1 files changed, 68 insertions, 0 deletions
diff --git a/include/llvm/DebugInfo/PDB/Raw/MappedBlockStream.h b/include/llvm/DebugInfo/PDB/Raw/MappedBlockStream.h
new file mode 100644
index 000000000000..36424c0d16ab
--- /dev/null
+++ b/include/llvm/DebugInfo/PDB/Raw/MappedBlockStream.h
@@ -0,0 +1,68 @@
+//===- MappedBlockStream.h - Reads stream data from a PDBFile ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_PDB_RAW_MAPPEDBLOCKSTREAM_H
+#define LLVM_DEBUGINFO_PDB_RAW_MAPPEDBLOCKSTREAM_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/DebugInfo/CodeView/StreamInterface.h"
+#include "llvm/DebugInfo/PDB/Raw/IPDBStreamData.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Error.h"
+#include <cstdint>
+#include <vector>
+
+namespace llvm {
+namespace pdb {
+
+class IPDBFile;
+class PDBFile;
+
+class MappedBlockStream : public codeview::StreamInterface {
+public:
+  Error readBytes(uint32_t Offset, uint32_t Size,
+                  ArrayRef<uint8_t> &Buffer) const override;
+  Error readLongestContiguousChunk(uint32_t Offset,
+                                   ArrayRef<uint8_t> &Buffer) const override;
+  Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Buffer) const override;
+
+  uint32_t getLength() const override;
+  Error commit() const override;
+
+  uint32_t getNumBytesCopied() const;
+
+  static Expected<std::unique_ptr<MappedBlockStream>>
+  createIndexedStream(uint32_t StreamIdx, const IPDBFile &File);
+  static Expected<std::unique_ptr<MappedBlockStream>>
+  createDirectoryStream(const PDBFile &File);
+
+  llvm::BumpPtrAllocator &getAllocator() { return Pool; }
+
+protected:
+  MappedBlockStream(std::unique_ptr<IPDBStreamData> Data, const IPDBFile &File);
+
+  Error readBytes(uint32_t Offset, MutableArrayRef<uint8_t> Buffer) const;
+  bool tryReadContiguously(uint32_t Offset, uint32_t Size,
+                           ArrayRef<uint8_t> &Buffer) const;
+
+  const IPDBFile &Pdb;
+  std::unique_ptr<IPDBStreamData> Data;
+
+  typedef MutableArrayRef<uint8_t> CacheEntry;
+  mutable llvm::BumpPtrAllocator Pool;
+  mutable DenseMap<uint32_t, std::vector<CacheEntry>> CacheMap;
+};
+
+} // end namespace pdb
+} // end namespace llvm
+
+#endif // LLVM_DEBUGINFO_PDB_RAW_MAPPEDBLOCKSTREAM_H