exceljs
Version:
Excel Workbook Manager - Read and Write xlsx and csv Files.
67 lines (60 loc) • 1.87 kB
JavaScript
const Stream = require('readable-stream');
// =============================================================================
// StreamBase64 - A utility to convert to/from base64 stream
// Note: does not buffer data, must be piped
class StreamBase64 extends Stream.Duplex {
constructor() {
super();
// consuming pipe streams go here
this.pipes = [];
}
// writable
// event drain - if write returns false (which it won't), indicates when safe to write again.
// finish - end() has been called
// pipe(src) - pipe() has been called on readable
// unpipe(src) - unpipe() has been called on readable
// error - duh
write( /* data, encoding */
) {
return true;
}
cork() {}
uncork() {}
end( /* chunk, encoding, callback */) {}
// readable
// event readable - some data is now available
// event data - switch to flowing mode - feeds chunks to handler
// event end - no more data
// event close - optional, indicates upstream close
// event error - duh
read( /* size */) {}
setEncoding(encoding) {
// causes stream.read or stream.on('data) to return strings of encoding instead of Buffer objects
this.encoding = encoding;
}
pause() {}
resume() {}
isPaused() {}
pipe(destination) {
// add destination to pipe list & write current buffer
this.pipes.push(destination);
}
unpipe(destination) {
// remove destination from pipe list
this.pipes = this.pipes.filter(pipe => pipe !== destination);
}
unshift( /* chunk */
) {
// some numpty has read some data that's not for them and they want to put it back!
// Might implement this some day
throw new Error('Not Implemented');
}
wrap( /* stream */
) {
// not implemented
throw new Error('Not Implemented');
}
}
module.exports = StreamBase64;
//# sourceMappingURL=stream-base64.js.map
;