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Differential D109923 Diff 373100 llvm/include/llvm/Support/BinaryStream.h

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llvm/include/llvm/Support/BinaryStream.h

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public: public:
virtual ~BinaryStream() = default; virtual ~BinaryStream() = default;
virtual llvm::support::endianness getEndian() const = 0; virtual llvm::support::endianness getEndian() const = 0;
/// Given an offset into the stream and a number of bytes, attempt to /// Given an offset into the stream and a number of bytes, attempt to
/// read the bytes and set the output ArrayRef to point to data owned by the /// read the bytes and set the output ArrayRef to point to data owned by the
/// stream. /// stream.
virtual Error readBytes(uint32_t Offset, uint32_t Size, virtual Error readBytes(uint64_t Offset, uint64_t Size,
ArrayRef<uint8_t> &Buffer) = 0; ArrayRef<uint8_t> &Buffer) = 0;
/// Given an offset into the stream, read as much as possible without /// Given an offset into the stream, read as much as possible without
/// copying any data. /// copying any data.
virtual Error readLongestContiguousChunk(uint32_t Offset, virtual Error readLongestContiguousChunk(uint64_t Offset,
ArrayRef<uint8_t> &Buffer) = 0; ArrayRef<uint8_t> &Buffer) = 0;
/// Return the number of bytes of data in this stream. /// Return the number of bytes of data in this stream.
virtual uint32_t getLength() = 0; virtual uint64_t getLength() = 0;
/// Return the properties of this stream. /// Return the properties of this stream.
virtual BinaryStreamFlags getFlags() const { return BSF_None; } virtual BinaryStreamFlags getFlags() const { return BSF_None; }
protected: protected:
Error checkOffsetForRead(uint32_t Offset, uint32_t DataSize) { Error checkOffsetForRead(uint64_t Offset, uint64_t DataSize) {
if (Offset > getLength()) if (Offset > getLength())
return make_error<BinaryStreamError>(stream_error_code::invalid_offset); return make_error<BinaryStreamError>(stream_error_code::invalid_offset);
if (getLength() < DataSize + Offset) if (getLength() < DataSize + Offset)
return make_error<BinaryStreamError>(stream_error_code::stream_too_short); return make_error<BinaryStreamError>(stream_error_code::stream_too_short);
return Error::success(); return Error::success();
} }
}; };
/// A BinaryStream which can be read from as well as written to. Note /// A BinaryStream which can be read from as well as written to. Note
/// that writing to a BinaryStream always necessitates copying from the input /// that writing to a BinaryStream always necessitates copying from the input
/// buffer to the stream's backing store. Streams are assumed to be buffered /// buffer to the stream's backing store. Streams are assumed to be buffered
/// so that to be portable it is necessary to call commit() on the stream when /// so that to be portable it is necessary to call commit() on the stream when
/// all data has been written. /// all data has been written.
class WritableBinaryStream : public BinaryStream { class WritableBinaryStream : public BinaryStream {
public: public:
~WritableBinaryStream() override = default; ~WritableBinaryStream() override = default;
/// Attempt to write the given bytes into the stream at the desired /// Attempt to write the given bytes into the stream at the desired
/// offset. This will always necessitate a copy. Cannot shrink or grow the /// offset. This will always necessitate a copy. Cannot shrink or grow the
/// stream, only writes into existing allocated space. /// stream, only writes into existing allocated space.
virtual Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Data) = 0; virtual Error writeBytes(uint64_t Offset, ArrayRef<uint8_t> Data) = 0;
/// For buffered streams, commits changes to the backing store. /// For buffered streams, commits changes to the backing store.
virtual Error commit() = 0; virtual Error commit() = 0;
/// Return the properties of this stream. /// Return the properties of this stream.
BinaryStreamFlags getFlags() const override { return BSF_Write; } BinaryStreamFlags getFlags() const override { return BSF_Write; }
protected: protected:
Error checkOffsetForWrite(uint32_t Offset, uint32_t DataSize) { Error checkOffsetForWrite(uint64_t Offset, uint64_t DataSize) {
if (!(getFlags() & BSF_Append)) if (!(getFlags() & BSF_Append))
return checkOffsetForRead(Offset, DataSize); return checkOffsetForRead(Offset, DataSize);
if (Offset > getLength()) if (Offset > getLength())
return make_error<BinaryStreamError>(stream_error_code::invalid_offset); return make_error<BinaryStreamError>(stream_error_code::invalid_offset);
return Error::success(); return Error::success();
} }
}; };
} // end namespace llvm } // end namespace llvm
#endif // LLVM_SUPPORT_BINARYSTREAM_H #endif // LLVM_SUPPORT_BINARYSTREAM_H