flink-doris-connector/src/main/java/org/apache/doris/flink/sink/schema/SchemaChangeManager.java

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// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
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// specific language governing permissions and limitations
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package org.apache.doris.flink.sink.schema;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.commons.codec.binary.Base64;
import org.apache.doris.flink.catalog.doris.DorisSystem;
import org.apache.doris.flink.catalog.doris.FieldSchema;
import org.apache.doris.flink.catalog.doris.TableSchema;
import org.apache.doris.flink.cfg.DorisOptions;
import org.apache.doris.flink.exception.IllegalArgumentException;
import org.apache.doris.flink.rest.RestService;
import org.apache.doris.flink.sink.HttpGetWithEntity;
import org.apache.flink.util.CollectionUtil;
import org.apache.flink.util.StringUtils;
import org.apache.http.HttpHeaders;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.Serializable;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

public class SchemaChangeManager implements Serializable {
    private static final long serialVersionUID = 1L;
    private static final Logger LOG = LoggerFactory.getLogger(SchemaChangeManager.class);
    private static final String CHECK_SCHEMA_CHANGE_API = "http://%s/api/enable_light_schema_change/%s/%s";
    private static final String SCHEMA_CHANGE_API = "http://%s/api/query/default_cluster/";
    private ObjectMapper objectMapper = new ObjectMapper();
    private DorisOptions dorisOptions;

    public SchemaChangeManager(DorisOptions dorisOptions) {
        this.dorisOptions = dorisOptions;
    }

    public boolean createTable(TableSchema table) throws IOException, IllegalArgumentException {
        String createTableDDL = DorisSystem.buildCreateTableDDL(table);
        return execute(createTableDDL);
    }

    public boolean addColumn(String database, String table, FieldSchema field) throws IOException, IllegalArgumentException {
        String tableIdentifier = getTableIdentifier(database, table);
        String addColumnDDL = SchemaChangeHelper.buildAddColumnDDL(tableIdentifier, field);
        return schemaChange(database, table, buildRequestParam(false, field.getName()), addColumnDDL);
    }

    public boolean dropColumn(String database, String table, String columnName) throws IOException, IllegalArgumentException {
        String tableIdentifier = getTableIdentifier(database, table);
        String dropColumnDDL = SchemaChangeHelper.buildDropColumnDDL(tableIdentifier, columnName);
        return schemaChange(database, table, buildRequestParam(true, columnName), dropColumnDDL);
    }

    public boolean renameColumn(String database, String table, String oldColumnName, String newColumnName) throws IOException, IllegalArgumentException {
        String tableIdentifier = getTableIdentifier(database, table);
        String renameColumnDDL = SchemaChangeHelper.buildRenameColumnDDL(tableIdentifier, oldColumnName, newColumnName);
        return schemaChange(database, table, buildRequestParam(true, oldColumnName), renameColumnDDL);
    }

    public boolean schemaChange(String database, String table, Map<String, Object> params, String sql) throws IOException, IllegalArgumentException {
        if(checkSchemaChange(database, table, params)){
            return execute(sql);
        }
        return false;
    }

    public static Map<String, Object> buildRequestParam(boolean dropColumn, String columnName) {
        Map<String, Object> params = new HashMap<>();
        params.put("isDropColumn", dropColumn);
        params.put("columnName", columnName);
        return params;
    }

    /**
     * check ddl can do light schema change
     */
    public boolean checkSchemaChange(String database, String table, Map<String, Object> params) throws IOException, IllegalArgumentException {
        if(CollectionUtil.isNullOrEmpty(params)){
            return false;
        }
        String requestUrl = String.format(CHECK_SCHEMA_CHANGE_API,
                RestService.randomEndpoint(dorisOptions.getFenodes(), LOG), database, table);
        HttpGetWithEntity httpGet = new HttpGetWithEntity(requestUrl);
        httpGet.setHeader(HttpHeaders.AUTHORIZATION, authHeader());
        httpGet.setEntity(new StringEntity(objectMapper.writeValueAsString(params)));
        boolean success = handleResponse(httpGet);
        if (!success) {
            LOG.warn("schema change can not do table {}.{}", database, table);
        }
        return success;
    }

    /**
     * execute sql in doris
     */
    public boolean execute(String ddl) throws IOException, IllegalArgumentException {
        if(StringUtils.isNullOrWhitespaceOnly(ddl)){
            return false;
        }
        Map<String, String> param = new HashMap<>();
        param.put("stmt", ddl);
        String requestUrl = String.format(SCHEMA_CHANGE_API, RestService.randomEndpoint(dorisOptions.getFenodes(), LOG));
        HttpPost httpPost = new HttpPost(requestUrl);
        httpPost.setHeader(HttpHeaders.AUTHORIZATION, authHeader());
        httpPost.setHeader(HttpHeaders.CONTENT_TYPE, "application/json");
        httpPost.setEntity(new StringEntity(objectMapper.writeValueAsString(param)));
        boolean success = handleResponse(httpPost);
        return success;
    }

    private boolean handleResponse(HttpUriRequest request) {
        try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
            CloseableHttpResponse response = httpclient.execute(request);
            final int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode == 200 && response.getEntity() != null) {
                String loadResult = EntityUtils.toString(response.getEntity());
                Map<String, Object> responseMap = objectMapper.readValue(loadResult, Map.class);
                String code = responseMap.getOrDefault("code", "-1").toString();
                if (code.equals("0")) {
                    return true;
                } else {
                    LOG.error("schema change response:{}", loadResult);
                }
            }
        } catch (Exception e) {
            LOG.error("http request error,", e);
        }
        return false;
    }

    private String authHeader() {
        return "Basic " + new String(Base64.encodeBase64(
                (dorisOptions.getUsername() + ":" + dorisOptions.getPassword()).getBytes(StandardCharsets.UTF_8)));
    }

    private String getTableIdentifier(String database, String table){
        return String.format("%s.%s", database, table);
    }
}