bool MySqlShardingPool::init() {
for (int i = 0; i < shardNum(); i++) {
MySqlConnectionByShard shard(i, this);
}
return true;
}
StoragePtr TableFunctionShardByHash::execute(ASTPtr ast_function, Context & context) const
{
ASTs & args_func = typeid_cast<ASTFunction &>(*ast_function).children;
const char * err = "Table function 'shardByHash' requires 4 parameters: "
"cluster name, key string to hash, name of remote database, name of remote table.";
if (args_func.size() != 1)
throw Exception(err, ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
ASTs & args = typeid_cast<ASTExpressionList &>(*args_func.at(0)).children;
if (args.size() != 4)
throw Exception(err, ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
String cluster_name;
String key;
String remote_database;
String remote_table;
auto getStringLiteral = [](const IAST & node, const char * description)
{
const ASTLiteral * lit = typeid_cast<const ASTLiteral *>(&node);
if (!lit)
throw Exception(description + String(" must be string literal (in single quotes)."), ErrorCodes::BAD_ARGUMENTS);
if (lit->value.getType() != Field::Types::String)
throw Exception(description + String(" must be string literal (in single quotes)."), ErrorCodes::BAD_ARGUMENTS);
return safeGet<const String &>(lit->value);
};
cluster_name = getClusterName(*args[0]);
key = getStringLiteral(*args[1], "Key to hash");
args[2] = evaluateConstantExpressionOrIdentidierAsLiteral(args[2], context);
args[3] = evaluateConstantExpressionOrIdentidierAsLiteral(args[3], context);
remote_database = static_cast<const ASTLiteral &>(*args[2]).value.safeGet<String>();
remote_table = static_cast<const ASTLiteral &>(*args[3]).value.safeGet<String>();
/// Аналогично другим TableFunctions.
for (auto & arg : args)
if (ASTIdentifier * id = typeid_cast<ASTIdentifier *>(arg.get()))
id->kind = ASTIdentifier::Table;
const Cluster & cluster = context.getCluster(cluster_name);
size_t shard_index = sipHash64(key) % cluster.getShardCount();
std::shared_ptr<Cluster> shard(cluster.getClusterWithSingleShard(shard_index).release());
return StorageDistributed::create(
getName(),
std::make_shared<NamesAndTypesList>(getStructureOfRemoteTable(*shard, remote_database, remote_table, context)),
remote_database,
remote_table,
shard,
context);
}
DBConfig::CollectionInfo::CollectionInfo( const BSONObj& in ) {
_dirty = false;
_dropped = in["dropped"].trueValue();
if ( in["key"].isABSONObj() ) {
_key = in["key"].Obj().getOwned();
_unqiue = in["unique"].trueValue();
shard( in["_id"].String() , _key , _unqiue );
}
_dirty = false;
}
void setSingleChunkForShards( const vector<BSONObj> &splitPoints ) {
ChunkMap &chunkMap = const_cast<ChunkMap&>( _chunkMap );
ChunkRangeManager &chunkRanges = const_cast<ChunkRangeManager&>( _chunkRanges );
set<Shard> &shards = const_cast<set<Shard>&>( _shards );
vector<BSONObj> mySplitPoints( splitPoints );
mySplitPoints.insert( mySplitPoints.begin(), _key.globalMin() );
mySplitPoints.push_back( _key.globalMax() );
for( unsigned i = 1; i < mySplitPoints.size(); ++i ) {
string name = str::stream() << (i-1);
Shard shard( name, name );
shards.insert( shard );
ChunkPtr chunk( new Chunk( this, mySplitPoints[ i-1 ], mySplitPoints[ i ],
shard ) );
chunkMap[ mySplitPoints[ i ] ] = chunk;
}
chunkRanges.reloadAll( chunkMap );
}
DBConfig::CollectionInfo::CollectionInfo( const BSONObj& in ) {
_dirty = false;
_dropped = in["dropped"].trueValue();
if ( in["key"].isABSONObj() )
shard( in["_id"].String() , in["key"].Obj() , in["unique"].trueValue() );
}
