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