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#include "server/database.hh"
namespace server {
namespace database {
sqlite3* get_database() noexcept {
static sqlite3* const database = []() -> sqlite3* {
std::filesystem::create_directory(server::state.directory);
const std::string path = server::state.directory + "world.dat";
if (!std::filesystem::exists(path)) {
shared::print::warn(
"server: regenerating non-existent world data\n");
}
sqlite3* database = nullptr;
if (const int status = sqlite3_open(path.c_str(), &database);
status != SQLITE_OK) {
throw std::runtime_error("failed to open chunk database at " +
path);
}
return database;
}();
return database;
}
static void prepare(sqlite3_stmt*& statement, const std::string& sql) noexcept {
sqlite3* const db = get_database();
if (const int status = sqlite3_prepare_v2(
db, sql.c_str(), static_cast<int>(std::size(sql) + 1), &statement,
nullptr);
status != SQLITE_OK) {
throw std::runtime_error(std::string{"sqlite prepare error \""} +
sqlite3_errmsg(db) + '\"');
}
}
static auto step(sqlite3_stmt*& statement) noexcept {
const int status = sqlite3_step(statement);
if (status == SQLITE_ERROR) {
sqlite3* const db = get_database();
throw std::runtime_error(std::string{"sqlite step error \""} +
sqlite3_errmsg(db) + '\"');
}
return status;
}
static void finalise(sqlite3_stmt*& statement) noexcept {
if (const int status = sqlite3_finalize(statement); status != SQLITE_OK) {
throw std::runtime_error(std::string{"sqlite bind blob error \""} +
sqlite3_errstr(status) + '\"');
}
}
static void bind_int64(sqlite3_stmt*& statement, const int index,
const std::uint64_t& key) noexcept {
if (const int status = sqlite3_bind_int64(statement, index,
std::bit_cast<std::int64_t>(key));
status != SQLITE_OK) {
throw std::runtime_error(std::string{"sqlite bind int error \""} +
sqlite3_errstr(status) + '\"');
}
}
static void bind_text(sqlite3_stmt*& statement, const int index,
const std::string& text) noexcept {
if (const int status =
sqlite3_bind_text(statement, index, std::data(text),
static_cast<int>(std::size(text)), SQLITE_STATIC);
status != SQLITE_OK) {
throw std::runtime_error(std::string{"sqlite bind text error \""} +
sqlite3_errstr(status) + '\"');
}
}
template <typename T>
static void bind_blob(sqlite3_stmt*& statement, const int index,
const T& blob) noexcept {
if (const int status =
sqlite3_bind_blob(statement, index, std::data(blob),
static_cast<int>(std::size(blob)), SQLITE_STATIC);
status != SQLITE_OK) {
throw std::runtime_error(std::string{"sqlite bind blob error \""} +
sqlite3_errstr(status) + '\"');
}
}
static void exec_void_stmt(const std::string& sql) noexcept {
sqlite3_stmt* statement = nullptr;
prepare(statement, sql);
step(statement);
finalise(statement);
}
void init() noexcept {
exec_void_stmt("CREATE TABLE IF NOT EXISTS Chunks ("
" coords BIGINT PRIMARY KEY,"
" blocks BLOB NOT NULL"
");");
exec_void_stmt("CREATE TABLE IF NOT EXISTS Players ("
" username TEXT PRIMARY KEY,"
" password TEXT NOT NULL,"
" player BLOB NOT NULL"
");");
}
void quit() noexcept {
sqlite3* database = get_database();
if (const int status = sqlite3_close(database); status != SQLITE_OK) {
throw std::runtime_error(std::string{"failed to close chunk database"} +
sqlite3_errmsg(database));
};
}
// We have to store our key in network byte order!
static std::uint64_t make_key(const shared::math::coords& coords) noexcept {
const auto to_64 = [](const std::int32_t& val, const int lshift) {
return static_cast<std::uint64_t>(
htonl(std::bit_cast<std::uint32_t>(val)))
<< lshift;
};
return to_64(coords.x, 32) + to_64(coords.z, 0);
}
std::optional<proto::chunk>
maybe_read_chunk(const shared::math::coords& pos) noexcept {
sqlite3_stmt* statement = nullptr;
prepare(statement, "SELECT blocks FROM Chunks WHERE Chunks.coords = ?;");
bind_int64(statement, 1, make_key(pos));
if (step(statement) != SQLITE_ROW) {
finalise(statement);
return std::nullopt;
}
const char* addr =
static_cast<const char*>(sqlite3_column_blob(statement, 0));
std::string blocks{addr, addr + sqlite3_column_bytes(statement, 0)};
finalise(statement);
shared::decompress_string(blocks);
proto::chunk chunk;
if (!chunk.ParseFromString(blocks)) {
shared::print::fault("server: chunk [" + std::to_string(pos.x) + ", " +
std::to_string(pos.z) +
"] failed to parse and was evicted\n");
statement = nullptr;
prepare(statement, "DELETE FROM Chunks WHERE Chunks.coords = ?;");
bind_int64(statement, 1, make_key(pos));
step(statement);
finalise(statement);
return std::nullopt;
}
return chunk;
}
void write_chunk(const shared::math::coords& pos,
const proto::chunk& chunk) noexcept {
std::string blocks;
chunk.SerializeToString(&blocks);
shared::compress_string(blocks);
sqlite3_stmt* statement = nullptr;
prepare(statement, "INSERT OR REPLACE INTO Chunks VALUES(?, ?);");
bind_int64(statement, 1, make_key(pos));
bind_blob(statement, 2, blocks);
step(statement);
finalise(statement);
}
std::optional<std::pair<proto::player, std::string>>
maybe_read_player(const std::string& username) noexcept {
sqlite3_stmt* statement = nullptr;
prepare(statement, "SELECT player, password "
"FROM Players "
"WHERE Players.username = ?");
bind_text(statement, 1, username);
if (step(statement) != SQLITE_ROW) {
finalise(statement);
return std::nullopt;
}
const char* plr_adr =
static_cast<const char*>(sqlite3_column_blob(statement, 0));
std::string player_bytes{plr_adr, plr_adr + sqlite3_column_bytes(statement, 0)};
const unsigned char* pass_adr = sqlite3_column_text(statement, 1);
std::string pass_bytes{pass_adr, pass_adr + sqlite3_column_bytes(statement, 1)};
finalise(statement);
shared::decompress_string(player_bytes);
proto::player player;
if (!player.ParseFromString(player_bytes)) {
shared::print::fault("server: player \"" + username +
"\" failed to parse and was evicted\n");
statement = nullptr;
prepare(statement, "DELETE FROM Players WHERE Players.username = ?;");
bind_text(statement, 1, username);
step(statement);
finalise(statement);
return std::nullopt;
}
return std::make_pair(player, pass_bytes);
}
void write_player(const std::string& username, const std::string& password,
const proto::player& player) noexcept {
std::string player_bytes;
player.SerializeToString(&player_bytes);
shared::compress_string(player_bytes);
sqlite3_stmt* statement = nullptr;
prepare(statement, "INSERT OR REPLACE INTO Players VALUES(?, ?, ?);");
bind_text(statement, 1, username);
bind_text(statement, 2, password);
bind_blob(statement, 3, player_bytes);
step(statement);
finalise(statement);
}
} // namespace database
} // namespace server
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