amogh-jahagirdar commented on code in PR #6559: URL: https://github.com/apache/iceberg/pull/6559#discussion_r1066526193
########## core/src/main/java/org/apache/iceberg/view/ViewMetadataParser.java: ########## @@ -0,0 +1,180 @@ +/* + * 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.iceberg.view; + +import com.fasterxml.jackson.core.JsonGenerator; +import com.fasterxml.jackson.databind.JsonNode; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; +import java.io.OutputStreamWriter; +import java.nio.charset.StandardCharsets; +import java.util.List; +import java.util.Map; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SchemaParser; +import org.apache.iceberg.exceptions.RuntimeIOException; +import org.apache.iceberg.io.InputFile; +import org.apache.iceberg.io.OutputFile; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList; +import org.apache.iceberg.util.JsonUtil; +import org.apache.iceberg.util.PropertyUtil; + +class ViewMetadataParser { + + // visible for testing + static final String FORMAT_VERSION = "format-version"; + static final String LOCATION = "location"; + static final String CURRENT_VERSION_ID = "current-version-id"; + static final String VERSIONS = "versions"; + static final String VERSION_LOG = "version-log"; + static final String PROPERTIES = "properties"; + static final String SCHEMAS = "schemas"; + static final String CURRENT_SCHEMA_ID = "current-schema-id"; + + public static void overwrite(ViewMetadata metadata, OutputFile outputFile) { + internalWrite(metadata, outputFile, true); + } + + public static void write(ViewMetadata metadata, OutputFile outputFile) { + internalWrite(metadata, outputFile, false); + } + + public static void internalWrite( + ViewMetadata metadata, OutputFile outputFile, boolean overwrite) { + OutputStream stream = overwrite ? outputFile.createOrOverwrite() : outputFile.create(); + try (OutputStreamWriter writer = new OutputStreamWriter(stream, StandardCharsets.UTF_8)) { + JsonGenerator generator = JsonUtil.factory().createGenerator(writer); + generator.useDefaultPrettyPrinter(); + toJson(metadata, generator); + generator.flush(); + } catch (IOException e) { + throw new RuntimeIOException(e, "Failed to write json to file: %s", outputFile); + } + } + + public static void toJson(ViewMetadata metadata, JsonGenerator generator) throws IOException { + generator.writeStartObject(); + + generator.writeNumberField(FORMAT_VERSION, metadata.formatVersion()); + generator.writeStringField(LOCATION, metadata.location()); + JsonUtil.writeStringMap(PROPERTIES, metadata.properties(), generator); + + if (metadata.currentSchemaId() != null) { + generator.writeNumberField(CURRENT_SCHEMA_ID, metadata.currentSchemaId()); + } + + if (metadata.schemas() != null) { + JsonUtil.writeObjectList(SCHEMAS, metadata.schemas(), SchemaParser::toJson, generator); + } + + generator.writeNumberField(CURRENT_VERSION_ID, metadata.currentVersionId()); + JsonUtil.writeObjectList(VERSIONS, metadata.versions(), ViewVersionParser::toJson, generator); + JsonUtil.writeObjectList( + VERSION_LOG, metadata.history(), ViewHistoryEntryParser::toJson, generator); + + generator.writeEndObject(); + } + + public static ViewMetadata read(InputFile file) { + try (InputStream is = file.newStream()) { + return fromJson(JsonUtil.mapper().readValue(is, JsonNode.class)); + } catch (IOException e) { + throw new RuntimeIOException(e, "Failed to read file: %s", file); + } + } + + public static ViewMetadata fromJson(JsonNode node) { + return fromJson(node, null); + } + + public static ViewMetadata fromJson(JsonNode node, String metadataFileLocation) { + + Preconditions.checkArgument( + node.isObject(), "Cannot parse metadata from a non-object: %s", node); + + int formatVersion = JsonUtil.getInt(FORMAT_VERSION, node); + Preconditions.checkArgument( + formatVersion <= ViewMetadata.SUPPORTED_VIEW_FORMAT_VERSION, + "Cannot read unsupported version %s", + formatVersion); + + String location = JsonUtil.getString(LOCATION, node); + + int currentVersionId = JsonUtil.getInt(CURRENT_VERSION_ID, node); + + Map<String, String> properties = JsonUtil.getStringMap(PROPERTIES, node); + + List<ViewVersion> versions = + JsonUtil.getObjectList(VERSIONS, node, ViewVersionParser::fromJson); + + List<ViewHistoryEntry> history = + JsonUtil.getObjectList(VERSION_LOG, node, ViewHistoryEntryParser::fromJson); + + int numVersionsToKeep = + PropertyUtil.propertyAsInt( + properties, + ViewProperties.VERSION_HISTORY_SIZE, + ViewProperties.VERSION_HISTORY_SIZE_DEFAULT); + + versions = versions.subList(0, Math.min(numVersionsToKeep, versions.size())); + + List<Schema> schemas = null; + Integer currentSchemaId = null; + if (node.has(SCHEMAS)) { + JsonNode schemaArray = node.get(SCHEMAS); + Schema currentSchema = null; + Preconditions.checkArgument( + schemaArray.isArray(), "Cannot parse schemas from non-array: %s", schemaArray); + // current schema ID is required when the schema array is present + currentSchemaId = JsonUtil.getInt(CURRENT_SCHEMA_ID, node); + // parse the schema array + ImmutableList.Builder<Schema> builder = ImmutableList.builder(); + for (JsonNode schemaNode : schemaArray) { + Schema schema = SchemaParser.fromJson(schemaNode); + if (schema.schemaId() == currentSchemaId) { + currentSchema = schema; + } + builder.add(schema); + } Review Comment: The doubt I still have is I think schemas and current schema should always be set, and thus the spec should be reflected so that it's required. Maybe there's a case that we don't want schema for the entire view. But at least in my mind for any SQL representation in the view, the schema-id should be required (which then means there must be a schema list considering we only support SQL representations) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
