Data binding startup improvement

This CL replaces how we map tags(string) to layout ids in the
generated DataBindingMapper class. Previously, we would create
a hashmap which was some unnecessary work in startup. The alternative
was using switch(string) but we did not want to require java 7.
This CL does what java 7's switch(string) would do thanks to the
well defined API of String.hashCode.

This CL also adds a method to DataBindingUtil to convert BR.ids
back to String for debugging purposes.

Bug: 22108735
Change-Id: I4b8ef816f4aac99b2963793dd46519b056ce4a30

1 files changed, 6 insertions, 0 deletions

diff --git a/compilerCommon/src/main/java/android/databinding/tool/util/Preconditions.java b/compilerCommon/src/main/java/android/databinding/tool/util/Preconditions.java
index f1a790cd..8041cd40 100644
--- a/compilerCommon/src/main/java/android/databinding/tool/util/Preconditions.java
+++ b/compilerCommon/src/main/java/android/databinding/tool/util/Preconditions.java
@@ -31,4 +31,10 @@ public class Preconditions {
             L.e(error, args);
         }
     }
+
+    public static void checkNull(Object value, String error, Object... args) {
+        if (value != null) {
+            L.e(error, args);
+        }
+    }
 }