Files
fluxengine/lib/bytes.cc
2023-11-02 01:17:44 +01:00

441 lines
8.7 KiB
C++

#include "lib/globals.h"
#include "lib/bytes.h"
#include <fstream>
#include <zlib.h>
static std::shared_ptr<std::vector<uint8_t>> createVector(unsigned size)
{
return std::make_shared<std::vector<uint8_t>>(size);
}
static std::shared_ptr<std::vector<uint8_t>> createVector(
const uint8_t* ptr, unsigned size)
{
auto vector = std::make_shared<std::vector<uint8_t>>(size);
std::uninitialized_copy(ptr, ptr + size, vector->begin());
return vector;
}
static std::shared_ptr<std::vector<uint8_t>> createVector(
std::initializer_list<uint8_t> data)
{
auto vector = std::make_shared<std::vector<uint8_t>>(data.size());
std::uninitialized_copy(data.begin(), data.end(), vector->begin());
return vector;
}
Bytes::Bytes(): _data(createVector(0)), _low(0), _high(0) {}
Bytes::Bytes(unsigned size): _data(createVector(size)), _low(0), _high(size) {}
Bytes::Bytes(const uint8_t* ptr, size_t len):
_data(createVector(ptr, len)),
_low(0),
_high(len)
{
}
Bytes::Bytes(const std::string& s):
_data(createVector((const uint8_t*)&s[0], s.size())),
_low(0),
_high(s.size())
{
}
Bytes::Bytes(const char* s):
_data(createVector((const uint8_t*)s, strlen(s))),
_low(0),
_high(strlen(s))
{
}
Bytes::Bytes(std::initializer_list<uint8_t> data):
_data(createVector(data)),
_low(0),
_high(data.size())
{
}
Bytes::Bytes(std::shared_ptr<std::vector<uint8_t>> data):
_data(data),
_low(0),
_high(data->size())
{
}
Bytes::Bytes(
std::shared_ptr<std::vector<uint8_t>> data, unsigned start, unsigned end):
_data(data),
_low(start),
_high(end)
{
}
Bytes::Bytes(std::istream& istream, size_t len):
_data(createVector(0)),
_low(0),
_high(0)
{
ByteWriter bw(*this);
bw.append(istream, len);
}
Bytes* Bytes::operator=(const Bytes& other)
{
_data = other._data;
_low = other._low;
_high = other._high;
return this;
}
void Bytes::boundsCheck(unsigned pos) const
{
if (pos >= _high)
throw std::out_of_range("byte access out of range");
}
void Bytes::checkWritable()
{
if (_data.use_count() != 1)
{
auto newData = createVector(size());
std::uninitialized_copy(cbegin(), cend(), newData->begin());
_data = newData;
_low = 0;
_high = newData->size();
}
}
void Bytes::adjustBounds(unsigned pos)
{
checkWritable();
if (pos >= _high)
{
_high = pos + 1;
_data->resize(_high);
}
}
Bytes& Bytes::resize(unsigned size)
{
unsigned oldsize = _high - _low;
if (size > oldsize)
{
checkWritable();
_data->resize(_low + size);
}
_high = _low + size;
return *this;
}
const uint8_t& Bytes::operator[](unsigned pos) const
{
pos += _low;
boundsCheck(pos);
return (*_data)[pos];
}
uint8_t& Bytes::operator[](unsigned pos)
{
checkWritable();
pos += _low;
boundsCheck(pos);
return (*_data)[pos];
}
Bytes Bytes::readFromFile(const std::string& filename)
{
Bytes bytes;
ByteWriter bw(bytes);
std::ifstream f(filename);
if (!f)
error("cannot open '{}': {}", filename, strerror(errno));
bw += f;
return bytes;
}
Bytes Bytes::slice(unsigned start, unsigned len) const
{
start += _low;
unsigned end = start + len;
if (start >= _high)
{
/* Asking for a completely out-of-range slice --- just return zeroes. */
return Bytes(len);
}
else if (end > _high)
{
/* Can't share the buffer, as we need to zero-pad the end. */
Bytes b(len);
std::uninitialized_copy(
_data->cbegin() + start, _data->cbegin() + _high, b._data->begin());
return b;
}
else
{
/* Use the magic of shared_ptr to share the data. */
Bytes b(_data, start, end);
return b;
}
}
Bytes Bytes::slice(unsigned start) const
{
int len = 0;
if (start < size())
len = size() - start;
return slice(start, len);
}
std::vector<Bytes> Bytes::split(uint8_t separator) const
{
std::vector<Bytes> vector;
int lastEnd = 0;
for (int i = 0; i < size(); i++)
{
if ((*this)[i] == separator)
{
vector.push_back(this->slice(lastEnd, i - lastEnd));
lastEnd = i + 1;
}
}
vector.push_back(this->slice(lastEnd));
return vector;
}
std::vector<bool> Bytes::toBits() const
{
std::vector<bool> bits;
for (uint8_t byte : *this)
{
for (int i = 0; i < 8; i++)
{
bits.push_back(byte & 0x80);
byte <<= 1;
}
}
return bits;
}
Bytes Bytes::reverseBits() const
{
Bytes output;
ByteWriter bw(output);
for (uint8_t b : *this)
bw.write_8(reverse_bits(b));
return output;
}
Bytes Bytes::operator+(const Bytes& other)
{
Bytes output;
ByteWriter bw(output);
bw += *this;
bw += other;
return output;
}
Bytes Bytes::operator*(size_t count)
{
Bytes output;
ByteWriter bw(output);
while (count--)
bw += *this;
return output;
}
uint8_t toByte(std::vector<bool>::const_iterator start,
std::vector<bool>::const_iterator end)
{
return toBytes(start, end)[0];
}
Bytes toBytes(std::vector<bool>::const_iterator start,
std::vector<bool>::const_iterator end)
{
Bytes bytes;
ByteWriter bw(bytes);
BitWriter bitw(bw);
while (start != end)
bitw.push(*start++, 1);
bitw.flush();
return bytes;
}
Bytes Bytes::swab() const
{
Bytes output;
ByteWriter bw(output);
ByteReader br(*this);
while (!br.eof())
{
uint8_t a = br.read_8();
uint8_t b = br.read_8();
bw.write_8(b);
bw.write_8(a);
}
return output;
}
Bytes Bytes::compress() const
{
uLongf destsize = compressBound(size());
Bytes dest(destsize);
if (::compress(dest.begin(), &destsize, cbegin(), size()) != Z_OK)
error("error compressing data");
dest.resize(destsize);
return dest;
}
Bytes Bytes::decompress() const
{
Bytes output;
ByteWriter bw(output);
Bytes outputBuffer(1024 * 1024);
z_stream stream = {};
inflateInit(&stream);
stream.avail_in = size();
stream.next_in = (uint8_t*)cbegin();
int ret;
do
{
stream.avail_out = outputBuffer.size();
stream.next_out = &outputBuffer[0];
ret = inflate(&stream, Z_NO_FLUSH);
if (ret == Z_BUF_ERROR)
ret = Z_OK;
if ((ret != Z_OK) && (ret != Z_STREAM_END))
error("failed to decompress data: {}",
stream.msg ? stream.msg : "(unknown error)");
bw += outputBuffer.slice(0, outputBuffer.size() - stream.avail_out);
} while (ret != Z_STREAM_END);
inflateEnd(&stream);
return output;
}
void Bytes::writeToFile(const std::string& filename) const
{
std::ofstream f(filename, std::ios::out | std::ios::binary);
if (!f.is_open())
error("cannot open output file '{}'", filename);
f.write((const char*)cbegin(), size());
f.close();
}
void Bytes::writeTo(std::ostream& stream) const
{
stream.write((const char*)cbegin(), size());
}
ByteReader Bytes::reader() const
{
return ByteReader(*this);
}
ByteWriter Bytes::writer()
{
return ByteWriter(*this);
}
uint64_t ByteReader::read_be48()
{
return ((uint64_t)read_be16() << 32) | read_be32();
}
uint64_t ByteReader::read_be64()
{
return ((uint64_t)read_be32() << 32) | read_be32();
}
ByteWriter& ByteWriter::append(std::istream& stream, size_t length)
{
Bytes buffer(4096);
while (length != 0)
{
size_t chunk = std::min((size_t)buffer.size(), length);
if (!stream.read((char*)buffer.begin(), chunk))
{
this->append(buffer.slice(0, stream.gcount()));
break;
}
else
this->append(buffer);
length -= chunk;
}
return *this;
}
ByteWriter& ByteWriter::pad(unsigned count, uint8_t b)
{
while (count--)
this->write_8(b);
return *this;
}
void BitWriter::push(uint32_t bits, size_t size)
{
bits <<= 32 - size;
while (size-- != 0)
{
_fifo = (_fifo << 1) | (bits >> 31);
_bitcount++;
bits <<= 1;
if (_bitcount == 8)
{
_bw.write_8(_fifo);
_bitcount = 0;
_fifo = 0;
}
}
}
void BitWriter::flush()
{
if (_bitcount != 0)
{
_bw.write_8(_fifo);
_bitcount = 0;
}
}
bool BitReader::eof()
{
return (_bitcount == 0) && _br.eof();
}
bool BitReader::get()
{
if (_bitcount == 0)
_fifo = _br.read_8();
bool bit = _fifo & 0x80;
_fifo <<= 1;
_bitcount = (_bitcount + 1) & 7;
return bit;
}
std::vector<bool> reverseBits(const std::vector<bool>& bits)
{
std::vector<bool> output(bits.rbegin(), bits.rend());
return output;
}