file_writer: Make file_write_open() a no-op.
[paraslash.git] / file_write.c
1 /*
2 * Copyright (C) 2006-2010 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file file_write.c simple output plugin for testing purposes */
8
9 #include <regex.h>
10 #include <sys/types.h>
11 #include <dirent.h>
12 #include <sys/time.h>
13 #include <stdbool.h>
14
15 #include "para.h"
16 #include "list.h"
17 #include "sched.h"
18 #include "ggo.h"
19 #include "buffer_tree.h"
20 #include "write.h"
21 #include "write_common.h"
22 #include "string.h"
23 #include "fd.h"
24 #include "file_write.cmdline.h"
25 #include "error.h"
26
27 /** Data specific to the file writer. */
28 struct private_file_write_data {
29 /** The file descriptor of the output file. */
30 int fd;
31 };
32
33 /*
34 * Get a random filename.
35 *
36 * This is by no means a secure way to create temporary files in a hostile
37 * directory like \p /tmp. However, we use it only for creating temp files in
38 * ~/.paraslash, for which it is OK. Result must be freed by the caller.
39 */
40 __must_check __malloc static char *random_filename(void)
41 {
42 char *result, *home = para_homedir();
43 struct timeval tv;
44
45 gettimeofday(&tv, NULL);
46 srandom(tv.tv_usec);
47 result = make_message("%s/.paraslash/%08lu", home,
48 para_random(99999999));
49 free(home);
50 return result;
51 }
52
53 static void file_write_open(__a_unused struct writer_node *wn)
54 {
55 }
56
57 static int prepare_output_file(struct writer_node *wn)
58 {
59 struct file_write_args_info *conf = wn->conf;
60 char *filename;
61 int ret;
62 struct private_file_write_data *pfwd = para_calloc(sizeof(*pfwd));
63
64 if (conf->filename_given)
65 filename = conf->filename_arg;
66 else
67 filename = random_filename();
68 ret = para_open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
69 if (!conf->filename_given)
70 free(filename);
71 if (ret < 0)
72 goto out;
73 pfwd->fd = ret;
74 ret = mark_fd_blocking(pfwd->fd);
75 if (ret < 0)
76 goto out_close;
77 wn->private_data = pfwd;
78 return 1;
79 out_close:
80 close(pfwd->fd);
81 out:
82 free(pfwd);
83 return ret;
84 }
85
86 static void file_write_pre_select(struct sched *s, struct task *t)
87 {
88 struct writer_node *wn = container_of(t, struct writer_node, task);
89 struct private_file_write_data *pfwd = wn->private_data;
90 int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
91
92 if (ret == 0)
93 return;
94 if (ret < 0 || !pfwd)
95 return sched_min_delay(s);
96 para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
97 }
98
99 static void file_write_close(struct writer_node *wn)
100 {
101 struct private_file_write_data *pfwd = wn->private_data;
102
103 if (!pfwd)
104 return;
105 close(pfwd->fd);
106 free(pfwd);
107 }
108
109 static void file_write_post_select(__a_unused struct sched *s,
110 struct task *t)
111 {
112 struct writer_node *wn = container_of(t, struct writer_node, task);
113 struct private_file_write_data *pfwd = wn->private_data;
114 struct btr_node *btrn = wn->btrn;
115 int ret;
116 char *buf;
117 size_t bytes;
118
119 t->error = 0;
120 ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
121 if (ret <= 0)
122 goto out;
123 if (!pfwd) {
124 ret = prepare_output_file(wn);
125 goto out;
126 }
127 if (!FD_ISSET(pfwd->fd, &s->wfds))
128 return;
129 bytes = btr_next_buffer(btrn, &buf);
130 assert(bytes > 0);
131 //PARA_INFO_LOG("writing %zu\n", bytes);
132 ret = write(pfwd->fd, buf, bytes);
133 if (ret < 0)
134 goto out;
135 btr_consume(btrn, ret);
136 out:
137 if (ret < 0)
138 btr_remove_node(btrn);
139 t->error = ret;
140 }
141
142 __malloc static void *file_write_parse_config_or_die(const char *options)
143 {
144 struct file_write_args_info *conf = para_calloc(sizeof(*conf));
145
146 /* exits on errors */
147 file_cmdline_parser_string(options, conf, "file_write");
148 return conf;
149 }
150
151 static void file_write_free_config(void *conf)
152 {
153 file_cmdline_parser_free(conf);
154 }
155
156 /** the init function of the file writer */
157 void file_write_init(struct writer *w)
158 {
159 struct file_write_args_info dummy;
160
161 file_cmdline_parser_init(&dummy);
162 w->open = file_write_open;
163 w->pre_select = file_write_pre_select;
164 w->post_select = file_write_post_select;
165 w->parse_config_or_die = file_write_parse_config_or_die;
166 w->free_config = file_write_free_config;
167 w->close = file_write_close;
168 w->shutdown = NULL; /* nothing to do */
169 w->help = (struct ggo_help) {
170 .short_help = file_write_args_info_help,
171 .detailed_help = file_write_args_info_detailed_help
172 };
173 file_cmdline_parser_free(&dummy);
174 }