将无限字节写入bytes.Buffer

Question

When I run the following code

func writeBytes() ([]byte, error) {
    var buf bytes.Buffer
    dstBytes := bufio.NewWriter(&buf)
    writeTonsOfBytes(dstBytes)
    b := buf.Bytes()
    fmt.Println(len(b))
    return b, nil
}

I get the output

32768

Which is signaling to me that there must be a limit on my bytes.Buffer instance, which I can't find documentation for.

How can I write an unlimited number of bytes to a bytes.Buffer?

Answer 1

There is no call to

dstBytes.Flush()

in the code. Any bytes that are currently unwritten to buf will remain unwritten, causing buf to have an incomplete record of the bytes written to dstBytes in writeTonsOfBytes.

It also explains why the number of written bytes would end up as a power of 2 because new bytes are written to the underlying buffer at such an increment.