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         // if redis_address contains '/' assume unix socket, else hostname/ip
  48         ctx = tmp.find('/') != std::string::npos ? redisConnectUnix(addr) : redisConnect(addr, port);
  49         if (!ctx) {
  50                 throw DatabaseException("Cannot allocate redis context");
  51         } else if (ctx->err) {
  52                 std::string err = std::string("Connection error: ") + ctx->errstr;
  53                 redisFree(ctx);
  54                 throw DatabaseException(err);
  55         }
  56 }
  57
  58 Database_Redis::~Database_Redis()
  59 {
  60         redisFree(ctx);
  61 }
  62
  63 void Database_Redis::beginSave() {
  64         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx, "MULTI"));
  65         if (!reply) {
  66                 throw DatabaseException(std::string(
  67                         "Redis command 'MULTI' failed: ") + ctx->errstr);
  68         }
  69         freeReplyObject(reply);
  70 }
  71
  72 void Database_Redis::endSave() {
  73         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx, "EXEC"));
  74         if (!reply) {
  75                 throw DatabaseException(std::string(
  76                         "Redis command 'EXEC' failed: ") + ctx->errstr);
  77         }
  78         freeReplyObject(reply);
  79 }
  80
  81 bool Database_Redis::saveBlock(const v3s16 &pos, const std::string &data)
  82 {
  83         std::string tmp = i64tos(getBlockAsInteger(pos));
  84
  85         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx, "HSET %s %s %b",
  86                         hash.c_str(), tmp.c_str(), data.c_str(), data.size()));
  87         if (!reply) {
  88                 warningstream << "saveBlock: redis command 'HSET' failed on "
  89                         "block " << PP(pos) << ": " << ctx->errstr << std::endl;
  90                 freeReplyObject(reply);
  91                 return false;
  92         }
  93
  94         if (reply->type == REDIS_REPLY_ERROR) {
  95                 warningstream << "saveBlock: saving block " << PP(pos)
  96                         << " failed: " << std::string(reply->str, reply->len) << std::endl;
  97                 freeReplyObject(reply);
  98                 return false;
  99         }
 100
 101         freeReplyObject(reply);
 102         return true;
 103 }
 104
 105 void Database_Redis::loadBlock(const v3s16 &pos, std::string *block)
 106 {
 107         std::string tmp = i64tos(getBlockAsInteger(pos));
 108         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx,
 109                         "HGET %s %s", hash.c_str(), tmp.c_str()));
 110
 111         if (!reply) {
 112                 throw DatabaseException(std::string(
 113                         "Redis command 'HGET %s %s' failed: ") + ctx->errstr);
 114         }
 115
 116         switch (reply->type) {
 117         case REDIS_REPLY_STRING: {
 118                 *block = std::string(reply->str, reply->len);
 119                 // std::string copies the memory so this won't cause any problems
 120                 freeReplyObject(reply);
 121                 return;
 122         }
 123         case REDIS_REPLY_ERROR: {
 124                 std::string errstr(reply->str, reply->len);
 125                 freeReplyObject(reply);
 126                 errorstream << "loadBlock: loading block " << PP(pos)
 127                         << " failed: " << errstr << std::endl;
 128                 throw DatabaseException(std::string(
 129                         "Redis command 'HGET %s %s' errored: ") + errstr);
 130         }
 131         case REDIS_REPLY_NIL: {
 132                 *block = "";
 133                 // block not found in database
 134                 freeReplyObject(reply);
 135                 return;
 136         }
 137         }
 138
 139         errorstream << "loadBlock: loading block " << PP(pos)
 140                 << " returned invalid reply type " << reply->type
 141                 << ": " << std::string(reply->str, reply->len) << std::endl;
 142         freeReplyObject(reply);
 143         throw DatabaseException(std::string(
 144                 "Redis command 'HGET %s %s' gave invalid reply."));
 145 }
 146
 147 bool Database_Redis::deleteBlock(const v3s16 &pos)
 148 {
 149         std::string tmp = i64tos(getBlockAsInteger(pos));
 150
 151         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx,
 152                 "HDEL %s %s", hash.c_str(), tmp.c_str()));
 153         if (!reply) {
 154                 throw DatabaseException(std::string(
 155                         "Redis command 'HDEL %s %s' failed: ") + ctx->errstr);
 156         } else if (reply->type == REDIS_REPLY_ERROR) {
 157                 warningstream << "deleteBlock: deleting block " << PP(pos)
 158                         << " failed: " << std::string(reply->str, reply->len) << std::endl;
 159                 freeReplyObject(reply);
 160                 return false;
 161         }
 162
 163         freeReplyObject(reply);
 164         return true;
 165 }
 166
 167 void Database_Redis::listAllLoadableBlocks(std::vector<v3s16> &dst)
 168 {
 169         redisReply *reply = static_cast<redisReply *>(redisCommand(ctx, "HKEYS %s", hash.c_str()));
 170         if (!reply) {
 171                 throw DatabaseException(std::string(
 172                         "Redis command 'HKEYS %s' failed: ") + ctx->errstr);
 173         }
 174         switch (reply->type) {
 175         case REDIS_REPLY_ARRAY:
 176                 dst.reserve(reply->elements);
 177                 for (size_t i = 0; i < reply->elements; i++) {
 178                         assert(reply->element[i]->type == REDIS_REPLY_STRING);
 179                         dst.push_back(getIntegerAsBlock(stoi64(reply->element[i]->str)));
 180                 }
 181                 break;
 182         case REDIS_REPLY_ERROR:
 183                 throw DatabaseException(std::string(
 184                         "Failed to get keys from database: ") +
 185                         std::string(reply->str, reply->len));
 186         }
 187         freeReplyObject(reply);
 188 }
 189
 190 #endif // USE_REDIS
 191