85521944dd
1. Delete useless variables
2. Add const modifier for read-only function
3. Delete the empty destructor, the compiler will automatically generate it, refer to the 3/5/0 rule:
[https://en.cppreference.com/w/cpp/language/rule_of_three]
4. It is recommended to add the override keyword (instead of the virtual keyword) to the subclass virtual function.
Override will let the compiler help check and improve security. This is also the reason why C++11 introduces override
104 lines
4.2 KiB
C++
104 lines
4.2 KiB
C++
// Licensed to the Apache Software Foundation (ASF) under one
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// or more contributor license agreements. See the NOTICE file
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// distributed with this work for additional information
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// regarding copyright ownership. The ASF licenses this file
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// to you under the Apache License, Version 2.0 (the
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// "License"); you may not use this file except in compliance
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// with the License. You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing,
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// software distributed under the License is distributed on an
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// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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// KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations
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// under the License.
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#ifndef DORIS_BE_SRC_QUERY_EXEC_SCAN_NODE_H
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#define DORIS_BE_SRC_QUERY_EXEC_SCAN_NODE_H
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#include <string>
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#include "exec/exec_node.h"
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#include "gen_cpp/PaloInternalService_types.h"
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#include "util/runtime_profile.h"
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namespace doris {
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class TScanRange;
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// Abstract base class of all scan nodes; introduces set_scan_range().
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//
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// Includes ScanNode common counters:
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// BytesRead - total bytes read by this scan node
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//
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// TotalRawHdfsReadTime - it measures the total time spent in the disk-io-mgr's reading
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// threads for this node. For example, if we have 3 reading threads and each spent
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// 1 sec, this counter will report 3 sec.
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//
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// TotalReadThroughput - BytesRead divided by the total time spent in this node
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// (from Open to Close). For IO bounded queries, this should be very close to the
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// total throughput of all the disks.
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//
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// PerDiskRawHdfsThroughput - the read throughput for each disk. If all the data reside
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// on disk, this should be the read throughput the disk, regardless of whether the
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// query is IO bounded or not.
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//
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// NumDisksAccessed - number of disks accessed.
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//
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// AverageIoMgrQueueCapcity - the average queue capacity in the io mgr for this node.
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// AverageIoMgrQueueSize - the average queue size (for ready buffers) in the io mgr
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// for this node.
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//
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// AverageScannerThreadConcurrency - the average number of active scanner threads. A
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// scanner thread is considered active if it is not blocked by IO. This number would
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// be low (less than 1) for IO bounded queries. For cpu bounded queries, this number
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// would be close to the max scanner threads allowed.
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//
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// AverageHdfsReadThreadConcurrency - the average number of active hdfs reading threads
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// reading for this scan node. For IO bound queries, this should be close to the
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// number of disk.
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//
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// HdfsReadThreadConcurrencyCount=<i> - the number of samples taken when the hdfs read
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// thread concurrency is <i>.
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//
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// ScanRangesComplete - number of scan ranges completed
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//
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class ScanNode : public ExecNode {
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public:
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ScanNode(ObjectPool* pool, const TPlanNode& tnode, const DescriptorTbl& descs)
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: ExecNode(pool, tnode, descs) {}
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// Set up counters
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Status prepare(RuntimeState* state) override;
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// Convert scan_ranges into node-specific scan restrictions. This should be
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// called after prepare()
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virtual Status set_scan_ranges(const std::vector<TScanRangeParams>& scan_ranges) = 0;
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bool is_scan_node() const override { return true; }
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RuntimeProfile::Counter* bytes_read_counter() const { return _bytes_read_counter; }
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RuntimeProfile::Counter* rows_read_counter() const { return _rows_read_counter; }
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RuntimeProfile::Counter* total_throughput_counter() const { return _total_throughput_counter; }
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// names of ScanNode common counters
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static const std::string _s_bytes_read_counter;
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static const std::string _s_rows_read_counter;
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static const std::string _s_total_throughput_counter;
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static const std::string _s_num_disks_accessed_counter;
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protected:
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RuntimeProfile::Counter* _bytes_read_counter; // # bytes read from the scanner
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// # rows/tuples read from the scanner (including those discarded by eval_conjucts())
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RuntimeProfile::Counter* _rows_read_counter;
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// Wall based aggregate read throughput [bytes/sec]
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RuntimeProfile::Counter* _total_throughput_counter;
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RuntimeProfile::Counter* _num_disks_accessed_counter;
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};
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} // namespace doris
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#endif
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