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Diffstat (limited to 'lib/asyn.h')
| -rw-r--r-- | lib/asyn.h | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/lib/asyn.h b/lib/asyn.h new file mode 100644 index 000000000..1b681ea12 --- /dev/null +++ b/lib/asyn.h @@ -0,0 +1,168 @@ +#ifndef HEADER_CURL_ASYN_H +#define HEADER_CURL_ASYN_H +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at http://curl.haxx.se/docs/copyright.html. + * + * You may opt to use, copy, modify, merge, publish, distribute and/or sell + * copies of the Software, and permit persons to whom the Software is + * furnished to do so, under the terms of the COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ***************************************************************************/ + +#include "curl_setup.h" +#include "curl_addrinfo.h" + +struct addrinfo; +struct hostent; +struct SessionHandle; +struct connectdata; +struct Curl_dns_entry; + +/* + * This header defines all functions in the internal asynch resolver interface. + * All asynch resolvers need to provide these functions. + * asyn-ares.c and asyn-thread.c are the current implementations of asynch + * resolver backends. + */ + +/* + * Curl_resolver_global_init() + * + * Called from curl_global_init() to initialize global resolver environment. + * Returning anything else than CURLE_OK fails curl_global_init(). + */ +int Curl_resolver_global_init(void); + +/* + * Curl_resolver_global_cleanup() + * Called from curl_global_cleanup() to destroy global resolver environment. + */ +void Curl_resolver_global_cleanup(void); + +/* + * Curl_resolver_init() + * Called from curl_easy_init() -> Curl_open() to initialize resolver + * URL-state specific environment ('resolver' member of the UrlState + * structure). Should fill the passed pointer by the initialized handler. + * Returning anything else than CURLE_OK fails curl_easy_init() with the + * correspondent code. + */ +CURLcode Curl_resolver_init(void **resolver); + +/* + * Curl_resolver_cleanup() + * Called from curl_easy_cleanup() -> Curl_close() to cleanup resolver + * URL-state specific environment ('resolver' member of the UrlState + * structure). Should destroy the handler and free all resources connected to + * it. + */ +void Curl_resolver_cleanup(void *resolver); + +/* + * Curl_resolver_duphandle() + * Called from curl_easy_duphandle() to duplicate resolver URL-state specific + * environment ('resolver' member of the UrlState structure). Should + * duplicate the 'from' handle and pass the resulting handle to the 'to' + * pointer. Returning anything else than CURLE_OK causes failed + * curl_easy_duphandle() call. + */ +int Curl_resolver_duphandle(void **to, void *from); + +/* + * Curl_resolver_cancel(). + * + * It is called from inside other functions to cancel currently performing + * resolver request. Should also free any temporary resources allocated to + * perform a request. + */ +void Curl_resolver_cancel(struct connectdata *conn); + +/* Curl_resolver_getsock() + * + * This function is called from the multi_getsock() function. 'sock' is a + * pointer to an array to hold the file descriptors, with 'numsock' being the + * size of that array (in number of entries). This function is supposed to + * return bitmask indicating what file descriptors (referring to array indexes + * in the 'sock' array) to wait for, read/write. + */ +int Curl_resolver_getsock(struct connectdata *conn, curl_socket_t *sock, + int numsocks); + +/* + * Curl_resolver_is_resolved() + * + * Called repeatedly to check if a previous name resolve request has + * completed. It should also make sure to time-out if the operation seems to + * take too long. + * + * Returns normal CURLcode errors. + */ +CURLcode Curl_resolver_is_resolved(struct connectdata *conn, + struct Curl_dns_entry **dns); + +/* + * Curl_resolver_wait_resolv() + * + * waits for a resolve to finish. This function should be avoided since using + * this risk getting the multi interface to "hang". + * + * If 'entry' is non-NULL, make it point to the resolved dns entry + * + * Returns CURLE_COULDNT_RESOLVE_HOST if the host was not resolved, and + * CURLE_OPERATION_TIMEDOUT if a time-out occurred. + + */ +CURLcode Curl_resolver_wait_resolv(struct connectdata *conn, + struct Curl_dns_entry **dnsentry); + +/* + * Curl_resolver_getaddrinfo() - when using this resolver + * + * Returns name information about the given hostname and port number. If + * successful, the 'hostent' is returned and the forth argument will point to + * memory we need to free after use. That memory *MUST* be freed with + * Curl_freeaddrinfo(), nothing else. + * + * Each resolver backend must of course make sure to return data in the + * correct format to comply with this. + */ +Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn, + const char *hostname, + int port, + int *waitp); + +#ifndef CURLRES_ASYNCH +/* convert these functions if an asynch resolver isn't used */ +#define Curl_resolver_cancel(x) Curl_nop_stmt +#define Curl_resolver_is_resolved(x,y) CURLE_COULDNT_RESOLVE_HOST +#define Curl_resolver_wait_resolv(x,y) CURLE_COULDNT_RESOLVE_HOST +#define Curl_resolver_getsock(x,y,z) 0 +#define Curl_resolver_duphandle(x,y) CURLE_OK +#define Curl_resolver_init(x) CURLE_OK +#define Curl_resolver_global_init() CURLE_OK +#define Curl_resolver_global_cleanup() Curl_nop_stmt +#define Curl_resolver_cleanup(x) Curl_nop_stmt +#endif + +#ifdef CURLRES_ASYNCH +#define Curl_resolver_asynch() 1 +#else +#define Curl_resolver_asynch() 0 +#endif + + +/********** end of generic resolver interface functions *****************/ +#endif /* HEADER_CURL_ASYN_H */ |