src/database-redis.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2014 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 #include "config.h"
  21
  22 #if USE_REDIS
  23
  24 #include "database-redis.h"
  25
  26 #include "settings.h"
  27 #include "log.h"
  28 #include "exceptions.h"
  29 #include "util/string.h"
  30
  31 #include <hiredis.h>
  32 #include <cassert>
  33
  34
  35 Database_Redis::Database_Redis(Settings &conf)
  36 {
  37         std::string tmp;
  38         try {
  39                 tmp = conf.get("redis_address");
  40                 hash = conf.get("redis_hash");
  41         } catch (SettingNotFoundException) {
  42                 throw SettingNotFoundException("Set redis_address and "
  43                         "redis_hash in world.mt to use the redis backend");
  44         }
  45         const char *addr = tmp.c_str();
  46         int port = conf.exists("redis_port") ? conf.getU16("redis_port") : 6379;
  47         ctx = redisConnect(addr, port);
  48         if (!ctx) {
  49                 throw FileNotGoodException("Cannot allocate redis context");
  50         } else if (ctx->err) {
  51                 std::string err = std::string("Connection error: ") + ctx->errstr;
  52                 redisFree(ctx);
  53                 throw FileNotGoodException(err);
  54         }
  55 }
  56
  57 Database_Redis::~Database_Redis()
  58 {
  59         redisFree(ctx);
  60 }
  61
  62 void Database_Redis::beginSave() {
  63         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx, "MULTI"));
  64         if (!reply) {
  65                 throw FileNotGoodException(std::string(
  66                         "Redis command 'MULTI' failed: ") + ctx->errstr);
  67         }
  68         freeReplyObject(reply);
  69 }
  70
  71 void Database_Redis::endSave() {
  72         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx, "EXEC"));
  73         if (!reply) {
  74                 throw FileNotGoodException(std::string(
  75                         "Redis command 'EXEC' failed: ") + ctx->errstr);
  76         }
  77         freeReplyObject(reply);
  78 }
  79
  80 bool Database_Redis::saveBlock(const v3s16 &pos, const std::string &data)
  81 {
  82         std::string tmp = i64tos(getBlockAsInteger(pos));
  83
  84         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx, "HSET %s %s %b",
  85                         hash.c_str(), tmp.c_str(), data.c_str(), data.size()));
  86         if (!reply) {
  87                 warningstream << "saveBlock: redis command 'HSET' failed on "
  88                         "block " << PP(pos) << ": " << ctx->errstr << std::endl;
  89                 freeReplyObject(reply);
  90                 return false;
  91         }
  92
  93         if (reply->type == REDIS_REPLY_ERROR) {
  94                 warningstream << "saveBlock: saving block " << PP(pos)
  95                         << " failed: " << std::string(reply->str, reply->len) << std::endl;
  96                 freeReplyObject(reply);
  97                 return false;
  98         }
  99
 100         freeReplyObject(reply);
 101         return true;
 102 }
 103
 104 void Database_Redis::loadBlock(const v3s16 &pos, std::string *block)
 105 {
 106         std::string tmp = i64tos(getBlockAsInteger(pos));
 107         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx,
 108                         "HGET %s %s", hash.c_str(), tmp.c_str()));
 109
 110         if (!reply) {
 111                 throw FileNotGoodException(std::string(
 112                         "Redis command 'HGET %s %s' failed: ") + ctx->errstr);
 113         }
 114
 115         switch (reply->type) {
 116         case REDIS_REPLY_STRING: {
 117                 *block = std::string(reply->str, reply->len);
 118                 // std::string copies the memory so this won't cause any problems
 119                 freeReplyObject(reply);
 120                 return;
 121         }
 122         case REDIS_REPLY_ERROR: {
 123                 std::string errstr(reply->str, reply->len);
 124                 freeReplyObject(reply);
 125                 errorstream << "loadBlock: loading block " << PP(pos)
 126                         << " failed: " << errstr << std::endl;
 127                 throw FileNotGoodException(std::string(
 128                         "Redis command 'HGET %s %s' errored: ") + errstr);
 129         }
 130         case REDIS_REPLY_NIL: {
 131                 *block = "";
 132                 // block not found in database
 133                 freeReplyObject(reply);
 134                 return;
 135         }
 136         }
 137
 138         errorstream << "loadBlock: loading block " << PP(pos)
 139                 << " returned invalid reply type " << reply->type
 140                 << ": " << std::string(reply->str, reply->len) << std::endl;
 141         freeReplyObject(reply);
 142         throw FileNotGoodException(std::string(
 143                 "Redis command 'HGET %s %s' gave invalid reply."));
 144 }
 145
 146 bool Database_Redis::deleteBlock(const v3s16 &pos)
 147 {
 148         std::string tmp = i64tos(getBlockAsInteger(pos));
 149
 150         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx,
 151                 "HDEL %s %s", hash.c_str(), tmp.c_str()));
 152         if (!reply) {
 153                 throw FileNotGoodException(std::string(
 154                         "Redis command 'HDEL %s %s' failed: ") + ctx->errstr);
 155         } else if (reply->type == REDIS_REPLY_ERROR) {
 156                 warningstream << "deleteBlock: deleting block " << PP(pos)
 157                         << " failed: " << std::string(reply->str, reply->len) << std::endl;
 158                 freeReplyObject(reply);
 159                 return false;
 160         }
 161
 162         freeReplyObject(reply);
 163         return true;
 164 }
 165
 166 void Database_Redis::listAllLoadableBlocks(std::vector<v3s16> &dst)
 167 {
 168         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx, "HKEYS %s", hash.c_str()));
 169         if (!reply) {
 170                 throw FileNotGoodException(std::string(
 171                         "Redis command 'HKEYS %s' failed: ") + ctx->errstr);
 172         }
 173         switch (reply->type) {
 174         case REDIS_REPLY_ARRAY:
 175                 dst.reserve(reply->elements);
 176                 for (size_t i = 0; i < reply->elements; i++) {
 177                         assert(reply->element[i]->type == REDIS_REPLY_STRING);
 178                         dst.push_back(getIntegerAsBlock(stoi64(reply->element[i]->str)));
 179                 }
 180                 break;
 181         case REDIS_REPLY_ERROR:
 182                 throw FileNotGoodException(std::string(
 183                         "Failed to get keys from database: ") +
 184                         std::string(reply->str, reply->len));
 185         }
 186         freeReplyObject(reply);
 187 }
 188
 189 #endif // USE_REDIS
 190