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 "main.h"
  34 #include "settings.h"
  35 #include "util/string.h"
  36
  37 #include <cassert>
  38
  39
  40 #define SQLRES(s, r) \
  41         if ((s) != (r)) { \
  42                 throw FileNotGoodException(std::string(\
  43                                         "SQLite3 database error (" \
  44                                         __FILE__ ":" TOSTRING(__LINE__) \
  45                                         "): ") +\
  46                                 sqlite3_errmsg(m_database)); \
  47         }
  48 #define SQLOK(s) SQLRES(s, SQLITE_OK)
  49
  50 #define PREPARE_STATEMENT(name, query) \
  51         SQLOK(sqlite3_prepare_v2(m_database, query, -1, &m_stmt_##name, NULL))
  52
  53 #define FINALIZE_STATEMENT(statement) \
  54         if (sqlite3_finalize(statement) != SQLITE_OK) { \
  55                 throw FileNotGoodException(std::string( \
  56                         "SQLite3: Failed to finalize " #statement ": ") + \
  57                          sqlite3_errmsg(m_database)); \
  58         }
  59
  60
  61 Database_SQLite3::Database_SQLite3(const std::string &savedir) :
  62         m_initialized(false),
  63         m_savedir(savedir),
  64         m_database(NULL),
  65         m_stmt_read(NULL),
  66         m_stmt_write(NULL),
  67         m_stmt_list(NULL),
  68         m_stmt_delete(NULL)
  69 {
  70 }
  71
  72 void Database_SQLite3::beginSave() {
  73         verifyDatabase();
  74         SQLRES(sqlite3_step(m_stmt_begin), SQLITE_DONE);
  75         sqlite3_reset(m_stmt_begin);
  76 }
  77
  78 void Database_SQLite3::endSave() {
  79         verifyDatabase();
  80         SQLRES(sqlite3_step(m_stmt_end), SQLITE_DONE);
  81         sqlite3_reset(m_stmt_end);
  82 }
  83
  84 void Database_SQLite3::openDatabase()
  85 {
  86         if (m_database) return;
  87
  88         std::string dbp = m_savedir + DIR_DELIM + "map.sqlite";
  89
  90         // Open the database connection
  91
  92         if (!fs::CreateAllDirs(m_savedir)) {
  93                 infostream << "Database_SQLite3: Failed to create directory \""
  94                         << m_savedir << "\"" << std::endl;
  95                 throw FileNotGoodException("Failed to create database "
  96                                 "save directory");
  97         }
  98
  99         bool needs_create = !fs::PathExists(dbp);
 100
 101         if (sqlite3_open_v2(dbp.c_str(), &m_database,
 102                         SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
 103                         NULL) != SQLITE_OK) {
 104                 errorstream << "SQLite3 database failed to open: "
 105                         << sqlite3_errmsg(m_database) << std::endl;
 106                 throw FileNotGoodException("Cannot open database file");
 107         }
 108
 109         if (needs_create) {
 110                 createDatabase();
 111         }
 112
 113         std::string query_str = std::string("PRAGMA synchronous = ")
 114                          + itos(g_settings->getU16("sqlite_synchronous"));
 115         SQLOK(sqlite3_exec(m_database, query_str.c_str(), NULL, NULL, NULL));
 116 }
 117
 118 void Database_SQLite3::verifyDatabase()
 119 {
 120         if (m_initialized) return;
 121
 122         openDatabase();
 123
 124         PREPARE_STATEMENT(begin, "BEGIN");
 125         PREPARE_STATEMENT(end, "COMMIT");
 126         PREPARE_STATEMENT(read, "SELECT `data` FROM `blocks` WHERE `pos` = ? LIMIT 1");
 127 #ifdef __ANDROID__
 128         PREPARE_STATEMENT(write,  "INSERT INTO `blocks` (`pos`, `data`) VALUES (?, ?)");
 129 #else
 130         PREPARE_STATEMENT(write, "REPLACE INTO `blocks` (`pos`, `data`) VALUES (?, ?)");
 131 #endif
 132         PREPARE_STATEMENT(delete, "DELETE FROM `blocks` WHERE `pos` = ?");
 133         PREPARE_STATEMENT(list, "SELECT `pos` FROM `blocks`");
 134
 135         m_initialized = true;
 136
 137         verbosestream << "ServerMap: SQLite3 database opened." << std::endl;
 138 }
 139
 140 inline void Database_SQLite3::bindPos(sqlite3_stmt *stmt, const v3s16 &pos, int index)
 141 {
 142         SQLOK(sqlite3_bind_int64(stmt, index, getBlockAsInteger(pos)));
 143 }
 144
 145 bool Database_SQLite3::deleteBlock(const v3s16 &pos)
 146 {
 147         verifyDatabase();
 148
 149         bindPos(m_stmt_delete, pos);
 150
 151         bool good = sqlite3_step(m_stmt_delete) == SQLITE_DONE;
 152         sqlite3_reset(m_stmt_delete);
 153
 154         if (!good) {
 155                 errorstream << "WARNING: deleteBlock: Block failed to delete "
 156                         << PP(pos) << ": " << sqlite3_errmsg(m_database) << std::endl;
 157         }
 158         return good;
 159 }
 160
 161 bool Database_SQLite3::saveBlock(const v3s16 &pos, const std::string &data)
 162 {
 163         verifyDatabase();
 164
 165 #ifdef __ANDROID__
 166         /**
 167          * Note: For some unknown reason SQLite3 fails to REPLACE blocks on Android,
 168          * deleting them and then inserting works.
 169          */
 170         bindPos(m_stmt_read, pos);
 171
 172         if (sqlite3_step(m_stmt_read) == SQLITE_ROW) {
 173                 deleteBlock(pos);
 174         }
 175         sqlite3_reset(m_stmt_read);
 176 #endif
 177
 178         bindPos(m_stmt_write, pos);
 179         SQLOK(sqlite3_bind_blob(m_stmt_write, 2, data.data(), data.size(), NULL));
 180
 181         SQLRES(sqlite3_step(m_stmt_write), SQLITE_DONE)
 182         sqlite3_reset(m_stmt_write);
 183
 184         return true;
 185 }
 186
 187 std::string Database_SQLite3::loadBlock(const v3s16 &pos)
 188 {
 189         verifyDatabase();
 190
 191         bindPos(m_stmt_read, pos);
 192
 193         if (sqlite3_step(m_stmt_read) != SQLITE_ROW) {
 194                 sqlite3_reset(m_stmt_read);
 195                 return "";
 196         }
 197         const char *data = (const char *) sqlite3_column_blob(m_stmt_read, 0);
 198         size_t len = sqlite3_column_bytes(m_stmt_read, 0);
 199
 200         std::string s;
 201         if (data)
 202                 s = std::string(data, len);
 203
 204         sqlite3_step(m_stmt_read);
 205         // We should never get more than 1 row, so ok to reset
 206         sqlite3_reset(m_stmt_read);
 207
 208         return s;
 209 }
 210
 211 void Database_SQLite3::createDatabase()
 212 {
 213         assert(m_database); // Pre-condition
 214         SQLOK(sqlite3_exec(m_database,
 215                 "CREATE TABLE IF NOT EXISTS `blocks` (\n"
 216                 "       `pos` INT PRIMARY KEY,\n"
 217                 "       `data` BLOB\n"
 218                 ");\n",
 219                 NULL, NULL, NULL));
 220 }
 221
 222 void Database_SQLite3::listAllLoadableBlocks(std::vector<v3s16> &dst)
 223 {
 224         verifyDatabase();
 225
 226         while (sqlite3_step(m_stmt_list) == SQLITE_ROW) {
 227                 dst.push_back(getIntegerAsBlock(sqlite3_column_int64(m_stmt_list, 0)));
 228         }
 229         sqlite3_reset(m_stmt_list);
 230 }
 231
 232 Database_SQLite3::~Database_SQLite3()
 233 {
 234         FINALIZE_STATEMENT(m_stmt_read)
 235         FINALIZE_STATEMENT(m_stmt_write)
 236         FINALIZE_STATEMENT(m_stmt_list)
 237         FINALIZE_STATEMENT(m_stmt_begin)
 238         FINALIZE_STATEMENT(m_stmt_end)
 239         FINALIZE_STATEMENT(m_stmt_delete)
 240
 241         if (sqlite3_close(m_database) != SQLITE_OK) {
 242                 errorstream << "Database_SQLite3::~Database_SQLite3(): "
 243                                 << "Failed to close database: "
 244                                 << sqlite3_errmsg(m_database) << std::endl;
 245         }
 246 }
 247