feat(grpc): can set buffer config on monitor open

Ref: arduino/pluggable-monitor-protocol-handler#33
Signed-off-by: dankeboy36 <dankeboy36@gmail.com>

Author: dankeboy36

commands/service_monitor.go

@@ -20,6 +20,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strconv"
 	"sync/atomic"
 
 	"github.com/arduino/arduino-cli/commands/cmderrors"
@@ -95,6 +96,38 @@ func (s *monitorPipeClient) Close() error {
 	return nil
 }
 
+// configurer is the minimal subset of the monitor used to apply settings.
+type configurer interface {
+	Configure(parameterName, value string) error
+}
+
+// applyBufferConfig translates the gRPC buffer config into pluggable-monitor CONFIGURE calls.
+func applyBufferConfig(c configurer, cfg *rpc.MonitorBufferConfig) {
+	if cfg == nil {
+		return
+	}
+	if v := cfg.GetHighWaterMarkBytes(); v > 0 {
+		_ = c.Configure("_buffer.hwm", strconv.Itoa(int(v)))
+	}
+	// Interval (0 disables)
+	_ = c.Configure("_buffer.interval_ms", strconv.Itoa(int(cfg.GetFlushIntervalMs())))
+	// Line buffering
+	_ = c.Configure("_buffer.line", strconv.FormatBool(cfg.GetLineBuffering()))
+	// Queue capacity
+	if v := cfg.GetFlushQueueCapacity(); v > 0 {
+		_ = c.Configure("_buffer.queue", strconv.Itoa(int(v)))
+	}
+	// Overflow strategy (default to drop if unspecified)
+	switch cfg.GetOverflowStrategy() {
+	case rpc.BufferOverflowStrategy_BUFFER_OVERFLOW_STRATEGY_WAIT:
+		_ = c.Configure("_buffer.overflow", "wait")
+	default: // unspecified or drop
+		_ = c.Configure("_buffer.overflow", "drop")
+	}
+	// Bounded wait for overflow (ms)
+	_ = c.Configure("_buffer.overflow_wait_ms", strconv.Itoa(int(cfg.GetOverflowWaitMs())))
+}
+
 // MonitorServerToReadWriteCloser creates a monitor server that proxies the data to a ReadWriteCloser.
 // The server is returned along with the ReadWriteCloser that can be used to send and receive data
 // to the server. The MonitorPortOpenRequest is used to configure the monitor.
@@ -148,6 +181,7 @@ func (s *arduinoCoreServerImpl) Monitor(stream rpc.ArduinoCoreService_MonitorSer
 	for setting, value := range boardSettings.AsMap() {
 		monitor.Configure(setting, value)
 	}
+	applyBufferConfig(monitor, openReq.GetBufferConfig())
 	monitorIO, err := monitor.Open(openReq.GetPort().GetAddress(), openReq.GetPort().GetProtocol())
 	if err != nil {
 		monitor.Quit()
@@ -165,7 +199,7 @@ func (s *arduinoCoreServerImpl) Monitor(stream rpc.ArduinoCoreService_MonitorSer
 
 	ctx, cancel := context.WithCancel(stream.Context())
 	gracefulCloseInitiated := &atomic.Bool{}
-	gracefuleCloseCtx, gracefulCloseCancel := context.WithCancel(context.Background())
+	gracefulCloseCtx, gracefulCloseCancel := context.WithCancel(context.Background())
 
 	// gRPC stream receiver (gRPC data -> monitor, config, close)
 	go func() {
@@ -230,7 +264,7 @@ func (s *arduinoCoreServerImpl) Monitor(stream rpc.ArduinoCoreService_MonitorSer
 	<-ctx.Done()
 	if gracefulCloseInitiated.Load() {
 		// Port closing has been initiated in the receiver
-		<-gracefuleCloseCtx.Done()
+		<-gracefulCloseCtx.Done()
 	} else {
 		monitorClose()
 	}

commands/service_monitor_test.go

@@ -0,0 +1,101 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2025 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to license@arduino.cc.
+
+package commands
+
+import (
+	"testing"
+
+	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
+)
+
+type fakeConfigurer struct{ calls [][2]string }
+
+func (f *fakeConfigurer) Configure(k, v string) error {
+	f.calls = append(f.calls, [2]string{k, v})
+	return nil
+}
+
+func haveCall(calls [][2]string, k, v string) bool {
+	for _, kv := range calls {
+		if kv[0] == k && kv[1] == v {
+			return true
+		}
+	}
+	return false
+}
+
+// Test that we correctly read all buffer_config fields from the gRPC request
+// and emit the expected CONFIGURE _buffer.* key/value pairs.
+func Test_applyBufferConfig_AllFields(t *testing.T) {
+	f := &fakeConfigurer{}
+	cfg := &rpc.MonitorBufferConfig{
+		HighWaterMarkBytes: 64,
+		FlushIntervalMs:    16,
+		LineBuffering:      true,
+		FlushQueueCapacity: 256,
+		OverflowStrategy:   rpc.BufferOverflowStrategy_BUFFER_OVERFLOW_STRATEGY_WAIT,
+		OverflowWaitMs:     50,
+	}
+	applyBufferConfig(f, cfg)
+
+	want := map[string]string{
+		"_buffer.hwm":              "64",
+		"_buffer.interval_ms":      "16",
+		"_buffer.line":             "true",
+		"_buffer.queue":            "256",
+		"_buffer.overflow":         "wait",
+		"_buffer.overflow_wait_ms": "50",
+	}
+	for k, v := range want {
+		if !haveCall(f.calls, k, v) {
+			t.Fatalf("missing or wrong CONFIGURE %s=%s; calls=%v", k, v, f.calls)
+		}
+	}
+}
+
+// Test that zeros/defaults are handled as intended: we still emit interval/line/overflow,
+// default overflow to 'drop', and omit hwm/queue when zero.
+func Test_applyBufferConfig_DefaultsAndZeros(t *testing.T) {
+	f := &fakeConfigurer{}
+	cfg := &rpc.MonitorBufferConfig{ // zeros/unset
+		HighWaterMarkBytes: 0,
+		FlushIntervalMs:    0,
+		LineBuffering:      false,
+		FlushQueueCapacity: 0,
+		OverflowStrategy:   rpc.BufferOverflowStrategy_BUFFER_OVERFLOW_STRATEGY_UNSPECIFIED,
+		OverflowWaitMs:     0,
+	}
+	applyBufferConfig(f, cfg)
+
+	expects := map[string]string{
+		"_buffer.interval_ms":      "0",
+		"_buffer.line":             "false",
+		"_buffer.overflow":         "drop",
+		"_buffer.overflow_wait_ms": "0",
+	}
+	for k, v := range expects {
+		if !haveCall(f.calls, k, v) {
+			t.Fatalf("expected CONFIGURE %s=%s not found; calls=%v", k, v, f.calls)
+		}
+	}
+	for _, dis := range []string{"_buffer.hwm", "_buffer.queue"} {
+		for _, kv := range f.calls {
+			if kv[0] == dis {
+				t.Fatalf("did not expect CONFIGURE for %s when value is zero", dis)
+			}
+		}
+	}
+}

internal/locales/locale.go

@@ -54,9 +54,9 @@ func findMatchingLanguage(language string, supportedLocales []string) string {
 }
 
 func findMatchingLocale(locale string, supportedLocales []string) string {
-	for _, suportedLocale := range supportedLocales {
-		if locale == suportedLocale {
-			return suportedLocale
+	for _, supportedLocale := range supportedLocales {
+		if locale == supportedLocale {
+			return supportedLocale
 		}
 	}
 

rpc/cc/arduino/cli/commands/v1/commands.pb.go

@@ -161,7 +161,7 @@ service ArduinoCoreService {
   // Start a debug session and communicate with the debugger tool.
   rpc Debug(stream DebugRequest) returns (stream DebugResponse) {}
 
-  // Determine if debugging is suported given a specific configuration.
+  // Determine if debugging is supported given a specific configuration.
   rpc IsDebugSupported(IsDebugSupportedRequest) returns (IsDebugSupportedResponse) {}
 
   // Query the debugger information given a specific configuration.
@@ -336,7 +336,7 @@ message NewSketchRequest {
   // Default Sketchbook directory "directories.User" is used if sketch_dir is
   // empty.
   string sketch_dir = 3;
-  // Specificies if an existing .ino sketch should be overwritten.
+  // Specifies if an existing .ino sketch should be overwritten.
   bool overwrite = 4;
 
   reserved 1;
@@ -387,7 +387,7 @@ message SetSketchDefaultsRequest {
 }
 
 message SetSketchDefaultsResponse {
-  // The value of default_fqnn that has been written in project file
+  // The value of default_fqbn that has been written in project file
   // (sketch.yaml).
   string default_fqbn = 1;
   // The value of default_port that has been written in project file

rpc/cc/arduino/cli/commands/v1/commands.proto

@@ -155,7 +155,7 @@ message LibraryResolveDependenciesRequest {
   // The version of the library to check dependencies of. If no version is
   // specified, dependencies of the newest version will be listed.
   string version = 3;
-  // If true the computed solution will try to keep exising libraries
+  // If true the computed solution will try to keep existing libraries
   // at their current version.
   bool do_not_update_installed_libraries = 4;
 }