AAPT2

First checking of AAPT2. The individual phases of AAPT2 work, but there
are some missing pieces.

For early testing we are missing:
- Need to properly mark file references and include them in package
- Need to package into zip

Final AAPT for apps we are missing:
- Need to crush PNGs
- Need to parse 9-patches
- Need to validate all of AndroidManifest.xml
- Need to write align method to align resource tables for splits.

Final AAPT for apps + system we are missing:
- Need to handle overlays
- Need to store comments for R file
- Need to handle --shared-lib (dynamic references too).

New AAPT features coming:
- Need to import compiled libraries
    - Name mangling
    - R file generation for library code

Change-Id: I95f8a63581b81a1f424ae6fb2c373c883b72c18d
diff --git a/tools/aapt2/BigBuffer.cpp b/tools/aapt2/BigBuffer.cpp
new file mode 100644
index 0000000..8f57172
--- /dev/null
+++ b/tools/aapt2/BigBuffer.cpp
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "BigBuffer.h"
+
+#include <algorithm>
+#include <memory>
+#include <vector>
+
+namespace aapt {
+
+void* BigBuffer::nextBlockImpl(size_t size) {
+    if (!mBlocks.empty()) {
+        Block& block = mBlocks.back();
+        if (block.mBlockSize - block.size >= size) {
+            void* outBuffer = block.buffer.get() + block.size;
+            block.size += size;
+            mSize += size;
+            return outBuffer;
+        }
+    }
+
+    const size_t actualSize = std::max(mBlockSize, size);
+
+    Block block = {};
+
+    // Zero-allocate the block's buffer.
+    block.buffer = std::unique_ptr<uint8_t[]>(new uint8_t[actualSize]());
+    assert(block.buffer);
+
+    block.size = size;
+    block.mBlockSize = actualSize;
+
+    mBlocks.push_back(std::move(block));
+    mSize += size;
+    return mBlocks.back().buffer.get();
+}
+
+} // namespace aapt