input: unbreak automatic format detection when reading from stdin
[sigrok-cli/gsi.git] / input.c
blobeb496ee7a54d4c2a806c248f282bbf05efb94178
1 /*
2 * This file is part of the sigrok-cli project.
4 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <config.h>
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <fcntl.h>
24 #include <unistd.h>
25 #include <errno.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <glib.h>
29 #include "sigrok-cli.h"
31 #define CHUNK_SIZE (4 * 1024 * 1024)
33 static void load_input_file_module(struct df_arg_desc *df_arg)
35 struct sr_session *session;
36 const struct sr_input *in;
37 const struct sr_input_module *imod;
38 const struct sr_option **options;
39 struct sr_dev_inst *sdi;
40 GHashTable *mod_args, *mod_opts;
41 GString *buf;
42 gboolean got_sdi;
43 int fd;
44 ssize_t len;
45 char *mod_id;
46 gboolean is_stdin;
47 gboolean push_scan_data;
49 if (!sr_input_list())
50 g_critical("No supported input formats available.");
52 mod_id = NULL;
53 mod_args = NULL;
54 if (opt_input_format) {
55 mod_args = parse_generic_arg(opt_input_format, TRUE, NULL);
56 mod_id = g_hash_table_lookup(mod_args, "sigrok_key");
59 is_stdin = strcmp(opt_input_file, "-") == 0;
60 push_scan_data = FALSE;
61 fd = 0;
62 buf = g_string_sized_new(CHUNK_SIZE);
63 if (mod_id) {
64 /* User specified an input module to use. */
65 if (!(imod = sr_input_find(mod_id)))
66 g_critical("Error: unknown input module '%s'.", mod_id);
67 g_hash_table_remove(mod_args, "sigrok_key");
68 if ((options = sr_input_options_get(imod))) {
69 mod_opts = generic_arg_to_opt(options, mod_args);
70 (void)warn_unknown_keys(options, mod_args, NULL);
71 sr_output_options_free(options);
72 } else {
73 mod_opts = NULL;
75 if (!(in = sr_input_new(imod, mod_opts)))
76 g_critical("Error: failed to initialize input module.");
77 if (mod_opts)
78 g_hash_table_destroy(mod_opts);
79 if (mod_args)
80 g_hash_table_destroy(mod_args);
81 if (!is_stdin && (fd = open(opt_input_file, O_RDONLY)) < 0)
82 g_critical("Failed to load %s: %s.", opt_input_file,
83 g_strerror(errno));
84 } else {
85 if (!is_stdin) {
87 * An actual filename: let the input modules try to
88 * identify the file.
90 if (sr_input_scan_file(opt_input_file, &in) == SR_OK) {
91 /* That worked, reopen the file for reading. */
92 fd = open(opt_input_file, O_RDONLY);
94 } else {
96 * Taking input from a pipe: let the input modules try
97 * to identify the stream content.
99 if (is_stdin) {
100 /* stdin */
101 fd = 0;
102 } else {
103 fd = open(opt_input_file, O_RDONLY);
104 if (fd == -1)
105 g_critical("Failed to load %s: %s.", opt_input_file,
106 g_strerror(errno));
108 if ((len = read(fd, buf->str, CHUNK_SIZE)) < 1)
109 g_critical("Failed to read %s: %s.", opt_input_file,
110 g_strerror(errno));
111 buf->len = len;
112 sr_input_scan_buffer(buf, &in);
113 push_scan_data = TRUE;
115 if (!in)
116 g_critical("Error: no input module found for this file.");
118 sr_session_new(sr_ctx, &session);
119 df_arg->session = session;
120 sr_session_datafeed_callback_add(session, datafeed_in, df_arg);
123 * Implementation detail: The combination of reading from stdin
124 * and automatic file format detection may have pushed the first
125 * chunk of input data into the input module's data accumulator,
126 * _bypassing_ the .receive() callback. It is essential to call
127 * .receive() before calling .end() for files of size smaller than
128 * CHUNK_SIZE (which is a typical case). So that sdi becomes ready.
129 * Fortunately all input modules accept .receive() calls with
130 * a zero length, and inspect whatever was accumulated so far.
132 * After that optional initial push of data which was queued
133 * above during format detection, continue reading remaining
134 * chunks from the input file until EOF is seen.
136 got_sdi = FALSE;
137 while (TRUE) {
138 g_string_truncate(buf, 0);
139 if (push_scan_data)
140 len = 0;
141 else
142 len = read(fd, buf->str, CHUNK_SIZE);
143 if (len < 0)
144 g_critical("Read failed: %s", g_strerror(errno));
145 if (len == 0 && !push_scan_data)
146 /* End of file or stream. */
147 break;
148 push_scan_data = FALSE;
149 buf->len = len;
150 if (sr_input_send(in, buf) != SR_OK)
151 break;
153 sdi = sr_input_dev_inst_get(in);
154 if (!got_sdi && sdi) {
155 /* First time we got a valid sdi. */
156 if (select_channels(sdi) != SR_OK)
157 return;
158 if (sr_session_dev_add(session, sdi) != SR_OK) {
159 g_critical("Failed to use device.");
160 sr_session_destroy(session);
161 return;
163 got_sdi = TRUE;
166 sr_input_end(in);
167 sr_input_free(in);
168 g_string_free(buf, TRUE);
170 df_arg->session = NULL;
171 sr_session_destroy(session);
174 void load_input_file(gboolean do_props)
176 struct df_arg_desc df_arg;
177 struct sr_session *session;
178 struct sr_dev_inst *sdi;
179 GSList *devices;
180 GMainLoop *main_loop;
181 int ret;
183 memset(&df_arg, 0, sizeof(df_arg));
184 df_arg.do_props = do_props;
186 if (!strcmp(opt_input_file, "-")) {
187 /* Input from stdin is never a session file. */
188 load_input_file_module(&df_arg);
189 } else {
190 if ((ret = sr_session_load(sr_ctx, opt_input_file,
191 &session)) == SR_OK) {
192 /* sigrok session file */
193 ret = sr_session_dev_list(session, &devices);
194 if (ret != SR_OK || !devices || !devices->data) {
195 g_critical("Failed to access session device.");
196 g_slist_free(devices);
197 sr_session_destroy(session);
198 return;
200 sdi = devices->data;
201 g_slist_free(devices);
202 if (select_channels(sdi) != SR_OK) {
203 sr_session_destroy(session);
204 return;
206 main_loop = g_main_loop_new(NULL, FALSE);
208 df_arg.session = session;
209 sr_session_datafeed_callback_add(session,
210 datafeed_in, &df_arg);
211 sr_session_stopped_callback_set(session,
212 (sr_session_stopped_callback)g_main_loop_quit,
213 main_loop);
214 if (sr_session_start(session) == SR_OK)
215 g_main_loop_run(main_loop);
217 g_main_loop_unref(main_loop);
218 df_arg.session = NULL;
219 sr_session_destroy(session);
220 } else if (ret != SR_ERR) {
221 /* It's a session file, but it didn't work out somehow. */
222 g_critical("Failed to load session file.");
223 } else {
224 /* Fall back on input modules. */
225 load_input_file_module(&df_arg);