Reduce memory footprint while downloading a file with HTTPCLient

Question

I was wondering if there's a way I can avoid of getting all the buffer, then writing them to a file using HttpClient and File.WriteAllBytes.

Here's the code snippet I use

public async Task<byte[]> DownloadAsByteArray(string filename)
{
    _logger.LogDebug($"Start downloading {filename} file at {DateTime.Now}");
    
    var result = await _httpClient.GetByteArrayAsync(filename);
    
    return result;
}

var bytes = await _downloadFileService.DownloadAsByteArray(fileDownload);

await File.WriteAllBytesAsync(fullFlePathName, bytes);

For quite huge file, the application memory grows really fast.

Answer 1

How about using GetAsync instead of GetByteArrayAsync and using Content's CopyTo?

var response = await _httpClient.GetAsync(uri);
using var fs = new FileStream(...);
await response.Content.CopyToAsync(fs);

---

Or using GetStreamAsync

using var responseStream = await _httpClient.GetStreamAsync(uri);
using var fs = new FileStream(...);
await responseStream.CopyToAsync(fs);