Node-zstandard NPM

node-zstandard

Node.js interface to Zstandard (zstd)

Includes Zstd 1.0.0 version for Linux (x86-64, glibc >=2.19), Windows (32 and 64 bits), and Mac OS X (Darwin).

Interface

var zstd = require ('node-zstandard')

Compression

zstd.compress (inputFile, outputFile , compLevel, callback)

zstd.compressFileToFile (inputFile, outputFile , compLevel, callback)

inputFile: Path to the to file to be compressed.
outputFile: Path to store the resulting compressed file.
compLevel: Compression level (default=3).
callback: Function to be executed on task completion. Follows Node.js (err, result) pattern, being result equal to outputFile when succedded.

NOTE: Input and output files should be different. Output file is overwritten if it exists.

zstd.compress('./test', './test.zst', 3, (err, result) => {
  if (err)
    throw err;
  console.log (result);
});

compressStreamToFile (readableStream, outputFile , compLevel, callback)

readableStream: Data Node.js Stream to be compressed.
outputFile: Path to store the resulting compressed file.
compLevel: Compression level (default=3).
callback: Function to be executed on task initialization. Follows Node.js (err, result) pattern, being result an EventEmitter that can emit the following events:
- error: Emitted when an error reading the stream or creating the compressed file occurred. Error message is provided.
- end: Emitted when task ended successfully.

NOTE: Output file is overwritten if it exists.

zstd.compressStreamToFile(aReadableStream, './test.zst', 3, (err, result) => {
  if (err)
    throw err;
  result.on('error', (err) => {
    throw err;
  }
  result.on('end', () => {
    console.log ('Compression ended');
  }
  console.log ('Compression started');
});

Decompression

zstd.decompress (inputFile, outputFile, callback)

zstd.decompressFileToFile (inputFile, outputFile, callback)

inputFile: Path to the to compressed input file.
outputFile: Path to store the resulting decompressed file.
callback: Function to be executed on task completion. Follows Node.js (err, result) pattern, being result equal to outputFile when succedded.

NOTE: Input and output files should be different. Output file is overwritten if it exists.

zstd.decompress('./test.zst','./test', (err, result) => {
  if (err)
    throw err;
  console.log (result);
});

decompressFileToStream (inputFile, writableStream, callback)

inputFile: Path to the to compressed input file.
writableStream: Node.js Stream where to output decompressed data.
callback: Function to be executed on task initialization. Follows Node.js (err, result) pattern, being result an EventEmitter that can emit the following events:
- error: Emitted when an error involving streams or file decompression occurred. Error message is provided.
- finish: Emitted when finished writting decompressed data to output stream.

zstd.decompressFileToStream ('./test', aWritableStream, (err, result) => {
  if (err)
    throw err;
  result.on('error', (err) => {
    throw err;
  }
  result.on('finish', () => {
    console.log ('Decompression finished');
  }
  console.log ('Decompression started');
});

decompressionStreamFromFile (inputFile, callback)

inputFile: Path to the to compressed input file.
callback: Function to be executed on task initialization. Follows Node.js (err, result) pattern, being result an EventEmitter that can emit the following events:
- error: Emitted when an error involving streams or file decompression occurred. Error message is provided.
- data: Emitted when a chunk of decompressed data is generated. Data is obviously provided.
- end: Emitted when decompression ended and all data events have been emitted.

zstd.decompressionStreamFromFile ('./test', (err, result) => {
  if (err)
    throw err;
  var decompressedData = '';
  result.on('error', (err) => {
    throw err;
  }
  result.on('data', (data) => {
    decompressedData += data;
  }
  result.on('end', () => {
    console.log (decompressedData);
  }
});