YoutubeCrawler/cpp/crawlerthread.cpp

98 lines
3.0 KiB
C++

#include "de_mrbesen_youtubecrawler_CrawlerThread.h"
#include <iostream>
#include <string>
#include <sstream>
#include <regex>
#include <vector>
#include <curl/curl.h>
static const std::string YOUTUBEBASE = "https://youtube.com/watch?v=";
static const std::regex YOUTUBELINKPATTERN("watch\\?v=([-_a-zA-Z0-9]{11})");
std::vector<CURL*> curls;
static size_t WriteCallback(void* contents, size_t size, size_t nmemb, void* userp) {
*((std::ostringstream*) userp) << std::string((char*) contents, size * nmemb);
return size * nmemb;
}
JNIEXPORT void JNICALL Java_de_mrbesen_youtubecrawler_CrawlerThread_initLib(JNIEnv* env, jclass clazz, jint threadcount) {
curls.reserve(threadcount);
for(int i = 0; i < threadcount; ++i) {
CURL* curl = curl_easy_init();
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
curls.push_back(curl);
}
}
JNIEXPORT void JNICALL Java_de_mrbesen_youtubecrawler_CrawlerThread_deinitLib(JNIEnv* env, jclass) {
for(int i = 0; i < curls.size(); ++i) {
CURL* curl = curls.at(i);
curl_easy_cleanup(curl);
}
curls.clear();
}
std::string download(CURL* curl, const std::string& url) {
curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
std::ostringstream out;
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &out);
CURLcode res = curl_easy_perform(curl);
long responsecode = 404;
curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &responsecode);
if(responsecode != 200) {
std::cout << "Curl error: got " << responsecode << std::endl;
return "";
}
if(res != CURLE_OK) {
std::cout << "Curl error: " << res << std::endl;
return "";
}
return out.str();
}
JNIEXPORT void JNICALL Java_de_mrbesen_youtubecrawler_CrawlerThread_crawl(JNIEnv* env, jobject that, jstring videoid, jint threadid) {
// get videoid argument
jboolean myfalseval = false;
const char* cvideid = env->GetStringUTFChars(videoid, &myfalseval);
std::string svideoid(cvideid);
env->ReleaseStringUTFChars(videoid, cvideid);
// std::cout << "crawl: " << svideoid << std::endl;
// use curl to get the website
CURL* curl = curls.at(threadid);
std::string webcontent = download(curl, YOUTUBEBASE + svideoid);
if(webcontent.empty()) {
std::cout << "webcontent is empty" << std::endl;
}
jclass jclass_ct = env->FindClass("de/mrbesen/youtubecrawler/CrawlerThread");
jfieldID fid_ctfound = env->GetFieldID(jclass_ct, "found" , "Ljava/util/LinkedList;");
jclass jclass_ll = env->FindClass("java/util/LinkedList");
jmethodID mid_add = env->GetMethodID(jclass_ll, "add", "(Ljava/lang/Object;)Z");
// match regex
auto it = std::sregex_iterator(webcontent.begin(), webcontent.end(), YOUTUBELINKPATTERN);
auto itend = std::sregex_iterator();
for( ; it != itend; ++it) {
std::string ytid = (*it)[1].str();
// add to the found list
if(ytid != svideoid) {
//construct java string
jstring jytid = env->NewStringUTF(ytid.c_str());
jobject ll_found = env->GetObjectField(that, fid_ctfound);
jboolean b = env->CallBooleanMethod(ll_found, mid_add, jytid);
}
}
}