freebsd-dev/contrib/llvm/lib/Support/BinaryStreamRef.cpp
2017-12-20 14:16:56 +00:00

132 lines
4.7 KiB
C++

//===- BinaryStreamRef.cpp - ----------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/BinaryStreamRef.h"
#include "llvm/Support/BinaryByteStream.h"
using namespace llvm;
using namespace llvm::support;
namespace {
class ArrayRefImpl : public BinaryStream {
public:
ArrayRefImpl(ArrayRef<uint8_t> Data, endianness Endian) : BBS(Data, Endian) {}
llvm::support::endianness getEndian() const override {
return BBS.getEndian();
}
Error readBytes(uint32_t Offset, uint32_t Size,
ArrayRef<uint8_t> &Buffer) override {
return BBS.readBytes(Offset, Size, Buffer);
}
Error readLongestContiguousChunk(uint32_t Offset,
ArrayRef<uint8_t> &Buffer) override {
return BBS.readLongestContiguousChunk(Offset, Buffer);
}
uint32_t getLength() override { return BBS.getLength(); }
private:
BinaryByteStream BBS;
};
class MutableArrayRefImpl : public WritableBinaryStream {
public:
MutableArrayRefImpl(MutableArrayRef<uint8_t> Data, endianness Endian)
: BBS(Data, Endian) {}
// Inherited via WritableBinaryStream
llvm::support::endianness getEndian() const override {
return BBS.getEndian();
}
Error readBytes(uint32_t Offset, uint32_t Size,
ArrayRef<uint8_t> &Buffer) override {
return BBS.readBytes(Offset, Size, Buffer);
}
Error readLongestContiguousChunk(uint32_t Offset,
ArrayRef<uint8_t> &Buffer) override {
return BBS.readLongestContiguousChunk(Offset, Buffer);
}
uint32_t getLength() override { return BBS.getLength(); }
Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Data) override {
return BBS.writeBytes(Offset, Data);
}
Error commit() override { return BBS.commit(); }
private:
MutableBinaryByteStream BBS;
};
}
BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream)
: BinaryStreamRefBase(Stream) {}
BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream, uint32_t Offset,
Optional<uint32_t> Length)
: BinaryStreamRefBase(Stream, Offset, Length) {}
BinaryStreamRef::BinaryStreamRef(ArrayRef<uint8_t> Data, endianness Endian)
: BinaryStreamRefBase(std::make_shared<ArrayRefImpl>(Data, Endian), 0,
Data.size()) {}
BinaryStreamRef::BinaryStreamRef(StringRef Data, endianness Endian)
: BinaryStreamRef(makeArrayRef(Data.bytes_begin(), Data.bytes_end()),
Endian) {}
Error BinaryStreamRef::readBytes(uint32_t Offset, uint32_t Size,
ArrayRef<uint8_t> &Buffer) const {
if (auto EC = checkOffsetForRead(Offset, Size))
return EC;
return BorrowedImpl->readBytes(ViewOffset + Offset, Size, Buffer);
}
Error BinaryStreamRef::readLongestContiguousChunk(
uint32_t Offset, ArrayRef<uint8_t> &Buffer) const {
if (auto EC = checkOffsetForRead(Offset, 1))
return EC;
if (auto EC =
BorrowedImpl->readLongestContiguousChunk(ViewOffset + Offset, Buffer))
return EC;
// This StreamRef might refer to a smaller window over a larger stream. In
// that case we will have read out more bytes than we should return, because
// we should not read past the end of the current view.
uint32_t MaxLength = getLength() - Offset;
if (Buffer.size() > MaxLength)
Buffer = Buffer.slice(0, MaxLength);
return Error::success();
}
WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream)
: BinaryStreamRefBase(Stream) {}
WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream,
uint32_t Offset,
Optional<uint32_t> Length)
: BinaryStreamRefBase(Stream, Offset, Length) {}
WritableBinaryStreamRef::WritableBinaryStreamRef(MutableArrayRef<uint8_t> Data,
endianness Endian)
: BinaryStreamRefBase(std::make_shared<MutableArrayRefImpl>(Data, Endian),
0, Data.size()) {}
Error WritableBinaryStreamRef::writeBytes(uint32_t Offset,
ArrayRef<uint8_t> Data) const {
if (auto EC = checkOffsetForWrite(Offset, Data.size()))
return EC;
return BorrowedImpl->writeBytes(ViewOffset + Offset, Data);
}
WritableBinaryStreamRef::operator BinaryStreamRef() const {
return BinaryStreamRef(*BorrowedImpl, ViewOffset, Length);
}
/// \brief For buffered streams, commits changes to the backing store.
Error WritableBinaryStreamRef::commit() { return BorrowedImpl->commit(); }