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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/Support/BinaryStreamRef.h" 10 #include "llvm/Support/BinaryByteStream.h" 11 12 using namespace llvm; 13 using namespace llvm::support; 14 15 namespace { 16 17 class ArrayRefImpl : public BinaryStream { 18 public: 19 ArrayRefImpl(ArrayRef<uint8_t> Data, endianness Endian) : BBS(Data, Endian) {} 20 21 llvm::support::endianness getEndian() const override { 22 return BBS.getEndian(); 23 } 24 Error readBytes(uint32_t Offset, uint32_t Size, 25 ArrayRef<uint8_t> &Buffer) override { 26 return BBS.readBytes(Offset, Size, Buffer); 27 } 28 Error readLongestContiguousChunk(uint32_t Offset, 29 ArrayRef<uint8_t> &Buffer) override { 30 return BBS.readLongestContiguousChunk(Offset, Buffer); 31 } 32 uint32_t getLength() override { return BBS.getLength(); } 33 34 private: 35 BinaryByteStream BBS; 36 }; 37 38 class MutableArrayRefImpl : public WritableBinaryStream { 39 public: 40 MutableArrayRefImpl(MutableArrayRef<uint8_t> Data, endianness Endian) 41 : BBS(Data, Endian) {} 42 43 // Inherited via WritableBinaryStream 44 llvm::support::endianness getEndian() const override { 45 return BBS.getEndian(); 46 } 47 Error readBytes(uint32_t Offset, uint32_t Size, 48 ArrayRef<uint8_t> &Buffer) override { 49 return BBS.readBytes(Offset, Size, Buffer); 50 } 51 Error readLongestContiguousChunk(uint32_t Offset, 52 ArrayRef<uint8_t> &Buffer) override { 53 return BBS.readLongestContiguousChunk(Offset, Buffer); 54 } 55 uint32_t getLength() override { return BBS.getLength(); } 56 57 Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Data) override { 58 return BBS.writeBytes(Offset, Data); 59 } 60 Error commit() override { return BBS.commit(); } 61 62 private: 63 MutableBinaryByteStream BBS; 64 }; 65 } 66 67 BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream) 68 : BinaryStreamRefBase(Stream) {} 69 BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream, uint32_t Offset, 70 Optional<uint32_t> Length) 71 : BinaryStreamRefBase(Stream, Offset, Length) {} 72 BinaryStreamRef::BinaryStreamRef(ArrayRef<uint8_t> Data, endianness Endian) 73 : BinaryStreamRefBase(std::make_shared<ArrayRefImpl>(Data, Endian), 0, 74 Data.size()) {} 75 BinaryStreamRef::BinaryStreamRef(StringRef Data, endianness Endian) 76 : BinaryStreamRef(makeArrayRef(Data.bytes_begin(), Data.bytes_end()), 77 Endian) {} 78 79 Error BinaryStreamRef::readBytes(uint32_t Offset, uint32_t Size, 80 ArrayRef<uint8_t> &Buffer) const { 81 if (auto EC = checkOffsetForRead(Offset, Size)) 82 return EC; 83 return BorrowedImpl->readBytes(ViewOffset + Offset, Size, Buffer); 84 } 85 86 Error BinaryStreamRef::readLongestContiguousChunk( 87 uint32_t Offset, ArrayRef<uint8_t> &Buffer) const { 88 if (auto EC = checkOffsetForRead(Offset, 1)) 89 return EC; 90 91 if (auto EC = 92 BorrowedImpl->readLongestContiguousChunk(ViewOffset + Offset, Buffer)) 93 return EC; 94 // This StreamRef might refer to a smaller window over a larger stream. In 95 // that case we will have read out more bytes than we should return, because 96 // we should not read past the end of the current view. 97 uint32_t MaxLength = getLength() - Offset; 98 if (Buffer.size() > MaxLength) 99 Buffer = Buffer.slice(0, MaxLength); 100 return Error::success(); 101 } 102 103 WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream) 104 : BinaryStreamRefBase(Stream) {} 105 106 WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream, 107 uint32_t Offset, 108 Optional<uint32_t> Length) 109 : BinaryStreamRefBase(Stream, Offset, Length) {} 110 111 WritableBinaryStreamRef::WritableBinaryStreamRef(MutableArrayRef<uint8_t> Data, 112 endianness Endian) 113 : BinaryStreamRefBase(std::make_shared<MutableArrayRefImpl>(Data, Endian), 114 0, Data.size()) {} 115 116 117 Error WritableBinaryStreamRef::writeBytes(uint32_t Offset, 118 ArrayRef<uint8_t> Data) const { 119 if (auto EC = checkOffsetForWrite(Offset, Data.size())) 120 return EC; 121 122 return BorrowedImpl->writeBytes(ViewOffset + Offset, Data); 123 } 124 125 WritableBinaryStreamRef::operator BinaryStreamRef() const { 126 return BinaryStreamRef(*BorrowedImpl, ViewOffset, Length); 127 } 128 129 /// For buffered streams, commits changes to the backing store. 130 Error WritableBinaryStreamRef::commit() { return BorrowedImpl->commit(); } 131