2 This file is part of GNUnet
3 Copyright (C) 2014, 2015, 2016 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
19 * @file src/include/gnunet_curl_lib.h
20 * @brief library to make it easy to download JSON replies over HTTP
21 * @author Sree Harsha Totakura <sreeharsha@totakura.in>
22 * @author Christian Grothoff
24 * @defgroup curl CURL integration library
25 * Download JSON using libcurl.
28 #ifndef GNUNET_CURL_LIB_H
29 #define GNUNET_CURL_LIB_H
31 #include <curl/curl.h>
32 #elif HAVE_GNURL_CURL_H
33 #include <gnurl/curl.h>
35 #error "needs curl or gnurl"
38 #include "gnunet_util_lib.h"
42 * Function called by the context to ask for the event loop to be
43 * rescheduled, that is the application should call
44 * #GNUNET_CURL_get_select_info() as the set of sockets we care about
50 (*GNUNET_CURL_RescheduleCallback)(void *cls);
54 * Initialise this library. This function should be called before using any of
55 * the following functions.
57 * @param cb function to call when rescheduling is required
58 * @param cb_cls closure for @a cb
59 * @return library context
61 struct GNUNET_CURL_Context *
62 GNUNET_CURL_init (GNUNET_CURL_RescheduleCallback cb,
67 * Obtain the information for a select() call to wait until
68 * #GNUNET_CURL_perform() is ready again.
70 * Basically, a client should use this API to prepare for select(),
71 * then block on select(), then call #GNUNET_CURL_perform() and then
72 * start again until the work with the context is done.
74 * This function will NOT zero out the sets and assumes that @a max_fd
75 * and @a timeout are already set to minimal applicable values. It is
76 * safe to give this API FD-sets and @a max_fd and @a timeout that are
77 * already initialized to some other descriptors that need to go into
80 * @param ctx context to get the event loop information for
81 * @param read_fd_set will be set for any pending read operations
82 * @param write_fd_set will be set for any pending write operations
83 * @param except_fd_set is here because curl_multi_fdset() has this argument
84 * @param max_fd set to the highest FD included in any set;
85 * if the existing sets have no FDs in it, the initial
86 * value should be "-1". (Note that `max_fd + 1` will need
87 * to be passed to select().)
88 * @param timeout set to the timeout in milliseconds (!); -1 means
89 * no timeout (NULL, blocking forever is OK), 0 means to
90 * proceed immediately with #GNUNET_CURL_perform().
93 GNUNET_CURL_get_select_info (struct GNUNET_CURL_Context *ctx,
96 fd_set *except_fd_set,
102 * Run the main event loop for the CURL interaction.
104 * @param ctx the library context
107 GNUNET_CURL_perform (struct GNUNET_CURL_Context *ctx);
111 * Cleanup library initialisation resources. This function should be called
112 * after using this library to cleanup the resources occupied during library's
115 * @param ctx the library context
118 GNUNET_CURL_fini (struct GNUNET_CURL_Context *ctx);
122 * Entry in the context's job queue.
124 struct GNUNET_CURL_Job;
127 * Function to call upon completion of a job.
130 * @param response_code HTTP response code from server, 0 on hard error
131 * @param json response, NULL if response was not in JSON format
134 (*GNUNET_CURL_JobCompletionCallback)(void *cls,
140 * Schedule a CURL request to be executed and call the given @a jcc
141 * upon its completion. Note that the context will make use of the
142 * CURLOPT_PRIVATE facility of the CURL @a eh.
144 * This function modifies the CURL handle to add the
145 * "Content-Type: application/json" header if @a add_json is set.
147 * @param ctx context to execute the job in
148 * @param eh curl easy handle for the request, will
149 * be executed AND cleaned up
150 * @param add_json add "application/json" content type header
151 * @param jcc callback to invoke upon completion
152 * @param jcc_cls closure for @a jcc
153 * @return NULL on error (in this case, @eh is still released!)
155 struct GNUNET_CURL_Job *
156 GNUNET_CURL_job_add (struct GNUNET_CURL_Context *ctx,
159 GNUNET_CURL_JobCompletionCallback jcc,
164 * Cancel a job. Must only be called before the job completion
165 * callback is called for the respective job.
167 * @param job job to cancel
170 GNUNET_CURL_job_cancel (struct GNUNET_CURL_Job *job);
173 /* ******* GNUnet SCHEDULER integration ************ */
177 * Closure for #GNUNET_CURL_gnunet_scheduler_reschedule().
179 struct GNUNET_CURL_RescheduleContext;
183 * Initialize reschedule context.
185 * @param ctx context to manage
186 * @return closure for #GNUNET_CURL_gnunet_scheduler_reschedule().
188 struct GNUNET_CURL_RescheduleContext *
189 GNUNET_CURL_gnunet_rc_create (struct GNUNET_CURL_Context *ctx);
192 * Destroy reschedule context.
194 * @param rc context to destroy
197 GNUNET_CURL_gnunet_rc_destroy (struct GNUNET_CURL_RescheduleContext *rc);
201 * Implementation of the #GNUNET_CURL_RescheduleCallback for GNUnet's
202 * scheduler. Will run the CURL context using GNUnet's scheduler.
203 * Note that you MUST immediately destroy the reschedule context after
204 * calling #GNUNET_CURL_fini().
206 * @param cls must point to a `struct GNUNET_CURL_RescheduleContext *`
207 * (pointer to a pointer!)
210 GNUNET_CURL_gnunet_scheduler_reschedule (void *cls);
214 /** @} */ /* end of group */
216 /* end of gnunet_curl_lib.h */