Issue 4125 - [emscripten] Convert filter classes to C++

compiled/ElemHideBase.cpp

+#include "ElemHideBase.h"
+#include "ElemHideFilter.h"
+#include "ElemHideException.h"
+#include "CSSPropertyFilter.h"
+#include "InvalidFilter.h"
+#include "StringScanner.h"
+
+ElemHideBase::ElemHideBase(const std::u16string& text,
+    const std::u16string& domains, const std::u16string& selector)
+    : ActiveFilter(text, false), selector(selector)
+{
+  if (!domains.empty())
+    ParseDomains(domains, u',');
+}
+
+Filter::Type ElemHideBase::Parse(const std::u16string& text, size_t* domainsEnd,
+    size_t* selectorStart, size_t* prefixEnd, size_t* regexpStart,
+    size_t* regexpEnd, size_t* suffixStart)
+{
+  StringScanner scanner(text);
+
+  // Domains part
+  loop:
+  while (!scanner.done())
+  {
+    char16_t next = scanner.next();
+    if (next == u'#')
+    {
+      *domainsEnd = scanner.position();
+      break;
+    }
+
+    switch (next)
+    {
+      case u'/':
+      case u'*':
+      case u'|':
+      case u'@':
+      case u'"':
+      case u'!':
+        return Type::UNKNOWN;
+    }
+  }
+
+  bool exception = false;
+  char16_t next = scanner.next();
+  if (next == u'@')
+  {
+    exception = true;
+    next = scanner.next();
+  }
+
+  if (next != u'#')
+    return Type::UNKNOWN;
+
+  // Selector part
+
+  // Selector shouldn't be empty
+  if (scanner.done())
+    return Type::UNKNOWN;
+
+  *selectorStart = scanner.position() + 1;
+  while (!scanner.done())
+  {
+    switch (scanner.next())
+    {
+      case u'{':
+      case u'}':
+        return Type::UNKNOWN;
+    }
+  }
+
+  if (exception)
+    return Type::ELEMHIDEEXCEPTION;
+
+  do
+  {
+    // Is this a CSS property rule maybe?
+    if (!prefixEnd)
+    {
+      // Caller doesn't care
+      break;
+    }
+
+    const std::u16string searchString(u"[-abp-properties=");
+    *prefixEnd = text.find(searchString, *selectorStart);
+    if (*prefixEnd == text.npos ||
+        *prefixEnd + searchString.length() + 1 >= text.length())
+    {
+      break;
+    }
+
+    *regexpStart = *prefixEnd + searchString.length() + 1;
+    char16_t quotation = text[*regexpStart - 1];
+    if (quotation != u'\'' && quotation != u'"')
+      break;
+
+    *regexpEnd = text.find(quotation, *regexpStart);
+    if (*regexpEnd == text.npos || *regexpEnd + 1 >= text.length() ||
+      text[*regexpEnd + 1] != u']')
+    {
+      break;
+    }
+
+    *suffixStart = *regexpEnd + 2;
+    return Type::CSSPROPERTY;
+  } while (false);
+
+  return Type::ELEMHIDE;
+}
+
+Filter* ElemHideBase::Create(const std::u16string& text)
+{
+  size_t domainsEnd;
+  size_t selectorStart;
+  size_t prefixEnd;
+  size_t regexpStart;
+  size_t regexpEnd;
+  size_t suffixStart;
+  Type type = Parse(text, &domainsEnd, &selectorStart, &prefixEnd, &regexpStart,
+      &regexpEnd, &suffixStart);
+  if (type == Type::UNKNOWN)
+    return nullptr;
+
+  try
+  {
+    std::u16string domains(text.substr(0, domainsEnd));
+    std::u16string selector(text.substr(selectorStart));
+    if (type == Type::ELEMHIDEEXCEPTION)
+      return new ElemHideException(text, domains, selector);
+    else if (type == Type::CSSPROPERTY)
+    {
+      std::u16string prefix(text.substr(selectorStart, prefixEnd - selectorStart));
+      std::u16string regexpSource(text.substr(regexpStart, regexpEnd - regexpStart));
+      std::u16string suffix(text.substr(suffixStart));
+      return new CSSPropertyFilter(text, domains, selector, regexpSource, prefix,
+          suffix);
+    }
+    else
+      return new ElemHideFilter(text, domains, selector);
+  }
+  catch (const std::u16string& e)
+  {
+    return new InvalidFilter(text, e);
+  }
+}
+
+const std::u16string ElemHideBase::GetSelectorDomain() const
+{
+  std::u16string result;
+  for (auto it = domains.begin(); it != domains.end(); ++it)
+  {
+    if (it->second && !it->first.empty())
+    {
+      if (!result.empty())
+        result.append(u",");
+      result.append(it->first);
+    }
+  }
+  return result;
+}