src/database-sqlite3.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 /*
  21 SQLite format specification:
  22         blocks:
  23                 (PK) INT id
  24                 BLOB data
  25 */
  26
  27
  28 #include "database-sqlite3.h"
  29
  30 #include "log.h"
  31 #include "filesys.h"
  32 #include "exceptions.h"
  33 #include "settings.h"
  34 #include "util/string.h"
  35
  36 #include <cassert>
  37
  38
  39 #define SQLRES(s, r) \
  40         if ((s) != (r)) { \
  41                 throw FileNotGoodException(std::string(\
  42                                         "SQLite3 database error (" \
  43                                         __FILE__ ":" TOSTRING(__LINE__) \
  44                                         "): ") +\
  45                                 sqlite3_errmsg(m_database)); \
  46         }
  47 #define SQLOK(s) SQLRES(s, SQLITE_OK)
  48
  49 #define PREPARE_STATEMENT(name, query) \
  50         SQLOK(sqlite3_prepare_v2(m_database, query, -1, &m_stmt_##name, NULL))
  51
  52 #define FINALIZE_STATEMENT(statement) \
  53         if (sqlite3_finalize(statement) != SQLITE_OK) { \
  54                 throw FileNotGoodException(std::string( \
  55                         "SQLite3: Failed to finalize " #statement ": ") + \
  56                          sqlite3_errmsg(m_database)); \
  57         }
  58
  59
  60 Database_SQLite3::Database_SQLite3(const std::string &savedir) :
  61         m_initialized(false),
  62         m_savedir(savedir),
  63         m_database(NULL),
  64         m_stmt_read(NULL),
  65         m_stmt_write(NULL),
  66         m_stmt_list(NULL),
  67         m_stmt_delete(NULL),
  68         m_stmt_begin(NULL),
  69         m_stmt_end(NULL)
  70 {
  71 }
  72
  73 void Database_SQLite3::beginSave() {
  74         verifyDatabase();
  75         SQLRES(sqlite3_step(m_stmt_begin), SQLITE_DONE);
  76         sqlite3_reset(m_stmt_begin);
  77 }
  78
  79 void Database_SQLite3::endSave() {
  80         verifyDatabase();
  81         SQLRES(sqlite3_step(m_stmt_end), SQLITE_DONE);
  82         sqlite3_reset(m_stmt_end);
  83 }
  84
  85 void Database_SQLite3::openDatabase()
  86 {
  87         if (m_database) return;
  88
  89         std::string dbp = m_savedir + DIR_DELIM + "map.sqlite";
  90
  91         // Open the database connection
  92
  93         if (!fs::CreateAllDirs(m_savedir)) {
  94                 infostream << "Database_SQLite3: Failed to create directory \""
  95                         << m_savedir << "\"" << std::endl;
  96                 throw FileNotGoodException("Failed to create database "
  97                                 "save directory");
  98         }
  99
 100         bool needs_create = !fs::PathExists(dbp);
 101
 102         if (sqlite3_open_v2(dbp.c_str(), &m_database,
 103                         SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
 104                         NULL) != SQLITE_OK) {
 105                 errorstream << "SQLite3 database failed to open: "
 106                         << sqlite3_errmsg(m_database) << std::endl;
 107                 throw FileNotGoodException("Cannot open database file");
 108         }
 109
 110         if (needs_create) {
 111                 createDatabase();
 112         }
 113
 114         std::string query_str = std::string("PRAGMA synchronous = ")
 115                          + itos(g_settings->getU16("sqlite_synchronous"));
 116         SQLOK(sqlite3_exec(m_database, query_str.c_str(), NULL, NULL, NULL));
 117 }
 118
 119 void Database_SQLite3::verifyDatabase()
 120 {
 121         if (m_initialized) return;
 122
 123         openDatabase();
 124
 125         PREPARE_STATEMENT(begin, "BEGIN");
 126         PREPARE_STATEMENT(end, "COMMIT");
 127         PREPARE_STATEMENT(read, "SELECT `data` FROM `blocks` WHERE `pos` = ? LIMIT 1");
 128 #ifdef __ANDROID__
 129         PREPARE_STATEMENT(write,  "INSERT INTO `blocks` (`pos`, `data`) VALUES (?, ?)");
 130 #else
 131         PREPARE_STATEMENT(write, "REPLACE INTO `blocks` (`pos`, `data`) VALUES (?, ?)");
 132 #endif
 133         PREPARE_STATEMENT(delete, "DELETE FROM `blocks` WHERE `pos` = ?");
 134         PREPARE_STATEMENT(list, "SELECT `pos` FROM `blocks`");
 135
 136         m_initialized = true;
 137
 138         verbosestream << "ServerMap: SQLite3 database opened." << std::endl;
 139 }
 140
 141 inline void Database_SQLite3::bindPos(sqlite3_stmt *stmt, const v3s16 &pos, int index)
 142 {
 143         SQLOK(sqlite3_bind_int64(stmt, index, getBlockAsInteger(pos)));
 144 }
 145
 146 bool Database_SQLite3::deleteBlock(const v3s16 &pos)
 147 {
 148         verifyDatabase();
 149
 150         bindPos(m_stmt_delete, pos);
 151
 152         bool good = sqlite3_step(m_stmt_delete) == SQLITE_DONE;
 153         sqlite3_reset(m_stmt_delete);
 154
 155         if (!good) {
 156                 errorstream << "WARNING: deleteBlock: Block failed to delete "
 157                         << PP(pos) << ": " << sqlite3_errmsg(m_database) << std::endl;
 158         }
 159         return good;
 160 }
 161
 162 bool Database_SQLite3::saveBlock(const v3s16 &pos, const std::string &data)
 163 {
 164         verifyDatabase();
 165
 166 #ifdef __ANDROID__
 167         /**
 168          * Note: For some unknown reason SQLite3 fails to REPLACE blocks on Android,
 169          * deleting them and then inserting works.
 170          */
 171         bindPos(m_stmt_read, pos);
 172
 173         if (sqlite3_step(m_stmt_read) == SQLITE_ROW) {
 174                 deleteBlock(pos);
 175         }
 176         sqlite3_reset(m_stmt_read);
 177 #endif
 178
 179         bindPos(m_stmt_write, pos);
 180         SQLOK(sqlite3_bind_blob(m_stmt_write, 2, data.data(), data.size(), NULL));
 181
 182         SQLRES(sqlite3_step(m_stmt_write), SQLITE_DONE)
 183         sqlite3_reset(m_stmt_write);
 184
 185         return true;
 186 }
 187
 188 std::string Database_SQLite3::loadBlock(const v3s16 &pos)
 189 {
 190         verifyDatabase();
 191
 192         bindPos(m_stmt_read, pos);
 193
 194         if (sqlite3_step(m_stmt_read) != SQLITE_ROW) {
 195                 sqlite3_reset(m_stmt_read);
 196                 return "";
 197         }
 198         const char *data = (const char *) sqlite3_column_blob(m_stmt_read, 0);
 199         size_t len = sqlite3_column_bytes(m_stmt_read, 0);
 200
 201         std::string s;
 202         if (data)
 203                 s = std::string(data, len);
 204
 205         sqlite3_step(m_stmt_read);
 206         // We should never get more than 1 row, so ok to reset
 207         sqlite3_reset(m_stmt_read);
 208
 209         return s;
 210 }
 211
 212 void Database_SQLite3::createDatabase()
 213 {
 214         assert(m_database); // Pre-condition
 215         SQLOK(sqlite3_exec(m_database,
 216                 "CREATE TABLE IF NOT EXISTS `blocks` (\n"
 217                 "       `pos` INT PRIMARY KEY,\n"
 218                 "       `data` BLOB\n"
 219                 ");\n",
 220                 NULL, NULL, NULL));
 221 }
 222
 223 void Database_SQLite3::listAllLoadableBlocks(std::vector<v3s16> &dst)
 224 {
 225         verifyDatabase();
 226
 227         while (sqlite3_step(m_stmt_list) == SQLITE_ROW) {
 228                 dst.push_back(getIntegerAsBlock(sqlite3_column_int64(m_stmt_list, 0)));
 229         }
 230         sqlite3_reset(m_stmt_list);
 231 }
 232
 233 Database_SQLite3::~Database_SQLite3()
 234 {
 235         FINALIZE_STATEMENT(m_stmt_read)
 236         FINALIZE_STATEMENT(m_stmt_write)
 237         FINALIZE_STATEMENT(m_stmt_list)
 238         FINALIZE_STATEMENT(m_stmt_begin)
 239         FINALIZE_STATEMENT(m_stmt_end)
 240         FINALIZE_STATEMENT(m_stmt_delete)
 241
 242         if (sqlite3_close(m_database) != SQLITE_OK) {
 243                 errorstream << "Database_SQLite3::~Database_SQLite3(): "
 244                                 << "Failed to close database: "
 245                                 << sqlite3_errmsg(m_database) << std::endl;
 246         }
 247 }
 248