Implement extended file open modes on JVM

Raku · Oct 5, 2015 · 09ae178 · 09ae178
1 parent 72b284c
commit 09ae178
Showing 1 changed file with 40 additions and 15 deletions.
diff --git a/src/vm/jvm/runtime/org/perl6/nqp/io/FileHandle.java b/src/vm/jvm/runtime/org/perl6/nqp/io/FileHandle.java
@@ -4,8 +4,11 @@
 import java.io.IOException;
 import java.nio.channels.FileChannel;
 import java.nio.charset.Charset;
+import java.nio.file.OpenOption;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
+import java.util.ArrayList;
+import java.util.List;
 
 import org.perl6.nqp.runtime.ExceptionHandling;
 import org.perl6.nqp.runtime.ThreadContext;
@@ -15,25 +18,47 @@ public class FileHandle extends SyncHandle implements IIOSeekable {
     FileChannel fc;
     protected boolean eof = false;
 
+    public static OpenOption[] resolveOpenMode(String mode) {
+        if(mode.length() == 0)
+            return null;
+
+        int pos = 0;
+        List<OpenOption> opts = new ArrayList<OpenOption>();
+
+        switch (mode.charAt(pos++)) {
+            case 'r': opts.add(StandardOpenOption.READ); break;
+            case '-': opts.add(StandardOpenOption.WRITE); break;
+            case '+': opts.add(StandardOpenOption.READ);
+                      opts.add(StandardOpenOption.WRITE); break;
+
+            /* legacy alias for "-c" or "-ct" if by itself */
+            case 'w': opts.add(StandardOpenOption.WRITE);
+                      opts.add(StandardOpenOption.CREATE);
+                      if(pos == mode.length())
+                          opts.add(StandardOpenOption.TRUNCATE_EXISTING);
+                      break;
+
+            default : return null;
+        }
+
+        while (pos < mode.length()) switch (mode.charAt(pos++)) {
+            case 'a': opts.add(StandardOpenOption.APPEND); break;
+            case 'c': opts.add(StandardOpenOption.CREATE); break;
+            case 't': opts.add(StandardOpenOption.TRUNCATE_EXISTING); break;
+            case 'x': opts.add(StandardOpenOption.CREATE_NEW); break;
+            default : return null;
+        }
+
+        return opts.toArray(new OpenOption[opts.size()]);
+    }
+
     public FileHandle(ThreadContext tc, String filename, String mode) {
         try {
             Path p = new File(filename).toPath();
-            if (mode.equals("r")) {
-                fc = FileChannel.open(p, StandardOpenOption.READ);
-            }
-            else if (mode.equals("w")) {
-                fc = FileChannel.open(p, StandardOpenOption.WRITE,
-                                           StandardOpenOption.CREATE,
-                                           StandardOpenOption.TRUNCATE_EXISTING);
-            }
-            else if (mode.equals("wa")) {
-                fc = FileChannel.open(p, StandardOpenOption.WRITE,
-                                           StandardOpenOption.CREATE,
-                                           StandardOpenOption.APPEND);
-            }
-            else {
+            OpenOption[] opts = resolveOpenMode(mode);
+            if(opts == null)
                 ExceptionHandling.dieInternal(tc, "Unhandled file open mode '" + mode + "'");
-            }
+            fc = FileChannel.open(p, opts);
             chan = fc;
             setEncoding(tc, Charset.forName("UTF-8"));
         } catch (IOException e) {