Files
smartarchive/ts/classes.gziptools.ts

144 lines
3.4 KiB
TypeScript

import * as plugins from './plugins.js';
import type { TCompressionLevel } from './interfaces.js';
/**
* Transform stream for GZIP compression using fflate
*/
export class GzipCompressionTransform extends plugins.stream.Transform {
private gzip: plugins.fflate.Gzip;
constructor(level: TCompressionLevel = 6) {
super();
// Create a streaming Gzip compressor
this.gzip = new plugins.fflate.Gzip({ level }, (chunk, final) => {
this.push(Buffer.from(chunk));
if (final) {
this.push(null);
}
});
}
_transform(
chunk: Buffer,
encoding: BufferEncoding,
callback: plugins.stream.TransformCallback
): void {
try {
this.gzip.push(chunk, false);
callback();
} catch (err) {
callback(err as Error);
}
}
_flush(callback: plugins.stream.TransformCallback): void {
try {
this.gzip.push(new Uint8Array(0), true);
callback();
} catch (err) {
callback(err as Error);
}
}
}
/**
* Transform stream for GZIP decompression using fflate
*/
export class GzipDecompressionTransform extends plugins.stream.Transform {
private gunzip: plugins.fflate.Gunzip;
constructor() {
super();
// Create a streaming Gunzip decompressor
this.gunzip = new plugins.fflate.Gunzip((chunk, final) => {
this.push(Buffer.from(chunk));
if (final) {
this.push(null);
}
});
}
_transform(
chunk: Buffer,
encoding: BufferEncoding,
callback: plugins.stream.TransformCallback
): void {
try {
this.gunzip.push(chunk, false);
callback();
} catch (err) {
callback(err as Error);
}
}
_flush(callback: plugins.stream.TransformCallback): void {
try {
this.gunzip.push(new Uint8Array(0), true);
callback();
} catch (err) {
callback(err as Error);
}
}
}
/**
* GZIP compression and decompression utilities
*/
export class GzipTools {
/**
* Get a streaming compression transform
*/
public getCompressionStream(level?: TCompressionLevel): plugins.stream.Transform {
return new GzipCompressionTransform(level);
}
/**
* Get a streaming decompression transform
*/
public getDecompressionStream(): plugins.stream.Transform {
return new GzipDecompressionTransform();
}
/**
* Compress data synchronously
*/
public compressSync(data: Buffer, level?: TCompressionLevel): Buffer {
const options = level !== undefined ? { level } : undefined;
return Buffer.from(plugins.fflate.gzipSync(data, options));
}
/**
* Decompress data synchronously
*/
public decompressSync(data: Buffer): Buffer {
return Buffer.from(plugins.fflate.gunzipSync(data));
}
/**
* Compress data asynchronously
*/
public async compress(data: Buffer, level?: TCompressionLevel): Promise<Buffer> {
return new Promise((resolve, reject) => {
const options = level !== undefined ? { level } : undefined;
plugins.fflate.gzip(data, options as plugins.fflate.AsyncGzipOptions, (err, result) => {
if (err) reject(err);
else resolve(Buffer.from(result));
});
});
}
/**
* Decompress data asynchronously
*/
public async decompress(data: Buffer): Promise<Buffer> {
return new Promise((resolve, reject) => {
plugins.fflate.gunzip(data, (err, result) => {
if (err) reject(err);
else resolve(Buffer.from(result));
});
});
}
}