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/*
* Copyright (c) 2017 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __included_maplog_h__
#define __included_maplog_h__
/** \file
mmap-based fixed-size record double-buffered logging
*/
#include <vppinfra/clib.h>
#include <vppinfra/cache.h>
#include <vppinfra/format.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h>
typedef struct
{
/* rw: atomic ticket-counter, file index */
CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
volatile u64 next_record_index;
u64 file_size_in_records; /**< power of two */
u32 log2_file_size_in_records;
volatile u32 current_file_index;
volatile u32 flags;
/* ro: size parameters */
CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
u32 record_size_in_cachelines;
/* double-buffered mmap'ed logfiles */
volatile u8 *file_baseva[2];
u8 *filenames[2];
/* vector not c-string */
u8 *file_basename;
} clib_maplog_main_t;
int clib_maplog_init (clib_maplog_main_t * mm, char *file_basename,
u64 file_size, u32 record_size_in_bytes);
void clib_maplog_close (clib_maplog_main_t * mm);
#define CLIB_MAPLOG_FLAG_INIT (1<<0)
u8 *_clib_maplog_get_entry_slowpath (clib_maplog_main_t * mm,
u64 my_record_index);
static inline void *
clib_maplog_get_entry (clib_maplog_main_t * mm)
{
u64 my_record_index;
u8 *rv;
ASSERT (mm->flags & CLIB_MAPLOG_FLAG_INIT);
my_record_index = __sync_fetch_and_add (&mm->next_record_index, 1);
/* Time to unmap and create a new logfile? */
if (PREDICT_FALSE ((my_record_index & (mm->file_size_in_records - 1)) == 0))
{
/* Yes, but not the very first time... (;-)... */
if (my_record_index)
return _clib_maplog_get_entry_slowpath (mm, my_record_index);
/* FALLTHROUGH */
}
rv = (u8 *)
mm->file_baseva[(my_record_index >> mm->log2_file_size_in_records) & 1] +
(my_record_index & (mm->file_size_in_records - 1))
* mm->record_size_in_cachelines * CLIB_CACHE_LINE_BYTES;
return rv;
}
#endif /* __included_maplog_h__ */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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