diff --git a/libs/androidfw/BigBufferStream.cpp b/libs/androidfw/BigBufferStream.cpp
new file mode 100644
index 0000000..f18199c
--- /dev/null
+++ b/libs/androidfw/BigBufferStream.cpp
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2017 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 "androidfw/BigBufferStream.h"
+
+#include <algorithm>
+
+namespace android {
+
+//
+// BigBufferInputStream
+//
+
+bool BigBufferInputStream::Next(const void** data, size_t* size) {
+  if (iter_ == buffer_->end()) {
+    return false;
+  }
+
+  if (offset_ == iter_->size) {
+    ++iter_;
+    if (iter_ == buffer_->end()) {
+      return false;
+    }
+    offset_ = 0;
+  }
+
+  *data = iter_->buffer.get() + offset_;
+  *size = iter_->size - offset_;
+  bytes_read_ += iter_->size - offset_;
+  offset_ = iter_->size;
+  return true;
+}
+
+void BigBufferInputStream::BackUp(size_t count) {
+  if (count > offset_) {
+    bytes_read_ -= offset_;
+    offset_ = 0;
+  } else {
+    offset_ -= count;
+    bytes_read_ -= count;
+  }
+}
+
+bool BigBufferInputStream::CanRewind() const {
+  return true;
+}
+
+bool BigBufferInputStream::Rewind() {
+  iter_ = buffer_->begin();
+  offset_ = 0;
+  bytes_read_ = 0;
+  return true;
+}
+
+size_t BigBufferInputStream::ByteCount() const {
+  return bytes_read_;
+}
+
+bool BigBufferInputStream::HadError() const {
+  return false;
+}
+
+size_t BigBufferInputStream::TotalSize() const {
+  return buffer_->size();
+}
+
+bool BigBufferInputStream::ReadFullyAtOffset(void* data, size_t byte_count, off64_t offset) {
+  if (byte_count == 0) {
+    return true;
+  }
+  if (offset < 0) {
+    return false;
+  }
+  if (offset > std::numeric_limits<off64_t>::max() - byte_count) {
+    return false;
+  }
+  if (offset + byte_count > buffer_->size()) {
+    return false;
+  }
+  auto p = reinterpret_cast<uint8_t*>(data);
+  for (auto iter = buffer_->begin(); iter != buffer_->end() && byte_count > 0; ++iter) {
+    if (offset < iter->size) {
+      size_t to_read = std::min(byte_count, (size_t)(iter->size - offset));
+      memcpy(p, iter->buffer.get() + offset, to_read);
+      byte_count -= to_read;
+      p += to_read;
+      offset = 0;
+    } else {
+      offset -= iter->size;
+    }
+  }
+  return byte_count == 0;
+}
+
+//
+// BigBufferOutputStream
+//
+
+bool BigBufferOutputStream::Next(void** data, size_t* size) {
+  *data = buffer_->NextBlock(size);
+  return true;
+}
+
+void BigBufferOutputStream::BackUp(size_t count) {
+  buffer_->BackUp(count);
+}
+
+size_t BigBufferOutputStream::ByteCount() const {
+  return buffer_->size();
+}
+
+bool BigBufferOutputStream::HadError() const {
+  return false;
+}
+
+}  // namespace android