yihua commented on code in PR #12781: URL: https://github.com/apache/hudi/pull/12781#discussion_r1980247803
########## hudi-client/hudi-client-common/src/main/java/org/apache/hudi/client/transaction/ConcurrentSchemaEvolutionTableSchemaGetter.java: ########## @@ -0,0 +1,281 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * 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 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.hudi.client.transaction; + +import org.apache.hudi.avro.HoodieAvroUtils; +import org.apache.hudi.common.HoodieSchemaNotFoundException; +import org.apache.hudi.common.model.HoodieCommitMetadata; +import org.apache.hudi.common.table.HoodieTableMetaClient; +import org.apache.hudi.common.table.timeline.HoodieActiveTimeline; +import org.apache.hudi.common.table.timeline.HoodieInstant; +import org.apache.hudi.common.table.timeline.TimelineLayout; +import org.apache.hudi.common.util.ClusteringUtils; +import org.apache.hudi.common.util.Option; +import org.apache.hudi.common.util.StringUtils; +import org.apache.hudi.common.util.VisibleForTesting; +import org.apache.hudi.common.util.collection.Pair; +import org.apache.hudi.exception.HoodieException; +import org.apache.hudi.internal.schema.HoodieSchemaException; +import org.apache.hudi.util.Lazy; + +import org.apache.avro.JsonProperties; +import org.apache.avro.Schema; +import org.apache.avro.Schema.Field; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Comparator; +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.function.Supplier; +import java.util.stream.Stream; + +import static org.apache.hudi.avro.AvroSchemaUtils.appendFieldsToSchema; +import static org.apache.hudi.avro.AvroSchemaUtils.containsFieldInSchema; +import static org.apache.hudi.avro.AvroSchemaUtils.createNullableSchema; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.DELTA_COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.REPLACE_COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.InstantComparison.LESSER_THAN_OR_EQUALS; +import static org.apache.hudi.common.table.timeline.InstantComparison.compareTimestamps; + +/** + * Helper class to read table schema. ONLY USE IT FOR SimpleConcurrentFileWritesConflictResolutionStrategy. + */ +class ConcurrentSchemaEvolutionTableSchemaGetter { + + private static final Logger LOG = LoggerFactory.getLogger(ConcurrentSchemaEvolutionTableSchemaGetter.class); + + protected final HoodieTableMetaClient metaClient; + + private final Lazy<ConcurrentHashMap<HoodieInstant, Schema>> tableSchemaCache; + + private Option<HoodieInstant> latestCommitWithValidSchema = Option.empty(); + + @VisibleForTesting + public ConcurrentHashMap<HoodieInstant, Schema> getTableSchemaCache() { + return tableSchemaCache.get(); + } + + public ConcurrentSchemaEvolutionTableSchemaGetter(HoodieTableMetaClient metaClient) { + this.metaClient = metaClient; + // Unbounded sized map. Should replace with some caching library. + this.tableSchemaCache = Lazy.lazily(ConcurrentHashMap::new); + } + + /** + * Handles partition column logic for a given schema. + * + * @param schema the input schema to process + * @return the processed schema with partition columns handled appropriately + */ + private Schema handlePartitionColumnsIfNeeded(Schema schema) { + if (metaClient.getTableConfig().shouldDropPartitionColumns()) { + return metaClient.getTableConfig().getPartitionFields() + .map(partitionFields -> appendPartitionColumns(schema, Option.ofNullable(partitionFields))) + .or(() -> Option.of(schema)) + .get(); + } + return schema; + } + + public Option<Schema> getTableAvroSchemaIfPresent(boolean includeMetadataFields, Option<HoodieInstant> instant) { + return getTableAvroSchemaFromTimelineWithCache(instant) // Get table schema from schema evolution timeline. + .or(this::getTableCreateSchemaWithoutMetaField) // Fall back: read create schema from table config. + .map(tableSchema -> includeMetadataFields ? HoodieAvroUtils.addMetadataFields(tableSchema, false) : HoodieAvroUtils.removeMetadataFields(tableSchema)) + .map(this::handlePartitionColumnsIfNeeded); + } + + private Option<Schema> getTableCreateSchemaWithoutMetaField() { + return metaClient.getTableConfig().getTableCreateSchema(); + } + + private void setCachedLatestCommitWithValidSchema(Option<HoodieInstant> instantOption) { + latestCommitWithValidSchema = instantOption; + } + + private Option<HoodieInstant> getCachedLatestCommitWithValidSchema() { + return latestCommitWithValidSchema; + } + + @VisibleForTesting + Option<Schema> getTableAvroSchemaFromTimelineWithCache(Option<HoodieInstant> instantTime) { + return getTableAvroSchemaFromTimelineWithCache(computeSchemaEvolutionTimelineInReverseOrder(), instantTime); + } + + Option<Schema> getTableAvroSchemaFromTimelineWithCache(Stream<HoodieInstant> reversedTimelineStream, Option<HoodieInstant> instantTime) { + // If instantTime is empty it means read the latest one. In that case, get the cached instant if there is one. + boolean fetchFromLastValidCommit = instantTime.isEmpty(); + Option<HoodieInstant> targetInstant = instantTime.or(getCachedLatestCommitWithValidSchema()); + Schema cachedTableSchema = null; + + // Try cache first if there is a target instant to fetch for. + if (!targetInstant.isEmpty()) { + cachedTableSchema = tableSchemaCache.get().getOrDefault(targetInstant.get(), null); + } + + // Cache miss on either latestCommitWithValidSchema or commitMetadataCache. Compute the result. + if (cachedTableSchema == null) { + Option<Pair<HoodieInstant, Schema>> instantWithSchema = getLastCommitMetadataWithValidSchemaFromTimeline(reversedTimelineStream, targetInstant); + if (instantWithSchema.isPresent()) { + targetInstant = Option.of(instantWithSchema.get().getLeft()); + cachedTableSchema = instantWithSchema.get().getRight(); + } + } + + // After computation, update the cache for the instant and commit metadata. + if (fetchFromLastValidCommit) { + setCachedLatestCommitWithValidSchema(targetInstant); + } + if (cachedTableSchema != null) { + // We save cache for 2 cases + // - input specifies a specific instant, we update the cache for that instant, which is instantTime. + // - input is empty implying fetch the latest schema, update the cache for the + // latest valid commit which is targetInstant + if (instantTime.isPresent()) { + tableSchemaCache.get().putIfAbsent(instantTime.get(), cachedTableSchema); + } + if (targetInstant.isPresent()) { + tableSchemaCache.get().putIfAbsent(targetInstant.get(), cachedTableSchema); + } + } + + // Finally process the computation results and return. + if (cachedTableSchema == null) { + return Option.empty(); + } + + return Option.of(cachedTableSchema); + } + + @VisibleForTesting + Option<Pair<HoodieInstant, Schema>> getLastCommitMetadataWithValidSchemaFromTimeline(Stream<HoodieInstant> reversedTimelineStream, Option<HoodieInstant> instant) { + // To find the table schema given an instant time, need to walk backwards from the latest instant in + // the timeline finding a completed instant containing a valid schema. + ConcurrentHashMap<HoodieInstant, Schema> tableSchemaAtInstant = new ConcurrentHashMap<>(); + Option<HoodieInstant> instantWithTableSchema = Option.fromJavaOptional(reversedTimelineStream + // If a completion time is specified, find the first eligible instant in the schema evolution timeline. + // Should switch to completion time based. + .filter(s -> instant.isEmpty() || compareTimestamps(s.requestedTime(), LESSER_THAN_OR_EQUALS, instant.get().requestedTime())) Review Comment: is completion time here? ########## hudi-client/hudi-client-common/src/main/java/org/apache/hudi/client/transaction/ConcurrentSchemaEvolutionTableSchemaGetter.java: ########## @@ -0,0 +1,281 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * 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 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.hudi.client.transaction; + +import org.apache.hudi.avro.HoodieAvroUtils; +import org.apache.hudi.common.HoodieSchemaNotFoundException; +import org.apache.hudi.common.model.HoodieCommitMetadata; +import org.apache.hudi.common.table.HoodieTableMetaClient; +import org.apache.hudi.common.table.timeline.HoodieActiveTimeline; +import org.apache.hudi.common.table.timeline.HoodieInstant; +import org.apache.hudi.common.table.timeline.TimelineLayout; +import org.apache.hudi.common.util.ClusteringUtils; +import org.apache.hudi.common.util.Option; +import org.apache.hudi.common.util.StringUtils; +import org.apache.hudi.common.util.VisibleForTesting; +import org.apache.hudi.common.util.collection.Pair; +import org.apache.hudi.exception.HoodieException; +import org.apache.hudi.internal.schema.HoodieSchemaException; +import org.apache.hudi.util.Lazy; + +import org.apache.avro.JsonProperties; +import org.apache.avro.Schema; +import org.apache.avro.Schema.Field; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Comparator; +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.function.Supplier; +import java.util.stream.Stream; + +import static org.apache.hudi.avro.AvroSchemaUtils.appendFieldsToSchema; +import static org.apache.hudi.avro.AvroSchemaUtils.containsFieldInSchema; +import static org.apache.hudi.avro.AvroSchemaUtils.createNullableSchema; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.DELTA_COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.REPLACE_COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.InstantComparison.LESSER_THAN_OR_EQUALS; +import static org.apache.hudi.common.table.timeline.InstantComparison.compareTimestamps; + +/** + * Helper class to read table schema. ONLY USE IT FOR SimpleConcurrentFileWritesConflictResolutionStrategy. + */ +class ConcurrentSchemaEvolutionTableSchemaGetter { + + private static final Logger LOG = LoggerFactory.getLogger(ConcurrentSchemaEvolutionTableSchemaGetter.class); + + protected final HoodieTableMetaClient metaClient; + + private final Lazy<ConcurrentHashMap<HoodieInstant, Schema>> tableSchemaCache; + + private Option<HoodieInstant> latestCommitWithValidSchema = Option.empty(); + + @VisibleForTesting + public ConcurrentHashMap<HoodieInstant, Schema> getTableSchemaCache() { + return tableSchemaCache.get(); + } + + public ConcurrentSchemaEvolutionTableSchemaGetter(HoodieTableMetaClient metaClient) { + this.metaClient = metaClient; + // Unbounded sized map. Should replace with some caching library. + this.tableSchemaCache = Lazy.lazily(ConcurrentHashMap::new); + } + + /** + * Handles partition column logic for a given schema. + * + * @param schema the input schema to process + * @return the processed schema with partition columns handled appropriately + */ + private Schema handlePartitionColumnsIfNeeded(Schema schema) { + if (metaClient.getTableConfig().shouldDropPartitionColumns()) { + return metaClient.getTableConfig().getPartitionFields() + .map(partitionFields -> appendPartitionColumns(schema, Option.ofNullable(partitionFields))) + .or(() -> Option.of(schema)) + .get(); + } + return schema; + } + + public Option<Schema> getTableAvroSchemaIfPresent(boolean includeMetadataFields, Option<HoodieInstant> instant) { + return getTableAvroSchemaFromTimelineWithCache(instant) // Get table schema from schema evolution timeline. + .or(this::getTableCreateSchemaWithoutMetaField) // Fall back: read create schema from table config. + .map(tableSchema -> includeMetadataFields ? HoodieAvroUtils.addMetadataFields(tableSchema, false) : HoodieAvroUtils.removeMetadataFields(tableSchema)) + .map(this::handlePartitionColumnsIfNeeded); + } + + private Option<Schema> getTableCreateSchemaWithoutMetaField() { + return metaClient.getTableConfig().getTableCreateSchema(); + } + + private void setCachedLatestCommitWithValidSchema(Option<HoodieInstant> instantOption) { + latestCommitWithValidSchema = instantOption; + } + + private Option<HoodieInstant> getCachedLatestCommitWithValidSchema() { + return latestCommitWithValidSchema; + } + + @VisibleForTesting + Option<Schema> getTableAvroSchemaFromTimelineWithCache(Option<HoodieInstant> instantTime) { + return getTableAvroSchemaFromTimelineWithCache(computeSchemaEvolutionTimelineInReverseOrder(), instantTime); + } + + Option<Schema> getTableAvroSchemaFromTimelineWithCache(Stream<HoodieInstant> reversedTimelineStream, Option<HoodieInstant> instantTime) { + // If instantTime is empty it means read the latest one. In that case, get the cached instant if there is one. + boolean fetchFromLastValidCommit = instantTime.isEmpty(); + Option<HoodieInstant> targetInstant = instantTime.or(getCachedLatestCommitWithValidSchema()); + Schema cachedTableSchema = null; + + // Try cache first if there is a target instant to fetch for. + if (!targetInstant.isEmpty()) { + cachedTableSchema = tableSchemaCache.get().getOrDefault(targetInstant.get(), null); + } + + // Cache miss on either latestCommitWithValidSchema or commitMetadataCache. Compute the result. + if (cachedTableSchema == null) { + Option<Pair<HoodieInstant, Schema>> instantWithSchema = getLastCommitMetadataWithValidSchemaFromTimeline(reversedTimelineStream, targetInstant); + if (instantWithSchema.isPresent()) { + targetInstant = Option.of(instantWithSchema.get().getLeft()); + cachedTableSchema = instantWithSchema.get().getRight(); + } + } + + // After computation, update the cache for the instant and commit metadata. + if (fetchFromLastValidCommit) { + setCachedLatestCommitWithValidSchema(targetInstant); + } + if (cachedTableSchema != null) { + // We save cache for 2 cases + // - input specifies a specific instant, we update the cache for that instant, which is instantTime. + // - input is empty implying fetch the latest schema, update the cache for the + // latest valid commit which is targetInstant + if (instantTime.isPresent()) { + tableSchemaCache.get().putIfAbsent(instantTime.get(), cachedTableSchema); + } + if (targetInstant.isPresent()) { + tableSchemaCache.get().putIfAbsent(targetInstant.get(), cachedTableSchema); + } + } + + // Finally process the computation results and return. + if (cachedTableSchema == null) { + return Option.empty(); + } + + return Option.of(cachedTableSchema); + } + + @VisibleForTesting + Option<Pair<HoodieInstant, Schema>> getLastCommitMetadataWithValidSchemaFromTimeline(Stream<HoodieInstant> reversedTimelineStream, Option<HoodieInstant> instant) { + // To find the table schema given an instant time, need to walk backwards from the latest instant in + // the timeline finding a completed instant containing a valid schema. + ConcurrentHashMap<HoodieInstant, Schema> tableSchemaAtInstant = new ConcurrentHashMap<>(); + Option<HoodieInstant> instantWithTableSchema = Option.fromJavaOptional(reversedTimelineStream + // If a completion time is specified, find the first eligible instant in the schema evolution timeline. + // Should switch to completion time based. + .filter(s -> instant.isEmpty() || compareTimestamps(s.requestedTime(), LESSER_THAN_OR_EQUALS, instant.get().requestedTime())) + // Make sure the commit metadata has a valid schema inside. Same caching the result for expensive operation. + .filter(s -> { + try { + // If we processed the instant before, do not parse the commit metadata again. + if (tableSchemaCache.get().containsKey(s)) { + tableSchemaAtInstant.putIfAbsent(s, tableSchemaCache.get().get(s)); + return true; + } + HoodieCommitMetadata metadata = metaClient.getActiveTimeline().readCommitMetadata(s); + String schemaStr = metadata.getMetadata(HoodieCommitMetadata.SCHEMA_KEY); + boolean validSchemaStr = !StringUtils.isNullOrEmpty(schemaStr); Review Comment: ```suggestion boolean isValidSchemaStr = !StringUtils.isNullOrEmpty(schemaStr); ``` ########## hudi-client/hudi-client-common/src/main/java/org/apache/hudi/client/transaction/ConcurrentSchemaEvolutionTableSchemaGetter.java: ########## @@ -0,0 +1,281 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * 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 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.hudi.client.transaction; + +import org.apache.hudi.avro.HoodieAvroUtils; +import org.apache.hudi.common.HoodieSchemaNotFoundException; +import org.apache.hudi.common.model.HoodieCommitMetadata; +import org.apache.hudi.common.table.HoodieTableMetaClient; +import org.apache.hudi.common.table.timeline.HoodieActiveTimeline; +import org.apache.hudi.common.table.timeline.HoodieInstant; +import org.apache.hudi.common.table.timeline.TimelineLayout; +import org.apache.hudi.common.util.ClusteringUtils; +import org.apache.hudi.common.util.Option; +import org.apache.hudi.common.util.StringUtils; +import org.apache.hudi.common.util.VisibleForTesting; +import org.apache.hudi.common.util.collection.Pair; +import org.apache.hudi.exception.HoodieException; +import org.apache.hudi.internal.schema.HoodieSchemaException; +import org.apache.hudi.util.Lazy; + +import org.apache.avro.JsonProperties; +import org.apache.avro.Schema; +import org.apache.avro.Schema.Field; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Comparator; +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.function.Supplier; +import java.util.stream.Stream; + +import static org.apache.hudi.avro.AvroSchemaUtils.appendFieldsToSchema; +import static org.apache.hudi.avro.AvroSchemaUtils.containsFieldInSchema; +import static org.apache.hudi.avro.AvroSchemaUtils.createNullableSchema; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.DELTA_COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.REPLACE_COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.InstantComparison.LESSER_THAN_OR_EQUALS; +import static org.apache.hudi.common.table.timeline.InstantComparison.compareTimestamps; + +/** + * Helper class to read table schema. ONLY USE IT FOR SimpleConcurrentFileWritesConflictResolutionStrategy. + */ +class ConcurrentSchemaEvolutionTableSchemaGetter { + + private static final Logger LOG = LoggerFactory.getLogger(ConcurrentSchemaEvolutionTableSchemaGetter.class); + + protected final HoodieTableMetaClient metaClient; + + private final Lazy<ConcurrentHashMap<HoodieInstant, Schema>> tableSchemaCache; + + private Option<HoodieInstant> latestCommitWithValidSchema = Option.empty(); + + @VisibleForTesting + public ConcurrentHashMap<HoodieInstant, Schema> getTableSchemaCache() { + return tableSchemaCache.get(); + } + + public ConcurrentSchemaEvolutionTableSchemaGetter(HoodieTableMetaClient metaClient) { + this.metaClient = metaClient; + // Unbounded sized map. Should replace with some caching library. + this.tableSchemaCache = Lazy.lazily(ConcurrentHashMap::new); + } + + /** + * Handles partition column logic for a given schema. + * + * @param schema the input schema to process + * @return the processed schema with partition columns handled appropriately + */ + private Schema handlePartitionColumnsIfNeeded(Schema schema) { + if (metaClient.getTableConfig().shouldDropPartitionColumns()) { + return metaClient.getTableConfig().getPartitionFields() + .map(partitionFields -> appendPartitionColumns(schema, Option.ofNullable(partitionFields))) + .or(() -> Option.of(schema)) + .get(); + } + return schema; + } + + public Option<Schema> getTableAvroSchemaIfPresent(boolean includeMetadataFields, Option<HoodieInstant> instant) { + return getTableAvroSchemaFromTimelineWithCache(instant) // Get table schema from schema evolution timeline. + .or(this::getTableCreateSchemaWithoutMetaField) // Fall back: read create schema from table config. + .map(tableSchema -> includeMetadataFields ? HoodieAvroUtils.addMetadataFields(tableSchema, false) : HoodieAvroUtils.removeMetadataFields(tableSchema)) + .map(this::handlePartitionColumnsIfNeeded); + } + + private Option<Schema> getTableCreateSchemaWithoutMetaField() { + return metaClient.getTableConfig().getTableCreateSchema(); + } + + private void setCachedLatestCommitWithValidSchema(Option<HoodieInstant> instantOption) { + latestCommitWithValidSchema = instantOption; + } + + private Option<HoodieInstant> getCachedLatestCommitWithValidSchema() { + return latestCommitWithValidSchema; + } + + @VisibleForTesting + Option<Schema> getTableAvroSchemaFromTimelineWithCache(Option<HoodieInstant> instantTime) { + return getTableAvroSchemaFromTimelineWithCache(computeSchemaEvolutionTimelineInReverseOrder(), instantTime); + } + + Option<Schema> getTableAvroSchemaFromTimelineWithCache(Stream<HoodieInstant> reversedTimelineStream, Option<HoodieInstant> instantTime) { Review Comment: This method is a bit complex, having a few `if` checks. Wondering if it can be simplified. ########## hudi-client/hudi-client-common/src/main/java/org/apache/hudi/client/transaction/ConcurrentSchemaEvolutionTableSchemaGetter.java: ########## @@ -0,0 +1,281 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * 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 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.hudi.client.transaction; + +import org.apache.hudi.avro.HoodieAvroUtils; +import org.apache.hudi.common.HoodieSchemaNotFoundException; +import org.apache.hudi.common.model.HoodieCommitMetadata; +import org.apache.hudi.common.table.HoodieTableMetaClient; +import org.apache.hudi.common.table.timeline.HoodieActiveTimeline; +import org.apache.hudi.common.table.timeline.HoodieInstant; +import org.apache.hudi.common.table.timeline.TimelineLayout; +import org.apache.hudi.common.util.ClusteringUtils; +import org.apache.hudi.common.util.Option; +import org.apache.hudi.common.util.StringUtils; +import org.apache.hudi.common.util.VisibleForTesting; +import org.apache.hudi.common.util.collection.Pair; +import org.apache.hudi.exception.HoodieException; +import org.apache.hudi.internal.schema.HoodieSchemaException; +import org.apache.hudi.util.Lazy; + +import org.apache.avro.JsonProperties; +import org.apache.avro.Schema; +import org.apache.avro.Schema.Field; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Comparator; +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.function.Supplier; +import java.util.stream.Stream; + +import static org.apache.hudi.avro.AvroSchemaUtils.appendFieldsToSchema; +import static org.apache.hudi.avro.AvroSchemaUtils.containsFieldInSchema; +import static org.apache.hudi.avro.AvroSchemaUtils.createNullableSchema; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.DELTA_COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.HoodieTimeline.REPLACE_COMMIT_ACTION; +import static org.apache.hudi.common.table.timeline.InstantComparison.LESSER_THAN_OR_EQUALS; +import static org.apache.hudi.common.table.timeline.InstantComparison.compareTimestamps; + +/** + * Helper class to read table schema. ONLY USE IT FOR SimpleConcurrentFileWritesConflictResolutionStrategy. + */ +class ConcurrentSchemaEvolutionTableSchemaGetter { + + private static final Logger LOG = LoggerFactory.getLogger(ConcurrentSchemaEvolutionTableSchemaGetter.class); + + protected final HoodieTableMetaClient metaClient; + + private final Lazy<ConcurrentHashMap<HoodieInstant, Schema>> tableSchemaCache; + + private Option<HoodieInstant> latestCommitWithValidSchema = Option.empty(); + + @VisibleForTesting + public ConcurrentHashMap<HoodieInstant, Schema> getTableSchemaCache() { + return tableSchemaCache.get(); + } + + public ConcurrentSchemaEvolutionTableSchemaGetter(HoodieTableMetaClient metaClient) { + this.metaClient = metaClient; + // Unbounded sized map. Should replace with some caching library. + this.tableSchemaCache = Lazy.lazily(ConcurrentHashMap::new); + } + + /** + * Handles partition column logic for a given schema. + * + * @param schema the input schema to process + * @return the processed schema with partition columns handled appropriately + */ + private Schema handlePartitionColumnsIfNeeded(Schema schema) { + if (metaClient.getTableConfig().shouldDropPartitionColumns()) { + return metaClient.getTableConfig().getPartitionFields() + .map(partitionFields -> appendPartitionColumns(schema, Option.ofNullable(partitionFields))) + .or(() -> Option.of(schema)) + .get(); + } + return schema; + } + + public Option<Schema> getTableAvroSchemaIfPresent(boolean includeMetadataFields, Option<HoodieInstant> instant) { + return getTableAvroSchemaFromTimelineWithCache(instant) // Get table schema from schema evolution timeline. + .or(this::getTableCreateSchemaWithoutMetaField) // Fall back: read create schema from table config. + .map(tableSchema -> includeMetadataFields ? HoodieAvroUtils.addMetadataFields(tableSchema, false) : HoodieAvroUtils.removeMetadataFields(tableSchema)) + .map(this::handlePartitionColumnsIfNeeded); + } + + private Option<Schema> getTableCreateSchemaWithoutMetaField() { + return metaClient.getTableConfig().getTableCreateSchema(); + } + + private void setCachedLatestCommitWithValidSchema(Option<HoodieInstant> instantOption) { + latestCommitWithValidSchema = instantOption; + } + + private Option<HoodieInstant> getCachedLatestCommitWithValidSchema() { + return latestCommitWithValidSchema; + } + + @VisibleForTesting + Option<Schema> getTableAvroSchemaFromTimelineWithCache(Option<HoodieInstant> instantTime) { + return getTableAvroSchemaFromTimelineWithCache(computeSchemaEvolutionTimelineInReverseOrder(), instantTime); + } + + Option<Schema> getTableAvroSchemaFromTimelineWithCache(Stream<HoodieInstant> reversedTimelineStream, Option<HoodieInstant> instantTime) { + // If instantTime is empty it means read the latest one. In that case, get the cached instant if there is one. + boolean fetchFromLastValidCommit = instantTime.isEmpty(); + Option<HoodieInstant> targetInstant = instantTime.or(getCachedLatestCommitWithValidSchema()); + Schema cachedTableSchema = null; + + // Try cache first if there is a target instant to fetch for. + if (!targetInstant.isEmpty()) { + cachedTableSchema = tableSchemaCache.get().getOrDefault(targetInstant.get(), null); + } + + // Cache miss on either latestCommitWithValidSchema or commitMetadataCache. Compute the result. + if (cachedTableSchema == null) { + Option<Pair<HoodieInstant, Schema>> instantWithSchema = getLastCommitMetadataWithValidSchemaFromTimeline(reversedTimelineStream, targetInstant); + if (instantWithSchema.isPresent()) { + targetInstant = Option.of(instantWithSchema.get().getLeft()); + cachedTableSchema = instantWithSchema.get().getRight(); + } + } + + // After computation, update the cache for the instant and commit metadata. + if (fetchFromLastValidCommit) { + setCachedLatestCommitWithValidSchema(targetInstant); + } + if (cachedTableSchema != null) { + // We save cache for 2 cases + // - input specifies a specific instant, we update the cache for that instant, which is instantTime. + // - input is empty implying fetch the latest schema, update the cache for the + // latest valid commit which is targetInstant + if (instantTime.isPresent()) { + tableSchemaCache.get().putIfAbsent(instantTime.get(), cachedTableSchema); + } + if (targetInstant.isPresent()) { + tableSchemaCache.get().putIfAbsent(targetInstant.get(), cachedTableSchema); + } + } + + // Finally process the computation results and return. + if (cachedTableSchema == null) { + return Option.empty(); + } + + return Option.of(cachedTableSchema); + } + + @VisibleForTesting + Option<Pair<HoodieInstant, Schema>> getLastCommitMetadataWithValidSchemaFromTimeline(Stream<HoodieInstant> reversedTimelineStream, Option<HoodieInstant> instant) { + // To find the table schema given an instant time, need to walk backwards from the latest instant in + // the timeline finding a completed instant containing a valid schema. + ConcurrentHashMap<HoodieInstant, Schema> tableSchemaAtInstant = new ConcurrentHashMap<>(); + Option<HoodieInstant> instantWithTableSchema = Option.fromJavaOptional(reversedTimelineStream + // If a completion time is specified, find the first eligible instant in the schema evolution timeline. + // Should switch to completion time based. + .filter(s -> instant.isEmpty() || compareTimestamps(s.requestedTime(), LESSER_THAN_OR_EQUALS, instant.get().requestedTime())) Review Comment: Does the instant stream passed in contain completed instants only? -- This is an automated message from the Apache Git Service. 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