Add buffering to ELF file generation

Bug: 10496017
Change-Id: I3cbad249e0fb33f726bd0a504b3b6bd9b4f759c8

1 files changed, 59 insertions, 0 deletions

diff --git a/compiler/buffered_output_stream.cc b/compiler/buffered_output_stream.cc
new file mode 100644
index 0000000..81a58f6
--- /dev/null
+++ b/compiler/buffered_output_stream.cc
@@ -0,0 +1,59 @@
+/*
+ * 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.
+ */
+
+#include "buffered_output_stream.h"
+
+#include <string.h>
+
+namespace art {
+
+BufferedOutputStream::BufferedOutputStream(OutputStream* out)
+    : OutputStream(out->GetLocation()), out_(out), used_(0) {}
+
+bool BufferedOutputStream::WriteFully(const void* buffer, int64_t byte_count) {
+  if (byte_count > kBufferSize) {
+    Flush();
+    return out_->WriteFully(buffer, byte_count);
+  }
+  if (used_ + byte_count > kBufferSize) {
+    bool success = Flush();
+    if (!success) {
+      return false;
+    }
+  }
+  const uint8_t* src = reinterpret_cast<const uint8_t*>(buffer);
+  memcpy(&buffer_[used_], src, byte_count);
+  used_ += byte_count;
+  return true;
+}
+
+bool BufferedOutputStream::Flush() {
+  bool success = true;
+  if (used_ > 0) {
+    success = out_->WriteFully(&buffer_[0], used_);
+    used_ = 0;
+  }
+  return success;
+}
+
+off_t BufferedOutputStream::Seek(off_t offset, Whence whence) {
+  if (!Flush()) {
+    return -1;
+  }
+  return out_->Seek(offset, whence);
+}
+
+}  // namespace art