The libpmemlog library
libpmemlog implements a pmem-resident log file.
This library is provided for cases requiring an append-mostly
file to record variable length entries. Most
developers will find higher level libraries like
libpmemobj to be more generally useful.
Man pages that contains a list of the Linux interfaces provided:
Man pages that contains a list of the Windows interfaces provided:
libpmemlog Examples
More Detail Coming Soon
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
| #include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <libpmemlog.h>
/* size of the pmemlog pool -- 1 GB */
#define POOL_SIZE ((off_t)(1 << 30))
/*
* printit -- log processing callback for use with pmemlog_walk()
*/
int
printit(const void *buf, size_t len, void *arg)
{
fwrite(buf, len, 1, stdout);
return 0;
}
int
main(int argc, char *argv[])
{
const char path[] = "/pmem-fs/myfile";
PMEMlogpool *plp;
size_t nbyte;
char *str;
/* create the pmemlog pool or open it if it already exists */
plp = pmemlog_create(path, POOL_SIZE, 0666);
if (plp == NULL)
plp = pmemlog_open(path);
if (plp == NULL) {
perror(path);
exit(1);
}
/* how many bytes does the log hold? */
nbyte = pmemlog_nbyte(plp);
printf("log holds %zu bytes\n", nbyte);
/* append to the log... */
str = "This is the first string appended\n";
if (pmemlog_append(plp, str, strlen(str)) < 0) {
perror("pmemlog_append");
exit(1);
}
str = "This is the second string appended\n";
if (pmemlog_append(plp, str, strlen(str)) < 0) {
perror("pmemlog_append");
exit(1);
}
/* print the log contents */
printf("log contains:\n");
pmemlog_walk(plp, 0, printit, NULL);
pmemlog_close(plp);
}
|
