Add buffering to ELF file generation

Bug: 10496017
Change-Id: I3cbad249e0fb33f726bd0a504b3b6bd9b4f759c8

6 files changed, 133 insertions, 1 deletions

diff --git a/compiler/Android.mk b/compiler/Android.mk
index 0abe9ba3b3..8eb8db7140 100644
--- a/compiler/Android.mk
+++ b/compiler/Android.mk
@@ -83,6 +83,7 @@ LIBART_COMPILER_SRC_FILES := \
 	utils/mips/managed_register_mips.cc \
 	utils/x86/assembler_x86.cc \
 	utils/x86/managed_register_x86.cc \
+	buffered_output_stream.cc \
 	elf_fixup.cc \
 	elf_stripper.cc \
 	elf_writer.cc \
diff --git a/compiler/buffered_output_stream.cc b/compiler/buffered_output_stream.cc
new file mode 100644
index 0000000000..81a58f6284
--- /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
diff --git a/compiler/buffered_output_stream.h b/compiler/buffered_output_stream.h
new file mode 100644
index 0000000000..7d874fbc5c
--- /dev/null
+++ b/compiler/buffered_output_stream.h
@@ -0,0 +1,54 @@
+/*
+ * 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_BUFFERED_OUTPUT_STREAM_H_
+#define ART_COMPILER_BUFFERED_OUTPUT_STREAM_H_
+
+#include "output_stream.h"
+
+#include "globals.h"
+
+namespace art {
+
+class BufferedOutputStream : public OutputStream {
+ public:
+  explicit BufferedOutputStream(OutputStream* out);
+
+  virtual ~BufferedOutputStream() {
+    delete out_;
+  }
+
+  virtual bool WriteFully(const void* buffer, int64_t byte_count);
+
+  virtual off_t Seek(off_t offset, Whence whence);
+
+ private:
+  static const size_t kBufferSize = 8 * KB;
+
+  bool Flush();
+
+  OutputStream* const out_;
+
+  uint8_t buffer_[kBufferSize];
+
+  size_t used_;
+
+  DISALLOW_COPY_AND_ASSIGN(BufferedOutputStream);
+};
+
+}  // namespace art
+
+#endif  // ART_COMPILER_BUFFERED_OUTPUT_STREAM_H_
diff --git a/compiler/elf_writer_quick.cc b/compiler/elf_writer_quick.cc
index 014c51ea64..60c8f076de 100644
--- a/compiler/elf_writer_quick.cc
+++ b/compiler/elf_writer_quick.cc
@@ -18,6 +18,7 @@
 
 #include "base/logging.h"
 #include "base/unix_file/fd_file.h"
+#include "buffered_output_stream.h"
 #include "driver/compiler_driver.h"
 #include "file_output_stream.h"
 #include "globals.h"
@@ -619,7 +620,7 @@ bool ElfWriterQuick::Write(OatWriter& oat_writer,
                 << " for " << elf_file_->GetPath();
     return false;
   }
-  FileOutputStream output_stream(elf_file_);
+  BufferedOutputStream output_stream(new FileOutputStream(elf_file_));
   if (!oat_writer.Write(output_stream)) {
     PLOG(ERROR) << "Failed to write .rodata and .text for " << elf_file_->GetPath();
     return false;
diff --git a/compiler/output_stream_test.cc b/compiler/output_stream_test.cc
index d5e97558c0..a957ee375a 100644
--- a/compiler/output_stream_test.cc
+++ b/compiler/output_stream_test.cc
@@ -15,6 +15,7 @@
  */
 
 #include "base/logging.h"
+#include "buffered_output_stream.h"
 #include "common_test.h"
 #include "file_output_stream.h"
 #include "vector_output_stream.h"
@@ -70,6 +71,21 @@ TEST_F(OutputStreamTest, File) {
   CheckTestOutput(actual);
 }
 
+TEST_F(OutputStreamTest, Buffered) {
+  ScratchFile tmp;
+  UniquePtr<FileOutputStream> file_output_stream(new FileOutputStream(tmp.GetFile()));
+  CHECK(file_output_stream.get() != NULL);
+  BufferedOutputStream buffered_output_stream(file_output_stream.release());
+  SetOutputStream(buffered_output_stream);
+  GenerateTestOutput();
+  UniquePtr<File> in(OS::OpenFileForReading(tmp.GetFilename().c_str()));
+  EXPECT_TRUE(in.get() != NULL);
+  std::vector<uint8_t> actual(in->GetLength());
+  bool readSuccess = in->ReadFully(&actual[0], actual.size());
+  EXPECT_TRUE(readSuccess);
+  CheckTestOutput(actual);
+}
+
 TEST_F(OutputStreamTest, Vector) {
   std::vector<uint8_t> output;
   VectorOutputStream output_stream("test vector output", output);
diff --git a/compiler/sea_ir/debug/dot_gen.h b/compiler/sea_ir/debug/dot_gen.h
index f2ab8c4384..d7d21ad05a 100644
--- a/compiler/sea_ir/debug/dot_gen.h
+++ b/compiler/sea_ir/debug/dot_gen.h
@@ -104,6 +104,7 @@ class DotConversion {
     LOG(INFO) << "Starting to write SEA string to file " << filename << std::endl;
     DotGenerationVisitor dgv = DotGenerationVisitor(&options_, types);
     graph->Accept(&dgv);
+    // TODO: UniquePtr to close file properly. Switch to BufferedOutputStream.
     art::File* file = art::OS::CreateEmptyFile(filename.c_str());
     art::FileOutputStream fos(file);
     std::string graph_as_string = dgv.GetResult();