Improve the type descriptor conversion in heap dump outputs

2 files changed, 84 insertions, 36 deletions

diff --git a/spark-common/src/main/java/me/lucko/spark/memory/HeapDump.java b/spark-common/src/main/java/me/lucko/spark/memory/HeapDump.java
index dc8bfec..4007bad 100644
--- a/spark-common/src/main/java/me/lucko/spark/memory/HeapDump.java
+++ b/spark-common/src/main/java/me/lucko/spark/memory/HeapDump.java
@@ -22,6 +22,8 @@ package me.lucko.spark.memory;
 
 import com.google.gson.stream.JsonWriter;
 
+import me.lucko.spark.util.TypeDescriptors;
+
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStreamWriter;
@@ -92,7 +94,7 @@ public class HeapDump {
                             Integer.parseInt(matcher.group(1)),
                             Integer.parseInt(matcher.group(2)),
                             Long.parseLong(matcher.group(3)),
-                            getFriendlyTypeName(matcher.group(4))
+                            TypeDescriptors.getJavaType(matcher.group(4))
                     );
                 })
                 .filter(Objects::nonNull)
@@ -134,41 +136,6 @@ public class HeapDump {
         return byteOut.toByteArray();
     }
 
-    private static String getPrimitiveTypeName(char character) {
-        switch (character) {
-            case 'B':
-                return "byte";
-            case 'C':
-                return "char";
-            case 'D':
-                return "double";
-            case 'F':
-                return "float";
-            case 'I':
-                return "int";
-            case 'J':
-                return "long";
-            case 'S':
-                return "short";
-            case 'V':
-                return "void";
-            case 'Z':
-                return "boolean";
-            default:
-                throw new IllegalArgumentException();
-        }
-    }
-
-    private static String getFriendlyTypeName(String internalDesc) {
-        if (internalDesc.length() == 2 && internalDesc.charAt(0) == '[') {
-            return getPrimitiveTypeName(internalDesc.charAt(1)) + " array";
-        }
-        if (internalDesc.startsWith("[L") && internalDesc.endsWith(";")) {
-            return internalDesc.substring(2, internalDesc.length() - 1) + " array";
-        }
-        return internalDesc;
-    }
-
     public static final class Entry {
         private final int order;
         private final int instances;
diff --git a/spark-common/src/main/java/me/lucko/spark/util/TypeDescriptors.java b/spark-common/src/main/java/me/lucko/spark/util/TypeDescriptors.java
new file mode 100644
index 0000000..20dbe17
--- /dev/null
+++ b/spark-common/src/main/java/me/lucko/spark/util/TypeDescriptors.java
@@ -0,0 +1,81 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.util;
+
+/**
+ * Utilities for working with Java type descriptors.
+ */
+public final class TypeDescriptors {
+
+    /**
+     * Returns the Java type corresponding to the given type descriptor.
+     *
+     * @param typeDescriptor a type descriptor.
+     * @return the Java type corresponding to the given type descriptor.
+     */
+    public static String getJavaType(String typeDescriptor) {
+        return getJavaType(typeDescriptor.toCharArray(), 0);
+    }
+
+    private static String getJavaType(char[] buf, int offset) {
+        int len;
+        switch (buf[offset]) {
+            case 'V':
+                return "void";
+            case 'Z':
+                return "boolean";
+            case 'C':
+                return "char";
+            case 'B':
+                return "byte";
+            case 'S':
+                return "short";
+            case 'I':
+                return "int";
+            case 'F':
+                return "float";
+            case 'J':
+                return "long";
+            case 'D':
+                return "double";
+            case '[': // array
+                len = 1;
+                while (buf[offset + len] == '[') {
+                    len++;
+                }
+
+                StringBuilder sb = new StringBuilder(getJavaType(buf, offset + len));
+                for (int i = len; i > 0; --i) {
+                    sb.append("[]");
+                }
+                return sb.toString();
+            case 'L': // object
+                len = 1;
+                while (buf[offset + len] != ';') {
+                    len++;
+                }
+                return new String(buf, offset + 1, len - 1);
+            default:
+                return new String(buf, offset, buf.length - offset);
+        }
+    }
+
+}