Re: [PD-dev] HTTP requests external : cURL threads ?

-- Alexandre Quessy http://alexandre.quessy.net > > > > On Jun 19, 2006, at 9:18 AM, Alexandre Quessy wrote: > > Hi, > > I am working on a simple external to do HTTP requests from PD. The idea is > to implement a simple way to send and receive simple data to a web server. > This is intended to work together with a set of classes that will interpret > the GET variables as key and values pairs where the values can be similar to > FUDI protocol messages. The web page would then answer with a FUDI message > or so. I don't use Python because I want it to be very fast, totally > portable and easy to install. (I also agree with Hans regarding small tools > to make a constellation of low level objects) > > Here are my bugs : perhaps I am not very good yet with strings in C, but I > have several errors when I try to execute this code from within PD as an > external. Well, when I get malloc errors, it must be only about memory size > arithmetics, but when it gets into segmentation faults, I was just wondering > if it could be because cURL starts a new thread. I think that thread are not > much appropriate in PD's context. Do you think this is the problem, or I am > just still a bit bad with memory maths ? > > Also, if you have ideas about this external, please don't hesitate. I think > I will rename it to http, as it is not intended in downloading whole files, > but just for simple HTTP requests. > > See below for the current code, the makefile and one of the errors it > creates. > > Alexandre Quessy > http://alexandre.quessy.net > > ============================= error when using it ==================== > t=0&ie > pd wget-help.pd > STACK_END old=0xbf9e5ffc; new=0xbf9efffc > PDP: pure data packet > PDP: version 0.12.4 > * About to connect() to alexandre.quessy.net port 80 > * Trying 64.15.134.165... * connected > * Connected to alexandre.quessy.net (64.15.134.165) port 80 > > GET /pd/curlme.php?asd=qwe+123 HTTP/1.1 > User-Agent: Pure Data > Host: alexandre.quessy.net > Accept: */* > > < HTTP/1.1 200 OK > < Date: Mon, 19 Jun 2006 16:03:44 GMT > < Server: Apache > < X-Powered-By: PHP/4.3.10-16 > < Connection: close > < Transfer-Encoding: chunked > < Content-Type: text/html > * Closing connection #0 > socket receive error: Connection reset by peer (104) > Erreur de segmentation > > ================== makefile > ==================================== > > all: wget.pd_linux > @echo "making wget" > > wget.pd_linux: wget.c > gcc -DPD -O2 -funroll-loops -fomit-frame-pointer \ > -Wall -W -Wshadow -Wstrict-prototypes \ > -Wno-unused -Wno-parentheses -Wno-switch -o wget.o -c wget.c > ld -export_dynamic -shared -o wget.pd_linux wget.o -lcurl -lc -lm > strip --strip-unneeded wget.pd_linux > rm wget.o > > > > ================== code : wget.c > ================================ > > /** > * [wget] is a Pure Data object for simple HTTP requests. > * > * @url http://alexandre.quessy.net/ > * @author Alexandre Quessy alexandre@quessy.net > * @license GNU General Public License 2006 > */ > #define PDWGET_VERSION "0.1.0" > > /* PD includes */ > #include "m_pd.h" > > /* cURL and standard C libraries */ > #include <curl/curl.h> > #include <string.h> > #include <stdlib.h> > > /* Download callback function prototype */ > size_t wget_callBack(void *ptr, size_t size, size_t nmemb, void *x); > > /** > * variables of the pd object > */ > typedef struct wget { > t_object x_ob; /* The instance. Contains inlets and outlets */ > t_outlet *x_outlet0; /* result string */ > t_outlet *x_outlet1; /* HTTP error codes */ > } t_wget; > > > > /** > * HTTP request. > */ > void wget_request(t_wget *x, t_symbol *s, int argc, t_atom *argv) { > post("wget : called request."); > > //curl_global_init(CURL_GLOBAL_NOTHING);//CURL_GLOBAL_ALL > > //t_symbol *sym_tmp = atom_getsymbol(&argv[0]); > if (argc < 1) { > post("wget : Error : needs arguments."); > } else { > t_symbol *sym_tmp = atom_getsymbolarg(0, argc, argv); > char *url = sym_tmp->s_name; > > post("wget : requesting : %s", url); > > /* cURL context */ > CURL *pContext = curl_easy_init(); > if (pContext == NULL) { > post("wget : Error : Null cURL handle."); > } else { > /* cURL options */ > CURLcode pCode = curl_easy_setopt(pContext, CURLOPT_URL, url); > curl_easy_setopt(pContext, CURLOPT_WRITEFUNCTION, wget_callBack, > (void *) x); > curl_easy_setopt(pContext, CURLOPT_VERBOSE, 1); > curl_easy_setopt(pContext, CURLOPT_HEADER, 0); > curl_easy_setopt(pContext, CURLOPT_NOPROGRESS, 1); > curl_easy_setopt(pContext, CURLOPT_USERAGENT, "Pure Data"); > curl_easy_setopt(pContext, CURLOPT_NOSIGNAL, 1); > curl_easy_setopt(pContext, CURLOPT_TIMEOUT, (long) 5); > > /* cURL performing */ > post("wget : Performing the request."); > const CURLcode result = curl_easy_perform(pContext); > if(CURLE_OK != result) { > post("wget : Error from cURL: %s", curl_easy_strerror(result)); > } else { > > /* HTTP code */ > long lHttpCode; > curl_easy_getinfo(pContext, CURLINFO_RESPONSE_CODE, &lHttpCode); > post("wget : HTTP response code: %ld ", lHttpCode); > //outlet_float(x->x_outlet1, (float) lHttpCode); > } > } > > post("[wget] cleaning up..."); > /* cURL cleanup */ > curl_easy_cleanup(pContext); > post("[wget] Local cleaned up."); > //curl_global_cleanup(); > post("[wget] Global cleaned up."); > //outlet_list(x->x_outlet0, gensym("A_FLOAT"), numCols+1, &atoms); // > &atoms ?? > } // else > } > > /** > * The representation of the class in PD. > */ > t_class *wget_class; > > /** > * constructor > */ > void *wget_new(t_symbol *selector, int argc, t_atom *argv) { > post("wget : creating a new object."); > t_wget *x = (t_wget *) pd_new(wget_class); > x->x_outlet0 = outlet_new(&x->x_ob, gensym("list")); > x->x_outlet1 = outlet_new(&x->x_ob, gensym("float")); > return (void *)x; > } > > /** > * setup > */ > void wget_setup(void) { > curl_global_init(CURL_GLOBAL_NOTHING); > wget_class = class_new(gensym("wget"), (t_newmethod) wget_new, 0, > sizeof(t_wget), 0, A_GIMME, 0); > class_addmethod(wget_class, (t_method)wget_request, gensym("request"), > A_GIMME, 0); > > > post("----------------------------------------------------"); > post(" [wget] %s (c) GPL Copyleft 2006 Alexandre Quessy", > PDWGET_VERSION); > post(" Simple HTTP requests for Pure Data."); > > post("----------------------------------------------------"); > } > > /** > * Callback implementation > */ > size_t wget_callBack(void *ptr, size_t size, size_t nmemb, void *x) { > size_t totalSize = nmemb * size; > char *dest = malloc(totalSize + 1); //(sizeof(char)) > strcpy(dest, (char *) ptr); > post("[wget] : Getting data."); > dest[totalSize] = '\0'; > post("result :"); > post("==============================="); > post("%s", dest); > post("==============================="); > > //outlet_symbol(((t_wget *)x)->x_outlet0, gensym(dest)); > //free(dest); > return(totalSize); > } > > > > > > > _______________________________________________ > PD-dev mailing list > PD-dev@iem.at > http://lists.puredata.info/listinfo/pd-dev > > > ------------------------------------------------------------------------ > > News is what people want to keep hidden and everything else is publicity. > - Bill Moyers > >