Refactor process builder code to be shared for sync and async

JAVA-3636

Author: jyemin

driver-async/src/main/com/mongodb/async/client/internal/CommandMarker.java

@@ -30,7 +30,8 @@
 
 import static com.mongodb.assertions.Assertions.notNull;
 import static com.mongodb.internal.capi.MongoCryptHelper.createMongocryptdClientSettings;
-import static com.mongodb.internal.capi.MongoCryptHelper.createMongocryptdSpawnArgs;
+import static com.mongodb.internal.capi.MongoCryptHelper.createProcessBuilder;
+import static com.mongodb.internal.capi.MongoCryptHelper.startProcess;
 
 @SuppressWarnings("UseOfProcessBuilder")
 class CommandMarker implements Closeable {
@@ -45,8 +46,8 @@ class CommandMarker implements Closeable {
         }
 
         if (!options.containsKey("mongocryptdBypassSpawn") || !((Boolean) options.get("mongocryptdBypassSpawn"))) {
-            processBuilder = new ProcessBuilder(createMongocryptdSpawnArgs(options));
-            startProcess();
+            processBuilder = createProcessBuilder(options);
+            startProcess(processBuilder);
         } else {
             processBuilder = null;
         }
@@ -106,18 +107,10 @@ private void runCommand(final String databaseName, final RawBsonDocument command
 
     private void startProcessAndContinue(final SingleResultCallback<Void> callback) {
         try {
-            startProcess();
+            startProcess(processBuilder);
             callback.onResult(null, null);
         } catch (Throwable t) {
             callback.onResult(null, t);
         }
     }
-
-    private void startProcess() {
-        try {
-            processBuilder.start();
-        } catch (Throwable t) {
-            throw new MongoClientException("Exception starting mongocryptd process. Is `mongocryptd` on the system path?", t);
-        }
-    }
 }

driver-core/src/main/com/mongodb/internal/capi/MongoCryptHelper.java

@@ -107,6 +107,19 @@ public void apply(final SocketSettings.Builder builder) {
                 .build();
     }
 
+    public static ProcessBuilder createProcessBuilder(final Map<String, Object> options) {
+        return new ProcessBuilder(createMongocryptdSpawnArgs(options));
+    }
+
+    public static void startProcess(final ProcessBuilder processBuilder) {
+        try {
+            processBuilder.redirectOutput(ProcessBuilder.Redirect.DISCARD);
+            processBuilder.start();
+        } catch (Throwable t) {
+            throw new MongoClientException("Exception starting mongocryptd process. Is `mongocryptd` on the system path?", t);
+        }
+    }
+
     private MongoCryptHelper() {
     }
 }

driver-sync/src/main/com/mongodb/client/internal/CommandMarker.java

@@ -26,12 +26,12 @@
 import org.bson.RawBsonDocument;
 
 import java.io.Closeable;
-import java.io.IOException;
 import java.util.Map;
 
 import static com.mongodb.assertions.Assertions.notNull;
 import static com.mongodb.internal.capi.MongoCryptHelper.createMongocryptdClientSettings;
-import static com.mongodb.internal.capi.MongoCryptHelper.createMongocryptdSpawnArgs;
+import static com.mongodb.internal.capi.MongoCryptHelper.createProcessBuilder;
+import static com.mongodb.internal.capi.MongoCryptHelper.startProcess;
 
 @SuppressWarnings("UseOfProcessBuilder")
 class CommandMarker implements Closeable {
@@ -46,8 +46,8 @@ class CommandMarker implements Closeable {
         }
 
         if (!options.containsKey("mongocryptdBypassSpawn") || !((Boolean) options.get("mongocryptdBypassSpawn"))) {
-            processBuilder = new ProcessBuilder(createMongocryptdSpawnArgs(options));
-            startProcess();
+                processBuilder = createProcessBuilder(options);
+                startProcess(processBuilder);
         } else {
             processBuilder = null;
         }
@@ -63,7 +63,7 @@ RawBsonDocument mark(final String databaseName, final RawBsonDocument command) {
                 if (processBuilder == null) {  // mongocryptdBypassSpawn=true
                     throw e;
                 }
-                startProcess();
+                    startProcess(processBuilder);
                 return executeCommand(databaseName, command);
             }
         } catch (MongoException e) {
@@ -85,14 +85,6 @@ private RawBsonDocument executeCommand(final String databaseName, final RawBsonD
                 .runCommand(markableCommand, RawBsonDocument.class);
     }
 
-    private void startProcess() {
-        try {
-            processBuilder.start();
-        } catch (IOException e) {
-            throw new MongoClientException("Exception starting mongocryptd process. Is `mongocryptd` on the system path?", e);
-        }
-    }
-
     private MongoClientException wrapInClientException(final MongoException e) {
         return new MongoClientException("Exception in encryption library: " + e.getMessage(), e);
     }