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Buffer.cc
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Buffer.cc
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#include "Buffer.h"
#include <errno.h>
#include <sys/uio.h>
#include <unistd.h>
/*
*从fd中读数据采用LT模式,如果有数据没有读完会发导致epoll_wait返回
*Buffer缓冲区有大小,但是从fd中读数据,不知道tcp数据的大小=>写进两个缓冲区
*/
size_t Buffer::readFd(int fd, int *saveErro)
{
char extrabuf[65536] = {0};
struct iovec vec[2];
const size_t writeable = writeableBytes();
vec[0].iov_base = begin() + writerIndex_;
vec[0].iov_len = writeable;
vec[1].iov_base = extrabuf;
vec[1].iov_len = sizeof extrabuf;
const int iovcnt = (writeable < sizeof extrabuf) ? 2 : 1;
// 使用两个缓冲区来读取数据
const ssize_t n = ::readv(fd, vec, iovcnt);
if (n < 0)
{
*saveErro = errno;
}
else if (n <= writeable)
{
writerIndex_ += n;
}
else
{
writerIndex_ = buffer_.size();
append(extrabuf, n - writeable);
}
return n;
}
size_t Buffer::writeFd(int fd, int *saveErro)
{
ssize_t n = ::write(fd, peek(), readabaleBytes());
if (n < 0)
{
*saveErro = errno;
}
return n;
}