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LibCompress: Port GzipDecompressor to Core::Stream

This commit is contained in:
Tim Schumacher 2022-11-29 15:43:31 +01:00 committed by Linus Groh
parent 4e7da96d58
commit f93c7fbb5e
9 changed files with 80 additions and 145 deletions

View file

@ -10,6 +10,7 @@
#include <AK/DeprecatedString.h>
#include <AK/MemoryStream.h>
#include <LibCore/DateTime.h>
#include <LibCore/MemoryStream.h>
namespace Compress {
@ -38,8 +39,8 @@ bool BlockHeader::supported_by_implementation() const
return true;
}
GzipDecompressor::GzipDecompressor(InputStream& stream)
: m_input_stream(stream)
GzipDecompressor::GzipDecompressor(NonnullOwnPtr<Core::Stream::Stream> stream)
: m_input_stream(move(stream))
{
}
@ -48,12 +49,11 @@ GzipDecompressor::~GzipDecompressor()
m_current_member.clear();
}
// FIXME: Again, there are surely a ton of bugs because the code doesn't check for read errors.
size_t GzipDecompressor::read(Bytes bytes)
ErrorOr<Bytes> GzipDecompressor::read(Bytes bytes)
{
size_t total_read = 0;
while (total_read < bytes.size()) {
if (has_any_error() || m_eof)
if (is_eof())
break;
auto slice = bytes.slice(total_read);
@ -63,26 +63,19 @@ size_t GzipDecompressor::read(Bytes bytes)
current_member().m_checksum.update(slice.trim(nread));
current_member().m_nread += nread;
if (current_member().m_stream.handle_any_error()) {
set_fatal_error();
break;
}
if (current_member().m_stream.handle_any_error())
return Error::from_string_literal("Underlying DeflateDecompressor indicated an error");
if (nread < slice.size()) {
LittleEndian<u32> crc32, input_size;
m_input_stream >> crc32 >> input_size;
TRY(m_input_stream->read(crc32.bytes()));
TRY(m_input_stream->read(input_size.bytes()));
if (crc32 != current_member().m_checksum.digest()) {
// FIXME: Somehow the checksum is incorrect?
if (crc32 != current_member().m_checksum.digest())
return Error::from_string_literal("Stored CRC32 does not match the calculated CRC32 of the current member");
set_fatal_error();
break;
}
if (input_size != current_member().m_nread) {
set_fatal_error();
break;
}
if (input_size != current_member().m_nread)
return Error::from_string_literal("Input size does not match the number of read bytes");
m_current_member.clear();
@ -93,12 +86,12 @@ size_t GzipDecompressor::read(Bytes bytes)
total_read += nread;
continue;
} else {
m_partial_header_offset += m_input_stream.read(Bytes { m_partial_header, sizeof(BlockHeader) }.slice(m_partial_header_offset));
auto current_partial_header_slice = Bytes { m_partial_header, sizeof(BlockHeader) }.slice(m_partial_header_offset);
auto current_partial_header_data = TRY(m_input_stream->read(current_partial_header_slice));
m_partial_header_offset += current_partial_header_data.size();
if (m_input_stream.handle_any_error() || m_input_stream.unreliable_eof()) {
m_eof = true;
if (is_eof())
break;
}
if (m_partial_header_offset < sizeof(BlockHeader)) {
break; // partial header read
@ -107,51 +100,45 @@ size_t GzipDecompressor::read(Bytes bytes)
BlockHeader header = *(reinterpret_cast<BlockHeader*>(m_partial_header));
if (!header.valid_magic_number() || !header.supported_by_implementation()) {
set_fatal_error();
break;
}
if (!header.valid_magic_number())
return Error::from_string_literal("Header does not have a valid magic number");
if (!header.supported_by_implementation())
return Error::from_string_literal("Header is not supported by implementation");
if (header.flags & Flags::FEXTRA) {
LittleEndian<u16> subfield_id, length;
m_input_stream >> subfield_id >> length;
m_input_stream.discard_or_error(length);
TRY(m_input_stream->read(subfield_id.bytes()));
TRY(m_input_stream->read(length.bytes()));
TRY(m_input_stream->discard(length));
}
auto discard_string = [&]() {
auto discard_string = [&]() -> ErrorOr<void> {
char next_char;
do {
m_input_stream >> next_char;
if (m_input_stream.has_any_error()) {
set_fatal_error();
break;
}
TRY(m_input_stream->read({ &next_char, sizeof(next_char) }));
} while (next_char);
return {};
};
if (header.flags & Flags::FNAME) {
discard_string();
if (has_any_error())
break;
}
if (header.flags & Flags::FNAME)
TRY(discard_string());
if (header.flags & Flags::FCOMMENT) {
discard_string();
if (has_any_error())
break;
}
if (header.flags & Flags::FCOMMENT)
TRY(discard_string());
if (header.flags & Flags::FHCRC) {
LittleEndian<u16> crc16;
m_input_stream >> crc16;
TRY(m_input_stream->read(crc16.bytes()));
// FIXME: we should probably verify this instead of just assuming it matches
}
m_current_member.emplace(header, m_input_stream);
m_current_member.emplace(header, *m_input_stream);
continue;
}
}
return total_read;
return bytes.slice(0, total_read);
}
Optional<DeprecatedString> GzipDecompressor::describe_header(ReadonlyBytes bytes)
@ -167,57 +154,26 @@ Optional<DeprecatedString> GzipDecompressor::describe_header(ReadonlyBytes bytes
return DeprecatedString::formatted("last modified: {}, original size {}", Core::DateTime::from_timestamp(header.modification_time).to_deprecated_string(), (u32)original_size);
}
bool GzipDecompressor::read_or_error(Bytes bytes)
ErrorOr<ByteBuffer> GzipDecompressor::decompress_all(ReadonlyBytes bytes)
{
if (read(bytes) < bytes.size()) {
set_fatal_error();
return false;
}
return true;
}
bool GzipDecompressor::discard_or_error(size_t count)
{
u8 buffer[4096];
size_t ndiscarded = 0;
while (ndiscarded < count) {
if (unreliable_eof()) {
set_fatal_error();
return false;
}
ndiscarded += read({ buffer, min<size_t>(count - ndiscarded, sizeof(buffer)) });
}
return true;
}
Optional<ByteBuffer> GzipDecompressor::decompress_all(ReadonlyBytes bytes)
{
InputMemoryStream memory_stream { bytes };
GzipDecompressor gzip_stream { memory_stream };
auto memory_stream = TRY(Core::Stream::MemoryStream::construct(bytes));
auto gzip_stream = make<GzipDecompressor>(move(memory_stream));
DuplexMemoryStream output_stream;
u8 buffer[4096];
while (!gzip_stream.has_any_error() && !gzip_stream.unreliable_eof()) {
auto const nread = gzip_stream.read({ buffer, sizeof(buffer) });
output_stream.write_or_error({ buffer, nread });
auto buffer = TRY(ByteBuffer::create_uninitialized(4096));
while (!gzip_stream->is_eof()) {
auto const data = TRY(gzip_stream->read(buffer));
output_stream.write_or_error(data);
}
if (gzip_stream.handle_any_error())
return {};
return output_stream.copy_into_contiguous_buffer();
}
bool GzipDecompressor::unreliable_eof() const { return m_eof; }
bool GzipDecompressor::is_eof() const { return m_input_stream->is_eof(); }
bool GzipDecompressor::handle_any_error()
ErrorOr<size_t> GzipDecompressor::write(ReadonlyBytes)
{
bool handled_errors = m_input_stream.handle_any_error();
return Stream::handle_any_error() || handled_errors;
VERIFY_NOT_REACHED();
}
GzipCompressor::GzipCompressor(OutputStream& stream)

View file

@ -8,6 +8,7 @@
#pragma once
#include <LibCompress/Deflate.h>
#include <LibCore/Stream.h>
#include <LibCrypto/Checksum/CRC32.h>
namespace Compress {
@ -37,32 +38,33 @@ struct Flags {
static constexpr u8 MAX = FTEXT | FHCRC | FEXTRA | FNAME | FCOMMENT;
};
class GzipDecompressor final : public InputStream {
class GzipDecompressor final : public Core::Stream::Stream {
public:
GzipDecompressor(InputStream&);
GzipDecompressor(NonnullOwnPtr<Core::Stream::Stream>);
~GzipDecompressor();
size_t read(Bytes) override;
bool read_or_error(Bytes) override;
bool discard_or_error(size_t) override;
virtual ErrorOr<Bytes> read(Bytes) override;
virtual ErrorOr<size_t> write(ReadonlyBytes) override;
virtual bool is_eof() const override;
virtual bool is_open() const override { return true; }
virtual void close() override {};
bool unreliable_eof() const override;
bool handle_any_error() override;
static Optional<ByteBuffer> decompress_all(ReadonlyBytes);
static ErrorOr<ByteBuffer> decompress_all(ReadonlyBytes);
static Optional<DeprecatedString> describe_header(ReadonlyBytes);
static bool is_likely_compressed(ReadonlyBytes bytes);
private:
class Member {
public:
Member(BlockHeader header, InputStream& stream)
Member(BlockHeader header, Core::Stream::Stream& stream)
: m_header(header)
, m_stream(stream)
, m_adapted_ak_stream(make<Core::Stream::WrapInAKInputStream>(stream))
, m_stream(*m_adapted_ak_stream)
{
}
BlockHeader m_header;
NonnullOwnPtr<InputStream> m_adapted_ak_stream;
DeflateDecompressor m_stream;
Crypto::Checksum::CRC32 m_checksum;
size_t m_nread { 0 };
@ -71,7 +73,7 @@ private:
Member const& current_member() const { return m_current_member.value(); }
Member& current_member() { return m_current_member.value(); }
InputStream& m_input_stream;
NonnullOwnPtr<Core::Stream::Stream> m_input_stream;
u8 m_partial_header[sizeof(BlockHeader)];
size_t m_partial_header_offset { 0 };
Optional<Member> m_current_member;