Method Write

src/net.cpp:1519–1553

CAddrDB::CAddrDB() { pathAddr = GetDataDir() / "peers.dat"; }

bool CAddrDB::Write(const CAddrMan& addr) {
    // Generate random temporary filename
    uint16_t randv = 0;
    RAND_bytes((uint8_t*)&randv, sizeof(randv));
    string tmpfn = strprintf("peers.dat.%04x", randv);

    // serialize addresses, checksum data up to that point, then append csum
    CDataStream ssPeers(SER_DISK, CLIENT_VERSION);
    ssPeers << FLATDATA(SysCfg().MessageStart());
    ssPeers << addr;
    uint256 hash = Hash(ssPeers.begin(), ssPeers.end());
    ssPeers << hash;

    // open temp output file, and associate with CAutoFile
    boost::filesystem::path pathTmp = GetDataDir() / tmpfn;
    FILE* file                      = fopen(pathTmp.string().c_str(), "wb");
    CAutoFile fileout               = CAutoFile(file, SER_DISK, CLIENT_VERSION);
    if (!fileout)
        return ERRORMSG("Failed to open file %s", pathTmp.string());

    // Write and commit header, data
    try {
        fileout << ssPeers;
    } catch (std::exception& e) {
        return ERRORMSG("Serialize or I/O error - %s", e.what());
    }
    FileCommit(fileout);
    fileout.fclose();

    // replace existing peers.dat, if any, with new peers.dat.XXXX
    if (!RenameOver(pathTmp, pathAddr))
        return ERRORMSG("Rename-into-path failed");

    return true;
}

bool CAddrDB::Read(CAddrMan& addr) {
    // open input file, and associate with CAutoFile