fix: refactored scraping components

src/Config.h

@@ -23,6 +23,13 @@
 #define INFOBOX_FIELD_COUNT 4
 #define MAX_RESULTS_PER_ENGINE 10
 
+#define CURL_TIMEOUT_SECS 15L
+#define CURL_DNS_TIMEOUT_SECS 300L
+
+#define BING_IMAGE_URL "https://www.bing.com/images/search"
+#define IMAGE_RESULTS_PER_PAGE 32
+#define IMAGE_RESULT_FIELDS 4
+
 typedef struct {
   char host[256];
   int port;

src/Routes/Images.c

@@ -1,15 +1,7 @@
 #include "Images.h"
-#include "../Scraping/Scraping.h"
-#include "../Utility/HttpClient.h"
+#include "../Scraping/ImageScraping.h"
 #include "../Utility/Unescape.h"
-#include "../Utility/XmlHelper.h"
-
-#include <curl/curl.h>
-#include <libxml/HTMLparser.h>
-#include <libxml/xpath.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+#include "Config.h"
 
 int images_handler(UrlParams *params) {
   TemplateContext ctx = new_context();
@@ -28,12 +20,12 @@ int images_handler(UrlParams *params) {
     }
   }
 
-  context_set(&ctx, "query", raw_query);
-
   char page_str[16], prev_str[16], next_str[16];
   snprintf(page_str, sizeof(page_str), "%d", page);
   snprintf(prev_str, sizeof(prev_str), "%d", page > 1 ? page - 1 : 0);
   snprintf(next_str, sizeof(next_str), "%d", page + 1);
+
+  context_set(&ctx, "query", raw_query);
   context_set(&ctx, "page", page_str);
   context_set(&ctx, "prev_page", prev_str);
   context_set(&ctx, "next_page", next_str);
@@ -49,208 +41,41 @@ int images_handler(UrlParams *params) {
     return -1;
   }
 
-  CURL *tmp = curl_easy_init();
-  if (!tmp) {
-    send_response("<h1>Error initializing curl</h1>");
-    if (display_query)
-      free(display_query);
-    free_context(&ctx);
-    return -1;
-  }
-  char *encoded_query = curl_easy_escape(tmp, raw_query, 0);
-  curl_easy_cleanup(tmp);
-
-  if (!encoded_query) {
-    send_response("<h1>Error encoding query</h1>");
-    if (display_query)
-      free(display_query);
-    free_context(&ctx);
-    return -1;
-  }
-
-  char url[1024];
-  int first = (page - 1) * 32 + 1;
-  snprintf(url, sizeof(url), "https://www.bing.com/images/search?q=%s&first=%d",
-           encoded_query, first);
+  ImageResult *results = NULL;
+  int result_count = 0;
 
-  HttpResponse resp = http_get(
-      url,
-      "Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko");
-  if (!resp.memory) {
+  if (scrape_images(raw_query, page, &results, &result_count) != 0 ||
+      !results) {
     send_response("<h1>Error fetching images</h1>");
-    free(encoded_query);
-    free(display_query);
-    free_context(&ctx);
-    return -1;
-  }
-
-  htmlDocPtr doc = htmlReadMemory(resp.memory, resp.size, NULL, NULL,
-                                  HTML_PARSE_RECOVER | HTML_PARSE_NOERROR);
-  if (!doc) {
-    http_response_free(&resp);
-    free(encoded_query);
     free(display_query);
     free_context(&ctx);
     return -1;
   }
 
-  xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
+  char ***image_matrix = malloc(sizeof(char **) * result_count);
+  int *inner_counts = malloc(sizeof(int) * result_count);
 
-  if (!xpathCtx) {
-    xmlFreeDoc(doc);
-    http_response_free(&resp);
-    free(encoded_query);
+  if (!image_matrix || !inner_counts) {
+    if (image_matrix)
+      free(image_matrix);
+    if (inner_counts)
+      free(inner_counts);
+    free_image_results(results, result_count);
     free(display_query);
     free_context(&ctx);
     return -1;
   }
 
-  xmlXPathObjectPtr xpathObj =
-      xmlXPathEvalExpression((const xmlChar *)"//div[@class='item']", xpathCtx);
-
-  int image_count = 0;
-  char ***image_matrix = NULL;
-  int *inner_counts = NULL;
-
-  if (xpathObj && xpathObj->nodesetval) {
-    int nodes = xpathObj->nodesetval->nodeNr;
-
-    int max_images = (nodes < 32) ? nodes : 32;
-    image_matrix = malloc(sizeof(char **) * max_images);
-    inner_counts = malloc(sizeof(int) * max_images);
-    if (!image_matrix || !inner_counts) {
-      if (image_matrix) free(image_matrix);
-      if (inner_counts) free(inner_counts);
-      image_matrix = NULL;
-      inner_counts = NULL;
-    }
-
-    for (int i = 0; i < nodes; i++) {
-      if (image_count >= 32)
-        break;
-
-      xmlNodePtr node = xpathObj->nodesetval->nodeTab[i];
-      xmlNodePtr img_node = NULL;
-      xmlNodePtr tit_node = NULL;
-      xmlNodePtr des_node = NULL;
-      xmlNodePtr thumb_link = NULL;
-
-      for (xmlNodePtr child = node->children; child; child = child->next) {
-        if (child->type != XML_ELEMENT_NODE)
-          continue;
-
-        if (xmlStrcmp(child->name, (const xmlChar *)"a") == 0) {
-          xmlChar *class = xmlGetProp(child, (const xmlChar *)"class");
-          if (class) {
-            if (xmlStrstr(class, (const xmlChar *)"thumb") != NULL) {
-              thumb_link = child;
-              for (xmlNodePtr thumb_child = child->children; thumb_child;
-                   thumb_child = thumb_child->next) {
-                if (xmlStrcmp(thumb_child->name, (const xmlChar *)"div") == 0) {
-                  xmlChar *div_class =
-                      xmlGetProp(thumb_child, (const xmlChar *)"class");
-                  if (div_class &&
-                      xmlStrcmp(div_class, (const xmlChar *)"cico") == 0) {
-                    for (xmlNodePtr cico_child = thumb_child->children;
-                         cico_child; cico_child = cico_child->next) {
-                      if (xmlStrcmp(cico_child->name, (const xmlChar *)"img") ==
-                          0) {
-                        img_node = cico_child;
-                        break;
-                      }
-                    }
-                  }
-                  if (div_class)
-                    xmlFree(div_class);
-                }
-              }
-            } else if (xmlStrstr(class, (const xmlChar *)"tit") != NULL) {
-              tit_node = child;
-            }
-            xmlFree(class);
-          }
-        } else if (xmlStrcmp(child->name, (const xmlChar *)"div") == 0) {
-          xmlChar *class = xmlGetProp(child, (const xmlChar *)"class");
-          if (class && xmlStrcmp(class, (const xmlChar *)"meta") == 0) {
-            for (xmlNodePtr meta_child = child->children; meta_child;
-                 meta_child = meta_child->next) {
-              if (xmlStrcmp(meta_child->name, (const xmlChar *)"div") == 0) {
-                xmlChar *div_class =
-                    xmlGetProp(meta_child, (const xmlChar *)"class");
-                if (div_class) {
-                  if (xmlStrcmp(div_class, (const xmlChar *)"des") == 0) {
-                    des_node = meta_child;
-                  }
-                  xmlFree(div_class);
-                }
-              } else if (xmlStrcmp(meta_child->name, (const xmlChar *)"a") ==
-                         0) {
-                xmlChar *a_class =
-                    xmlGetProp(meta_child, (const xmlChar *)"class");
-                if (a_class &&
-                    xmlStrstr(a_class, (const xmlChar *)"tit") != NULL) {
-                  tit_node = meta_child;
-                }
-                if (a_class)
-                  xmlFree(a_class);
-              }
-            }
-          }
-          if (class)
-            xmlFree(class);
-        }
-      }
-
-      xmlChar *iurl =
-          img_node ? xmlGetProp(img_node, (const xmlChar *)"src") : NULL;
-      xmlChar *full_url =
-          thumb_link ? xmlGetProp(thumb_link, (const xmlChar *)"href") : NULL;
-      xmlChar *title = des_node
-                           ? xmlNodeGetContent(des_node)
-                           : (tit_node ? xmlNodeGetContent(tit_node) : NULL);
-      xmlChar *rurl =
-          tit_node ? xmlGetProp(tit_node, (const xmlChar *)"href") : NULL;
-
-      if (iurl && strlen((char *)iurl) > 0) {
-        char *proxy_url = NULL;
-        CURL *esc_curl = curl_easy_init();
-        if (esc_curl) {
-          char *encoded = curl_easy_escape(esc_curl, (char *)iurl, 0);
-          if (encoded) {
-            size_t proxy_len = strlen("/proxy?url=") + strlen(encoded) + 1;
-            proxy_url = malloc(proxy_len);
-            if (proxy_url) {
-              snprintf(proxy_url, proxy_len, "/proxy?url=%s", encoded);
-            }
-            curl_free(encoded);
-          }
-          curl_easy_cleanup(esc_curl);
-        }
-
-        image_matrix[image_count] = malloc(sizeof(char *) * 4);
-        image_matrix[image_count][0] =
-            proxy_url ? strdup(proxy_url) : strdup((char *)iurl);
-        free(proxy_url);
-        image_matrix[image_count][1] = strdup(title ? (char *)title : "Image");
-        image_matrix[image_count][2] = strdup(rurl ? (char *)rurl : "#");
-        image_matrix[image_count][3] =
-            strdup(full_url ? (char *)full_url : "#");
-        inner_counts[image_count] = 4;
-        image_count++;
-      }
-
-      if (iurl)
-        xmlFree(iurl);
-      if (title)
-        xmlFree(title);
-      if (rurl)
-        xmlFree(rurl);
-      if (full_url)
-        xmlFree(full_url);
-    }
+  for (int i = 0; i < result_count; i++) {
+    image_matrix[i] = malloc(sizeof(char *) * IMAGE_RESULT_FIELDS);
+    image_matrix[i][0] = strdup(results[i].thumbnail_url);
+    image_matrix[i][1] = strdup(results[i].title);
+    image_matrix[i][2] = strdup(results[i].page_url);
+    image_matrix[i][3] = strdup(results[i].full_url);
+    inner_counts[i] = IMAGE_RESULT_FIELDS;
   }
 
-  context_set_array_of_arrays(&ctx, "images", image_matrix, image_count,
+  context_set_array_of_arrays(&ctx, "images", image_matrix, result_count,
                               inner_counts);
 
   char *rendered = render_template("images.html", &ctx);
@@ -261,27 +86,15 @@ int images_handler(UrlParams *params) {
     send_response("<h1>Error rendering image results</h1>");
   }
 
-  if (image_matrix) {
-    for (int i = 0; i < image_count; i++) {
-      for (int j = 0; j < 4; j++) {
-        free(image_matrix[i][j]);
-      }
-      free(image_matrix[i]);
-    }
-    free(image_matrix);
-  }
-  if (inner_counts) {
-    free(inner_counts);
+  for (int i = 0; i < result_count; i++) {
+    for (int j = 0; j < IMAGE_RESULT_FIELDS; j++)
+      free(image_matrix[i][j]);
+    free(image_matrix[i]);
   }
+  free(image_matrix);
+  free(inner_counts);
 
-  if (xpathObj)
-    xmlXPathFreeObject(xpathObj);
-  if (xpathCtx)
-    xmlXPathFreeContext(xpathCtx);
-  if (doc)
-    xmlFreeDoc(doc);
-  http_response_free(&resp);
-  curl_free(encoded_query);
+  free_image_results(results, result_count);
   free(display_query);
   free_context(&ctx);
 

src/Scraping/ImageScraping.c

@@ -0,0 +1,239 @@
+#include "ImageScraping.h"
+#include "../Utility/HttpClient.h"
+#include "Config.h"
+#include <libxml/HTMLparser.h>
+#include <libxml/xpath.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static char *build_proxy_url(const char *image_url) {
+  if (!image_url)
+    return NULL;
+
+  char *proxy_url = NULL;
+  CURL *curl = curl_easy_init();
+  if (curl) {
+    char *encoded = curl_easy_escape(curl, (char *)image_url, 0);
+    if (encoded) {
+      size_t len = strlen("/proxy?url=") + strlen(encoded) + 1;
+      proxy_url = malloc(len);
+      if (proxy_url)
+        snprintf(proxy_url, len, "/proxy?url=%s", encoded);
+      curl_free(encoded);
+    }
+    curl_easy_cleanup(curl);
+  }
+
+  return proxy_url;
+}
+
+static int parse_image_node(xmlNodePtr node, ImageResult *result) {
+  xmlNodePtr img_node = NULL;
+  xmlNodePtr tit_node = NULL;
+  xmlNodePtr des_node = NULL;
+  xmlNodePtr thumb_link = NULL;
+
+  for (xmlNodePtr child = node->children; child; child = child->next) {
+    if (child->type != XML_ELEMENT_NODE)
+      continue;
+
+    if (xmlStrcmp(child->name, (const xmlChar *)"a") == 0) {
+      xmlChar *class = xmlGetProp(child, (const xmlChar *)"class");
+      if (class) {
+        if (xmlStrstr(class, (const xmlChar *)"thumb") != NULL) {
+          thumb_link = child;
+          for (xmlNodePtr thumb_child = child->children; thumb_child;
+               thumb_child = thumb_child->next) {
+            if (xmlStrcmp(thumb_child->name, (const xmlChar *)"div") == 0) {
+              xmlChar *div_class =
+                  xmlGetProp(thumb_child, (const xmlChar *)"class");
+              if (div_class &&
+                  xmlStrcmp(div_class, (const xmlChar *)"cico") == 0) {
+                for (xmlNodePtr cico_child = thumb_child->children; cico_child;
+                     cico_child = cico_child->next) {
+                  if (xmlStrcmp(cico_child->name, (const xmlChar *)"img") ==
+                      0) {
+                    img_node = cico_child;
+                    break;
+                  }
+                }
+              }
+              if (div_class)
+                xmlFree(div_class);
+            }
+          }
+        } else if (xmlStrstr(class, (const xmlChar *)"tit") != NULL) {
+          tit_node = child;
+        }
+        xmlFree(class);
+      }
+    } else if (xmlStrcmp(child->name, (const xmlChar *)"div") == 0) {
+      xmlChar *class = xmlGetProp(child, (const xmlChar *)"class");
+      if (class && xmlStrcmp(class, (const xmlChar *)"meta") == 0) {
+        for (xmlNodePtr meta_child = child->children; meta_child;
+             meta_child = meta_child->next) {
+          if (xmlStrcmp(meta_child->name, (const xmlChar *)"div") == 0) {
+            xmlChar *div_class =
+                xmlGetProp(meta_child, (const xmlChar *)"class");
+            if (div_class) {
+              if (xmlStrcmp(div_class, (const xmlChar *)"des") == 0) {
+                des_node = meta_child;
+              }
+              xmlFree(div_class);
+            }
+          } else if (xmlStrcmp(meta_child->name, (const xmlChar *)"a") == 0) {
+            xmlChar *a_class = xmlGetProp(meta_child, (const xmlChar *)"class");
+            if (a_class && xmlStrstr(a_class, (const xmlChar *)"tit") != NULL) {
+              tit_node = meta_child;
+            }
+            if (a_class)
+              xmlFree(a_class);
+          }
+        }
+      }
+      if (class)
+        xmlFree(class);
+    }
+  }
+
+  xmlChar *iurl =
+      img_node ? xmlGetProp(img_node, (const xmlChar *)"src") : NULL;
+  xmlChar *full_url =
+      thumb_link ? xmlGetProp(thumb_link, (const xmlChar *)"href") : NULL;
+  xmlChar *title = des_node ? xmlNodeGetContent(des_node)
+                            : (tit_node ? xmlNodeGetContent(tit_node) : NULL);
+  xmlChar *rurl =
+      tit_node ? xmlGetProp(tit_node, (const xmlChar *)"href") : NULL;
+
+  if (!iurl || strlen((char *)iurl) == 0) {
+    if (iurl)
+      xmlFree(iurl);
+    if (title)
+      xmlFree(title);
+    if (rurl)
+      xmlFree(rurl);
+    if (full_url)
+      xmlFree(full_url);
+    return 0;
+  }
+
+  char *proxy_url = build_proxy_url((char *)iurl);
+  result->thumbnail_url = proxy_url ? strdup(proxy_url) : strdup((char *)iurl);
+  free(proxy_url);
+  result->title = strdup(title ? (char *)title : "Image");
+  result->page_url = strdup(rurl ? (char *)rurl : "#");
+  result->full_url = strdup(full_url ? (char *)full_url : "#");
+
+  if (iurl)
+    xmlFree(iurl);
+  if (title)
+    xmlFree(title);
+  if (rurl)
+    xmlFree(rurl);
+  if (full_url)
+    xmlFree(full_url);
+
+  return 1;
+}
+
+int scrape_images(const char *query, int page, ImageResult **out_results,
+                  int *out_count) {
+  *out_results = NULL;
+  *out_count = 0;
+
+  if (!query || strlen(query) == 0)
+    return -1;
+
+  CURL *tmp = curl_easy_init();
+  if (!tmp)
+    return -1;
+
+  char *encoded_query = curl_easy_escape(tmp, query, 0);
+  curl_easy_cleanup(tmp);
+
+  if (!encoded_query)
+    return -1;
+
+  char url[BUFFER_SIZE_LARGE];
+  int first = (page - 1) * IMAGE_RESULTS_PER_PAGE + 1;
+  snprintf(url, sizeof(url), "%s?q=%s&first=%d", BING_IMAGE_URL, encoded_query,
+           first);
+  free(encoded_query);
+
+  HttpResponse resp = http_get(
+      url,
+      "Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko");
+  if (!resp.memory) {
+    return -1;
+  }
+
+  htmlDocPtr doc = htmlReadMemory(resp.memory, resp.size, NULL, NULL,
+                                  HTML_PARSE_RECOVER | HTML_PARSE_NOERROR);
+  if (!doc) {
+    http_response_free(&resp);
+    return -1;
+  }
+
+  xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
+  if (!xpathCtx) {
+    xmlFreeDoc(doc);
+    http_response_free(&resp);
+    return -1;
+  }
+
+  xmlXPathObjectPtr xpathObj =
+      xmlXPathEvalExpression((const xmlChar *)"//div[@class='item']", xpathCtx);
+
+  if (!xpathObj || !xpathObj->nodesetval) {
+    if (xpathObj)
+      xmlXPathFreeObject(xpathObj);
+    xmlXPathFreeContext(xpathCtx);
+    xmlFreeDoc(doc);
+    http_response_free(&resp);
+    return 0;
+  }
+
+  int nodes = xpathObj->nodesetval->nodeNr;
+  int max_images =
+      (nodes < IMAGE_RESULTS_PER_PAGE) ? nodes : IMAGE_RESULTS_PER_PAGE;
+
+  ImageResult *results = malloc(sizeof(ImageResult) * max_images);
+  if (!results) {
+    xmlXPathFreeObject(xpathObj);
+    xmlXPathFreeContext(xpathCtx);
+    xmlFreeDoc(doc);
+    http_response_free(&resp);
+    return -1;
+  }
+
+  int count = 0;
+  for (int i = 0; i < nodes && count < IMAGE_RESULTS_PER_PAGE; i++) {
+    xmlNodePtr node = xpathObj->nodesetval->nodeTab[i];
+    if (parse_image_node(node, &results[count])) {
+      count++;
+    }
+  }
+
+  xmlXPathFreeObject(xpathObj);
+  xmlXPathFreeContext(xpathCtx);
+  xmlFreeDoc(doc);
+  http_response_free(&resp);
+
+  *out_results = results;
+  *out_count = count;
+  return 0;
+}
+
+void free_image_results(ImageResult *results, int count) {
+  if (!results)
+    return;
+
+  for (int i = 0; i < count; i++) {
+    free(results[i].thumbnail_url);
+    free(results[i].title);
+    free(results[i].page_url);
+    free(results[i].full_url);
+  }
+  free(results);
+}

src/Scraping/ImageScraping.h

@@ -0,0 +1,18 @@
+#ifndef IMAGESCRAPING_H
+#define IMAGESCRAPING_H
+
+#include <curl/curl.h>
+#include <libxml/HTMLparser.h>
+
+typedef struct {
+  char *thumbnail_url;
+  char *title;
+  char *page_url;
+  char *full_url;
+} ImageResult;
+
+int scrape_images(const char *query, int page, ImageResult **out_results,
+                  int *out_count);
+void free_image_results(ImageResult *results, int count);
+
+#endif

src/Scraping/Scraping.c

@@ -1,395 +1,20 @@
 #include "Scraping.h"
 #include "../Cache/Cache.h"
 #include "../Proxy/Proxy.h"
-#include "../Utility/Unescape.h"
-#include "../Utility/XmlHelper.h"
 #include "Config.h"
 #include <curl/curl.h>
 #include <libxml/HTMLparser.h>
-#include <libxml/xpath.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <time.h>
-#include <unistd.h>
-
-static size_t WriteMemoryCallback(void *contents, size_t size, size_t nmemb,
-                                  void *userp) {
-  size_t realsize = size * nmemb;
-  MemoryBuffer *mem = (MemoryBuffer *)userp;
-
-  if (mem->size + realsize + 1 > mem->capacity) {
-    size_t new_cap =
-        mem->capacity == 0 ? INITIAL_BUFFER_SIZE : mem->capacity * 2;
-    while (new_cap < mem->size + realsize + 1)
-      new_cap *= 2;
-
-    char *ptr = (char *)realloc(mem->memory, new_cap);
-    if (!ptr) {
-      return 0;
-    }
-    mem->memory = ptr;
-    mem->capacity = new_cap;
-  }
-
-  memcpy(&(mem->memory[mem->size]), contents, realsize);
-  mem->size += realsize;
-  mem->memory[mem->size] = 0;
-
-  return realsize;
-}
-
-static const char *get_random_user_agent(void) {
-  static const char *agents[] = {
-      "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, "
-      "like Gecko) Chrome/120.0.0.0 Safari/537.36",
-      "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 "
-      "(KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36",
-      "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like "
-      "Gecko) "
-      "Chrome/120.0.0.0` Safari/537.36",
-      "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 "
-      "Firefox/121.0",
-      "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 "
-      "(KHTML, like Gecko) Version/17.2 Safari/605.1.15"};
-  return agents[rand() % 5];
-}
-
-static int parse_ddg_lite(const char *engine_name, xmlDocPtr doc,
-                          SearchResult **out_results, int max_results) {
-  (void)engine_name;
-  int found_count = 0;
-
-  xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
-  if (!xpathCtx) {
-    return 0;
-  }
-
-  xmlXPathObjectPtr xpathObj = xml_xpath_eval(
-      xpathCtx, "//tr[not(contains(@class, "
-                "'result-sponsored'))]//a[@class='result-link']");
-
-  if (!xpathObj || !xpathObj->nodesetval || xpathObj->nodesetval->nodeNr == 0) {
-    if (xpathObj)
-      xmlXPathFreeObject(xpathObj);
-    xmlXPathFreeContext(xpathCtx);
-    return 0;
-  }
-
-  int num_links = xpathObj->nodesetval->nodeNr;
-  *out_results = xml_result_alloc(num_links, max_results);
-  if (!*out_results) {
-    xmlXPathFreeObject(xpathObj);
-    xmlXPathFreeContext(xpathCtx);
-    return 0;
-  }
-
-  for (int i = 0; i < num_links && found_count < max_results; i++) {
-    xmlNodePtr linkNode = xpathObj->nodesetval->nodeTab[i];
-    char *title = xml_node_content(linkNode);
-    char *url = (char *)xmlGetProp(linkNode, (xmlChar *)"href");
-    char *snippet_text = NULL;
-
-    xmlNodePtr current = linkNode->parent;
-    while (current && xmlStrcasecmp(current->name, (const xmlChar *)"tr") != 0)
-      current = current->parent;
-
-    if (current && current->next) {
-      xmlNodePtr snippetRow = current->next;
-      while (snippetRow &&
-             xmlStrcasecmp(snippetRow->name, (const xmlChar *)"tr") != 0)
-        snippetRow = snippetRow->next;
-      if (snippetRow) {
-        xpathCtx->node = snippetRow;
-        xmlXPathObjectPtr sObj =
-            xml_xpath_eval(xpathCtx, ".//td[@class='result-snippet']");
-        if (sObj && sObj->nodesetval && sObj->nodesetval->nodeNr > 0) {
-          snippet_text = xml_node_content(sObj->nodesetval->nodeTab[0]);
-        }
-        if (sObj)
-          xmlXPathFreeObject(sObj);
-        xpathCtx->node = NULL;
-      }
-    }
-
-    (*out_results)[found_count].url = unescape_search_url(url);
-    (*out_results)[found_count].title = strdup(title ? title : "No Title");
-    (*out_results)[found_count].snippet =
-        strdup(snippet_text ? snippet_text : "");
-    found_count++;
-
-    if (title)
-      xmlFree(title);
-    if (url)
-      xmlFree(url);
-    if (snippet_text)
-      xmlFree(snippet_text);
-  }
-
-  xmlXPathFreeObject(xpathObj);
-  xmlXPathFreeContext(xpathCtx);
-  return found_count;
-}
-
-static int parse_startpage(const char *engine_name, xmlDocPtr doc,
-                           SearchResult **out_results, int max_results) {
-  (void)engine_name;
-  int found_count = 0;
-
-  xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
-  if (!xpathCtx) {
-    return 0;
-  }
-
-  xmlXPathObjectPtr xpathObj =
-      xml_xpath_eval(xpathCtx, "//div[contains(@class, 'result')]");
-
-  if (!xpathObj || !xpathObj->nodesetval || xpathObj->nodesetval->nodeNr == 0) {
-    if (xpathObj)
-      xmlXPathFreeObject(xpathObj);
-    xmlXPathFreeContext(xpathCtx);
-    return 0;
-  }
-
-  int num_results = xpathObj->nodesetval->nodeNr;
-  *out_results = xml_result_alloc(num_results, max_results);
-  if (!*out_results) {
-    xmlXPathFreeObject(xpathObj);
-    xmlXPathFreeContext(xpathCtx);
-    return 0;
-  }
-
-  for (int i = 0; i < num_results && found_count < max_results; i++) {
-    xmlNodePtr resultNode = xpathObj->nodesetval->nodeTab[i];
-    xpathCtx->node = resultNode;
-
-    xmlXPathObjectPtr linkObj =
-        xml_xpath_eval(xpathCtx, ".//a[contains(@class, 'result-link')]");
-    char *url =
-        (linkObj && linkObj->nodesetval && linkObj->nodesetval->nodeNr > 0)
-            ? (char *)xmlGetProp(linkObj->nodesetval->nodeTab[0],
-                                 (xmlChar *)"href")
-            : NULL;
-
-    xmlXPathObjectPtr titleObj =
-        xml_xpath_eval(xpathCtx, ".//h2[contains(@class, 'wgl-title')]");
-    char *title =
-        (titleObj && titleObj->nodesetval && titleObj->nodesetval->nodeNr > 0)
-            ? xml_node_content(titleObj->nodesetval->nodeTab[0])
-            : NULL;
-
-    xmlXPathObjectPtr snippetObj =
-        xml_xpath_eval(xpathCtx, ".//p[contains(@class, 'description')]");
-    char *snippet_text =
-        (snippetObj && snippetObj->nodesetval &&
-         snippetObj->nodesetval->nodeNr > 0)
-            ? xml_node_content(snippetObj->nodesetval->nodeTab[0])
-            : NULL;
-
-    if (url && title) {
-      (*out_results)[found_count].url = strdup(url);
-      (*out_results)[found_count].title = strdup(title);
-      (*out_results)[found_count].snippet =
-          strdup(snippet_text ? snippet_text : "");
-      found_count++;
-    }
-
-    if (title)
-      xmlFree(title);
-    if (url)
-      xmlFree(url);
-    if (snippet_text)
-      xmlFree(snippet_text);
-    if (linkObj)
-      xmlXPathFreeObject(linkObj);
-    if (titleObj)
-      xmlXPathFreeObject(titleObj);
-    if (snippetObj)
-      xmlXPathFreeObject(snippetObj);
-  }
-
-  xpathCtx->node = NULL;
-  xmlXPathFreeObject(xpathObj);
-  xmlXPathFreeContext(xpathCtx);
-  return found_count;
-}
-
-static int parse_yahoo(const char *engine_name, xmlDocPtr doc,
-                       SearchResult **out_results, int max_results) {
-  (void)engine_name;
-  int found_count = 0;
-
-  xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
-  if (!xpathCtx) {
-    return 0;
-  }
-
-  xmlXPathObjectPtr xpathObj =
-      xml_xpath_eval(xpathCtx, "//div[contains(@class, 'algo-sr')]");
-
-  if (!xpathObj || !xpathObj->nodesetval || xpathObj->nodesetval->nodeNr == 0) {
-    if (xpathObj)
-      xmlXPathFreeObject(xpathObj);
-    xmlXPathFreeContext(xpathCtx);
-    return 0;
-  }
 
-  int num_results = xpathObj->nodesetval->nodeNr;
-  *out_results = xml_result_alloc(num_results, max_results);
-  if (!*out_results) {
-    xmlXPathFreeObject(xpathObj);
-    xmlXPathFreeContext(xpathCtx);
+int check_cache_for_job(ScrapeJob *job) {
+  if (get_cache_ttl_search() <= 0)
     return 0;
-  }
-
-  for (int i = 0; i < num_results && found_count < max_results; i++) {
-    xmlNodePtr resultNode = xpathObj->nodesetval->nodeTab[i];
-    xpathCtx->node = resultNode;
-
-    xmlXPathObjectPtr linkObj = xml_xpath_eval(
-        xpathCtx, ".//div[contains(@class, 'compTitle')]//a[@target='_blank']");
-    char *url =
-        (linkObj && linkObj->nodesetval && linkObj->nodesetval->nodeNr > 0)
-            ? (char *)xmlGetProp(linkObj->nodesetval->nodeTab[0],
-                                 (xmlChar *)"href")
-            : NULL;
-
-    xmlXPathObjectPtr titleObj =
-        xml_xpath_eval(xpathCtx, ".//h3[contains(@class, 'title')]");
-    char *title =
-        (titleObj && titleObj->nodesetval && titleObj->nodesetval->nodeNr > 0)
-            ? xml_node_content(titleObj->nodesetval->nodeTab[0])
-            : NULL;
-
-    xmlXPathObjectPtr snippetObj =
-        xml_xpath_eval(xpathCtx, ".//div[contains(@class, 'compText')]//p");
-    char *snippet_text =
-        (snippetObj && snippetObj->nodesetval &&
-         snippetObj->nodesetval->nodeNr > 0)
-            ? xml_node_content(snippetObj->nodesetval->nodeTab[0])
-            : NULL;
-
-    if (url && title) {
-      (*out_results)[found_count].url = unescape_search_url(url);
-      (*out_results)[found_count].title = strdup(title);
-      (*out_results)[found_count].snippet =
-          strdup(snippet_text ? snippet_text : "");
-      found_count++;
-    }
-
-    if (title)
-      xmlFree(title);
-    if (url)
-      xmlFree(url);
-    if (snippet_text)
-      xmlFree(snippet_text);
-    if (linkObj)
-      xmlXPathFreeObject(linkObj);
-    if (titleObj)
-      xmlXPathFreeObject(titleObj);
-    if (snippetObj)
-      xmlXPathFreeObject(snippetObj);
-  }
-
-  xpathCtx->node = NULL;
-  xmlXPathFreeObject(xpathObj);
-  xmlXPathFreeContext(xpathCtx);
-  return found_count;
-}
-
-const SearchEngine ENGINE_REGISTRY[] = {
-    {.name = "DuckDuckGo Lite",
-     .base_url = "https://lite.duckduckgo.com/lite/?q=",
-     .host_header = "lite.duckduckgo.com",
-     .referer = "https://lite.duckduckgo.com/",
-     .page_param = "s",
-     .page_multiplier = 30,
-     .page_base = 0,
-     .parser = parse_ddg_lite},
-    {.name = "Startpage",
-     .base_url = "https://www.startpage.com/sp/search?q=",
-     .host_header = "www.startpage.com",
-     .referer = "https://www.startpage.com/",
-     .page_param = "page",
-     .page_multiplier = 1,
-     .page_base = 1,
-     .parser = parse_startpage},
-    {.name = "Yahoo",
-     .base_url = "https://search.yahoo.com/search?p=",
-     .host_header = "search.yahoo.com",
-     .referer = "https://search.yahoo.com/",
-     .page_param = "b",
-     .page_multiplier = 10,
-     .page_base = 1,
-     .parser = parse_yahoo}};
-
-const int ENGINE_COUNT = sizeof(ENGINE_REGISTRY) / sizeof(SearchEngine);
-
-#define CURL_TIMEOUT 15L
-#define CURL_DNS_TIMEOUT 300L
-
-static void configure_curl_handle(CURL *curl, const char *full_url,
-                                  MemoryBuffer *chunk,
-                                  struct curl_slist *headers) {
-  curl_easy_setopt(curl, CURLOPT_URL, full_url);
-  curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
-  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
-  curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)chunk);
-  curl_easy_setopt(curl, CURLOPT_USERAGENT, get_random_user_agent());
-
-  curl_easy_setopt(curl, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
-  curl_easy_setopt(curl, CURLOPT_ACCEPT_ENCODING, "");
-  curl_easy_setopt(curl, CURLOPT_DNS_CACHE_TIMEOUT, CURL_DNS_TIMEOUT);
-  curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
-  curl_easy_setopt(curl, CURLOPT_TIMEOUT, CURL_TIMEOUT);
-  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
-  curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "");
-
-  apply_proxy_settings(curl);
-}
-
-static char *build_search_url(const char *base_url, const char *page_param,
-                              int page_multiplier, int page_base,
-                              const char *encoded_query, int page) {
-  int page_value = (page < 1 ? 1 : page - 1) * page_multiplier + page_base;
-  char *url = malloc(BUFFER_SIZE_LARGE);
-  if (!url) {
-    return NULL;
-  }
-  snprintf(url, BUFFER_SIZE_LARGE, "%s%s&%s=%d", base_url, encoded_query,
-           page_param, page_value);
-  return url;
-}
-
-static struct curl_slist *build_request_headers(const char *host_header,
-                                                const char *referer) {
-  struct curl_slist *headers = NULL;
-  char host_buf[BUFFER_SIZE_MEDIUM], ref_buf[BUFFER_SIZE_MEDIUM];
-
-  snprintf(host_buf, sizeof(host_buf), "Host: %s", host_header);
-  snprintf(ref_buf, sizeof(ref_buf), "Referer: %s", referer);
-
-  headers = curl_slist_append(headers, host_buf);
-  headers = curl_slist_append(headers, ref_buf);
-  headers = curl_slist_append(
-      headers,
-      "Accept: "
-      "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
-  headers = curl_slist_append(headers, "Accept-Language: en-US,en;q=0.5");
-  headers = curl_slist_append(headers, "DNT: 1");
-
-  return headers;
-}
-
-static int check_cache_for_job(ScrapeJob *job) {
-  if (get_cache_ttl_search() <= 0) {
-    return 0;
-  }
 
   char *key = cache_compute_key(job->query, job->page, job->engine->name);
-  if (!key) {
+  if (!key)
     return 0;
-  }
 
   char *cached_data = NULL;
   size_t cached_size = 0;
@@ -414,27 +39,31 @@ static int check_cache_for_job(ScrapeJob *job) {
   return 0;
 }
 
-static void process_job_response(ScrapeJob *job, CURL *handle, CURLMsg *msg) {
-  if (msg->data.result == CURLE_OK && job->response.size > 0) {
-    char *key = cache_compute_key(job->query, job->page, job->engine->name);
-    if (key && get_cache_ttl_search() > 0) {
-      cache_set(key, job->response.memory, job->response.size);
-      free(key);
-    }
+void parse_and_cache_response(ScrapeJob *job) {
+  if (job->response.size == 0) {
+    job->results_count = 0;
+    return;
+  }
 
-    xmlDocPtr doc = htmlReadMemory(
-        job->response.memory, job->response.size, NULL, NULL,
-        HTML_PARSE_RECOVER | HTML_PARSE_NOERROR | HTML_PARSE_NOWARNING);
+  char *key = cache_compute_key(job->query, job->page, job->engine->name);
+  if (key && get_cache_ttl_search() > 0)
+    cache_set(key, job->response.memory, job->response.size);
+  free(key);
 
-    if (doc) {
-      job->results_count = job->engine->parser(
-          job->engine->name, doc, job->out_results, job->max_results);
-      xmlFreeDoc(doc);
-    }
+  xmlDocPtr doc = htmlReadMemory(
+      job->response.memory, job->response.size, NULL, NULL,
+      HTML_PARSE_RECOVER | HTML_PARSE_NOERROR | HTML_PARSE_NOWARNING);
+
+  if (doc) {
+    job->results_count = job->engine->parser(
+        job->engine->name, doc, job->out_results, job->max_results);
+    xmlFreeDoc(doc);
   } else {
     job->results_count = 0;
   }
+}
 
+void cleanup_job_handle(ScrapeJob *job, CURL *handle) {
   struct curl_slist *headers = NULL;
   curl_easy_getinfo(handle, CURLINFO_PRIVATE, &headers);
   if (headers)
@@ -444,67 +73,112 @@ static void process_job_response(ScrapeJob *job, CURL *handle, CURLMsg *msg) {
   job->response.memory = NULL;
 }
 
-int scrape_engines_parallel(ScrapeJob *jobs, int num_jobs) {
-  int retries = 0;
+void process_response(ScrapeJob *job, CURL *handle, CURLMsg *msg) {
+  if (msg->data.result == CURLE_OK)
+    parse_and_cache_response(job);
+  else
+    job->results_count = 0;
 
-retry:
-  CURLM *multi_handle = curl_multi_init();
-  if (!multi_handle) {
+  cleanup_job_handle(job, handle);
+}
+
+int setup_job(ScrapeJob *job, CURLM *multi_handle) {
+  if (job->handle)
+    curl_easy_cleanup(job->handle);
+  if (job->response.memory)
+    free(job->response.memory);
+
+  if (check_cache_for_job(job)) {
+    job->results_count = job->results_count > 0 ? job->results_count : 0;
+    return 0;
+  }
+
+  char *encoded_query = curl_easy_escape(NULL, job->query, 0);
+  if (!encoded_query)
+    return -1;
+
+  char *full_url =
+      build_search_url(job->engine->base_url, job->engine->page_param,
+                       job->engine->page_multiplier, job->engine->page_base,
+                       encoded_query, job->page);
+  free(encoded_query);
+
+  if (!full_url)
+    return -1;
+
+  job->handle = curl_easy_init();
+  if (!job->handle) {
+    free(full_url);
     return -1;
   }
 
-  for (int i = 0; i < num_jobs; i++) {
-    ScrapeJob *job = &jobs[i];
+  job->response.memory = (char *)malloc(INITIAL_BUFFER_SIZE);
+  job->response.size = 0;
+  job->response.capacity = INITIAL_BUFFER_SIZE;
 
-    if (job->handle) {
-      curl_easy_cleanup(job->handle);
-      job->handle = NULL;
-    }
-    if (job->response.memory) {
-      free(job->response.memory);
-    }
+  struct curl_slist *headers =
+      build_request_headers(job->engine->host_header, job->engine->referer);
 
-    if (check_cache_for_job(job)) {
-      job->results_count = job->results_count > 0 ? job->results_count : 0;
-      continue;
-    }
+  configure_curl_handle(job->handle, full_url, &job->response, headers);
+  curl_easy_setopt(job->handle, CURLOPT_PRIVATE, headers);
 
-    char *encoded_query = curl_easy_escape(NULL, job->query, 0);
-    if (!encoded_query) {
-      continue;
-    }
+  free(full_url);
+  curl_multi_add_handle(multi_handle, job->handle);
+  return 0;
+}
 
-    char *full_url =
-        build_search_url(job->engine->base_url, job->engine->page_param,
-                         job->engine->page_multiplier, job->engine->page_base,
-                         encoded_query, job->page);
-    free(encoded_query);
+int handle_responses(CURLM *multi_handle, ScrapeJob *jobs, int num_jobs) {
+  CURLMsg *msg;
+  int msgs_left;
 
-    if (!full_url) {
+  while ((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
+    if (msg->msg != CURLMSG_DONE)
       continue;
-    }
 
-    job->handle = curl_easy_init();
-    if (!job->handle) {
-      free(full_url);
-      continue;
+    CURL *handle = msg->easy_handle;
+
+    for (int i = 0; i < num_jobs; i++) {
+      if (jobs[i].handle && jobs[i].handle == handle) {
+        process_response(&jobs[i], handle, msg);
+        curl_multi_remove_handle(multi_handle, handle);
+        curl_easy_cleanup(handle);
+        jobs[i].handle = NULL;
+        break;
+      }
     }
+  }
 
-    job->response.memory = (char *)malloc(INITIAL_BUFFER_SIZE);
-    job->response.size = 0;
-    job->response.capacity = INITIAL_BUFFER_SIZE;
+  return 0;
+}
 
-    struct curl_slist *headers =
-        build_request_headers(job->engine->host_header, job->engine->referer);
+int should_retry(ScrapeJob *jobs, int num_jobs) {
+  if (proxy_count <= 0)
+    return 0;
 
-    configure_curl_handle(job->handle, full_url, &job->response, headers);
-    curl_easy_setopt(job->handle, CURLOPT_PRIVATE, headers);
+  for (int i = 0; i < num_jobs; i++) {
+    if (jobs[i].results_count == 0 && jobs[i].response.size == 0)
+      return 1;
+  }
+  return 0;
+}
 
-    free(full_url);
-    curl_multi_add_handle(multi_handle, job->handle);
+int scrape_engines_parallel(ScrapeJob *jobs, int num_jobs) {
+  int retries = 0;
+
+retry:
+  CURLM *multi_handle = curl_multi_init();
+  if (!multi_handle)
+    return -1;
+
+  for (int i = 0; i < num_jobs; i++) {
+    if (setup_job(&jobs[i], multi_handle) != 0 && jobs[i].handle) {
+      curl_multi_remove_handle(multi_handle, jobs[i].handle);
+      curl_easy_cleanup(jobs[i].handle);
+      jobs[i].handle = NULL;
+    }
   }
 
-  usleep(100000 + (rand() % 100000));
+  http_delay();
 
   int still_running = 0;
   curl_multi_perform(multi_handle, &still_running);
@@ -512,50 +186,17 @@ retry:
   do {
     int numfds = 0;
     CURLMcode mc = curl_multi_wait(multi_handle, NULL, 0, 1000, &numfds);
-
-    if (mc != CURLM_OK) {
+    if (mc != CURLM_OK)
       break;
-    }
-
     curl_multi_perform(multi_handle, &still_running);
   } while (still_running);
 
-  CURLMsg *msg;
-  int msgs_left;
-  while ((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
-    if (msg->msg == CURLMSG_DONE) {
-      CURL *handle = msg->easy_handle;
-
-      for (int i = 0; i < num_jobs; i++) {
-        if (jobs[i].handle && jobs[i].handle == handle) {
-          ScrapeJob *job = &jobs[i];
-
-          process_job_response(job, handle, msg);
-
-          curl_multi_remove_handle(multi_handle, handle);
-          if (handle)
-            curl_easy_cleanup(handle);
-          job->handle = NULL;
-          break;
-        }
-      }
-    }
-  }
-
+  handle_responses(multi_handle, jobs, num_jobs);
   curl_multi_cleanup(multi_handle);
 
-  if (retries < max_proxy_retries && proxy_count > 0) {
-    int any_failed = 0;
-    for (int i = 0; i < num_jobs; i++) {
-      if (jobs[i].results_count == 0 && jobs[i].response.size == 0) {
-        any_failed = 1;
-        break;
-      }
-    }
-    if (any_failed) {
-      retries++;
-      goto retry;
-    }
+  if (retries < max_proxy_retries && should_retry(jobs, num_jobs)) {
+    retries++;
+    goto retry;
   }
 
   return 0;

src/Scraping/Scraping.h

@@ -3,6 +3,7 @@
 
 #include <curl/curl.h>
 #include <libxml/HTMLparser.h>
+#include <libxml/xpath.h>
 
 typedef struct {
   char *url;
@@ -45,6 +46,25 @@ typedef struct {
 extern const SearchEngine ENGINE_REGISTRY[];
 extern const int ENGINE_COUNT;
 
+size_t write_memory_callback(void *contents, size_t size, size_t nmemb,
+                             void *userp);
+const char *get_random_user_agent(void);
+void configure_curl_handle(CURL *curl, const char *full_url,
+                           MemoryBuffer *chunk, struct curl_slist *headers);
+char *build_search_url(const char *base_url, const char *page_param,
+                       int page_multiplier, int page_base,
+                       const char *encoded_query, int page);
+struct curl_slist *build_request_headers(const char *host_header,
+                                         const char *referer);
+void http_delay(void);
+
+xmlXPathContextPtr create_xpath_context(xmlDocPtr doc);
+void free_xpath_objects(xmlXPathContextPtr ctx, xmlXPathObjectPtr obj);
+SearchResult *alloc_results_array(int capacity, int max_results);
+void assign_result(SearchResult *result, char *url, char *title, char *snippet,
+                   int unescape);
+void free_xml_node_list(char *title, char *url, char *snippet);
+
 int scrape_engine(const SearchEngine *engine, const char *query,
                   SearchResult **out_results, int max_results);
 

src/Scraping/ScrapingHttp.c

@@ -0,0 +1,109 @@
+#include "../Proxy/Proxy.h"
+#include "Config.h"
+#include "Scraping.h"
+#include <curl/curl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define HTTP_DELAY_MIN_US 100000
+#define HTTP_DELAY_RANGE_US 100000
+
+static const char *USER_AGENTS[] = {
+    "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, "
+    "like Gecko) Chrome/120.0.0.0 Safari/537.36",
+    "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 "
+    "(KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36",
+    "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like "
+    "Gecko) Chrome/120.0.0.0 Safari/537.36",
+    "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 "
+    "Firefox/121.0",
+    "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 "
+    "(KHTML, like Gecko) Version/17.2 Safari/605.1.15"};
+
+#define USER_AGENT_COUNT (sizeof(USER_AGENTS) / sizeof(USER_AGENTS[0]))
+
+size_t write_memory_callback(void *contents, size_t size, size_t nmemb,
+                             void *userp) {
+  size_t realsize = size * nmemb;
+  MemoryBuffer *mem = (MemoryBuffer *)userp;
+
+  if (mem->size + realsize + 1 > mem->capacity) {
+    size_t new_cap =
+        mem->capacity == 0 ? INITIAL_BUFFER_SIZE : mem->capacity * 2;
+    while (new_cap < mem->size + realsize + 1)
+      new_cap *= 2;
+
+    char *ptr = (char *)realloc(mem->memory, new_cap);
+    if (!ptr)
+      return 0;
+    mem->memory = ptr;
+    mem->capacity = new_cap;
+  }
+
+  memcpy(&(mem->memory[mem->size]), contents, realsize);
+  mem->size += realsize;
+  mem->memory[mem->size] = 0;
+
+  return realsize;
+}
+
+const char *get_random_user_agent(void) {
+  return USER_AGENTS[rand() % USER_AGENT_COUNT];
+}
+
+void configure_curl_handle(CURL *curl, const char *full_url,
+                           MemoryBuffer *chunk, struct curl_slist *headers) {
+  curl_easy_setopt(curl, CURLOPT_URL, full_url);
+  curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
+  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_memory_callback);
+  curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)chunk);
+  curl_easy_setopt(curl, CURLOPT_USERAGENT, get_random_user_agent());
+
+  curl_easy_setopt(curl, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
+  curl_easy_setopt(curl, CURLOPT_ACCEPT_ENCODING, "");
+  curl_easy_setopt(curl, CURLOPT_DNS_CACHE_TIMEOUT, CURL_DNS_TIMEOUT_SECS);
+  curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+  curl_easy_setopt(curl, CURLOPT_TIMEOUT, CURL_TIMEOUT_SECS);
+  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
+  curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "");
+
+  apply_proxy_settings(curl);
+}
+
+char *build_search_url(const char *base_url, const char *page_param,
+                       int page_multiplier, int page_base,
+                       const char *encoded_query, int page) {
+  int page_value = (page < 1 ? 1 : page - 1) * page_multiplier + page_base;
+  char *url = malloc(BUFFER_SIZE_LARGE);
+  if (!url)
+    return NULL;
+  snprintf(url, BUFFER_SIZE_LARGE, "%s%s&%s=%d", base_url, encoded_query,
+           page_param, page_value);
+  return url;
+}
+
+struct curl_slist *build_request_headers(const char *host_header,
+                                         const char *referer) {
+  struct curl_slist *headers = NULL;
+  char host_buf[BUFFER_SIZE_MEDIUM], ref_buf[BUFFER_SIZE_MEDIUM];
+
+  snprintf(host_buf, sizeof(host_buf), "Host: %s", host_header);
+  snprintf(ref_buf, sizeof(ref_buf), "Referer: %s", referer);
+
+  headers = curl_slist_append(headers, host_buf);
+  headers = curl_slist_append(headers, ref_buf);
+  headers = curl_slist_append(
+      headers,
+      "Accept: "
+      "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
+  headers = curl_slist_append(headers, "Accept-Language: en-US,en;q=0.5");
+  headers = curl_slist_append(headers, "DNT: 1");
+
+  return headers;
+}
+
+void http_delay(void) {
+  usleep(HTTP_DELAY_MIN_US + (rand() % HTTP_DELAY_RANGE_US));
+}

src/Scraping/ScrapingParsers.c

@@ -0,0 +1,269 @@
+#include "../Utility/Unescape.h"
+#include "../Utility/XmlHelper.h"
+#include "Config.h"
+#include "Scraping.h"
+#include <libxml/HTMLparser.h>
+#include <libxml/xpath.h>
+#include <stdlib.h>
+#include <string.h>
+
+xmlXPathContextPtr create_xpath_context(xmlDocPtr doc) {
+  return xmlXPathNewContext(doc);
+}
+
+void free_xpath_objects(xmlXPathContextPtr ctx, xmlXPathObjectPtr obj) {
+  if (obj)
+    xmlXPathFreeObject(obj);
+  if (ctx)
+    xmlXPathFreeContext(ctx);
+}
+
+SearchResult *alloc_results_array(int capacity, int max_results) {
+  int count = capacity < max_results ? capacity : max_results;
+  return xml_result_alloc(capacity, count);
+}
+
+void assign_result(SearchResult *result, char *url, char *title, char *snippet,
+                   int unescape) {
+  result->url = unescape ? unescape_search_url(url) : strdup(url ? url : "");
+  result->title = strdup(title ? title : "No Title");
+  result->snippet = strdup(snippet ? snippet : "");
+}
+
+void free_xml_node_list(char *title, char *url, char *snippet) {
+  if (title)
+    xmlFree(title);
+  if (url)
+    xmlFree(url);
+  if (snippet)
+    xmlFree(snippet);
+}
+
+static int parse_ddg_lite(const char *engine_name, xmlDocPtr doc,
+                          SearchResult **out_results, int max_results) {
+  (void)engine_name;
+  int found_count = 0;
+
+  xmlXPathContextPtr ctx = create_xpath_context(doc);
+  if (!ctx)
+    return 0;
+
+  xmlXPathObjectPtr obj =
+      xml_xpath_eval(ctx, "//tr[not(contains(@class, "
+                          "'result-sponsored'))]//a[@class='result-link']");
+
+  if (!obj || !obj->nodesetval || obj->nodesetval->nodeNr == 0) {
+    free_xpath_objects(ctx, obj);
+    return 0;
+  }
+
+  int num_links = obj->nodesetval->nodeNr;
+  *out_results = alloc_results_array(num_links, max_results);
+  if (!*out_results) {
+    free_xpath_objects(ctx, obj);
+    return 0;
+  }
+
+  for (int i = 0; i < num_links && found_count < max_results; i++) {
+    xmlNodePtr link_node = obj->nodesetval->nodeTab[i];
+    char *title = xml_node_content(link_node);
+    char *url = (char *)xmlGetProp(link_node, (xmlChar *)"href");
+    char *snippet_text = NULL;
+
+    xmlNodePtr current = link_node->parent;
+    while (current && xmlStrcasecmp(current->name, (const xmlChar *)"tr") != 0)
+      current = current->parent;
+
+    if (current && current->next) {
+      xmlNodePtr snippet_row = current->next;
+      while (snippet_row &&
+             xmlStrcasecmp(snippet_row->name, (const xmlChar *)"tr") != 0)
+        snippet_row = snippet_row->next;
+      if (snippet_row) {
+        ctx->node = snippet_row;
+        xmlXPathObjectPtr s_obj =
+            xml_xpath_eval(ctx, ".//td[@class='result-snippet']");
+        if (s_obj && s_obj->nodesetval && s_obj->nodesetval->nodeNr > 0)
+          snippet_text = xml_node_content(s_obj->nodesetval->nodeTab[0]);
+        if (s_obj)
+          xmlXPathFreeObject(s_obj);
+        ctx->node = NULL;
+      }
+    }
+
+    assign_result(&(*out_results)[found_count], url, title, snippet_text, 1);
+    free_xml_node_list(title, url, snippet_text);
+    found_count++;
+  }
+
+  free_xpath_objects(ctx, obj);
+  return found_count;
+}
+
+static int parse_startpage(const char *engine_name, xmlDocPtr doc,
+                           SearchResult **out_results, int max_results) {
+  (void)engine_name;
+  int found_count = 0;
+
+  xmlXPathContextPtr ctx = create_xpath_context(doc);
+  if (!ctx)
+    return 0;
+
+  xmlXPathObjectPtr obj =
+      xml_xpath_eval(ctx, "//div[contains(@class, 'result')]");
+
+  if (!obj || !obj->nodesetval || obj->nodesetval->nodeNr == 0) {
+    free_xpath_objects(ctx, obj);
+    return 0;
+  }
+
+  int num_results = obj->nodesetval->nodeNr;
+  *out_results = alloc_results_array(num_results, max_results);
+  if (!*out_results) {
+    free_xpath_objects(ctx, obj);
+    return 0;
+  }
+
+  for (int i = 0; i < num_results && found_count < max_results; i++) {
+    xmlNodePtr result_node = obj->nodesetval->nodeTab[i];
+    ctx->node = result_node;
+
+    xmlXPathObjectPtr link_obj =
+        xml_xpath_eval(ctx, ".//a[contains(@class, 'result-link')]");
+    char *url =
+        (link_obj && link_obj->nodesetval && link_obj->nodesetval->nodeNr > 0)
+            ? (char *)xmlGetProp(link_obj->nodesetval->nodeTab[0],
+                                 (xmlChar *)"href")
+            : NULL;
+
+    xmlXPathObjectPtr title_obj =
+        xml_xpath_eval(ctx, ".//h2[contains(@class, 'wgl-title')]");
+    char *title = (title_obj && title_obj->nodesetval &&
+                   title_obj->nodesetval->nodeNr > 0)
+                      ? xml_node_content(title_obj->nodesetval->nodeTab[0])
+                      : NULL;
+
+    xmlXPathObjectPtr snippet_obj =
+        xml_xpath_eval(ctx, ".//p[contains(@class, 'description')]");
+    char *snippet_text =
+        (snippet_obj && snippet_obj->nodesetval &&
+         snippet_obj->nodesetval->nodeNr > 0)
+            ? xml_node_content(snippet_obj->nodesetval->nodeTab[0])
+            : NULL;
+
+    if (url && title) {
+      assign_result(&(*out_results)[found_count], url, title, snippet_text, 0);
+      found_count++;
+    }
+
+    free_xml_node_list(title, url, snippet_text);
+    if (link_obj)
+      xmlXPathFreeObject(link_obj);
+    if (title_obj)
+      xmlXPathFreeObject(title_obj);
+    if (snippet_obj)
+      xmlXPathFreeObject(snippet_obj);
+  }
+
+  ctx->node = NULL;
+  free_xpath_objects(ctx, obj);
+  return found_count;
+}
+
+static int parse_yahoo(const char *engine_name, xmlDocPtr doc,
+                       SearchResult **out_results, int max_results) {
+  (void)engine_name;
+  int found_count = 0;
+
+  xmlXPathContextPtr ctx = create_xpath_context(doc);
+  if (!ctx)
+    return 0;
+
+  xmlXPathObjectPtr obj =
+      xml_xpath_eval(ctx, "//div[contains(@class, 'algo-sr')]");
+
+  if (!obj || !obj->nodesetval || obj->nodesetval->nodeNr == 0) {
+    free_xpath_objects(ctx, obj);
+    return 0;
+  }
+
+  int num_results = obj->nodesetval->nodeNr;
+  *out_results = alloc_results_array(num_results, max_results);
+  if (!*out_results) {
+    free_xpath_objects(ctx, obj);
+    return 0;
+  }
+
+  for (int i = 0; i < num_results && found_count < max_results; i++) {
+    xmlNodePtr result_node = obj->nodesetval->nodeTab[i];
+    ctx->node = result_node;
+
+    xmlXPathObjectPtr link_obj = xml_xpath_eval(
+        ctx, ".//div[contains(@class, 'compTitle')]//a[@target='_blank']");
+    char *url =
+        (link_obj && link_obj->nodesetval && link_obj->nodesetval->nodeNr > 0)
+            ? (char *)xmlGetProp(link_obj->nodesetval->nodeTab[0],
+                                 (xmlChar *)"href")
+            : NULL;
+
+    xmlXPathObjectPtr title_obj =
+        xml_xpath_eval(ctx, ".//h3[contains(@class, 'title')]");
+    char *title = (title_obj && title_obj->nodesetval &&
+                   title_obj->nodesetval->nodeNr > 0)
+                      ? xml_node_content(title_obj->nodesetval->nodeTab[0])
+                      : NULL;
+
+    xmlXPathObjectPtr snippet_obj =
+        xml_xpath_eval(ctx, ".//div[contains(@class, 'compText')]//p");
+    char *snippet_text =
+        (snippet_obj && snippet_obj->nodesetval &&
+         snippet_obj->nodesetval->nodeNr > 0)
+            ? xml_node_content(snippet_obj->nodesetval->nodeTab[0])
+            : NULL;
+
+    if (url && title) {
+      assign_result(&(*out_results)[found_count], url, title, snippet_text, 1);
+      found_count++;
+    }
+
+    free_xml_node_list(title, url, snippet_text);
+    if (link_obj)
+      xmlXPathFreeObject(link_obj);
+    if (title_obj)
+      xmlXPathFreeObject(title_obj);
+    if (snippet_obj)
+      xmlXPathFreeObject(snippet_obj);
+  }
+
+  ctx->node = NULL;
+  free_xpath_objects(ctx, obj);
+  return found_count;
+}
+
+const SearchEngine ENGINE_REGISTRY[] = {
+    {.name = "DuckDuckGo Lite",
+     .base_url = "https://lite.duckduckgo.com/lite/?q=",
+     .host_header = "lite.duckduckgo.com",
+     .referer = "https://lite.duckduckgo.com/",
+     .page_param = "s",
+     .page_multiplier = 30,
+     .page_base = 0,
+     .parser = parse_ddg_lite},
+    {.name = "Startpage",
+     .base_url = "https://www.startpage.com/sp/search?q=",
+     .host_header = "www.startpage.com",
+     .referer = "https://www.startpage.com/",
+     .page_param = "page",
+     .page_multiplier = 1,
+     .page_base = 1,
+     .parser = parse_startpage},
+    {.name = "Yahoo",
+     .base_url = "https://search.yahoo.com/search?p=",
+     .host_header = "search.yahoo.com",
+     .referer = "https://search.yahoo.com/",
+     .page_param = "b",
+     .page_multiplier = 10,
+     .page_base = 1,
+     .parser = parse_yahoo}};
+
+const int ENGINE_COUNT = sizeof(ENGINE_REGISTRY) / sizeof(SearchEngine);