1 //===- BinaryStreamRef.cpp - ----------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "llvm/Support/BinaryStreamRef.h"
11 #include "llvm/Support/BinaryByteStream.h"
12
13 using namespace llvm;
14 using namespace llvm::support;
15
16 namespace {
17
18 class ArrayRefImpl : public BinaryStream {
19 public:
ArrayRefImpl(ArrayRef<uint8_t> Data,endianness Endian)20 ArrayRefImpl(ArrayRef<uint8_t> Data, endianness Endian) : BBS(Data, Endian) {}
21
getEndian() const22 llvm::support::endianness getEndian() const override {
23 return BBS.getEndian();
24 }
readBytes(uint32_t Offset,uint32_t Size,ArrayRef<uint8_t> & Buffer)25 Error readBytes(uint32_t Offset, uint32_t Size,
26 ArrayRef<uint8_t> &Buffer) override {
27 return BBS.readBytes(Offset, Size, Buffer);
28 }
readLongestContiguousChunk(uint32_t Offset,ArrayRef<uint8_t> & Buffer)29 Error readLongestContiguousChunk(uint32_t Offset,
30 ArrayRef<uint8_t> &Buffer) override {
31 return BBS.readLongestContiguousChunk(Offset, Buffer);
32 }
getLength()33 uint32_t getLength() override { return BBS.getLength(); }
34
35 private:
36 BinaryByteStream BBS;
37 };
38
39 class MutableArrayRefImpl : public WritableBinaryStream {
40 public:
MutableArrayRefImpl(MutableArrayRef<uint8_t> Data,endianness Endian)41 MutableArrayRefImpl(MutableArrayRef<uint8_t> Data, endianness Endian)
42 : BBS(Data, Endian) {}
43
44 // Inherited via WritableBinaryStream
getEndian() const45 llvm::support::endianness getEndian() const override {
46 return BBS.getEndian();
47 }
readBytes(uint32_t Offset,uint32_t Size,ArrayRef<uint8_t> & Buffer)48 Error readBytes(uint32_t Offset, uint32_t Size,
49 ArrayRef<uint8_t> &Buffer) override {
50 return BBS.readBytes(Offset, Size, Buffer);
51 }
readLongestContiguousChunk(uint32_t Offset,ArrayRef<uint8_t> & Buffer)52 Error readLongestContiguousChunk(uint32_t Offset,
53 ArrayRef<uint8_t> &Buffer) override {
54 return BBS.readLongestContiguousChunk(Offset, Buffer);
55 }
getLength()56 uint32_t getLength() override { return BBS.getLength(); }
57
writeBytes(uint32_t Offset,ArrayRef<uint8_t> Data)58 Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Data) override {
59 return BBS.writeBytes(Offset, Data);
60 }
commit()61 Error commit() override { return BBS.commit(); }
62
63 private:
64 MutableBinaryByteStream BBS;
65 };
66 }
67
BinaryStreamRef(BinaryStream & Stream)68 BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream)
69 : BinaryStreamRefBase(Stream) {}
BinaryStreamRef(BinaryStream & Stream,uint32_t Offset,Optional<uint32_t> Length)70 BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream, uint32_t Offset,
71 Optional<uint32_t> Length)
72 : BinaryStreamRefBase(Stream, Offset, Length) {}
BinaryStreamRef(ArrayRef<uint8_t> Data,endianness Endian)73 BinaryStreamRef::BinaryStreamRef(ArrayRef<uint8_t> Data, endianness Endian)
74 : BinaryStreamRefBase(std::make_shared<ArrayRefImpl>(Data, Endian), 0,
75 Data.size()) {}
BinaryStreamRef(StringRef Data,endianness Endian)76 BinaryStreamRef::BinaryStreamRef(StringRef Data, endianness Endian)
77 : BinaryStreamRef(makeArrayRef(Data.bytes_begin(), Data.bytes_end()),
78 Endian) {}
79
readBytes(uint32_t Offset,uint32_t Size,ArrayRef<uint8_t> & Buffer) const80 Error BinaryStreamRef::readBytes(uint32_t Offset, uint32_t Size,
81 ArrayRef<uint8_t> &Buffer) const {
82 if (auto EC = checkOffsetForRead(Offset, Size))
83 return EC;
84 return BorrowedImpl->readBytes(ViewOffset + Offset, Size, Buffer);
85 }
86
readLongestContiguousChunk(uint32_t Offset,ArrayRef<uint8_t> & Buffer) const87 Error BinaryStreamRef::readLongestContiguousChunk(
88 uint32_t Offset, ArrayRef<uint8_t> &Buffer) const {
89 if (auto EC = checkOffsetForRead(Offset, 1))
90 return EC;
91
92 if (auto EC =
93 BorrowedImpl->readLongestContiguousChunk(ViewOffset + Offset, Buffer))
94 return EC;
95 // This StreamRef might refer to a smaller window over a larger stream. In
96 // that case we will have read out more bytes than we should return, because
97 // we should not read past the end of the current view.
98 uint32_t MaxLength = getLength() - Offset;
99 if (Buffer.size() > MaxLength)
100 Buffer = Buffer.slice(0, MaxLength);
101 return Error::success();
102 }
103
WritableBinaryStreamRef(WritableBinaryStream & Stream)104 WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream)
105 : BinaryStreamRefBase(Stream) {}
106
WritableBinaryStreamRef(WritableBinaryStream & Stream,uint32_t Offset,Optional<uint32_t> Length)107 WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream,
108 uint32_t Offset,
109 Optional<uint32_t> Length)
110 : BinaryStreamRefBase(Stream, Offset, Length) {}
111
WritableBinaryStreamRef(MutableArrayRef<uint8_t> Data,endianness Endian)112 WritableBinaryStreamRef::WritableBinaryStreamRef(MutableArrayRef<uint8_t> Data,
113 endianness Endian)
114 : BinaryStreamRefBase(std::make_shared<MutableArrayRefImpl>(Data, Endian),
115 0, Data.size()) {}
116
117
writeBytes(uint32_t Offset,ArrayRef<uint8_t> Data) const118 Error WritableBinaryStreamRef::writeBytes(uint32_t Offset,
119 ArrayRef<uint8_t> Data) const {
120 if (auto EC = checkOffsetForWrite(Offset, Data.size()))
121 return EC;
122
123 return BorrowedImpl->writeBytes(ViewOffset + Offset, Data);
124 }
125
operator BinaryStreamRef() const126 WritableBinaryStreamRef::operator BinaryStreamRef() const {
127 return BinaryStreamRef(*BorrowedImpl, ViewOffset, Length);
128 }
129
130 /// For buffered streams, commits changes to the backing store.
commit()131 Error WritableBinaryStreamRef::commit() { return BorrowedImpl->commit(); }
132