Spaces:
Running
Running
import { Vector } from './vector.js'; | |
import { Data } from './data.js'; | |
import { DataType, Float, Int, Decimal, FixedSizeBinary, Date_, Time, Timestamp, Interval, Utf8, Binary, List, Map_ } from './type.js'; | |
import { BufferBuilder, BitmapBufferBuilder, DataBufferBuilder, OffsetsBufferBuilder } from './builder/buffer.js'; | |
/** | |
* A set of options required to create a `Builder` instance for a given `DataType`. | |
* @see {@link Builder} | |
*/ | |
export interface BuilderOptions<T extends DataType = any, TNull = any> { | |
type: T; | |
nullValues?: TNull[] | ReadonlyArray<TNull> | null; | |
children?: { | |
[key: string]: BuilderOptions; | |
} | BuilderOptions[]; | |
} | |
/** | |
* An abstract base class for types that construct Arrow Vectors from arbitrary JavaScript values. | |
* | |
* A `Builder` is responsible for writing arbitrary JavaScript values | |
* to ArrayBuffers and/or child Builders according to the Arrow specification | |
* for each DataType, creating or resizing the underlying ArrayBuffers as necessary. | |
* | |
* The `Builder` for each Arrow `DataType` handles converting and appending | |
* values for a given `DataType`. The high-level {@link makeBuilder `makeBuilder()`} convenience | |
* method creates the specific `Builder` subclass for the supplied `DataType`. | |
* | |
* Once created, `Builder` instances support both appending values to the end | |
* of the `Builder`, and random-access writes to specific indices | |
* (`Builder.prototype.append(value)` is a convenience method for | |
* `builder.set(builder.length, value)`). Appending or setting values beyond the | |
* Builder's current length may cause the builder to grow its underlying buffers | |
* or child Builders (if applicable) to accommodate the new values. | |
* | |
* After enough values have been written to a `Builder`, `Builder.prototype.flush()` | |
* will commit the values to the underlying ArrayBuffers (or child Builders). The | |
* internal Builder state will be reset, and an instance of `Data<T>` is returned. | |
* Alternatively, `Builder.prototype.toVector()` will flush the `Builder` and return | |
* an instance of `Vector<T>` instead. | |
* | |
* When there are no more values to write, use `Builder.prototype.finish()` to | |
* finalize the `Builder`. This does not reset the internal state, so it is | |
* necessary to call `Builder.prototype.flush()` or `toVector()` one last time | |
* if there are still values queued to be flushed. | |
* | |
* Note: calling `Builder.prototype.finish()` is required when using a `DictionaryBuilder`, | |
* because this is when it flushes the values that have been enqueued in its internal | |
* dictionary's `Builder`, and creates the `dictionaryVector` for the `Dictionary` `DataType`. | |
* | |
* @example | |
* ```ts | |
* import { Builder, Utf8 } from 'apache-arrow'; | |
* | |
* const utf8Builder = makeBuilder({ | |
* type: new Utf8(), | |
* nullValues: [null, 'n/a'] | |
* }); | |
* | |
* utf8Builder | |
* .append('hello') | |
* .append('n/a') | |
* .append('world') | |
* .append(null); | |
* | |
* const utf8Vector = utf8Builder.finish().toVector(); | |
* | |
* console.log(utf8Vector.toJSON()); | |
* // > ["hello", null, "world", null] | |
* ``` | |
* | |
* @typeparam T The `DataType` of this `Builder`. | |
* @typeparam TNull The type(s) of values which will be considered null-value sentinels. | |
*/ | |
export declare abstract class Builder<T extends DataType = any, TNull = any> { | |
/** @nocollapse */ | |
static throughNode<T extends DataType = any, TNull = any>(options: import('./io/node/builder').BuilderDuplexOptions<T, TNull>): import('stream').Duplex; | |
/** @nocollapse */ | |
static throughDOM<T extends DataType = any, TNull = any>(options: import('./io/whatwg/builder').BuilderTransformOptions<T, TNull>): import('./io/whatwg/builder').BuilderTransform<T, TNull>; | |
/** | |
* Construct a builder with the given Arrow DataType with optional null values, | |
* which will be interpreted as "null" when set or appended to the `Builder`. | |
* @param {{ type: T, nullValues?: any[] }} options A `BuilderOptions` object used to create this `Builder`. | |
*/ | |
constructor({ 'type': type, 'nullValues': nulls }: BuilderOptions<T, TNull>); | |
/** | |
* The Builder's `DataType` instance. | |
* @readonly | |
*/ | |
type: T; | |
/** | |
* The number of values written to the `Builder` that haven't been flushed yet. | |
* @readonly | |
*/ | |
length: number; | |
/** | |
* A boolean indicating whether `Builder.prototype.finish()` has been called on this `Builder`. | |
* @readonly | |
*/ | |
finished: boolean; | |
/** | |
* The number of elements in the underlying values TypedArray that | |
* represent a single logical element, determined by this Builder's | |
* `DataType`. This is 1 for most types, but is larger when the `DataType` | |
* is `Int64`, `Uint64`, `Decimal`, `DateMillisecond`, certain variants of | |
* `Interval`, `Time`, or `Timestamp`, `FixedSizeBinary`, and `FixedSizeList`. | |
* @readonly | |
*/ | |
readonly stride: number; | |
readonly children: Builder[]; | |
/** | |
* The list of null-value sentinels for this `Builder`. When one of these values | |
* is written to the `Builder` (either via `Builder.prototype.set()` or `Builder.prototype.append()`), | |
* a 1-bit is written to this Builder's underlying null BitmapBufferBuilder. | |
* @readonly | |
*/ | |
readonly nullValues?: TNull[] | ReadonlyArray<TNull> | null; | |
/** | |
* Flush the `Builder` and return a `Vector<T>`. | |
* @returns {Vector<T>} A `Vector<T>` of the flushed values. | |
*/ | |
toVector(): Vector<T>; | |
get ArrayType(): any; | |
get nullCount(): number; | |
get numChildren(): number; | |
/** | |
* @returns The aggregate length (in bytes) of the values that have been written. | |
*/ | |
get byteLength(): number; | |
/** | |
* @returns The aggregate number of rows that have been reserved to write new values. | |
*/ | |
get reservedLength(): number; | |
/** | |
* @returns The aggregate length (in bytes) that has been reserved to write new values. | |
*/ | |
get reservedByteLength(): number; | |
protected _offsets: DataBufferBuilder<Int32Array>; | |
get valueOffsets(): Int32Array | null; | |
protected _values: BufferBuilder<T['TArray'], any>; | |
get values(): T["TArray"] | null; | |
protected _nulls: BitmapBufferBuilder; | |
get nullBitmap(): Uint8Array | null; | |
protected _typeIds: DataBufferBuilder<Int8Array>; | |
get typeIds(): Int8Array | null; | |
protected _isValid: (value: T['TValue'] | TNull) => boolean; | |
protected _setValue: (inst: Builder<T>, index: number, value: T['TValue']) => void; | |
/** | |
* Appends a value (or null) to this `Builder`. | |
* This is equivalent to `builder.set(builder.length, value)`. | |
* @param {T['TValue'] | TNull } value The value to append. | |
*/ | |
append(value: T['TValue'] | TNull): this; | |
/** | |
* Validates whether a value is valid (true), or null (false) | |
* @param {T['TValue'] | TNull } value The value to compare against null the value representations | |
*/ | |
isValid(value: T['TValue'] | TNull): boolean; | |
/** | |
* Write a value (or null-value sentinel) at the supplied index. | |
* If the value matches one of the null-value representations, a 1-bit is | |
* written to the null `BitmapBufferBuilder`. Otherwise, a 0 is written to | |
* the null `BitmapBufferBuilder`, and the value is passed to | |
* `Builder.prototype.setValue()`. | |
* @param {number} index The index of the value to write. | |
* @param {T['TValue'] | TNull } value The value to write at the supplied index. | |
* @returns {this} The updated `Builder` instance. | |
*/ | |
set(index: number, value: T['TValue'] | TNull): this; | |
/** | |
* Write a value to the underlying buffers at the supplied index, bypassing | |
* the null-value check. This is a low-level method that | |
* @param {number} index | |
* @param {T['TValue'] | TNull } value | |
*/ | |
setValue(index: number, value: T['TValue']): void; | |
setValid(index: number, valid: boolean): boolean; | |
addChild(child: Builder, name?: string): void; | |
/** | |
* Retrieve the child `Builder` at the supplied `index`, or null if no child | |
* exists at that index. | |
* @param {number} index The index of the child `Builder` to retrieve. | |
* @returns {Builder | null} The child Builder at the supplied index or null. | |
*/ | |
getChildAt<R extends DataType = any>(index: number): Builder<R> | null; | |
/** | |
* Commit all the values that have been written to their underlying | |
* ArrayBuffers, including any child Builders if applicable, and reset | |
* the internal `Builder` state. | |
* @returns A `Data<T>` of the buffers and children representing the values written. | |
*/ | |
flush(): Data<T>; | |
/** | |
* Finalize this `Builder`, and child builders if applicable. | |
* @returns {this} The finalized `Builder` instance. | |
*/ | |
finish(): this; | |
/** | |
* Clear this Builder's internal state, including child Builders if applicable, and reset the length to 0. | |
* @returns {this} The cleared `Builder` instance. | |
*/ | |
clear(): this; | |
} | |
/** @ignore */ | |
export declare abstract class FixedWidthBuilder<T extends Int | Float | FixedSizeBinary | Date_ | Timestamp | Time | Decimal | Interval = any, TNull = any> extends Builder<T, TNull> { | |
constructor(opts: BuilderOptions<T, TNull>); | |
setValue(index: number, value: T['TValue']): void; | |
} | |
/** @ignore */ | |
export declare abstract class VariableWidthBuilder<T extends Binary | Utf8 | List | Map_, TNull = any> extends Builder<T, TNull> { | |
protected _pendingLength: number; | |
protected _offsets: OffsetsBufferBuilder; | |
protected _pending: Map<number, any> | undefined; | |
constructor(opts: BuilderOptions<T, TNull>); | |
setValue(index: number, value: T['TValue']): void; | |
setValid(index: number, isValid: boolean): boolean; | |
clear(): this; | |
flush(): Data<T>; | |
finish(): this; | |
protected _flush(): this; | |
protected abstract _flushPending(pending: Map<number, any>, pendingLength: number): void; | |
} | |