Encapsulate file mapping in preparation for providing a Windows implementation.

Progress on #276.

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MOS_MIGRATED_REVID=114740700

1 files changed, 82 insertions, 0 deletions

diff --git a/third_party/ijar/mapped_file.h b/third_party/ijar/mapped_file.h
new file mode 100644
index 0000000000..ea0ee824e0
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+++ b/third_party/ijar/mapped_file.h
@@ -0,0 +1,82 @@
+// Copyright 2015 The Bazel Authors. All rights reserved.
+//
+// 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 INCLUDED_THIRD_PARTY_IJAR_MAPPED_FILE_H
+#define INCLUDED_THIRD_PARTY_IJAR_MAPPED_FILE_H
+
+#include "third_party/ijar/common.h"
+
+namespace devtools_ijar {
+
+class MappedInputFileImpl;
+class MappedOutputFileImpl;
+
+// A memory mapped input file.
+class MappedInputFile {
+ private:
+  MappedInputFileImpl *impl_;
+
+ protected:
+  const char* errmsg_;
+  bool opened_;
+  u1* buffer_;
+  size_t length_;
+
+ public:
+  MappedInputFile(const char* name);
+  virtual ~MappedInputFile();
+
+  // If opening the file succeeded or not.
+  bool Opened() const { return opened_; }
+
+  // Description of the last error that happened.
+  const char* Error() const { return errmsg_; }
+
+  // The mapped contents of the file.
+  u1* Buffer() const { return buffer_ ; }
+
+  // The length of the file.
+  size_t Length() const { return length_; }
+
+  // Unmap a given number of bytes from the beginning of the file.
+  void Discard(size_t bytes);
+  int Close();
+};
+
+class MappedOutputFile {
+ private:
+  MappedOutputFileImpl *impl_;
+
+ protected:
+  const char* errmsg_;
+  bool opened_;
+  u1* buffer_;
+
+ public:
+  MappedOutputFile(const char* name, u8 estimated_size);
+  virtual ~MappedOutputFile();
+
+  // If opening the file succeeded or not.
+  bool Opened() const { return opened_; }
+
+  // Description of the last error that happened.
+  const char* Error() const { return errmsg_; }
+
+  // The mapped contents of the file.
+  u1* Buffer() const { return buffer_; }
+  int Close(int size);
+};
+
+}  // namespace devtools_ijar
+#endif