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16 * @file src/include/gnunet_curl_lib.h
17 * @brief library to make it easy to download JSON replies over HTTP
18 * @author Sree Harsha Totakura <sreeharsha@totakura.in>
19 * @author Christian Grothoff
21 * @defgroup curl CURL integration library
22 * Download JSON using libcurl.
25 #ifndef GNUNET_CURL_LIB_H
26 #define GNUNET_CURL_LIB_H
28 #include <curl/curl.h>
29 #elif HAVE_GNURL_CURL_H
30 #include <gnurl/curl.h>
32 #error "needs curl or gnurl"
35 #include "gnunet_util_lib.h"
39 * Function called by the context to ask for the event loop to be
40 * rescheduled, that is the application should call
41 * #GNUNET_CURL_get_select_info() as the set of sockets we care about
47 (*GNUNET_CURL_RescheduleCallback)(void *cls);
51 * Initialise this library. This function should be called before using any of
52 * the following functions.
54 * @param cb function to call when rescheduling is required
55 * @param cb_cls closure for @a cb
56 * @return library context
58 struct GNUNET_CURL_Context *
59 GNUNET_CURL_init (GNUNET_CURL_RescheduleCallback cb,
64 * Obtain the information for a select() call to wait until
65 * #GNUNET_CURL_perform() is ready again.
67 * Basically, a client should use this API to prepare for select(),
68 * then block on select(), then call #GNUNET_CURL_perform() and then
69 * start again until the work with the context is done.
71 * This function will NOT zero out the sets and assumes that @a max_fd
72 * and @a timeout are already set to minimal applicable values. It is
73 * safe to give this API FD-sets and @a max_fd and @a timeout that are
74 * already initialized to some other descriptors that need to go into
77 * @param ctx context to get the event loop information for
78 * @param read_fd_set will be set for any pending read operations
79 * @param write_fd_set will be set for any pending write operations
80 * @param except_fd_set is here because curl_multi_fdset() has this argument
81 * @param max_fd set to the highest FD included in any set;
82 * if the existing sets have no FDs in it, the initial
83 * value should be "-1". (Note that `max_fd + 1` will need
84 * to be passed to select().)
85 * @param timeout set to the timeout in milliseconds (!); -1 means
86 * no timeout (NULL, blocking forever is OK), 0 means to
87 * proceed immediately with #GNUNET_CURL_perform().
90 GNUNET_CURL_get_select_info (struct GNUNET_CURL_Context *ctx,
93 fd_set *except_fd_set,
99 * Run the main event loop for the CURL interaction.
101 * @param ctx the library context
104 GNUNET_CURL_perform (struct GNUNET_CURL_Context *ctx);
108 * Cleanup library initialisation resources. This function should be called
109 * after using this library to cleanup the resources occupied during library's
112 * @param ctx the library context
115 GNUNET_CURL_fini (struct GNUNET_CURL_Context *ctx);
119 * Entry in the context's job queue.
121 struct GNUNET_CURL_Job;
124 * Function to call upon completion of a job.
127 * @param response_code HTTP response code from server, 0 on hard error
128 * @param json response, NULL if response was not in JSON format
131 (*GNUNET_CURL_JobCompletionCallback)(void *cls,
137 * Schedule a CURL request to be executed and call the given @a jcc
138 * upon its completion. Note that the context will make use of the
139 * CURLOPT_PRIVATE facility of the CURL @a eh.
141 * This function modifies the CURL handle to add the
142 * "Content-Type: application/json" header if @a add_json is set.
144 * @param ctx context to execute the job in
145 * @param eh curl easy handle for the request, will
146 * be executed AND cleaned up
147 * @param add_json add "application/json" content type header
148 * @param jcc callback to invoke upon completion
149 * @param jcc_cls closure for @a jcc
150 * @return NULL on error (in this case, @eh is still released!)
152 struct GNUNET_CURL_Job *
153 GNUNET_CURL_job_add (struct GNUNET_CURL_Context *ctx,
156 GNUNET_CURL_JobCompletionCallback jcc,
161 * Cancel a job. Must only be called before the job completion
162 * callback is called for the respective job.
164 * @param job job to cancel
167 GNUNET_CURL_job_cancel (struct GNUNET_CURL_Job *job);
170 /* ******* GNUnet SCHEDULER integration ************ */
174 * Closure for #GNUNET_CURL_gnunet_scheduler_reschedule().
176 struct GNUNET_CURL_RescheduleContext;
180 * Initialize reschedule context.
182 * @param ctx context to manage
183 * @return closure for #GNUNET_CURL_gnunet_scheduler_reschedule().
185 struct GNUNET_CURL_RescheduleContext *
186 GNUNET_CURL_gnunet_rc_create (struct GNUNET_CURL_Context *ctx);
189 * Destroy reschedule context.
191 * @param rc context to destroy
194 GNUNET_CURL_gnunet_rc_destroy (struct GNUNET_CURL_RescheduleContext *rc);
198 * Implementation of the #GNUNET_CURL_RescheduleCallback for GNUnet's
199 * scheduler. Will run the CURL context using GNUnet's scheduler.
200 * Note that you MUST immediately destroy the reschedule context after
201 * calling #GNUNET_CURL_fini().
203 * @param cls must point to a `struct GNUNET_CURL_RescheduleContext *`
204 * (pointer to a pointer!)
207 GNUNET_CURL_gnunet_scheduler_reschedule (void *cls);
211 /** @} */ /* end of group */
213 /* end of gnunet_curl_lib.h */