apache-arrow/fb/schema.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.Schema = void 0;
const flatbuffers = require("flatbuffers");
const endianness_js_1 = require("./endianness.js");
const field_js_1 = require("./field.js");
const key_value_js_1 = require("./key-value.js");
/**
 * ----------------------------------------------------------------------
 * A Schema describes the columns in a row batch
 */
class Schema {
    constructor() {
        this.bb = null;
        this.bb_pos = 0;
    }
    __init(i, bb) {
        this.bb_pos = i;
        this.bb = bb;
        return this;
    }
    static getRootAsSchema(bb, obj) {
        return (obj || new Schema()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
    }
    static getSizePrefixedRootAsSchema(bb, obj) {
        bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
        return (obj || new Schema()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
    }
    /**
     * endianness of the buffer
     * it is Little Endian by default
     * if endianness doesn't match the underlying system then the vectors need to be converted
     */
    endianness() {
        const offset = this.bb.__offset(this.bb_pos, 4);
        return offset ? this.bb.readInt16(this.bb_pos + offset) : endianness_js_1.Endianness.Little;
    }
    fields(index, obj) {
        const offset = this.bb.__offset(this.bb_pos, 6);
        return offset ? (obj || new field_js_1.Field()).__init(this.bb.__indirect(this.bb.__vector(this.bb_pos + offset) + index * 4), this.bb) : null;
    }
    fieldsLength() {
        const offset = this.bb.__offset(this.bb_pos, 6);
        return offset ? this.bb.__vector_len(this.bb_pos + offset) : 0;
    }
    customMetadata(index, obj) {
        const offset = this.bb.__offset(this.bb_pos, 8);
        return offset ? (obj || new key_value_js_1.KeyValue()).__init(this.bb.__indirect(this.bb.__vector(this.bb_pos + offset) + index * 4), this.bb) : null;
    }
    customMetadataLength() {
        const offset = this.bb.__offset(this.bb_pos, 8);
        return offset ? this.bb.__vector_len(this.bb_pos + offset) : 0;
    }
    /**
     * Features used in the stream/file.
     */
    features(index) {
        const offset = this.bb.__offset(this.bb_pos, 10);
        return offset ? this.bb.readInt64(this.bb.__vector(this.bb_pos + offset) + index * 8) : BigInt(0);
    }
    featuresLength() {
        const offset = this.bb.__offset(this.bb_pos, 10);
        return offset ? this.bb.__vector_len(this.bb_pos + offset) : 0;
    }
    static startSchema(builder) {
        builder.startObject(4);
    }
    static addEndianness(builder, endianness) {
        builder.addFieldInt16(0, endianness, endianness_js_1.Endianness.Little);
    }
    static addFields(builder, fieldsOffset) {
        builder.addFieldOffset(1, fieldsOffset, 0);
    }
    static createFieldsVector(builder, data) {
        builder.startVector(4, data.length, 4);
        for (let i = data.length - 1; i >= 0; i--) {
            builder.addOffset(data[i]);
        }
        return builder.endVector();
    }
    static startFieldsVector(builder, numElems) {
        builder.startVector(4, numElems, 4);
    }
    static addCustomMetadata(builder, customMetadataOffset) {
        builder.addFieldOffset(2, customMetadataOffset, 0);
    }
    static createCustomMetadataVector(builder, data) {
        builder.startVector(4, data.length, 4);
        for (let i = data.length - 1; i >= 0; i--) {
            builder.addOffset(data[i]);
        }
        return builder.endVector();
    }
    static startCustomMetadataVector(builder, numElems) {
        builder.startVector(4, numElems, 4);
    }
    static addFeatures(builder, featuresOffset) {
        builder.addFieldOffset(3, featuresOffset, 0);
    }
    static createFeaturesVector(builder, data) {
        builder.startVector(8, data.length, 8);
        for (let i = data.length - 1; i >= 0; i--) {
            builder.addInt64(data[i]);
        }
        return builder.endVector();
    }
    static startFeaturesVector(builder, numElems) {
        builder.startVector(8, numElems, 8);
    }
    static endSchema(builder) {
        const offset = builder.endObject();
        return offset;
    }
    static finishSchemaBuffer(builder, offset) {
        builder.finish(offset);
    }
    static finishSizePrefixedSchemaBuffer(builder, offset) {
        builder.finish(offset, undefined, true);
    }
    static createSchema(builder, endianness, fieldsOffset, customMetadataOffset, featuresOffset) {
        Schema.startSchema(builder);
        Schema.addEndianness(builder, endianness);
        Schema.addFields(builder, fieldsOffset);
        Schema.addCustomMetadata(builder, customMetadataOffset);
        Schema.addFeatures(builder, featuresOffset);
        return Schema.endSchema(builder);
    }
}
exports.Schema = Schema;

//# sourceMappingURL=schema.js.map