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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 * Add custom request header.
104 * @param ctx cURL context.
105 * @param header header string; will be given to the context AS IS.
106 * @return #GNUNET_OK if no errors occurred, #GNUNET_SYSERR otherwise.
109 GNUNET_CURL_append_header (struct GNUNET_CURL_Context *ctx,
113 * Run the main event loop for the CURL interaction.
115 * @param ctx the library context
118 GNUNET_CURL_perform (struct GNUNET_CURL_Context *ctx);
122 * Cleanup library initialisation resources. This function should be called
123 * after using this library to cleanup the resources occupied during library's
126 * @param ctx the library context
129 GNUNET_CURL_fini (struct GNUNET_CURL_Context *ctx);
133 * Entry in the context's job queue.
135 struct GNUNET_CURL_Job;
138 * Function to call upon completion of a job.
141 * @param response_code HTTP response code from server, 0 on hard error
142 * @param json response, NULL if response was not in JSON format
145 (*GNUNET_CURL_JobCompletionCallback)(void *cls,
151 * Schedule a CURL request to be executed and call the given @a jcc
152 * upon its completion. Note that the context will make use of the
153 * CURLOPT_PRIVATE facility of the CURL @a eh.
155 * This function modifies the CURL handle to add the
156 * "Content-Type: application/json" header if @a add_json is set.
158 * @param ctx context to execute the job in
159 * @param eh curl easy handle for the request, will
160 * be executed AND cleaned up
161 * @param add_json add "application/json" content type header
162 * @param jcc callback to invoke upon completion
163 * @param jcc_cls closure for @a jcc
164 * @return NULL on error (in this case, @eh is still released!)
166 struct GNUNET_CURL_Job *
167 GNUNET_CURL_job_add (struct GNUNET_CURL_Context *ctx,
170 GNUNET_CURL_JobCompletionCallback jcc,
175 * Cancel a job. Must only be called before the job completion
176 * callback is called for the respective job.
178 * @param job job to cancel
181 GNUNET_CURL_job_cancel (struct GNUNET_CURL_Job *job);
184 /* ******* GNUnet SCHEDULER integration ************ */
188 * Closure for #GNUNET_CURL_gnunet_scheduler_reschedule().
190 struct GNUNET_CURL_RescheduleContext;
194 * Initialize reschedule context.
196 * @param ctx context to manage
197 * @return closure for #GNUNET_CURL_gnunet_scheduler_reschedule().
199 struct GNUNET_CURL_RescheduleContext *
200 GNUNET_CURL_gnunet_rc_create (struct GNUNET_CURL_Context *ctx);
203 * Destroy reschedule context.
205 * @param rc context to destroy
208 GNUNET_CURL_gnunet_rc_destroy (struct GNUNET_CURL_RescheduleContext *rc);
212 * Implementation of the #GNUNET_CURL_RescheduleCallback for GNUnet's
213 * scheduler. Will run the CURL context using GNUnet's scheduler.
214 * Note that you MUST immediately destroy the reschedule context after
215 * calling #GNUNET_CURL_fini().
217 * @param cls must point to a `struct GNUNET_CURL_RescheduleContext *`
218 * (pointer to a pointer!)
221 GNUNET_CURL_gnunet_scheduler_reschedule (void *cls);
225 /** @} */ /* end of group */
227 /* end of gnunet_curl_lib.h */