apache-arrow/src/ipc/serialization.ts

Apache Arrow columnar in-memory format

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// 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
//
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import { Table } from '../table.js';
import { TypeMap } from '../type.js';
import { isPromise } from '../util/compat.js';
import {
    FromArg0, FromArg1, FromArg2, FromArg3, FromArg4, FromArg5,
    RecordBatchReader,
    RecordBatchFileReader, RecordBatchStreamReader,
    AsyncRecordBatchFileReader, AsyncRecordBatchStreamReader
} from './reader.js';
import { RecordBatchFileWriter, RecordBatchStreamWriter } from './writer.js';

type RecordBatchReaders<T extends TypeMap = any> = RecordBatchFileReader<T> | RecordBatchStreamReader<T>;
type AsyncRecordBatchReaders<T extends TypeMap = any> = AsyncRecordBatchFileReader<T> | AsyncRecordBatchStreamReader<T>;

/**
 * Deserialize the IPC format into a {@link Table}. This function is a
 * convenience wrapper for {@link RecordBatchReader}. Opposite of {@link tableToIPC}.
 */
export function tableFromIPC<T extends TypeMap = any>(source: FromArg0 | FromArg2): Table<T>;
export function tableFromIPC<T extends TypeMap = any>(source: FromArg1): Promise<Table<T>>;
export function tableFromIPC<T extends TypeMap = any>(source: FromArg3 | FromArg4 | FromArg5): Promise<Table<T>>;
export function tableFromIPC<T extends TypeMap = any>(source: RecordBatchReaders<T>): Table<T>;
export function tableFromIPC<T extends TypeMap = any>(source: AsyncRecordBatchReaders<T>): Promise<Table<T>>;
export function tableFromIPC<T extends TypeMap = any>(source: RecordBatchReader<T>): Table<T> | Promise<Table<T>>;
export function tableFromIPC<T extends TypeMap = any>(input: any): Table<T> | Promise<Table<T>> {
    const reader = RecordBatchReader.from<T>(input) as RecordBatchReader<T> | Promise<RecordBatchReader<T>>;
    if (isPromise<RecordBatchReader<T>>(reader)) {
        return reader.then((reader) => tableFromIPC(reader)) as Promise<Table<T>>;
    }
    if (reader.isAsync()) {
        return (reader as AsyncRecordBatchReaders<T>).readAll().then((xs) => new Table(xs));
    }
    return new Table((reader as RecordBatchReaders<T>).readAll());
}

/**
 * Serialize a {@link Table} to the IPC format. This function is a convenience
 * wrapper for {@link RecordBatchStreamWriter} and {@link RecordBatchFileWriter}.
 * Opposite of {@link tableFromIPC}.
 *
 * @param table The Table to serialize.
 * @param type Whether to serialize the Table as a file or a stream.
 */
export function tableToIPC<T extends TypeMap = any>(table: Table, type: 'file' | 'stream' = 'stream'): Uint8Array {
    return (type === 'stream' ? RecordBatchStreamWriter : RecordBatchFileWriter)
        .writeAll<T>(table)
        .toUint8Array(true);
}