Function LoadPakDir

dev/src/compiler.cpp:291–326

This just loads the directory part of a pakfile such that subsequent LoadFile calls know how to load from it.

// This just loads the directory part of a pakfile such that subsequent LoadFile calls know how
// to load from it.
bool LoadPakDir(const char *lpak, uint64_t &src_hash_dest) {
    // This supports reading from a pakfile > 4GB even on a 32bit system! (as long as individual
    // files in it are <= 4GB).
    auto plen = LoadFile(lpak, nullptr, 0, 0);
    if (plen < 0) return false;
    string header;
    if (LoadFile(lpak, &header, plen - (int64_t)header_size, header_size) < 0 ||
        memcmp(header.c_str() + header_size - magic_size, magic, magic_size)) return false;
    auto read_unaligned64 = [](const void *p) {
        int64_t r;
        memcpy(&r, p, sizeof(int64_t));
        return LE(r);
    };
    auto src_hash = (uint64_t)read_unaligned64((int64_t *)header.c_str());
    auto num = read_unaligned64((int64_t *)header.c_str() + 1);
    auto dirstart = read_unaligned64((int64_t *)header.c_str() + 2);
    auto version = read_unaligned64((int64_t *)header.c_str() + 3);
    if (version != current_version) return false;
    if (dirstart > plen) return false;
    string dir;
    if (LoadFile(lpak, &dir, dirstart, plen - dirstart - (int64_t)header_size) < 0)
        return false;
    auto namestarts = (int64_t *)(dir.c_str() + dir.length()) - num;
    auto filestarts = namestarts - num;
    auto uncompressed = filestarts - num;
    for (int64_t i = 0; i < num; i++) {
        auto name = string_view(dir.c_str() + (read_unaligned64(namestarts + i) - dirstart));
        auto off = read_unaligned64(filestarts + i);
        auto end = i < num + 1 ? read_unaligned64(filestarts + i + 1) : dirstart;
        auto len = end - off;
        LOG_INFO("pakfile dir: ", name, " : ", len);
        AddPakFileEntry(lpak, name, off, len, read_unaligned64(uncompressed + i));
    }
    src_hash_dest = src_hash;
    return true;
}

bool LoadMetaDataAndCode(string &metadata, string &c_codegen) {
    if (LoadFile(mdname, &metadata) < 0) return false;