RUST-270 Make command monitoring lazy (#114)

Author: saghm

src/client/executor.rs

@@ -114,22 +114,24 @@ impl Client {
         let connection_info = connection.info();
         let request_id = crate::cmap::conn::next_request_id();
 
-        let should_redact = REDACTED_COMMANDS.contains(cmd.name.to_lowercase().as_str());
-
-        let command_body = if should_redact {
-            Document::new()
-        } else {
-            cmd.body.clone()
-        };
-        let command_started_event = CommandStartedEvent {
-            command: command_body,
-            db: cmd.target_db.clone(),
-            command_name: cmd.name.clone(),
-            request_id,
-            connection: connection_info.clone(),
-        };
-
-        self.send_command_started_event(command_started_event);
+        self.emit_command_event(|handler| {
+            let should_redact = REDACTED_COMMANDS.contains(cmd.name.to_lowercase().as_str());
+
+            let command_body = if should_redact {
+                Document::new()
+            } else {
+                cmd.body.clone()
+            };
+            let command_started_event = CommandStartedEvent {
+                command: command_body,
+                db: cmd.target_db.clone(),
+                command_name: cmd.name.clone(),
+                request_id,
+                connection: connection_info.clone(),
+            };
+
+            handler.handle_command_started_event(command_started_event);
+        });
 
         let start_time = PreciseTime::now();
 
@@ -148,31 +150,39 @@ impl Client {
 
         match response_result {
             Err(error) => {
-                let command_failed_event = CommandFailedEvent {
-                    duration,
-                    command_name: cmd.name,
-                    failure: error.clone(),
-                    request_id,
-                    connection: connection_info,
-                };
-                self.send_command_failed_event(command_failed_event);
+                self.emit_command_event(|handler| {
+                    let command_failed_event = CommandFailedEvent {
+                        duration,
+                        command_name: cmd.name,
+                        failure: error.clone(),
+                        request_id,
+                        connection: connection_info,
+                    };
+
+                    handler.handle_command_failed_event(command_failed_event);
+                });
                 Err(error)
             }
             Ok(response) => {
-                let reply = if should_redact {
-                    Document::new()
-                } else {
-                    response.raw_response.clone()
-                };
-
-                let command_succeeded_event = CommandSucceededEvent {
-                    duration,
-                    reply,
-                    command_name: cmd.name.clone(),
-                    request_id,
-                    connection: connection_info,
-                };
-                self.send_command_succeeded_event(command_succeeded_event);
+                self.emit_command_event(|handler| {
+                    let should_redact =
+                        REDACTED_COMMANDS.contains(cmd.name.to_lowercase().as_str());
+
+                    let reply = if should_redact {
+                        Document::new()
+                    } else {
+                        response.raw_response.clone()
+                    };
+
+                    let command_succeeded_event = CommandSucceededEvent {
+                        duration,
+                        reply,
+                        command_name: cmd.name.clone(),
+                        request_id,
+                        connection: connection_info,
+                    };
+                    handler.handle_command_succeeded_event(command_succeeded_event);
+                });
                 op.handle_response(response)
             }
         }

src/client/mod.rs

@@ -16,12 +16,7 @@ use crate::{
     concern::{ReadConcern, WriteConcern},
     db::Database,
     error::{ErrorKind, Result},
-    event::command::{
-        CommandEventHandler,
-        CommandFailedEvent,
-        CommandStartedEvent,
-        CommandSucceededEvent,
-    },
+    event::command::CommandEventHandler,
     operation::ListDatabases,
     options::{ClientOptions, DatabaseOptions},
     sdam::{Server, Topology, TopologyUpdateCondvar},
@@ -98,7 +93,7 @@ impl Client {
         Ok(Self { inner })
     }
 
-    fn emit_command_event(&self, emit: impl FnOnce(&Arc<dyn CommandEventHandler>)) {
+    pub(crate) fn emit_command_event(&self, emit: impl FnOnce(&Arc<dyn CommandEventHandler>)) {
         if let Some(ref handler) = self.inner.options.command_event_handler {
             emit(handler);
         }
@@ -166,18 +161,6 @@ impl Client {
         }
     }
 
-    pub(crate) fn send_command_started_event(&self, event: CommandStartedEvent) {
-        self.emit_command_event(|handler| handler.handle_command_started_event(event.clone()));
-    }
-
-    pub(crate) fn send_command_succeeded_event(&self, event: CommandSucceededEvent) {
-        self.emit_command_event(|handler| handler.handle_command_succeeded_event(event.clone()));
-    }
-
-    pub(crate) fn send_command_failed_event(&self, event: CommandFailedEvent) {
-        self.emit_command_event(|handler| handler.handle_command_failed_event(event.clone()));
-    }
-
     fn topology(&self) -> Arc<RwLock<Topology>> {
         self.inner.topology.clone()
     }