Files
psopeeps-newserv/src/AFSArchive.cc
T
Martin Michelsen 1bfbf09891 use phosg namespace
2024-07-28 11:54:41 -07:00

87 lines
2.4 KiB
C++

#include "AFSArchive.hh"
#include <stdio.h>
#include <string.h>
#include <phosg/Encoding.hh>
#include <phosg/Filesystem.hh>
#include <phosg/Strings.hh>
#include "Text.hh"
using namespace std;
AFSArchive::AFSArchive(shared_ptr<const string> data)
: data(data) {
struct FileHeader {
be_uint32_t magic;
le_uint32_t num_files;
} __packed_ws__(FileHeader, 8);
struct FileEntry {
le_uint32_t offset;
le_uint32_t size;
} __packed_ws__(FileEntry, 8);
phosg::StringReader r(*this->data);
const auto& header = r.get<FileHeader>();
if (header.magic != 0x41465300) { // 'AFS\0'
throw runtime_error("file is not an AFS archive");
}
while (this->entries.size() < header.num_files) {
const auto& entry = r.get<FileEntry>();
this->entries.emplace_back(Entry{.offset = entry.offset, .size = entry.size});
}
}
pair<const void*, size_t> AFSArchive::get(size_t index) const {
const auto& entry = this->entries.at(index);
if (entry.offset > this->data->size()) {
throw out_of_range("entry begins beyond end of archive");
}
if (entry.offset + entry.size > this->data->size()) {
throw out_of_range("entry extends beyond end of archive");
}
return make_pair(this->data->data() + entry.offset, entry.size);
}
string AFSArchive::get_copy(size_t index) const {
auto ret = this->get(index);
return string(reinterpret_cast<const char*>(ret.first), ret.second);
}
phosg::StringReader AFSArchive::get_reader(size_t index) const {
auto ret = this->get(index);
return phosg::StringReader(ret.first, ret.second);
}
string AFSArchive::generate(const vector<string>& files, bool big_endian) {
return big_endian ? AFSArchive::generate_t<true>(files) : AFSArchive::generate_t<false>(files);
}
template <bool BE>
string AFSArchive::generate_t(const vector<string>& files) {
phosg::StringWriter w;
w.put_u32b(0x41465300); // 'AFS\0'
w.put<U32T<BE>>(files.size());
// It seems entries are aligned to 0x800-byte boundaries, and the file's
// header is always 0x80000 (!) bytes, most of which is unused
uint32_t data_offset = 0x80000;
for (const auto& file : files) {
w.put<U32T<BE>>(data_offset);
w.put<U32T<BE>>(file.size());
data_offset = (data_offset + file.size() + 0x7FF) & (~0x7FF);
}
w.extend_to(0x80000);
for (const auto& file : files) {
w.write(file);
w.extend_to((w.size() + 0x7FF) & (~0x7FF));
}
return std::move(w.str());
}