c# - 如何使用 Stream.Write 正确保留更多空间？

Question

public override void Write(byte[] buffer, int offset, int count)
{            
   var bytesToWriteTotal = count;

   while (bytesToWriteTotal > 0)
   {
        // If we do not have enough space in the cloud, we'll reserve more
        var capacity = GetCurrentCapacity();
        var delta = Position + bytesToWriteTotal - capacity;

        if (delta > 0)
        {
            Resize(2 * (capacity + delta));
        }
        ...

这是确保我有足够空间的正确方法还是我应该像这样添加 offset:
var delta = Position + offset + bytesToWriteTotal - 容量；

Answer 1

不要添加offset，它是buffer中的一个位置，从这里开始读取。您读取了 count 个数字，所以这是您要写入的字节数。

您应该在 while 循环之前执行一次扩展:

var capacity = GetCurrentCapacity();
var delta = Position + count - capacity;
if (delta > 0) {
    Resize(2 * (capacity + delta));
}
var bytesToWrite = count;
while (bytesToWriteTotal > 0) {
    ...
}

在调整大小时乘以 2 可能过于激进，因为您只需要 (capacity + delta) 字节。