1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/* -*- mode: C; c-basic-offset: 4 -*- */
#ident "$Id: logcursor.c 13196 2009-07-10 14:41:51Z zardosht $"
#ident "Copyright (c) 2007, 2008, 2009 Tokutek Inc. All rights reserved."
#ident "The technology is licensed by the Massachusetts Institute of Technology, Rutgers State University of New Jersey, and the Research Foundation of State University of New York at Stony Brook under United States of America Serial No. 11/760379 and to the patents and/or patent applications resulting from it."
#include "includes.h"
struct toku_logcursor {
char *logdir;
char **logfiles;
int n_logfiles;
int cur_logfiles_index;
FILE *cur_fp;
BOOL is_open;
struct log_entry entry;
BOOL entry_valid;
};
static int lc_close_cur_logfile(TOKULOGCURSOR lc) {
int r=0;
if ( lc->is_open ) {
r = fclose(lc->cur_fp);
assert(0==r);
lc->is_open = FALSE;
}
return 0;
}
static int lc_open_logfile(TOKULOGCURSOR lc, int index) {
int r=0;
assert( !lc->is_open );
lc->cur_fp = fopen(lc->logfiles[index], "r");
if ( lc->cur_fp == NULL )
return DB_NOTFOUND;
// position fp past header
unsigned int version=0;
r = toku_read_logmagic(lc->cur_fp, &version);
if (r!=0)
return DB_BADFORMAT;
if (version != 1)
return DB_BADFORMAT;
// mark as open
lc->is_open = TRUE;
return r;
}
// toku_logcursor_create()
// - returns a pointer to a logcursor
int toku_logcursor_create(TOKULOGCURSOR *lc, const char *log_dir) {
int failresult=0;
int r=0;
// malloc a cursor
TOKULOGCURSOR cursor = (TOKULOGCURSOR) toku_malloc(sizeof(struct toku_logcursor));
if ( NULL==cursor )
return ENOMEM;
// find logfiles in logdir
cursor->is_open = FALSE;
cursor->cur_logfiles_index = 0;
cursor->entry_valid = FALSE;
cursor->logdir = (char *) toku_malloc(strlen(log_dir)+1);
if ( NULL==cursor->logdir )
return ENOMEM;
strcpy(cursor->logdir, log_dir);
r = toku_logger_find_logfiles(cursor->logdir, &(cursor->logfiles), &(cursor->n_logfiles));
if (r!=0) {
failresult=r;
goto fail;
}
*lc = cursor;
return r;
fail:
toku_logcursor_destroy(&cursor);
*lc = NULL;
return failresult;
}
int toku_logcursor_destroy(TOKULOGCURSOR *lc) {
int r=0;
if ( (*lc)->entry_valid )
toku_log_free_log_entry_resources(&((*lc)->entry));
r = lc_close_cur_logfile(*lc);
int lf;
for(lf=0;lf<(*lc)->n_logfiles;lf++) {
toku_free((*lc)->logfiles[lf]);
}
toku_free((*lc)->logfiles);
toku_free((*lc)->logdir);
toku_free(*lc);
*lc = NULL;
return r;
}
int toku_logcursor_next(TOKULOGCURSOR lc, struct log_entry **le) {
int r=0;
if ( lc->entry_valid )
toku_log_free_log_entry_resources(&(lc->entry));
if ( !lc->entry_valid ) {
r = toku_logcursor_first(lc, le);
return r;
}
r = toku_log_fread(lc->cur_fp, &(lc->entry));
while ( EOF == r ) {
// move to next file
r = lc_close_cur_logfile(lc);
if (r!=0)
return r;
if ( lc->cur_logfiles_index == lc->n_logfiles-1)
return DB_NOTFOUND;
lc->cur_logfiles_index++;
r = lc_open_logfile(lc, lc->cur_logfiles_index);
if (r!= 0)
return r;
r = toku_log_fread(lc->cur_fp, &(lc->entry));
}
if (r!=0) {
if (r==DB_BADFORMAT) {
fprintf(stderr, "Bad log format in %s\n", lc->logfiles[lc->cur_logfiles_index]);
return r;
} else {
fprintf(stderr, "Unexpected log format error '%s' in %s\n", strerror(r), lc->logfiles[lc->cur_logfiles_index]);
return r;
}
}
*le = &(lc->entry);
return r;
}
int toku_logcursor_prev(TOKULOGCURSOR lc, struct log_entry **le) {
int r=0;
if ( lc->entry_valid )
toku_log_free_log_entry_resources(&(lc->entry));
if ( !lc->entry_valid ) {
r = toku_logcursor_last(lc, le);
return r;
}
r = toku_log_fread_backward(lc->cur_fp, &(lc->entry));
while ( -1 == r) { // if within header length of top of file
// move to previous file
r = lc_close_cur_logfile(lc);
if (r!=0)
return r;
if ( lc->cur_logfiles_index == 0 )
return DB_NOTFOUND;
lc->cur_logfiles_index--;
r = lc_open_logfile(lc, lc->cur_logfiles_index);
if (r!=0)
return r;
r = toku_log_fread_backward(lc->cur_fp, &(lc->entry));
}
if (r!=0) {
if (r==DB_BADFORMAT) {
fprintf(stderr, "Bad log format in %s\n", lc->logfiles[lc->cur_logfiles_index]);
return r;
} else {
fprintf(stderr, "Unexpected log format error '%s' in %s\n", strerror(r), lc->logfiles[lc->cur_logfiles_index]);
return r;
}
}
*le = &(lc->entry);
return r;
}
int toku_logcursor_first(TOKULOGCURSOR lc, struct log_entry **le) {
int r=0;
if ( lc->entry_valid )
toku_log_free_log_entry_resources(&(lc->entry));
// close any but the first log file
if ( lc->cur_logfiles_index != 0 ) {
lc_close_cur_logfile(lc);
}
// open first log file if needed
if ( !lc->is_open ) {
r = lc_open_logfile(lc, 0);
if (r!=0)
return r;
lc->cur_logfiles_index = 0;
}
r = toku_log_fread(lc->cur_fp, &(lc->entry));
if (r!=0)
return r;
lc->entry_valid = TRUE;
*le = &(lc->entry);
return r;
}
int toku_logcursor_last(TOKULOGCURSOR lc, struct log_entry **le) {
int r=0;
if ( lc->entry_valid )
toku_log_free_log_entry_resources(&(lc->entry));
// close any but last log file
if ( lc->cur_logfiles_index != lc->n_logfiles-1 ) {
lc_close_cur_logfile(lc);
}
// open last log file if needed
if ( !lc->is_open ) {
r = lc_open_logfile(lc, lc->n_logfiles-1);
if (r!=0)
return r;
lc->cur_logfiles_index = lc->n_logfiles-1;
}
// seek to end
r = fseek(lc->cur_fp, 0, SEEK_END);
assert(0==r);
// read backward
r = toku_log_fread_backward(lc->cur_fp, &(lc->entry));
if (r!=0)
return r;
lc->entry_valid = TRUE;
*le = &(lc->entry);
return r;
}