NAME

       pmemlog_append(), pmemlog_appendv() - append bytes to the persistent memory resident log file

SYNOPSIS

              #include <libpmemlog.h>

              int pmemlog_append(PMEMlogpool *plp, const void *buf, size_t count);
              int pmemlog_appendv(PMEMlogpool *plp, const struct iovec *iov, int iovcnt);

DESCRIPTION

       The  pmemlog_append() function appends count bytes from buf to the current write offset in the log memory
       pool plp.  Calling this function is analogous to appending to a file.  The append is atomic and cannot be
       torn by a program failure or system crash.

       The  pmemlog_appendv()  function appends to the log memory pool plp from the scatter/gather list iov in a
       manner similar to writev(2).  The entire list of buffers is appended atomically, as if the buffers in iov
       were  concatenated  in  order.   The  append  is atomic and cannot be torn by a program failure or system
       crash.

RETURN VALUE

       On success, pmemlog_append() and pmemlog_appendv() return 0.  On error, they  return  -1  and  set  errno
       appropriately.

ERRORS

       EINVAL The vector count iovcnt is less than zero.

       ENOSPC There is no room for the data in the log file.

       EROFS The log file is open in read-only mode.

NOTES

       Since  libpmemlog(3)  is  designed  as  a low-latency code path, many of the checks routinely done by the
       operating system for writev(2) are not practical in the library's  implementation  of  pmemlog_appendv().
       No attempt is made to detect NULL or incorrect pointers, for example.

SEE ALSO

       writev(2), libpmemlog(7) and <http://pmem.io>