minetest/src/database-sqlite3.cpp
2016-07-08 07:08:33 +02:00

301 lines
8.8 KiB
C++

/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/*
SQLite format specification:
blocks:
(PK) INT id
BLOB data
*/
#include "database-sqlite3.h"
#include "log.h"
#include "filesys.h"
#include "exceptions.h"
#include "settings.h"
#include "porting.h"
#include "util/string.h"
#include <cassert>
// When to print messages when the database is being held locked by another process
// Note: I've seen occasional delays of over 250ms while running minetestmapper.
#define BUSY_INFO_TRESHOLD 100 // Print first informational message after 100ms.
#define BUSY_WARNING_TRESHOLD 250 // Print warning message after 250ms. Lag is increased.
#define BUSY_ERROR_TRESHOLD 1000 // Print error message after 1000ms. Significant lag.
#define BUSY_FATAL_TRESHOLD 3000 // Allow SQLITE_BUSY to be returned, which will cause a minetest crash.
#define BUSY_ERROR_INTERVAL 10000 // Safety net: report again every 10 seconds
#define SQLRES(s, r, m) \
if ((s) != (r)) { \
throw DatabaseException(std::string(m) + ": " +\
sqlite3_errmsg(m_database)); \
}
#define SQLOK(s, m) SQLRES(s, SQLITE_OK, m)
#define PREPARE_STATEMENT(name, query) \
SQLOK(sqlite3_prepare_v2(m_database, query, -1, &m_stmt_##name, NULL),\
"Failed to prepare query '" query "'")
#define SQLOK_ERRSTREAM(s, m) \
if ((s) != SQLITE_OK) { \
errorstream << (m) << ": " \
<< sqlite3_errmsg(m_database) << std::endl; \
}
#define FINALIZE_STATEMENT(statement) SQLOK_ERRSTREAM(sqlite3_finalize(statement), \
"Failed to finalize " #statement)
int Database_SQLite3::busyHandler(void *data, int count)
{
s64 &first_time = reinterpret_cast<s64 *>(data)[0];
s64 &prev_time = reinterpret_cast<s64 *>(data)[1];
s64 cur_time = getTimeMs();
if (count == 0) {
first_time = cur_time;
prev_time = first_time;
} else {
while (cur_time < prev_time)
cur_time += s64(1)<<32;
}
if (cur_time - first_time < BUSY_INFO_TRESHOLD) {
; // do nothing
} else if (cur_time - first_time >= BUSY_INFO_TRESHOLD &&
prev_time - first_time < BUSY_INFO_TRESHOLD) {
infostream << "SQLite3 database has been locked for "
<< cur_time - first_time << " ms." << std::endl;
} else if (cur_time - first_time >= BUSY_WARNING_TRESHOLD &&
prev_time - first_time < BUSY_WARNING_TRESHOLD) {
warningstream << "SQLite3 database has been locked for "
<< cur_time - first_time << " ms." << std::endl;
} else if (cur_time - first_time >= BUSY_ERROR_TRESHOLD &&
prev_time - first_time < BUSY_ERROR_TRESHOLD) {
errorstream << "SQLite3 database has been locked for "
<< cur_time - first_time << " ms; this causes lag." << std::endl;
} else if (cur_time - first_time >= BUSY_FATAL_TRESHOLD &&
prev_time - first_time < BUSY_FATAL_TRESHOLD) {
errorstream << "SQLite3 database has been locked for "
<< cur_time - first_time << " ms - giving up!" << std::endl;
} else if ((cur_time - first_time) / BUSY_ERROR_INTERVAL !=
(prev_time - first_time) / BUSY_ERROR_INTERVAL) {
// Safety net: keep reporting every BUSY_ERROR_INTERVAL
errorstream << "SQLite3 database has been locked for "
<< (cur_time - first_time) / 1000 << " seconds!" << std::endl;
}
prev_time = cur_time;
// Make sqlite transaction fail if delay exceeds BUSY_FATAL_TRESHOLD
return cur_time - first_time < BUSY_FATAL_TRESHOLD;
}
Database_SQLite3::Database_SQLite3(const std::string &savedir) :
m_initialized(false),
m_savedir(savedir),
m_database(NULL),
m_stmt_read(NULL),
m_stmt_write(NULL),
m_stmt_list(NULL),
m_stmt_delete(NULL),
m_stmt_begin(NULL),
m_stmt_end(NULL)
{
}
void Database_SQLite3::beginSave() {
verifyDatabase();
SQLRES(sqlite3_step(m_stmt_begin), SQLITE_DONE,
"Failed to start SQLite3 transaction");
sqlite3_reset(m_stmt_begin);
}
void Database_SQLite3::endSave() {
verifyDatabase();
SQLRES(sqlite3_step(m_stmt_end), SQLITE_DONE,
"Failed to commit SQLite3 transaction");
sqlite3_reset(m_stmt_end);
}
void Database_SQLite3::openDatabase()
{
if (m_database) return;
std::string dbp = m_savedir + DIR_DELIM + "map.sqlite";
// Open the database connection
if (!fs::CreateAllDirs(m_savedir)) {
infostream << "Database_SQLite3: Failed to create directory \""
<< m_savedir << "\"" << std::endl;
throw FileNotGoodException("Failed to create database "
"save directory");
}
bool needs_create = !fs::PathExists(dbp);
SQLOK(sqlite3_open_v2(dbp.c_str(), &m_database,
SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, NULL),
std::string("Failed to open SQLite3 database file ") + dbp);
SQLOK(sqlite3_busy_handler(m_database, Database_SQLite3::busyHandler,
m_busy_handler_data), "Failed to set SQLite3 busy handler");
if (needs_create) {
createDatabase();
}
std::string query_str = std::string("PRAGMA synchronous = ")
+ itos(g_settings->getU16("sqlite_synchronous"));
SQLOK(sqlite3_exec(m_database, query_str.c_str(), NULL, NULL, NULL),
"Failed to modify sqlite3 synchronous mode");
}
void Database_SQLite3::verifyDatabase()
{
if (m_initialized) return;
openDatabase();
PREPARE_STATEMENT(begin, "BEGIN");
PREPARE_STATEMENT(end, "COMMIT");
PREPARE_STATEMENT(read, "SELECT `data` FROM `blocks` WHERE `pos` = ? LIMIT 1");
#ifdef __ANDROID__
PREPARE_STATEMENT(write, "INSERT INTO `blocks` (`pos`, `data`) VALUES (?, ?)");
#else
PREPARE_STATEMENT(write, "REPLACE INTO `blocks` (`pos`, `data`) VALUES (?, ?)");
#endif
PREPARE_STATEMENT(delete, "DELETE FROM `blocks` WHERE `pos` = ?");
PREPARE_STATEMENT(list, "SELECT `pos` FROM `blocks`");
m_initialized = true;
verbosestream << "ServerMap: SQLite3 database opened." << std::endl;
}
inline void Database_SQLite3::bindPos(sqlite3_stmt *stmt, const v3s16 &pos, int index)
{
SQLOK(sqlite3_bind_int64(stmt, index, getBlockAsInteger(pos)),
"Internal error: failed to bind query at " __FILE__ ":" TOSTRING(__LINE__));
}
bool Database_SQLite3::deleteBlock(const v3s16 &pos)
{
verifyDatabase();
bindPos(m_stmt_delete, pos);
bool good = sqlite3_step(m_stmt_delete) == SQLITE_DONE;
sqlite3_reset(m_stmt_delete);
if (!good) {
warningstream << "deleteBlock: Block failed to delete "
<< PP(pos) << ": " << sqlite3_errmsg(m_database) << std::endl;
}
return good;
}
bool Database_SQLite3::saveBlock(const v3s16 &pos, const std::string &data)
{
verifyDatabase();
#ifdef __ANDROID__
/**
* Note: For some unknown reason SQLite3 fails to REPLACE blocks on Android,
* deleting them and then inserting works.
*/
bindPos(m_stmt_read, pos);
if (sqlite3_step(m_stmt_read) == SQLITE_ROW) {
deleteBlock(pos);
}
sqlite3_reset(m_stmt_read);
#endif
bindPos(m_stmt_write, pos);
SQLOK(sqlite3_bind_blob(m_stmt_write, 2, data.data(), data.size(), NULL),
"Internal error: failed to bind query at " __FILE__ ":" TOSTRING(__LINE__));
SQLRES(sqlite3_step(m_stmt_write), SQLITE_DONE, "Failed to save block")
sqlite3_reset(m_stmt_write);
return true;
}
void Database_SQLite3::loadBlock(const v3s16 &pos, std::string *block)
{
verifyDatabase();
bindPos(m_stmt_read, pos);
if (sqlite3_step(m_stmt_read) != SQLITE_ROW) {
sqlite3_reset(m_stmt_read);
return;
}
const char *data = (const char *) sqlite3_column_blob(m_stmt_read, 0);
size_t len = sqlite3_column_bytes(m_stmt_read, 0);
*block = (data) ? std::string(data, len) : "";
sqlite3_step(m_stmt_read);
// We should never get more than 1 row, so ok to reset
sqlite3_reset(m_stmt_read);
}
void Database_SQLite3::createDatabase()
{
assert(m_database); // Pre-condition
SQLOK(sqlite3_exec(m_database,
"CREATE TABLE IF NOT EXISTS `blocks` (\n"
" `pos` INT PRIMARY KEY,\n"
" `data` BLOB\n"
");\n",
NULL, NULL, NULL),
"Failed to create database table");
}
void Database_SQLite3::listAllLoadableBlocks(std::vector<v3s16> &dst)
{
verifyDatabase();
while (sqlite3_step(m_stmt_list) == SQLITE_ROW) {
dst.push_back(getIntegerAsBlock(sqlite3_column_int64(m_stmt_list, 0)));
}
sqlite3_reset(m_stmt_list);
}
Database_SQLite3::~Database_SQLite3()
{
FINALIZE_STATEMENT(m_stmt_read)
FINALIZE_STATEMENT(m_stmt_write)
FINALIZE_STATEMENT(m_stmt_list)
FINALIZE_STATEMENT(m_stmt_begin)
FINALIZE_STATEMENT(m_stmt_end)
FINALIZE_STATEMENT(m_stmt_delete)
SQLOK_ERRSTREAM(sqlite3_close(m_database), "Failed to close database");
}