frontend/node_modules/apache-arrow/visitor/jsonvectorassembler.mjs

// 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.
import { BN } from '../util/bn';
import { Column } from '../column';
import { Vector } from '../vector';
import { Visitor } from '../visitor';
import { BufferType } from '../enum';
import { RecordBatch } from '../recordbatch';
import { UnionMode, DateUnit, TimeUnit } from '../enum';
import { iterateBits, getBit, getBool } from '../util/bit';
import { selectColumnChildrenArgs } from '../util/args';
import { DataType, } from '../type';
/** @ignore */
export class JSONVectorAssembler extends Visitor {
    /** @nocollapse */
    static assemble(...args) {
        return new JSONVectorAssembler().visitMany(selectColumnChildrenArgs(RecordBatch, args));
    }
    visit(column) {
        const { data, name, length } = column;
        const { offset, nullCount, nullBitmap } = data;
        const type = DataType.isDictionary(column.type) ? column.type.indices : column.type;
        const buffers = Object.assign([], data.buffers, { [BufferType.VALIDITY]: undefined });
        return {
            'name': name,
            'count': length,
            'VALIDITY': DataType.isNull(type) ? undefined
                : nullCount <= 0 ? Array.from({ length }, () => 1)
                    : [...iterateBits(nullBitmap, offset, length, null, getBit)],
            ...super.visit(Vector.new(data.clone(type, offset, length, 0, buffers)))
        };
    }
    visitNull() { return {}; }
    visitBool({ values, offset, length }) {
        return { 'DATA': [...iterateBits(values, offset, length, null, getBool)] };
    }
    visitInt(vector) {
        return {
            'DATA': vector.type.bitWidth < 64
                ? [...vector.values]
                : [...bigNumsToStrings(vector.values, 2)]
        };
    }
    visitFloat(vector) {
        return { 'DATA': [...vector.values] };
    }
    visitUtf8(vector) {
        return { 'DATA': [...vector], 'OFFSET': [...vector.valueOffsets] };
    }
    visitBinary(vector) {
        return { 'DATA': [...binaryToString(vector)], OFFSET: [...vector.valueOffsets] };
    }
    visitFixedSizeBinary(vector) {
        return { 'DATA': [...binaryToString(vector)] };
    }
    visitDate(vector) {
        return {
            'DATA': vector.type.unit === DateUnit.DAY
                ? [...vector.values]
                : [...bigNumsToStrings(vector.values, 2)]
        };
    }
    visitTimestamp(vector) {
        return { 'DATA': [...bigNumsToStrings(vector.values, 2)] };
    }
    visitTime(vector) {
        return {
            'DATA': vector.type.unit < TimeUnit.MICROSECOND
                ? [...vector.values]
                : [...bigNumsToStrings(vector.values, 2)]
        };
    }
    visitDecimal(vector) {
        return { 'DATA': [...bigNumsToStrings(vector.values, 4)] };
    }
    visitList(vector) {
        return {
            'OFFSET': [...vector.valueOffsets],
            'children': vector.type.children.map((f, i) => this.visit(new Column(f, [vector.getChildAt(i)])))
        };
    }
    visitStruct(vector) {
        return {
            'children': vector.type.children.map((f, i) => this.visit(new Column(f, [vector.getChildAt(i)])))
        };
    }
    visitUnion(vector) {
        return {
            'TYPE': [...vector.typeIds],
            'OFFSET': vector.type.mode === UnionMode.Dense ? [...vector.valueOffsets] : undefined,
            'children': vector.type.children.map((f, i) => this.visit(new Column(f, [vector.getChildAt(i)])))
        };
    }
    visitInterval(vector) {
        return { 'DATA': [...vector.values] };
    }
    visitFixedSizeList(vector) {
        return {
            'children': vector.type.children.map((f, i) => this.visit(new Column(f, [vector.getChildAt(i)])))
        };
    }
    visitMap(vector) {
        return {
            'OFFSET': [...vector.valueOffsets],
            'children': vector.type.children.map((f, i) => this.visit(new Column(f, [vector.getChildAt(i)])))
        };
    }
}
/** @ignore */
function* binaryToString(vector) {
    for (const octets of vector) {
        yield octets.reduce((str, byte) => {
            return `${str}${('0' + (byte & 0xFF).toString(16)).slice(-2)}`;
        }, '').toUpperCase();
    }
}
/** @ignore */
function* bigNumsToStrings(values, stride) {
    for (let i = -1, n = values.length / stride; ++i < n;) {
        yield `${BN.new(values.subarray((i + 0) * stride, (i + 1) * stride), false)}`;
    }
}

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