What is string_decoder?
The string_decoder npm package is used to decode buffer objects into strings in a manner that preserves encoded multi-byte UTF-8 and UTF-16 characters. It is particularly useful when dealing with streams of data that may contain such characters.
What are string_decoder's main functionalities?
Decoding Buffers to Strings
This feature allows for the conversion of buffer objects into strings, ensuring that multi-byte characters are not improperly split at the end of a buffer.
{"const { StringDecoder } = require('string_decoder'); const decoder = new StringDecoder('utf8'); const buffer = Buffer.from([0xE2, 0x82, 0xAC]); console.log(decoder.write(buffer)); // Outputs: '€'"}
Handling Incomplete Multi-byte Characters
This feature is useful when buffers are received in chunks and multi-byte characters are spread across multiple chunks. The StringDecoder ensures that these characters are not converted until the complete character is received.
{"const { StringDecoder } = require('string_decoder'); const decoder = new StringDecoder('utf8'); const buffers = [Buffer.from([0xE2]), Buffer.from([0x82]), Buffer.from([0xAC])]; let result = ''; buffers.forEach((buffer) => { result += decoder.write(buffer); }); result += decoder.end(); console.log(result); // Outputs: '€'"}
Other packages similar to string_decoder
iconv-lite
iconv-lite is a pure JavaScript implementation of character encoding conversion. It supports many different encodings and is more versatile than string_decoder, which only supports UTF-8, UTF-16LE/BE, and Base64. However, string_decoder is a built-in module and may be preferred for its simplicity when only these encodings are needed.
buffer
The buffer package on npm is a node.js core module for binary data manipulation. It can be used to handle binary data directly, but it does not offer the same convenience functions for decoding multi-byte characters as string_decoder does.
string_decoder.js (require('string_decoder')
) from Node.js core
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