124 lines · cpp
1//===- BinaryStreamRef.cpp - ----------------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "llvm/Support/BinaryStreamRef.h"10#include "llvm/Support/BinaryByteStream.h"11 12using namespace llvm;13 14namespace {15 16class ArrayRefImpl : public BinaryStream {17public:18 ArrayRefImpl(ArrayRef<uint8_t> Data, endianness Endian) : BBS(Data, Endian) {}19 20 llvm::endianness getEndian() const override { return BBS.getEndian(); }21 Error readBytes(uint64_t Offset, uint64_t Size,22 ArrayRef<uint8_t> &Buffer) override {23 return BBS.readBytes(Offset, Size, Buffer);24 }25 Error readLongestContiguousChunk(uint64_t Offset,26 ArrayRef<uint8_t> &Buffer) override {27 return BBS.readLongestContiguousChunk(Offset, Buffer);28 }29 uint64_t getLength() override { return BBS.getLength(); }30 31private:32 BinaryByteStream BBS;33};34 35class MutableArrayRefImpl : public WritableBinaryStream {36public:37 MutableArrayRefImpl(MutableArrayRef<uint8_t> Data, endianness Endian)38 : BBS(Data, Endian) {}39 40 // Inherited via WritableBinaryStream41 llvm::endianness getEndian() const override { return BBS.getEndian(); }42 Error readBytes(uint64_t Offset, uint64_t Size,43 ArrayRef<uint8_t> &Buffer) override {44 return BBS.readBytes(Offset, Size, Buffer);45 }46 Error readLongestContiguousChunk(uint64_t Offset,47 ArrayRef<uint8_t> &Buffer) override {48 return BBS.readLongestContiguousChunk(Offset, Buffer);49 }50 uint64_t getLength() override { return BBS.getLength(); }51 52 Error writeBytes(uint64_t Offset, ArrayRef<uint8_t> Data) override {53 return BBS.writeBytes(Offset, Data);54 }55 Error commit() override { return BBS.commit(); }56 57private:58 MutableBinaryByteStream BBS;59};60} // namespace61 62BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream)63 : BinaryStreamRefBase(Stream) {}64BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream, uint64_t Offset,65 std::optional<uint64_t> Length)66 : BinaryStreamRefBase(Stream, Offset, Length) {}67BinaryStreamRef::BinaryStreamRef(ArrayRef<uint8_t> Data, endianness Endian)68 : BinaryStreamRefBase(std::make_shared<ArrayRefImpl>(Data, Endian), 0,69 Data.size()) {}70BinaryStreamRef::BinaryStreamRef(StringRef Data, endianness Endian)71 : BinaryStreamRef(ArrayRef(Data.bytes_begin(), Data.bytes_end()), Endian) {}72 73Error BinaryStreamRef::readBytes(uint64_t Offset, uint64_t Size,74 ArrayRef<uint8_t> &Buffer) const {75 if (auto EC = checkOffsetForRead(Offset, Size))76 return EC;77 return BorrowedImpl->readBytes(ViewOffset + Offset, Size, Buffer);78}79 80Error BinaryStreamRef::readLongestContiguousChunk(81 uint64_t Offset, ArrayRef<uint8_t> &Buffer) const {82 if (auto EC = checkOffsetForRead(Offset, 1))83 return EC;84 85 if (auto EC =86 BorrowedImpl->readLongestContiguousChunk(ViewOffset + Offset, Buffer))87 return EC;88 // This StreamRef might refer to a smaller window over a larger stream. In89 // that case we will have read out more bytes than we should return, because90 // we should not read past the end of the current view.91 uint64_t MaxLength = getLength() - Offset;92 if (Buffer.size() > MaxLength)93 Buffer = Buffer.slice(0, MaxLength);94 return Error::success();95}96 97WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream)98 : BinaryStreamRefBase(Stream) {}99 100WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream,101 uint64_t Offset,102 std::optional<uint64_t> Length)103 : BinaryStreamRefBase(Stream, Offset, Length) {}104 105WritableBinaryStreamRef::WritableBinaryStreamRef(MutableArrayRef<uint8_t> Data,106 endianness Endian)107 : BinaryStreamRefBase(std::make_shared<MutableArrayRefImpl>(Data, Endian),108 0, Data.size()) {}109 110Error WritableBinaryStreamRef::writeBytes(uint64_t Offset,111 ArrayRef<uint8_t> Data) const {112 if (auto EC = checkOffsetForWrite(Offset, Data.size()))113 return EC;114 115 return BorrowedImpl->writeBytes(ViewOffset + Offset, Data);116}117 118WritableBinaryStreamRef::operator BinaryStreamRef() const {119 return BinaryStreamRef(*BorrowedImpl, ViewOffset, Length);120}121 122/// For buffered streams, commits changes to the backing store.123Error WritableBinaryStreamRef::commit() { return BorrowedImpl->commit(); }124