Extension overhaul.

- Get rid of TypeLiteral<T>. It was introduced to read the component
  type of a List<T> at runtime. But we use arrays everywhere else,
  and we can always read the component type of an array type at
  runtime.
- Properly read/write "minor" types (e.g. sint32, sfixed32). The old
  implementation could only read/write data as the "typical" types
  (one per Java type), e.g. java.lang.Integer -> int32, java.lang.Long
  -> int64. So if e.g. an extension specifies sfixed32 as the type, it
  would be read/written in the totally incompatible int32 format.
- Properly serialize repeated packed fields. The old implementation
  doesn't do packed serialization. As an added bonus, and to be more
  aligned with the rest of protobuf nano / main, repeated packable
  extensions can deserialize both packed and non-packed data.
- Split Extension class into a hierarchy so under typical usage a
  large chunk of code dealing with primitive type extensions can be
  removed by ProGuard.

Bug: https://code.google.com/p/android/issues/detail?id=62586
Change-Id: I0d692f35cc2a8ad3a5a1cb3ce001282b2356b041

1 files changed, 29 insertions, 0 deletions

diff --git a/src/google/protobuf/unittest_extension_packed_nano.proto b/src/google/protobuf/unittest_extension_packed_nano.proto
new file mode 100644
index 0000000..3586de7
--- /dev/null
+++ b/src/google/protobuf/unittest_extension_packed_nano.proto
@@ -0,0 +1,29 @@
+syntax = "proto2";
+
+option java_multiple_files = true;
+option java_package = "com.google.protobuf.nano";
+
+import "google/protobuf/unittest_extension_nano.proto";
+
+// Must be compiled separately due to extension number reuse.
+// The reuse is deliberate, for testing wire compatibility.
+
+message PackedExtensions {
+  extend ExtendableMessage {
+    repeated int32    packed_int32    = 10 [ packed = true ];
+    repeated uint32   packed_uint32   = 11 [ packed = true ];
+    repeated sint32   packed_sint32   = 12 [ packed = true ];
+    repeated int64    packed_int64    = 13 [ packed = true ];
+    repeated uint64   packed_uint64   = 14 [ packed = true ];
+    repeated sint64   packed_sint64   = 15 [ packed = true ];
+    repeated fixed32  packed_fixed32  = 16 [ packed = true ];
+    repeated sfixed32 packed_sfixed32 = 17 [ packed = true ];
+    repeated fixed64  packed_fixed64  = 18 [ packed = true ];
+    repeated sfixed64 packed_sfixed64 = 19 [ packed = true ];
+    repeated bool     packed_bool     = 20 [ packed = true ];
+    repeated float    packed_float    = 21 [ packed = true ];
+    repeated double   packed_double   = 22 [ packed = true ];
+    repeated AnEnum   packed_enum     = 23 [ packed = true ];
+    // Non-packable types omitted.
+  }
+}