Merge "Suggest using SparseIntArray instead of SparseArray<Integer>"

3 files changed, 40 insertions, 3 deletions

diff --git a/lint/libs/lint_checks/src/com/android/tools/lint/checks/JavaPerformanceDetector.java b/lint/libs/lint_checks/src/com/android/tools/lint/checks/JavaPerformanceDetector.java
index fe3b713..34a697c 100644
--- a/lint/libs/lint_checks/src/com/android/tools/lint/checks/JavaPerformanceDetector.java
+++ b/lint/libs/lint_checks/src/com/android/tools/lint/checks/JavaPerformanceDetector.java
@@ -129,6 +129,7 @@ public class JavaPerformanceDetector extends Detector implements Detector.JavaSc
     private static final String DOUBLE = "Double";                          //$NON-NLS-1$
     private static final String FLOAT = "Float";                            //$NON-NLS-1$
     private static final String HASH_MAP = "HashMap";                       //$NON-NLS-1$
+    private static final String SPARSE_ARRAY = "SparseArray";               //$NON-NLS-1$
     private static final String CANVAS = "Canvas";                          //$NON-NLS-1$
     private static final String ON_DRAW = "onDraw";                         //$NON-NLS-1$
     private static final String ON_LAYOUT = "onLayout";                     //$NON-NLS-1$
@@ -199,6 +200,8 @@ public class JavaPerformanceDetector extends Detector implements Detector.JavaSc
                 // e.g. via Guava? This is a bit trickier since we need to infer the type
                 // arguments from the calling context.
                 if (typeName.equals(HASH_MAP)) {
+                    checkHashMap(node, reference);
+                } else if (typeName.equals(SPARSE_ARRAY)) {
                     checkSparseArray(node, reference);
                 }
             }
@@ -481,7 +484,7 @@ public class JavaPerformanceDetector extends Detector implements Detector.JavaSc
          * to a HashMap constructor call that is eligible for replacement by a
          * SparseArray call instead
          */
-        private void checkSparseArray(ConstructorInvocation node, TypeReference reference) {
+        private void checkHashMap(ConstructorInvocation node, TypeReference reference) {
             // reference.hasTypeArguments returns false where it should not
             StrictListAccessor<TypeReference, TypeReference> types = reference.getTypeArguments();
             if (types != null && types.size() == 2) {
@@ -510,6 +513,28 @@ public class JavaPerformanceDetector extends Detector implements Detector.JavaSc
                 }
             }
         }
+
+        private void checkSparseArray(ConstructorInvocation node, TypeReference reference) {
+            // reference.hasTypeArguments returns false where it should not
+            StrictListAccessor<TypeReference, TypeReference> types = reference.getTypeArguments();
+            if (types != null && types.size() == 1) {
+                TypeReference first = types.first();
+                String valueType = first.getTypeName();
+                if (valueType.equals(INTEGER)) {
+                    mContext.report(USE_SPARSEARRAY, node, mContext.getLocation(node),
+                        "Use new SparseIntArray(...) instead for better performance",
+                        null);
+                } else if (valueType.equals(BOOLEAN)) {
+                    mContext.report(USE_SPARSEARRAY, node, mContext.getLocation(node),
+                            "Use new SparseBooleanArray(...) instead for better performance",
+                            null);
+                } else if (valueType.equals(LONG) && mContext.getProject().getMinSdk() >= 17) {
+                    mContext.report(USE_SPARSEARRAY, node, mContext.getLocation(node),
+                            "Use new SparseLongArray(...) instead for better performance",
+                            null);
+                }
+            }
+        }
     }
 
     /** Visitor which records variable names assigned into */
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/JavaPerformanceDetectorTest.java b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/JavaPerformanceDetectorTest.java
index 1d2974c..9705dff 100644
--- a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/JavaPerformanceDetectorTest.java
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/JavaPerformanceDetectorTest.java
@@ -63,6 +63,12 @@ public class JavaPerformanceDetectorTest extends AbstractCheckTest {
             "src/test/pkg/JavaPerformanceTest.java:74: Warning: Use new SparseIntArray(...) instead for better performance [UseSparseArrays]\n" +
             "        Map<Integer, Integer> myIntMap = new java.util.HashMap<Integer, Integer>();\n" +
             "                                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n" +
+            "src/test/pkg/JavaPerformanceTest.java:190: Warning: Use new SparseIntArray(...) instead for better performance [UseSparseArrays]\n" +
+            "        new SparseArray<Integer>(); // Use SparseIntArray instead\n" +
+            "        ~~~~~~~~~~~~~~~~~~~~~~~~~~\n" +
+            "src/test/pkg/JavaPerformanceTest.java:192: Warning: Use new SparseBooleanArray(...) instead for better performance [UseSparseArrays]\n" +
+            "        new SparseArray<Boolean>(); // Use SparseBooleanArray instead\n" +
+            "        ~~~~~~~~~~~~~~~~~~~~~~~~~~\n" +
             "src/test/pkg/JavaPerformanceTest.java:33: Warning: Use Integer.valueOf(5) instead [UseValueOf]\n" +
             "        Integer i = new Integer(5);\n" +
             "                    ~~~~~~~~~~~~~~\n" +
@@ -84,8 +90,7 @@ public class JavaPerformanceDetectorTest extends AbstractCheckTest {
             "src/test/pkg/JavaPerformanceTest.java:150: Warning: Use Double.valueOf(1.0) instead [UseValueOf]\n" +
             "        Double d1 = new Double(1.0);\n" +
             "                    ~~~~~~~~~~~~~~~\n" +
-            "0 errors, 19 warnings\n" +
-            "",
+            "0 errors, 21 warnings\n",
 
             lintProject("src/test/pkg/JavaPerformanceTest.java.txt=>" +
                     "src/test/pkg/JavaPerformanceTest.java"));
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/src/test/pkg/JavaPerformanceTest.java.txt b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/src/test/pkg/JavaPerformanceTest.java.txt
index 55834ec..a8caccb 100644
--- a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/src/test/pkg/JavaPerformanceTest.java.txt
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/src/test/pkg/JavaPerformanceTest.java.txt
@@ -185,4 +185,11 @@ public class JavaPerformanceTest extends Button {
         if ((shader == null) || (lastWidth != getWidth()) || (lastHeight != getHeight())) {
         }
     }
+
+    public void inefficientSparseArray() {
+        new SparseArray<Integer>(); // Use SparseIntArray instead
+        new SparseArray<Long>();    // Use SparseLongArray instead
+        new SparseArray<Boolean>(); // Use SparseBooleanArray instead
+        new SparseArray<Object>();  // OK
+    }
 }