ladybird/AK/MemoryStream.h
Andreas Kling 5d180d1f99 Everywhere: Rename ASSERT => VERIFY
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)

Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.

We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
2021-02-23 20:56:54 +01:00

343 lines
9.5 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/ByteBuffer.h>
#include <AK/MemMem.h>
#include <AK/Stream.h>
#include <AK/Vector.h>
namespace AK {
class InputMemoryStream final : public InputStream {
public:
explicit InputMemoryStream(ReadonlyBytes bytes)
: m_bytes(bytes)
{
}
bool unreliable_eof() const override { return eof(); }
bool eof() const { return m_offset >= m_bytes.size(); }
size_t read(Bytes bytes) override
{
if (has_any_error())
return 0;
const auto count = min(bytes.size(), remaining());
__builtin_memcpy(bytes.data(), m_bytes.data() + m_offset, count);
m_offset += count;
return count;
}
bool read_or_error(Bytes bytes) override
{
if (remaining() < bytes.size()) {
set_recoverable_error();
return false;
}
__builtin_memcpy(bytes.data(), m_bytes.data() + m_offset, bytes.size());
m_offset += bytes.size();
return true;
}
bool discard_or_error(size_t count) override
{
if (remaining() < count) {
set_recoverable_error();
return false;
}
m_offset += count;
return true;
}
void seek(size_t offset)
{
VERIFY(offset < m_bytes.size());
m_offset = offset;
}
u8 peek_or_error() const
{
if (remaining() == 0) {
set_recoverable_error();
return 0;
}
return m_bytes[m_offset];
}
bool read_LEB128_unsigned(size_t& result)
{
const auto backup = m_offset;
result = 0;
size_t num_bytes = 0;
while (true) {
if (eof()) {
m_offset = backup;
set_recoverable_error();
return false;
}
const u8 byte = m_bytes[m_offset];
result = (result) | (static_cast<size_t>(byte & ~(1 << 7)) << (num_bytes * 7));
++m_offset;
if (!(byte & (1 << 7)))
break;
++num_bytes;
}
return true;
}
bool read_LEB128_signed(ssize_t& result)
{
const auto backup = m_offset;
result = 0;
size_t num_bytes = 0;
u8 byte = 0;
do {
if (eof()) {
m_offset = backup;
set_recoverable_error();
return false;
}
byte = m_bytes[m_offset];
result = (result) | (static_cast<size_t>(byte & ~(1 << 7)) << (num_bytes * 7));
++m_offset;
++num_bytes;
} while (byte & (1 << 7));
if (num_bytes * 7 < sizeof(size_t) * 4 && (byte & 0x40)) {
// sign extend
result |= ((size_t)(-1) << (num_bytes * 7));
}
return true;
}
ReadonlyBytes bytes() const { return m_bytes; }
size_t offset() const { return m_offset; }
size_t remaining() const { return m_bytes.size() - m_offset; }
private:
ReadonlyBytes m_bytes;
size_t m_offset { 0 };
};
class OutputMemoryStream final : public OutputStream {
public:
explicit OutputMemoryStream(Bytes bytes)
: m_bytes(bytes)
{
}
size_t write(ReadonlyBytes bytes) override
{
const auto nwritten = bytes.copy_trimmed_to(m_bytes.slice(m_offset));
m_offset += nwritten;
return nwritten;
}
bool write_or_error(ReadonlyBytes bytes) override
{
if (remaining() < bytes.size()) {
set_recoverable_error();
return false;
}
write(bytes);
return true;
}
size_t fill_to_end(u8 value)
{
const auto nwritten = m_bytes.slice(m_offset).fill(value);
m_offset += nwritten;
return nwritten;
}
bool is_end() const { return remaining() == 0; }
ReadonlyBytes bytes() const { return { data(), size() }; }
Bytes bytes() { return { data(), size() }; }
const u8* data() const { return m_bytes.data(); }
u8* data() { return m_bytes.data(); }
size_t size() const { return m_offset; }
size_t remaining() const { return m_bytes.size() - m_offset; }
private:
size_t m_offset { 0 };
Bytes m_bytes;
};
class DuplexMemoryStream final : public DuplexStream {
public:
static constexpr size_t chunk_size = 4 * 1024;
bool unreliable_eof() const override { return eof(); }
bool eof() const { return m_write_offset == m_read_offset; }
bool discard_or_error(size_t count) override
{
if (m_write_offset - m_read_offset < count) {
set_recoverable_error();
return false;
}
m_read_offset += count;
try_discard_chunks();
return true;
}
Optional<size_t> offset_of(ReadonlyBytes value) const
{
// We can't directly pass m_chunks to memmem since we have a limited read/write range we want to search in.
Vector<ReadonlyBytes> spans;
auto chunk_index = (m_read_offset - m_base_offset) / chunk_size;
auto chunk_read_offset = (m_read_offset - m_base_offset) % chunk_size;
auto bytes_to_search = m_write_offset - m_read_offset;
for (; bytes_to_search > 0;) {
ReadonlyBytes span = m_chunks[chunk_index];
if (chunk_read_offset) {
span = span.slice(chunk_read_offset);
chunk_read_offset = 0;
}
if (bytes_to_search < span.size()) {
spans.append(span.slice(0, bytes_to_search));
break;
}
bytes_to_search -= span.size();
spans.append(move(span));
++chunk_index;
}
return memmem(spans.begin(), spans.end(), value);
}
size_t read_without_consuming(Bytes bytes) const
{
size_t nread = 0;
while (bytes.size() - nread > 0 && m_write_offset - m_read_offset - nread > 0) {
const auto chunk_index = (m_read_offset - m_base_offset + nread) / chunk_size;
const auto chunk_bytes = m_chunks[chunk_index].bytes().slice((m_read_offset + nread) % chunk_size).trim(m_write_offset - m_read_offset - nread);
nread += chunk_bytes.copy_trimmed_to(bytes.slice(nread));
}
return nread;
}
size_t read(Bytes bytes) override
{
if (has_any_error())
return 0;
const auto nread = read_without_consuming(bytes);
m_read_offset += nread;
try_discard_chunks();
return nread;
}
bool read_or_error(Bytes bytes) override
{
if (m_write_offset - m_read_offset < bytes.size()) {
set_recoverable_error();
return false;
}
return read(bytes) == bytes.size();
}
size_t write(ReadonlyBytes bytes) override
{
// FIXME: This doesn't write around chunk borders correctly?
size_t nwritten = 0;
while (bytes.size() - nwritten > 0) {
if ((m_write_offset + nwritten) % chunk_size == 0)
m_chunks.append(ByteBuffer::create_uninitialized(chunk_size));
nwritten += bytes.slice(nwritten).copy_trimmed_to(m_chunks.last().bytes().slice((m_write_offset + nwritten) % chunk_size));
}
m_write_offset += nwritten;
return nwritten;
}
bool write_or_error(ReadonlyBytes bytes) override
{
write(bytes);
return true;
}
ByteBuffer copy_into_contiguous_buffer() const
{
auto buffer = ByteBuffer::create_uninitialized(size());
const auto nread = read_without_consuming(buffer);
VERIFY(nread == buffer.size());
return buffer;
}
size_t roffset() const { return m_read_offset; }
size_t woffset() const { return m_write_offset; }
size_t size() const { return m_write_offset - m_read_offset; }
private:
void try_discard_chunks()
{
while (m_read_offset - m_base_offset >= chunk_size) {
m_chunks.take_first();
m_base_offset += chunk_size;
}
}
Vector<ByteBuffer> m_chunks;
size_t m_write_offset { 0 };
size_t m_read_offset { 0 };
size_t m_base_offset { 0 };
};
}
using AK::DuplexMemoryStream;
using AK::InputMemoryStream;
using AK::InputStream;
using AK::OutputMemoryStream;