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:
ArrayRefImpl(ArrayRef<uint8_t> Data,endianness Endian)19 ArrayRefImpl(ArrayRef<uint8_t> Data, endianness Endian) : BBS(Data, Endian) {}
20
getEndian() const21 llvm::support::endianness getEndian() const override {
22 return BBS.getEndian();
23 }
readBytes(uint32_t Offset,uint32_t Size,ArrayRef<uint8_t> & Buffer)24 Error readBytes(uint32_t Offset, uint32_t Size,
25 ArrayRef<uint8_t> &Buffer) override {
26 return BBS.readBytes(Offset, Size, Buffer);
27 }
readLongestContiguousChunk(uint32_t Offset,ArrayRef<uint8_t> & Buffer)28 Error readLongestContiguousChunk(uint32_t Offset,
29 ArrayRef<uint8_t> &Buffer) override {
30 return BBS.readLongestContiguousChunk(Offset, Buffer);
31 }
getLength()32 uint32_t getLength() override { return BBS.getLength(); }
33
34 private:
35 BinaryByteStream BBS;
36 };
37
38 class MutableArrayRefImpl : public WritableBinaryStream {
39 public:
MutableArrayRefImpl(MutableArrayRef<uint8_t> Data,endianness Endian)40 MutableArrayRefImpl(MutableArrayRef<uint8_t> Data, endianness Endian)
41 : BBS(Data, Endian) {}
42
43 // Inherited via WritableBinaryStream
getEndian() const44 llvm::support::endianness getEndian() const override {
45 return BBS.getEndian();
46 }
readBytes(uint32_t Offset,uint32_t Size,ArrayRef<uint8_t> & Buffer)47 Error readBytes(uint32_t Offset, uint32_t Size,
48 ArrayRef<uint8_t> &Buffer) override {
49 return BBS.readBytes(Offset, Size, Buffer);
50 }
readLongestContiguousChunk(uint32_t Offset,ArrayRef<uint8_t> & Buffer)51 Error readLongestContiguousChunk(uint32_t Offset,
52 ArrayRef<uint8_t> &Buffer) override {
53 return BBS.readLongestContiguousChunk(Offset, Buffer);
54 }
getLength()55 uint32_t getLength() override { return BBS.getLength(); }
56
writeBytes(uint32_t Offset,ArrayRef<uint8_t> Data)57 Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Data) override {
58 return BBS.writeBytes(Offset, Data);
59 }
commit()60 Error commit() override { return BBS.commit(); }
61
62 private:
63 MutableBinaryByteStream BBS;
64 };
65 } // namespace
66
BinaryStreamRef(BinaryStream & Stream)67 BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream)
68 : BinaryStreamRefBase(Stream) {}
BinaryStreamRef(BinaryStream & Stream,uint32_t Offset,Optional<uint32_t> Length)69 BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream, uint32_t Offset,
70 Optional<uint32_t> Length)
71 : BinaryStreamRefBase(Stream, Offset, Length) {}
BinaryStreamRef(ArrayRef<uint8_t> Data,endianness Endian)72 BinaryStreamRef::BinaryStreamRef(ArrayRef<uint8_t> Data, endianness Endian)
73 : BinaryStreamRefBase(std::make_shared<ArrayRefImpl>(Data, Endian), 0,
74 Data.size()) {}
BinaryStreamRef(StringRef Data,endianness Endian)75 BinaryStreamRef::BinaryStreamRef(StringRef Data, endianness Endian)
76 : BinaryStreamRef(makeArrayRef(Data.bytes_begin(), Data.bytes_end()),
77 Endian) {}
78
readBytes(uint32_t Offset,uint32_t Size,ArrayRef<uint8_t> & Buffer) const79 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
readLongestContiguousChunk(uint32_t Offset,ArrayRef<uint8_t> & Buffer) const86 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
WritableBinaryStreamRef(WritableBinaryStream & Stream)103 WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream)
104 : BinaryStreamRefBase(Stream) {}
105
WritableBinaryStreamRef(WritableBinaryStream & Stream,uint32_t Offset,Optional<uint32_t> Length)106 WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream,
107 uint32_t Offset,
108 Optional<uint32_t> Length)
109 : BinaryStreamRefBase(Stream, Offset, Length) {}
110
WritableBinaryStreamRef(MutableArrayRef<uint8_t> Data,endianness Endian)111 WritableBinaryStreamRef::WritableBinaryStreamRef(MutableArrayRef<uint8_t> Data,
112 endianness Endian)
113 : BinaryStreamRefBase(std::make_shared<MutableArrayRefImpl>(Data, Endian),
114 0, Data.size()) {}
115
116
writeBytes(uint32_t Offset,ArrayRef<uint8_t> Data) const117 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
operator BinaryStreamRef() const125 WritableBinaryStreamRef::operator BinaryStreamRef() const {
126 return BinaryStreamRef(*BorrowedImpl, ViewOffset, Length);
127 }
128
129 /// For buffered streams, commits changes to the backing store.
commit()130 Error WritableBinaryStreamRef::commit() { return BorrowedImpl->commit(); }
131