Files
rman/lib/rlib/ar_fsb5.cpp
2022-10-20 21:22:29 +02:00

75 lines
2.7 KiB
C++

#include "ar.hpp"
using namespace rlib;
struct Ar::FSB5 {
struct Header;
static constexpr auto MAGIC = std::array{'F', 'S', 'B', '5'};
};
auto Ar::process_try_fsb5(IO const& io, offset_cb cb, Entry const& top_entry) const -> bool {
auto reader = IO::Reader(io, top_entry.offset, top_entry.size);
// check if the file is actually FSB5
auto magic = std::array<char, 4>{};
if (!reader.read(magic) || magic != FSB5::MAGIC) return false;
auto desc_count = std::size_t{};
auto toc_size = std::size_t{};
auto strings_size = std::size_t{};
auto data_size = std::size_t{};
auto mode = std::uint32_t{};
rlib_ar_assert(reader.skip(4)); // version
rlib_ar_assert(reader.read(desc_count, std::uint32_t{}));
rlib_ar_assert(reader.read(toc_size, std::uint32_t{}));
rlib_ar_assert(reader.read(strings_size, std::uint32_t{}));
rlib_ar_assert(reader.read(data_size, std::uint32_t{}));
rlib_ar_assert(reader.read(mode, std::uint32_t{}));
rlib_ar_assert(reader.skip(8)); // zero
rlib_ar_assert(reader.skip(16)); // hash
rlib_ar_assert(reader.skip(8)); // dummy
rlib_ar_assert(toc_size / 8 >= desc_count);
auto reader_toc = IO::Reader();
rlib_ar_assert(reader.read_within(reader_toc, toc_size));
rlib_ar_assert(reader.skip(strings_size));
auto reader_data = IO::Reader();
rlib_ar_assert(reader.offset() % 32 == 0);
rlib_ar_assert(reader.remains() == data_size);
rlib_ar_assert(reader.read_within(reader_data, data_size));
auto offsets = std::vector<std::size_t>(desc_count);
for (std::size_t i = 0; i != desc_count; ++i) {
auto packed = std::uint64_t{};
rlib_ar_assert(reader_toc.read(packed, std::uint64_t{}));
for (auto extra = packed & 1; extra & 1;) {
rlib_ar_assert(reader_toc.read(extra, std::uint32_t{}));
auto extra_size = (extra >> 1) & 0xFF'FF'FF;
rlib_ar_assert(reader_toc.skip(extra_size));
}
auto offset = ((packed >> 6) & 0xFFFFFFF) * 16;
rlib_ar_assert(offset <= data_size);
offsets[i] = offset;
}
std::sort(offsets.begin(), offsets.end());
auto entries = std::vector<Entry>(desc_count);
auto last_offset = data_size;
for (std::size_t i = desc_count; i != 0; --i) {
auto offset = offsets[i - 1];
entries[i - 1] = Entry{
.offset = reader_data.start() + offset,
.size = (last_offset - offset),
.high_entropy = true,
};
last_offset = offset;
}
rlib_ar_assert(last_offset == data_size || last_offset == 0);
rlib_ar_assert(this->process_iter(io, cb, top_entry, std::move(entries)));
return true;
}