ceph/src/arrow/js/src/visitor/bytewidth.ts

   1 /* istanbul ignore file */
   2
   3 // Licensed to the Apache Software Foundation (ASF) under one
   4 // or more contributor license agreements.  See the NOTICE file
   5 // distributed with this work for additional information
   6 // regarding copyright ownership.  The ASF licenses this file
   7 // to you under the Apache License, Version 2.0 (the
   8 // "License"); you may not use this file except in compliance
   9 // with the License.  You may obtain a copy of the License at
  10 //
  11 //   http://www.apache.org/licenses/LICENSE-2.0
  12 //
  13 // Unless required by applicable law or agreed to in writing,
  14 // software distributed under the License is distributed on an
  15 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  16 // KIND, either express or implied.  See the License for the
  17 // specific language governing permissions and limitations
  18 // under the License.
  19
  20 import { Data } from '../data';
  21 import { Visitor } from '../visitor';
  22 import { VectorType } from '../interfaces';
  23 import { Type, TimeUnit } from '../enum';
  24 import { Schema, Field } from '../schema';
  25 import {
  26     DataType, Dictionary,
  27     Float, Int, Date_, Interval, Time, Timestamp,
  28     Bool, Null, Utf8, Binary, Decimal, FixedSizeBinary,
  29     List, FixedSizeList, Map_, Struct, Union,
  30 } from '../type';
  31
  32 /** @ignore */ const sum = (x: number, y: number) => x + y;
  33 /** @ignore */ const variableWidthColumnErrorMessage = (type: DataType) => `Cannot compute the byte width of variable-width column ${type}`;
  34
  35 /** @ignore */
  36 export interface ByteWidthVisitor extends Visitor {
  37     visit<T extends DataType>(node: T): number;
  38     visitMany<T extends DataType>(nodes: T[]): number[];
  39     getVisitFn<T extends Type>    (node: T): (type: DataType<T>) => number;
  40     getVisitFn<T extends DataType>(node: VectorType<T> | Data<T> | T): (type: T) => number;
  41 }
  42
  43 /** @ignore */
  44 export class ByteWidthVisitor extends Visitor {
  45     public visitNull            (____: Null            ) { return 0; }
  46     public visitInt             (type: Int             ) { return type.bitWidth / 8; }
  47     public visitFloat           (type: Float           ) { return type.ArrayType.BYTES_PER_ELEMENT; }
  48     public visitBinary          (type: Binary          ) { throw new Error(variableWidthColumnErrorMessage(type)); }
  49     public visitUtf8            (type: Utf8            ) { throw new Error(variableWidthColumnErrorMessage(type)); }
  50     public visitBool            (____: Bool            ) { return 1 / 8; }
  51     public visitDecimal         (____: Decimal         ) { return 16; }
  52     public visitDate            (type: Date_           ) { return (type.unit + 1) * 4; }
  53     public visitTime            (type: Time            ) { return type.bitWidth / 8; }
  54     public visitTimestamp       (type: Timestamp       ) { return type.unit === TimeUnit.SECOND ? 4 : 8; }
  55     public visitInterval        (type: Interval        ) { return (type.unit + 1) * 4; }
  56     public visitList            (type: List            ) { throw new Error(variableWidthColumnErrorMessage(type)); }
  57     public visitStruct          (type: Struct          ) { return this.visitFields(type.children).reduce(sum, 0); }
  58     public visitUnion           (type: Union           ) { return this.visitFields(type.children).reduce(sum, 0); }
  59     public visitFixedSizeBinary (type: FixedSizeBinary ) { return type.byteWidth; }
  60     public visitFixedSizeList   (type: FixedSizeList   ) { return type.listSize * this.visitFields(type.children).reduce(sum, 0); }
  61     public visitMap             (type: Map_            ) { return this.visitFields(type.children).reduce(sum, 0); }
  62     public visitDictionary      (type: Dictionary      ) { return this.visit(type.indices); }
  63     public visitFields          (fields: Field[]       ) { return (fields || []).map((field) => this.visit(field.type)); }
  64     public visitSchema          (schema: Schema        ) { return this.visitFields(schema.fields).reduce(sum, 0); }
  65 }
  66
  67 /** @ignore */
  68 export const instance = new ByteWidthVisitor();