apache-arrow/fb/field-node.js

Apache Arrow columnar in-memory format

"use strict";
// automatically generated by the FlatBuffers compiler, do not modify
Object.defineProperty(exports, "__esModule", { value: true });
exports.FieldNode = void 0;
/**
 * ----------------------------------------------------------------------
 * Data structures for describing a table row batch (a collection of
 * equal-length Arrow arrays)
 * Metadata about a field at some level of a nested type tree (but not
 * its children).
 *
 * For example, a List<Int16> with values `[[1, 2, 3], null, [4], [5, 6], null]`
 * would have {length: 5, null_count: 2} for its List node, and {length: 6,
 * null_count: 0} for its Int16 node, as separate FieldNode structs
 */
class FieldNode {
    constructor() {
        this.bb = null;
        this.bb_pos = 0;
    }
    __init(i, bb) {
        this.bb_pos = i;
        this.bb = bb;
        return this;
    }
    /**
     * The number of value slots in the Arrow array at this level of a nested
     * tree
     */
    length() {
        return this.bb.readInt64(this.bb_pos);
    }
    /**
     * The number of observed nulls. Fields with null_count == 0 may choose not
     * to write their physical validity bitmap out as a materialized buffer,
     * instead setting the length of the bitmap buffer to 0.
     */
    nullCount() {
        return this.bb.readInt64(this.bb_pos + 8);
    }
    static sizeOf() {
        return 16;
    }
    static createFieldNode(builder, length, null_count) {
        builder.prep(8, 16);
        builder.writeInt64(BigInt(null_count !== null && null_count !== void 0 ? null_count : 0));
        builder.writeInt64(BigInt(length !== null && length !== void 0 ? length : 0));
        return builder.offset();
    }
}
exports.FieldNode = FieldNode;

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