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    • com.huaweicloud.dws.client.op.Scan Maven / Gradle / Ivy

    
package com.huaweicloud.dws.client.op;

import static com.huaweicloud.dws.client.model.OperationType.READ;

import com.huaweicloud.dws.client.model.Record;
import com.huaweicloud.dws.client.model.TableSchema;

import java.security.InvalidParameterException;
import java.util.BitSet;
import java.util.List;

/**
 * @ProjectName: dws-client
 * @Description: Scan operation
 * 相比 Scan operation，SCAN 兼容了 schema 主键与 lookup keys 不一致的情况
 * like:
 * primaryKeys = [id]
 * lookupKeys = [id, name] or []
 * @Date: 2023/09/27
 */
public class Scan extends Operate {
    private final BitSet selectedColumns;

    private final int fetchSize;

    private final int timeout;

    protected Scan(TableSchema schema, BitSet selectedColumns, int fetchSize, int timeout) {
        super(schema, null, READ);
        this.selectedColumns = selectedColumns;
        this.fetchSize = fetchSize;
        this.timeout = timeout;
    }

    protected Scan(Record record, BitSet selectedColumns, int fetchSize, int timeout) {
        super(record, null);
        this.selectedColumns = selectedColumns;
        this.fetchSize = fetchSize;
        this.timeout = timeout;
    }

    public BitSet getSelectedColumns() {
        return selectedColumns;
    }

    public int getTimeout() {
        return timeout;
    }

    public int getFetchSize() {
        return fetchSize;
    }

    public static Builder newBuilder(TableSchema schema) {
        return new Builder(schema);
    }

    public static class Builder {
        private final TableSchema schema;

        private final Record record;

        private BitSet selectedColumns = null;

        private int fetchSize = -1;

        private int timeout = -1;

        public Builder(TableSchema schema) {
            this.schema = schema;
            this.record = new Record(schema, READ);
        }

        public Builder setLookUpKeys(List columns, List values) {
            for (int i = 0; i < columns.size(); i++) {
                this.setLookUpKey(columns.get(i), values.get(i));
            }
            return this;
        }

        public Builder setLookUpKey(String columnName, Object value) {
            Integer index = schema.getColumnIndex(columnName);
            if (index == null) {
                throw new InvalidParameterException(
                    String.format("Table %s does not have column %s.", schema.getTableName(), columnName));
            }

            if (schema.isPrimaryKey(columnName) && value == null) {
                throw new InvalidParameterException("Primary key should not be null.");
            }
            record.setValue(index, value);
            return this;
        }

        public Builder withSelectedColumns(String[] columns) {
            for (String columnName : columns) {
                Integer index = schema.getColumnIndex(columnName);
                if (index == null) {
                    throw new InvalidParameterException(
                        String.format("Table %s does not have column %s.", schema.getTableName(), columnName));
                }
            }
            for (String columnName : columns) {
                this.withSelectedColumn(columnName);
            }
            return this;
        }

        public Builder withSelectedColumn(String columnName) {
            Integer index = schema.getColumnIndex(columnName);
            if (index == null) {
                throw new InvalidParameterException(
                    String.format("Table %s does not have column %s.", schema.getTableName(), columnName));
            }
            if (selectedColumns == null) {
                selectedColumns = new BitSet(schema.getColumns().size());
            }
            selectedColumns.set(index);
            return this;
        }

        public Builder setFetchSize(int fetchSize) {
            if (fetchSize <= 0) {
                throw new InvalidParameterException(
                    String.format("FetchSize must > 0 . Table %s.", schema.getTableName()));
            }
            this.fetchSize = fetchSize;
            return this;
        }

        public Builder setTimeout(int timeout) {
            if (timeout <= 0) {
                throw new InvalidParameterException(
                    String.format("Timeout must > 0 . Table %s.", schema.getTableName()));
            }
            this.timeout = timeout;
            return this;
        }

        public Scan build() {
            return new Scan(record, selectedColumns, fetchSize, timeout);
        }
    }
}
    
    
    
    

    




    
    
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