1 //===- BinaryStreamWriter.cpp - Writes objects to a BinaryStream ----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/Support/BinaryStreamWriter.h"
12 #include "llvm/Support/BinaryStreamError.h"
13 #include "llvm/Support/BinaryStreamReader.h"
14 #include "llvm/Support/BinaryStreamRef.h"
18 BinaryStreamWriter::BinaryStreamWriter(WritableBinaryStreamRef Ref)
21 BinaryStreamWriter::BinaryStreamWriter(WritableBinaryStream &Stream)
24 BinaryStreamWriter::BinaryStreamWriter(MutableArrayRef<uint8_t> Data,
25 llvm::support::endianness Endian)
26 : Stream(Data, Endian) {}
28 Error BinaryStreamWriter::writeBytes(ArrayRef<uint8_t> Buffer) {
29 if (auto EC = Stream.writeBytes(Offset, Buffer))
31 Offset += Buffer.size();
32 return Error::success();
35 Error BinaryStreamWriter::writeCString(StringRef Str) {
36 if (auto EC = writeFixedString(Str))
38 if (auto EC = writeObject('\0'))
41 return Error::success();
44 Error BinaryStreamWriter::writeFixedString(StringRef Str) {
45 return writeBytes(ArrayRef<uint8_t>(Str.bytes_begin(), Str.bytes_end()));
48 Error BinaryStreamWriter::writeStreamRef(BinaryStreamRef Ref) {
49 return writeStreamRef(Ref, Ref.getLength());
52 Error BinaryStreamWriter::writeStreamRef(BinaryStreamRef Ref, uint32_t Length) {
53 BinaryStreamReader SrcReader(Ref.slice(0, Length));
54 // This is a bit tricky. If we just call readBytes, we are requiring that it
55 // return us the entire stream as a contiguous buffer. There is no guarantee
56 // this can be satisfied by returning a reference straight from the buffer, as
57 // an implementation may not store all data in a single contiguous buffer. So
58 // we iterate over each contiguous chunk, writing each one in succession.
59 while (SrcReader.bytesRemaining() > 0) {
60 ArrayRef<uint8_t> Chunk;
61 if (auto EC = SrcReader.readLongestContiguousChunk(Chunk))
63 if (auto EC = writeBytes(Chunk))
66 return Error::success();
69 std::pair<BinaryStreamWriter, BinaryStreamWriter>
70 BinaryStreamWriter::split(uint32_t Off) const {
71 assert(getLength() >= Off);
73 WritableBinaryStreamRef First = Stream.drop_front(Offset);
75 WritableBinaryStreamRef Second = First.drop_front(Off);
76 First = First.keep_front(Off);
77 BinaryStreamWriter W1{First};
78 BinaryStreamWriter W2{Second};
79 return std::make_pair(W1, W2);
82 Error BinaryStreamWriter::padToAlignment(uint32_t Align) {
83 uint32_t NewOffset = alignTo(Offset, Align);
84 if (NewOffset > getLength())
85 return make_error<BinaryStreamError>(stream_error_code::stream_too_short);
87 return Error::success();