minio/pkgs/split/split.c
2014-12-01 01:00:56 -08:00

121 lines
2.8 KiB
C

/*
* Mini Object Storage, (C) 2014 Minio, Inc.
*
* 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.
*/
#include <sys/param.h>
#include <sys/types.h>
#include <ctype.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include "split.h"
static
size_t _get_filesize(int fd)
{
struct stat st;
assert(fstat(fd, &st) != -1);
return (ssize_t) st.st_size;
}
static
ssize_t read_write_chunk(int in, int out, ssize_t bytes)
{
ssize_t n, m;
char *buf = NULL;
buf = calloc(bytes, 1);
assert(buf != NULL);
n = read(in, buf, bytes);
if (n < 0)
return -1;
m = write(out, buf, n);
if (m < 0)
return -1;
if (buf)
free(buf);
return m;
}
static int
_allocate_newchunk(char *chunkname)
{
int chunk = -1;
if (!chunkname)
return -1;
if ((strlen(chunkname)) >= MAXPATHLEN) {
fprintf (stderr, "chunkname + suffix too long");
return -1;
}
chunk = open (chunkname, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
return chunk;
}
/*
* Generate chunks by chunking at input bytes.
*/
int
minio_split(char *filename, ssize_t bytecnt)
{
ssize_t fsize;
int output = -1;
int input = -1;
int remainder = 0;
char newchunk[MAXPATHLEN] = {0,};
int chunk_size = 0;
int i = 0;
if (bytecnt < 0)
return -1;
if ((input = open(filename, O_RDONLY)) < 0)
return -1;
fsize = _get_filesize(input);
remainder = fsize % bytecnt;
if (remainder == 0)
chunk_size = fsize / bytecnt;
else
chunk_size = (fsize + (bytecnt - remainder)) / bytecnt;
if (chunk_size == 0)
return -1;
for (i = 0; i < chunk_size; i++) {
snprintf (newchunk, sizeof(newchunk)-1, "%s.%d", filename, i);
if ((output = _allocate_newchunk(newchunk)) < 0)
return -1;
if (read_write_chunk(input, output, bytecnt) < 0)
return -1;
}
return 0;
}