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

compiled/String.h

+#ifndef ADBLOCK_PLUS_STRING_H
+#define ADBLOCK_PLUS_STRING_H
+
+#include <cstddef>
+#include <cstring>
+#include <algorithm>
+
+#include "debug.h"
+
+inline void String_assert_readonly(bool readOnly);
+
+class String
+{
+public:
+  typedef char16_t value_type;
+  typedef size_t size_type;
+
+  // Type flags, stored in the top 2 bits of the mLen member
+  static constexpr size_type OWNBUFFER = 0xC0000000;
+  static constexpr size_type INVALID = 0x80000000;
+  static constexpr size_type DELETED = 0x40000000;
+  static constexpr size_type DEPENDENT = 0x00000000;
+
+  // Read-only flag (for debug asserts only)
+  static constexpr size_type READ_ONLY = 0x20000000;
+  static constexpr size_type READ_WRITE = 0x00000000;
+
+  static constexpr size_type FLAGS_MASK = 0xE0000000;
+  static constexpr size_type LENGTH_MASK = 0x1FFFFFFF;
+
+  static constexpr size_type npos = -1;
+
+private:
+  value_type* mBuf;
+  size_type mLen;
+
+  value_type* allocate(size_type len)
+  {
+    if (len)
+      return new value_type[len];
+    else
+      return nullptr;
+  }
+
+  void resize(size_type newLength, bool copy)
+  {
+    bool owningOldBuffer = owns_buffer();
+    size_type oldLength = length();
+    value_type* oldBuffer = mBuf;
+
+    newLength &= LENGTH_MASK;
+    mBuf = allocate(newLength);
+    annotate_address(mBuf, "String");
+    mLen = OWNBUFFER | READ_WRITE | newLength;
+
+    if (copy && oldLength)
+      memcpy(mBuf, oldBuffer, sizeof(value_type) * std::min(oldLength, newLength));
+    if (owningOldBuffer)
+      delete[] oldBuffer;
+  }
+
+public:
+  String() : mBuf(nullptr), mLen(INVALID) {}
+
+  String(size_type len)
+      : mBuf(allocate(len & LENGTH_MASK)),
+        mLen(OWNBUFFER | READ_WRITE | (len & LENGTH_MASK))
+  {
+    annotate_address(mBuf, "String");
+  }
+
+  String(value_type* buf, size_type len)
+      : mBuf(buf), mLen(DEPENDENT | READ_WRITE | (buf ? len & LENGTH_MASK: 0))
+  {
+  }
+
+  String(const value_type* buf, size_type len)
+      : mBuf(const_cast<value_type*>(buf)),
+        mLen(DEPENDENT | READ_ONLY | (buf ? len & LENGTH_MASK: 0))
+  {
+  }
+
+  String(String& str, size_type pos = 0, size_type len = npos)
+      : mBuf(str.mBuf + std::min(pos, str.length())),
+        mLen(DEPENDENT | READ_WRITE | std::min(len, str.length() - (mBuf - str.mBuf)))
+  {
+  }
+
+  String(const String& str, size_type pos = 0, size_type len = npos)
+      : mBuf(str.mBuf + std::min(pos, str.length())),
+        mLen(DEPENDENT | READ_ONLY | std::min(len, str.length() - (mBuf - str.mBuf)))
+  {
+  }
+
+  String(String&& str)
+  {
+    *this = std::move(str);
+  }
+
+  String(const char* source, size_type len)
+      : String(len)
+  {
+    for (size_type i = 0; i < len; i++)
+      mBuf[i] = source[i];
+  }
+
+  String& operator=(const String& str)
+  {
+    reset(str);
+    return *this;
+  }
+
+  String& operator=(String& str)
+  {
+    reset(str);
+    return *this;
+  }
+
+  String& operator=(String&& str)
+  {
+    mBuf = str.mBuf;
+    mLen = str.mLen;
+    str.mBuf = nullptr;
+    str.mLen = INVALID;
+    return *this;
+  }
+
+  ~String()
+  {
+    if (owns_buffer())
+      delete[] mBuf;
+  }
+
+  void reset(value_type* buf, size_type len)
+  {
+    mBuf = buf;
+    mLen = (DEPENDENT | READ_WRITE | (buf ? len & LENGTH_MASK: 0));
+  }
+
+  void reset(const value_type* buf, size_type len)
+  {
+    mBuf = const_cast<value_type*>(buf);
+    mLen = (DEPENDENT | READ_ONLY | (buf ? len & LENGTH_MASK: 0));
+  }
+
+  void reset(String& str, size_type pos = 0, size_type len = npos)
+  {
+    pos = std::min(pos, str.length());
+    len = std::min(len, str.length() - pos);
+    reset(str.mBuf + pos, len);
+  }
+
+  void reset(const String& str, size_type pos = 0, size_type len = npos)
+  {
+    pos = std::min(pos, str.length());
+    len = std::min(len, str.length() - pos);
+    reset(const_cast<const value_type*>(str.mBuf + pos), len);
+  }
+
+  size_type length() const
+  {
+    return mLen & LENGTH_MASK;
+  }
+
+  bool empty() const
+  {
+    return !(mLen & LENGTH_MASK);
+  }
+
+  const value_type* data() const
+  {
+    return mBuf;
+  }
+
+  value_type* data()
+  {
+    String_assert_readonly(mLen & READ_ONLY);
+    return mBuf;
+  }
+
+  const value_type& operator[](size_type pos) const
+  {
+    return mBuf[pos];
+  }
+
+  value_type& operator[](size_type pos)
+  {
+    String_assert_readonly(mLen & READ_ONLY);
+    return mBuf[pos];
+  }
+
+  bool equals(const String& other) const
+  {
+    if (length() != other.length())
+      return false;
+
+    return memcmp(mBuf, other.mBuf, sizeof(value_type) * length()) == 0;
+  }
+
+  size_type find(value_type c, size_type pos = 0) const
+  {
+    for (size_type i = pos; i < length(); ++i)
+      if (mBuf[i] == c)
+        return i;
+    return npos;
+  }
+
+  size_type find(const String& str, size_type pos = 0) const
+  {
+    if (!str.length())
+      return pos;
+
+    if (length() - pos < str.length())
+      return npos;
+
+    for (; pos < length() - str.length(); ++pos)
+    {
+      if (mBuf[pos] == str[0] &&
+          memcmp(mBuf + pos, str.mBuf, sizeof(value_type) * str.length()) == 0)
+      {
+        return pos;
+      }
+    }
+
+    return npos;
+  }
+
+  size_type rfind(value_type c, size_type pos = npos) const
+  {
+    if (length() == 0)
+      return npos;
+
+    if (pos == npos)
+      pos = length() - 1;
+
+    for (int i = pos; i >= 0; --i)
+      if (mBuf[i] == c)
+        return i;
+    return npos;
+  }
+
+  void append(const value_type* source, size_type sourceLen)
+  {
+    if (!sourceLen)
+      return;
+
+    size_t oldLength = length();
+    resize(oldLength + sourceLen, true);
+    memcpy(mBuf + oldLength, source, sizeof(value_type) * sourceLen);
+  }
+
+  void append(const String& str)
+  {
+    append(str.mBuf, str.length());
+  }
+
+  void append(value_type c)
+  {
+    append(&c, 1);
+  }
+
+  bool owns_buffer() const
+  {
+    return mBuf && (mLen & FLAGS_MASK) == OWNBUFFER;
+  }
+
+  String& ensure_own_buffer()
+  {
+    size_type len = length();
+    if (len && !owns_buffer())
+      resize(len, true);
+    return *this;
+  }
+
+  bool is_dependent() const
+  {
+    return (mLen & FLAGS_MASK) == DEPENDENT;
+  }
+
+  bool is_invalid() const
+  {
+    return (mLen & FLAGS_MASK) == INVALID;
+  }
+
+  bool is_deleted() const
+  {
+    return (mLen & FLAGS_MASK) == DELETED;
+  }
+};
+
+inline String operator "" _str(const String::value_type* str,
+    String::size_type len)
+{
+  return String(const_cast<String::value_type*>(str), len);
+}
+
+inline void String_assert_readonly(bool readOnly)
+{
+  assert(!readOnly, u"Writing access to a read-only string"_str);
+}
+
+#endif