Implemented curl support for web requests

src/WebRequest.cpp

 #include <AdblockPlus/WebRequest.h>
 
 AdblockPlus::WebRequest::~WebRequest()
 {
 }
+
+#if defined(HAVE_CURL)
+
+#include <sstream>
+#include <cctype>
+#include <algorithm>
+#include <curl/curl.h>
+
+namespace
+{
+  struct HeaderData
+  {
+    int status;
+    bool expectingStatus;
+    std::vector<std::string> headers;
+
+    HeaderData()
+    {
+      status = 0;
+      expectingStatus = true;
+    }
+  };
+
+  unsigned int ConvertErrorCode(CURLcode code)
+  {
+    switch (code)
+    {
+      case CURLE_OK:
+        return NS_OK;
+      case CURLE_FAILED_INIT:
+        return NS_ERROR_NOT_INITIALIZED;
+      case CURLE_UNSUPPORTED_PROTOCOL:
+        return NS_ERROR_UNKNOWN_PROTOCOL;
+      case CURLE_URL_MALFORMAT:
+        return NS_ERROR_MALFORMED_URI;
+      case CURLE_COULDNT_RESOLVE_PROXY:
+        return NS_ERROR_UNKNOWN_PROXY_HOST;
+      case CURLE_COULDNT_RESOLVE_HOST:
+        return NS_ERROR_UNKNOWN_HOST;
+      case CURLE_COULDNT_CONNECT:
+        return NS_ERROR_CONNECTION_REFUSED;
+      case CURLE_OUT_OF_MEMORY:
+        return NS_ERROR_OUT_OF_MEMORY;
+      case CURLE_OPERATION_TIMEDOUT:
+        return NS_ERROR_NET_TIMEOUT;
+      case CURLE_TOO_MANY_REDIRECTS:
+        return NS_ERROR_REDIRECT_LOOP;
+      case CURLE_GOT_NOTHING:
+        return NS_ERROR_NO_CONTENT;
+      case CURLE_SEND_ERROR:
+        return NS_ERROR_NET_RESET;
+      case CURLE_RECV_ERROR:
+        return NS_ERROR_NET_RESET;
+      default:
+        return NS_CUSTOM_ERROR_BASE + code;
+    }
+  }
+
+  size_t ReceiveData(char* ptr, size_t size, size_t nmemb, void* userdata)
+  {
+    std::stringstream* stream = static_cast<std::stringstream*>(userdata);
+    stream->write(ptr, size * nmemb);
+    return nmemb;
+  }
+
+  size_t ReceiveHeader(char* ptr, size_t size, size_t nmemb, void* userdata)
+  {
+    HeaderData* data = static_cast<HeaderData*>(userdata);
+    std::string header(ptr, size * nmemb);
+    if (data->expectingStatus)
+    {
+      // Parse the status code out of something like "HTTP/1.1 200 OK"

[Felix Dahlke, 2013/04/12 03:53:50]

I think using std::tr1::regex would be preferable.

[Wladimir Palant, 2013/04/12 13:39:32]

See http://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.tr1 -
gcc didn't implement it. The headers are there but linking fails.

+      const std::string prefix("HTTP/1.");
+      size_t prefixLen = prefix.length();
+      if (header.length() >= prefixLen + 2 && !header.compare(0, prefixLen, prefix) &&
+          isdigit(header[prefixLen]) && isspace(header[prefixLen + 1]))
+      {
+        size_t statusStart = prefixLen + 2;
+        while (statusStart < header.length() && isspace(header[statusStart]))
+          statusStart++;
+
+        size_t statusEnd = statusStart;
+        while (statusEnd < header.length() && isdigit(header[statusEnd]))
+          statusEnd++;
+
+        if (statusEnd > statusStart && statusEnd < header.length() &&
+            isspace(header[statusEnd]))
+        {
+          std::istringstream(header.substr(statusStart, statusEnd - statusStart)) >> data->status;
+          data->headers.clear();
+          data->expectingStatus = false;
+        }
+      }
+    }
+    else
+    {
+      size_t headerEnd = header.length();
+      while (headerEnd > 0 && isspace(header[headerEnd - 1]))
+        headerEnd--;
+
+      if (headerEnd)
+        data->headers.push_back(header.substr(0, headerEnd));
+      else
+        data->expectingStatus = true;
+    }
+    return nmemb;
+  }
+}
+
+AdblockPlus::ServerResponse AdblockPlus::DefaultWebRequest::GET(
+    const std::string& url, const HeaderList& requestHeaders) const
+{
+  AdblockPlus::ServerResponse result;
+  result.status = NS_ERROR_NOT_INITIALIZED;
+  result.responseStatus = 0;
+
+  CURL *curl = curl_easy_init();
+  if (curl)
+  {
+    std::stringstream responseText;
+    HeaderData headerData;
+    curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
+    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, ReceiveData);
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &responseText);
+    curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, ReceiveHeader);
+    curl_easy_setopt(curl, CURLOPT_HEADERDATA, &headerData);
+
+    struct curl_slist* headerList = 0;
+    for (HeaderList::const_iterator it = requestHeaders.begin();
+      it != requestHeaders.end(); ++it)
+    {
+      curl_slist_append(headerList, (it->first + ": " + it->second).c_str());

[Felix Dahlke, 2013/04/12 03:53:50]

According to the documentation, I think this should be headerList =
curl_slist_append(...), otherwise headerList would always be 0

+    }
+    if (headerList)
+      curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerList);
+
+    result.status = ConvertErrorCode(curl_easy_perform(curl));
+    result.responseStatus = headerData.status;
+    result.responseText = responseText.str();
+    for (std::vector<std::string>::iterator it = headerData.headers.begin();
+        it != headerData.headers.end(); ++it)
+    {
+      // Parse header name and value out of something like "Foo: bar"

[Felix Dahlke, 2013/04/12 03:53:50]

I'd vote for std::tr1::regex here as well.

+      std::string header = *it;
+      size_t colonPos = header.find(':');
+      if (colonPos != std::string::npos)
+      {
+        size_t nameStart = 0;
+        size_t nameEnd = colonPos;
+        while (nameEnd > nameStart && isspace(header[nameEnd - 1]))
+          nameEnd--;
+
+        size_t valueStart = colonPos + 1;
+        while (valueStart < header.length() && isspace(header[valueStart]))
+          valueStart++;
+        size_t valueEnd = header.length();
+
+        if (nameEnd > nameStart && valueEnd > valueStart)
+        {
+          std::string name = header.substr(nameStart, nameEnd - nameStart);
+          std::transform(name.begin(), name.end(), name.begin(), ::tolower);
+          std::string value = header.substr(valueStart, valueEnd - valueStart);
+          result.responseHeaders.push_back(std::pair<std::string, std::string>(
+              name, value));
+        }
+      }
+    }
+
+    if (headerList)
+      curl_slist_free_all(headerList);
+    curl_easy_cleanup(curl);
+  }
+  return result;
+}
+#else
+AdblockPlus::ServerResponse AdblockPlus::DefaultWebRequest::GET(
+    const std::string& url, const HeaderList& requestHeaders) const
+{
+  AdblockPlus::ServerResponse result;
+  result.status = NS_ERROR_FAILURE;
+  result.responseStatus = 0;
+  return result;
+}
+#endif