ladybird/AK/BufferStream.h
Andreas Kling 18aeda2e0d BufferStream: It's not an error to read up to the very end of a buffer
Don't signal an error before we've reached the very end of the buffer.
2019-08-03 19:20:05 +02:00

231 lines
5.3 KiB
C++

#pragma once
#include <AK/AKString.h>
#include <AK/ByteBuffer.h>
namespace AK {
class BufferStream {
public:
explicit BufferStream(ByteBuffer& buffer)
: m_buffer(buffer)
{
}
~BufferStream()
{
ASSERT(!m_read_failure);
}
BufferStream& operator<<(i8 value)
{
m_buffer[m_offset++] = value;
return *this;
}
BufferStream& operator>>(i8& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = m_buffer[m_offset++];
return *this;
}
BufferStream& operator<<(u8 value)
{
m_buffer[m_offset++] = value;
return *this;
}
BufferStream& operator>>(u8& value )
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = m_buffer[m_offset++];
return *this;
}
BufferStream& operator<<(bool value)
{
m_buffer[m_offset++] = value;
return *this;
}
BufferStream& operator>>(bool& value )
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = m_buffer[m_offset++];
return *this;
}
BufferStream& operator<<(char value)
{
m_buffer[m_offset++] = (u8)value;
return *this;
}
BufferStream& operator>>(char& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = (u8)m_buffer[m_offset++];
return *this;
}
BufferStream& operator<<(u16 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
return *this;
}
BufferStream& operator>>(u16& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = 0;
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
value |= (u8(b1) << 8);
value |= (u8(b0));
return *this;
}
BufferStream& operator<<(i16 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
return *this;
}
BufferStream& operator>>(i16& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = 0;
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
value |= (u8(b1) << 8);
value |= (u8(b0));
return *this;
}
BufferStream& operator<<(u32 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
m_buffer[m_offset++] = (u8)(value >> 16);
m_buffer[m_offset++] = (u8)(value >> 24);
return *this;
}
BufferStream& operator>>(u32& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
u8 b2 = m_buffer[m_offset++];
u8 b3 = m_buffer[m_offset++];
value = 0;
value |= (u8(b3) << 24);
value |= (u8(b2) << 16);
value |= (u8(b1) << 8);
value |= (u8(b0));
return *this;
}
BufferStream& operator<<(i32 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
m_buffer[m_offset++] = (u8)(value >> 16);
m_buffer[m_offset++] = (u8)(value >> 24);
return *this;
}
BufferStream& operator>>(i32& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
u8 b2 = m_buffer[m_offset++];
u8 b3 = m_buffer[m_offset++];
value = 0;
value |= (u8(b3) << 24);
value |= (u8(b2) << 16);
value |= (u8(b1) << 8);
value |= (u8(b0));
return *this;
}
BufferStream& operator<<(const char* value)
{
return *this << StringView(value);
}
BufferStream& operator<<(const StringView& value)
{
for (ssize_t i = 0; i < value.length(); ++i)
m_buffer[m_offset++] = value[i];
return *this;
}
BufferStream& operator<<(const ByteBuffer& value)
{
for (ssize_t i = 0; i < value.size(); ++i)
m_buffer[m_offset++] = value[i];
return *this;
}
bool at_end() const
{
return m_offset == m_buffer.size();
}
void fill_to_end(u8 ch)
{
while (!at_end())
m_buffer[m_offset++] = ch;
}
ssize_t offset() const { return m_offset; }
void snip()
{
m_buffer.trim(m_offset);
}
void reset()
{
m_offset = 0;
m_read_failure = false;
}
bool handle_read_failure() {
bool old = m_read_failure;
m_read_failure = false;
return old;
}
private:
ByteBuffer& m_buffer;
ssize_t m_offset { 0 };
bool m_read_failure { false };
};
}
using AK::BufferStream;