "current": 0_i32,
+            "available": i32::MAX,
+        },
+        "logicalSessionRecordCache": {
+            "activeSessionsCount": ctx.sessions.len() as i64,
+        },
+        "transactions": {
+            "currentActive": ctx.transactions.len() as i64,
+        },
+        "oplog": {
+            "currentSeq": oplog_stats.current_seq as i64,
+            "totalEntries": oplog_stats.total_entries as i64,
+            "oldestSeq": oplog_stats.oldest_seq as i64,
+            "entriesByOp": {
+                "insert": oplog_stats.inserts as i64,
+                "update": oplog_stats.updates as i64,
+                "delete": oplog_stats.deletes as i64,
+            },
+        },
+        "security": {
+            "authentication": ctx.auth.enabled(),
+            "users": ctx.auth.user_count() as i64,
+        },
+        "ok": 1.0,
+    })
+}
+
+fn handle_connection_status(connection: &ConnectionState) -> Document {
+    let authenticated_users: Vec<Bson> = connection
+        .authenticated_users
+        .iter()
+        .map(|user| {
+            Bson::Document(doc! {
+                "user": user.username.clone(),
+                "db": user.database.clone(),
+            })
+        })
+        .collect();
+
+    let authenticated_roles: Vec<Bson> = connection
+        .authenticated_users
+        .iter()
+        .flat_map(|user| {
+            user.roles
+                .iter()
+                .map(|role| Bson::Document(role_to_document(&user.database, role)))
+        })
+        .collect();
+
+    doc! {
+        "authInfo": {
+            "authenticatedUsers": authenticated_users,
+            "authenticatedUserRoles": authenticated_roles,
+        },
+        "ok": 1.0,
+    }
+}
+
 async fn handle_create_user(
     cmd: &Document,
     db: &str,