2 Copyright 2002 Kevin O'Donnell
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 * Include the core server components.
23 #include "http_config.h"
24 #include "http_core.h"
25 #include "http_protocol.h"
26 #include "apr_compat.h"
27 #include "apr_strings.h"
32 #include "opensrf/transport_client.h"
33 #include "opensrf/generic_utils.h"
34 #include "opensrf/osrf_message.h"
35 #include "opensrf/osrf_app_session.h"
39 * This function is registered as a handler for HTTP methods and will
40 * therefore be invoked for all GET requests (and others). Regardless
41 * of the request type, this function simply sends a message to
42 * STDERR (which httpd redirects to logs/error_log). A real module
43 * would do *alot* more at this point.
45 #define MODULE_NAME "ils_gateway_module"
47 struct session_list_struct {
49 osrf_app_session* session;
50 struct session_list_struct* next;
53 typedef struct session_list_struct session_list;
55 /* the global session cache */
56 static session_list* the_list = NULL;
58 static void del_session( char* service ) {
59 if(!service || ! the_list)
62 debug_handler("In del_sesion for %s", service );
63 session_list* prev = the_list;
64 session_list* item = prev->next;
66 if(!strcmp(prev->session->remote_service, service)) {
67 info_handler("Removing gateway session for %s", service );
69 osrf_app_session_destroy(prev->session);
75 if( !strcmp(item->session->remote_service, service)) {
76 info_handler("Removing gateway session for %s", service );
77 prev->next = item->next;
78 osrf_app_session_destroy(item->session);
86 warning_handler("Attempt to remove gateway session "
87 "that does not exist: %s", service );
91 /* find a session in the list */
92 /* if(update) we add 1 to the serve_count */
93 static osrf_app_session* find_session( char* service, int update ) {
95 session_list* item = the_list;
98 if(!strcmp(item->session->remote_service,service)) {
100 if( item->serve_count++ > 20 ) {
101 debug_handler("Disconnected session on 20 requests => %s", service);
102 osrf_app_session_disconnect(item->session);
103 del_session(service);
105 //item->serve_count = 0;
108 debug_handler("Found session for %s in gateway cache", service);
109 return item->session;
117 /* add a session to the list */
118 static void add_session( char* service, osrf_app_session* session ) {
122 if(find_session(service,0))
125 debug_handler("Add session for %s to the cache", service );
127 session_list* new_item = (session_list*) safe_malloc(sizeof(session_list));
128 new_item->session = session;
129 //new_item->service = service;
130 new_item->serve_count = 0;
133 session_list* second = the_list->next;
135 new_item->next = second;
141 static void mod_ils_gateway_child_init(apr_pool_t *p, server_rec *s) {
142 if( ! osrf_system_bootstrap_client(
143 "/pines/cvs/ILS/OpenSRF/src/gateway/gateway.xml") ) { /* config option */
146 /* we don't want to waste time parsing json that we're not going to look at*/
147 osrf_message_set_json_parse(0);
148 fprintf(stderr, "Bootstrapping %d\n", getpid() );
152 static int mod_ils_gateway_method_handler (request_rec *r) {
155 /* make sure we're needed first thing*/
156 if (strcmp(r->handler, MODULE_NAME ))
160 apr_pool_t *p = r->pool; /* memory pool */
161 char* arg = r->args; /* url query string */
163 char* service = NULL; /* service to connect to */
164 char* method = NULL; /* method to perform */
166 json* params = NULL; /* method parameters */
167 json* exception = NULL; /* returned in error conditions */
169 growing_buffer* buffer = NULL; /* POST data */
170 growing_buffer* tmp_buf = NULL; /* temp buffer */
172 char* key = NULL; /* query item name */
173 char* val = NULL; /* query item value */
177 /* verify we are connected */
178 if(!osrf_system_get_transport_client()) {
179 fatal_handler("Bootstrap Failed, no transport client");
180 return HTTP_INTERNAL_SERVER_ERROR;
183 /* set content type to text/plain for passing around JSON objects */
184 ap_set_content_type(r, "text/plain");
188 /* gather the post args and append them to the url query string */
189 if( !strcmp(r->method,"POST") ) {
191 ap_setup_client_block(r,REQUEST_CHUNKED_DECHUNK);
193 if(! ap_should_client_block(r)) {
194 warning_handler("No Post Body");
199 buffer = buffer_init(1024);
201 while(ap_get_client_block(r, body, 1024)) {
202 buffer_add( buffer, body );
207 tmp_buf = buffer_init(1024);
208 buffer_add(tmp_buf,arg);
209 buffer_add(tmp_buf,buffer->buf);
210 arg = (char*) apr_pstrdup(p, tmp_buf->buf);
211 buffer_free(tmp_buf);
213 arg = (char*) apr_pstrdup(p, buffer->buf);
220 if( ! arg || !arg[0] ) { /* we received no request */
221 warning_handler("No Args");
225 r->allowed |= (AP_METHOD_BIT << M_GET);
226 r->allowed |= (AP_METHOD_BIT << M_POST);
229 char* argcopy = (char*) apr_pstrdup(p, arg);
231 params = json_object_new_array();;
232 while( argcopy && (val = ap_getword(p, &argcopy, '&'))) {
234 key = ap_getword(r->pool,&val, '=');
238 ap_unescape_url((char*)key);
239 ap_unescape_url((char*)val);
241 if(!strcmp(key,"service"))
244 if(!strcmp(key,"method"))
247 if(!strcmp(key,"__param"))
248 json_object_array_add( params, json_tokener_parse(val));
251 info_handler("Performing(%d): service %s | method %s | \nparams %s\n\n",
252 getpid(), service, method, json_object_to_json_string(params));
254 osrf_app_session* session = find_session(service,1);
257 debug_handler("building new session for %s", service );
258 session = osrf_app_client_session_init(service);
259 add_session(service, session);
262 debug_handler("MOD session service: %s", session->remote_service );
265 /* connect to the remote service */
266 if(!osrf_app_session_connect(session)) {
267 exception = json_object_new_object();
268 json_object_object_add( exception, "is_err", json_object_new_int(1));
269 json_object_object_add( exception,
270 "err_msg", json_object_new_string("Unable to connect to remote service"));
272 ap_rputs(json_object_to_json_string(exception), r );
273 json_object_put(exception);
277 int req_id = osrf_app_session_make_request( session, params, method, 1 );
278 json_object_put(params);
280 osrf_message* omsg = NULL;
282 growing_buffer* result_data = buffer_init(256);
283 buffer_add(result_data, "[");
285 /* gather result data */
286 while((omsg = osrf_app_session_request_recv( session, req_id, 30 ))) {
288 if( omsg->result_string ) {
289 buffer_add(result_data, omsg->result_string);
290 buffer_add( result_data, ",");
295 /* build the exception information */
296 growing_buffer* exc_buffer = buffer_init(256);
297 buffer_add( exc_buffer, "\nReceived Exception:\nName: " );
298 buffer_add( exc_buffer, omsg->status_name );
299 buffer_add( exc_buffer, "\nStatus: " );
300 buffer_add( exc_buffer, omsg->status_text );
301 buffer_add( exc_buffer, "\nStatus: " );
304 sprintf( code, "%d", omsg->status_code );
305 buffer_add( exc_buffer, code );
307 /* build the exception object */
308 exception = json_object_new_object();
309 json_object_object_add( exception, "is_err", json_object_new_int(1));
310 json_object_object_add( exception,
311 "err_msg", json_object_new_string(exc_buffer->buf));
313 warning_handler("*** Looks like we got a "
314 "server exception\n%s", exc_buffer->buf );
316 buffer_free(exc_buffer);
317 osrf_message_free(omsg);
321 osrf_message_free(omsg);
325 /* remove trailing comma */
326 if( result_data->buf[strlen(result_data->buf)-1] == ',') {
327 result_data->buf[strlen(result_data->buf)-1] = '\0';
328 result_data->n_used--;
331 buffer_add(result_data,"]");
333 char* content = NULL;
335 /* round up our data */
337 content = strdup(json_object_to_json_string(exception));
338 json_object_put(exception);
340 content = buffer_data(result_data);
343 buffer_free(result_data);
350 osrf_app_session_request_finish( session, req_id );
357 * This function is a callback and it declares what other functions
358 * should be called for request processing and configuration requests.
359 * This callback function declares the Handlers for other events. */
360 static void mod_ils_gateway_register_hooks (apr_pool_t *p) {
361 // I think this is the call to make to register a handler for method calls (GET PUT et. al.).
362 // We will ask to be last so that the comment has a higher tendency to
364 ap_hook_handler(mod_ils_gateway_method_handler, NULL, NULL, APR_HOOK_MIDDLE);
365 ap_hook_child_init(mod_ils_gateway_child_init,NULL,NULL,APR_HOOK_MIDDLE);
369 * Declare and populate the module's data structure. The
370 * name of this structure ('tut1_module') is important - it
371 * must match the name of the module. This structure is the
372 * only "glue" between the httpd core and the module.
375 module AP_MODULE_DECLARE_DATA ils_gateway_module =
377 STANDARD20_MODULE_STUFF,
383 mod_ils_gateway_register_hooks,