void AsyncLogging::threadFunc() 的防止日志堆积的部分是不是写的有点琐碎了？

[Tracker647]

如下，如果buffersToWrite内buffer数大于25，为了防止日志堆积将buffersToWrite的buffer数减少至2。

如果bufferToWrite内buffer数在[3,25]之间，最上面的if就不会触发了，但是同样将buffer数减少至2。

    if (buffersToWrite.size() > 25)
    {
      char buf[256];
      snprintf(buf, sizeof buf, "Dropped log messages at %s, %zd larger buffers\n",
               Timestamp::now().toFormattedString().c_str(),
               buffersToWrite.size()-2);
      fputs(buf, stderr);
      output.append(buf, static_cast<int>(strlen(buf)));
      buffersToWrite.erase(buffersToWrite.begin()+2, buffersToWrite.end());
    }

    for (const auto& buffer : buffersToWrite)
    {
      // FIXME: use unbuffered stdio FILE ? or use ::writev ?
      output.append(buffer->data(), buffer->length());
    }

    if (buffersToWrite.size() > 2)
    {
      // drop non-bzero-ed buffers, avoid trashing
      buffersToWrite.resize(2);
    }

既然最终都只能留两个buffer，何不改成

if (buffersToWrite.size() > 2)
{
    // drop non-bzero-ed buffers, avoid trashing
    char buf[256];
    snprintf(buf, sizeof buf, "Dropped log messages at %s, %zd larger buffers\n",
             Timestamp::now().toFormattedString().c_str(),
             buffersToWrite.size()-2);
    fputs(buf, stderr);
    output.append(buf, static_cast<int>(strlen(buf)));
    buffersToWrite.resize(2);
}

for (const auto& buffer : buffersToWrite)
{
// FIXME: use unbuffered stdio FILE ? or use ::writev ?
output.append(buffer->data(), buffer->length());
}

？