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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
#include "rbd_replay/BufferReader.h"
#include "include/ceph_assert.h"
#include "include/intarith.h"
namespace rbd_replay {
BufferReader::BufferReader(int fd, size_t min_bytes, size_t max_bytes)
: m_fd(fd), m_min_bytes(min_bytes), m_max_bytes(max_bytes),
m_bl_it(m_bl.begin()), m_eof_reached(false) {
ceph_assert(m_min_bytes <= m_max_bytes);
}
int BufferReader::fetch(bufferlist::const_iterator **it) {
if (m_bl_it.get_remaining() < m_min_bytes) {
ssize_t bytes_to_read = round_up_to(m_max_bytes - m_bl_it.get_remaining(),
CEPH_PAGE_SIZE);
while (!m_eof_reached && bytes_to_read > 0) {
int r = m_bl.read_fd(m_fd, CEPH_PAGE_SIZE);
if (r < 0) {
return r;
}
if (r == 0) {
m_eof_reached = true;
}
ceph_assert(r <= bytes_to_read);
bytes_to_read -= r;
}
}
*it = &m_bl_it;
return 0;
}
} // namespace rbd_replay
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