Move vector output stream to compiler.

Change-Id: Ia4c5edabb6be31a7d953c932b490ed2d89f941c1
diff --git a/compiler/vector_output_stream.h b/compiler/vector_output_stream.h
new file mode 100644
index 0000000..a3f8226
--- /dev/null
+++ b/compiler/vector_output_stream.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#ifndef ART_COMPILER_VECTOR_OUTPUT_STREAM_H_
+#define ART_COMPILER_VECTOR_OUTPUT_STREAM_H_
+
+#include "output_stream.h"
+
+#include <string>
+#include <string.h>
+#include <vector>
+
+namespace art {
+
+class VectorOutputStream : public OutputStream {
+ public:
+  VectorOutputStream(const std::string& location, std::vector<uint8_t>& vector);
+
+  virtual ~VectorOutputStream() {}
+
+  bool WriteFully(const void* buffer, int64_t byte_count) {
+    if (static_cast<size_t>(offset_) == vector_.size()) {
+      const uint8_t* start = reinterpret_cast<const uint8_t*>(buffer);
+      vector_.insert(vector_.end(), &start[0], &start[byte_count]);
+      offset_ += byte_count;
+    } else {
+      off_t new_offset = offset_ + byte_count;
+      EnsureCapacity(new_offset);
+      memcpy(&vector_[offset_], buffer, byte_count);
+      offset_ = new_offset;
+    }
+    return true;
+  }
+
+  off_t Seek(off_t offset, Whence whence);
+
+ private:
+  void EnsureCapacity(off_t new_offset) {
+    if (new_offset > static_cast<off_t>(vector_.size())) {
+      vector_.resize(new_offset);
+    }
+  }
+
+  off_t offset_;
+  std::vector<uint8_t>& vector_;
+
+  DISALLOW_COPY_AND_ASSIGN(VectorOutputStream);
+};
+
+}  // namespace art
+
+#endif  // ART_COMPILER_VECTOR_OUTPUT_STREAM_H_