include/llvm/XRay/FDRRecordProducer.h

   1 //===- FDRRecordProducer.h - XRay FDR Mode Record Producer ----------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 #ifndef LLVM_INCLUDE_LLVM_XRAY_FDRRECORDPRODUCER_H_
   9 #define LLVM_INCLUDE_LLVM_XRAY_FDRRECORDPRODUCER_H_
  10
  11 #include "llvm/Support/Error.h"
  12 #include "llvm/XRay/FDRRecords.h"
  13 #include "llvm/XRay/XRayRecord.h"
  14 #include <memory>
  15
  16 namespace llvm {
  17 namespace xray {
  18
  19 class RecordProducer {
  20 public:
  21   /// All producer implementations must yield either an Error or a non-nullptr
  22   /// unique_ptr<Record>.
  23   virtual Expected<std::unique_ptr<Record>> produce() = 0;
  24   virtual ~RecordProducer() = default;
  25 };
  26
  27 class FileBasedRecordProducer : public RecordProducer {
  28   const XRayFileHeader &Header;
  29   DataExtractor &E;
  30   uint64_t &OffsetPtr;
  31   uint32_t CurrentBufferBytes = 0;
  32
  33   // Helper function which gets the next record by speculatively reading through
  34   // the log, finding a buffer extents record.
  35   Expected<std::unique_ptr<Record>> findNextBufferExtent();
  36
  37 public:
  38   FileBasedRecordProducer(const XRayFileHeader &FH, DataExtractor &DE,
  39                           uint64_t &OP)
  40       : Header(FH), E(DE), OffsetPtr(OP) {}
  41
  42   /// This producer encapsulates the logic for loading a File-backed
  43   /// RecordProducer hidden behind a DataExtractor.
  44   Expected<std::unique_ptr<Record>> produce() override;
  45 };
  46
  47 } // namespace xray
  48 } // namespace llvm
  49
  50 #endif // LLVM_INCLUDE_LLVM_XRAY_FDRRECORDPRODUCER_H_