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ASF GitHub Bot commented on PARQUET-1647: ----------------------------------------- zhangjiashen commented on code in PR #1142: URL: https://github.com/apache/parquet-mr/pull/1142#discussion_r1335132272 ########## parquet-common/src/main/java/org/apache/parquet/util/Float16.java: ########## @@ -0,0 +1,192 @@ +/** + * 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.parquet.util; + +/** + * The class is a utility class to manipulate half-precision 16-bit + * <a href="https://en.wikipedia.org/wiki/Half-precision_floating-point_format">IEEE 754</a> + * floating point data types (also called fp16 or binary16). A half-precision float can be + * created from or converted to single-precision floats, and is stored in a short data type. + * The IEEE 754 standard specifies an float16 as having the following format: + * <ul> + * <li>Sign bit: 1 bit</li> + * <li>Exponent width: 5 bits</li> + * <li>Significand: 10 bits</li> + * </ul> + * + * <p>The format is laid out as follows:</p> + * <pre> + * 1 11111 1111111111 + * ^ --^ > [Java] support for Arrow's float16 > ---------------------------------- > > Key: PARQUET-1647 > URL: https://issues.apache.org/jira/browse/PARQUET-1647 > Project: Parquet > Issue Type: Improvement > Components: parquet-format, parquet-thrift > Reporter: The Alchemist > Priority: Minor > > h2. DESCRIPTION > > I'm wondering if there's any interest in supporting Arrow's {{float16}} type > in Parquet. > There seem to be one or two {{float16}} / {{halffloat}} tickets here (e.g., > PARQUET-1403) but nothing that speaks to adding half-float support to Parquet > in-general. > > h2. PLANS > I'm able to spend some time on this, if someone points me in the right > direction. > > # Add the {{HALFFLOAT}} or {{FLOAT16}} enum (any preferred naming > convention?) to > [https://github.com/apache/parquet-format/blob/master/src/main/thrift/parquet.thrift#L32] > # Add {{HALFFLOAT}} to {{org.apache.parquet.schema.PrimitiveType}} > # Add {{HALFFLOAT}} support to > {{org.apache.parquet.arrow.schema.SchemaConverter}} > # Add encoding for new type at {{org.apache.parquet.column.Encoding}} > # ?? > If anyone has any interest in this, pointers, or comments, they would be > greatly appreciated! -- This message was sent by Atlassian Jira (v8.20.10#820010)