import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

xpcom/string/nsCharTraits.h

@@ -0,0 +1,587 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsCharTraits_h___
+#define nsCharTraits_h___
+
+#include <ctype.h> // for |EOF|, |WEOF|
+#include <string.h> // for |memcpy|, et al
+
+#include "nscore.h" // for |char16_t|
+
+// This file may be used (through nsUTF8Utils.h) from non-XPCOM code, in
+// particular the standalone software updater. In that case stub out
+// the macros provided by nsDebug.h which are only usable when linking XPCOM
+
+#ifdef NS_NO_XPCOM
+#define NS_WARNING(msg)
+#define NS_ASSERTION(cond, msg)
+#define NS_ERROR(msg)
+#else
+#include "nsDebug.h"  // for NS_ASSERTION
+#endif
+
+/*
+ * Some macros for converting char16_t (UTF-16) to and from Unicode scalar
+ * values.
+ *
+ * Note that UTF-16 represents all Unicode scalar values up to U+10FFFF by
+ * using "surrogate pairs". These consist of a high surrogate, i.e. a code
+ * point in the range U+D800 - U+DBFF, and a low surrogate, i.e. a code point
+ * in the range U+DC00 - U+DFFF, like this:
+ *
+ *  U+D800 U+DC00 =  U+10000
+ *  U+D800 U+DC01 =  U+10001
+ *  ...
+ *  U+DBFF U+DFFE = U+10FFFE
+ *  U+DBFF U+DFFF = U+10FFFF
+ *
+ * These surrogate code points U+D800 - U+DFFF are not themselves valid Unicode
+ * scalar values and are not well-formed UTF-16 except as high-surrogate /
+ * low-surrogate pairs.
+ */
+
+#define PLANE1_BASE          uint32_t(0x00010000)
+// High surrogates are in the range 0xD800 -- OxDBFF
+#define NS_IS_HIGH_SURROGATE(u) ((uint32_t(u) & 0xFFFFFC00) == 0xD800)
+// Low surrogates are in the range 0xDC00 -- 0xDFFF
+#define NS_IS_LOW_SURROGATE(u)  ((uint32_t(u) & 0xFFFFFC00) == 0xDC00)
+// Faster than testing NS_IS_HIGH_SURROGATE || NS_IS_LOW_SURROGATE
+#define IS_SURROGATE(u)      ((uint32_t(u) & 0xFFFFF800) == 0xD800)
+
+// Everything else is not a surrogate: 0x000 -- 0xD7FF, 0xE000 -- 0xFFFF
+
+// N = (H - 0xD800) * 0x400 + 0x10000 + (L - 0xDC00)
+// I wonder whether we could somehow assert that H is a high surrogate
+// and L is a low surrogate
+#define SURROGATE_TO_UCS4(h, l) (((uint32_t(h) & 0x03FF) << 10) + \
+                                 (uint32_t(l) & 0x03FF) + PLANE1_BASE)
+
+// Extract surrogates from a UCS4 char
+// Reference: the Unicode standard 4.0, section 3.9
+// Since (c - 0x10000) >> 10 == (c >> 10) - 0x0080 and
+// 0xD7C0 == 0xD800 - 0x0080,
+// ((c - 0x10000) >> 10) + 0xD800 can be simplified to
+#define H_SURROGATE(c) char16_t(char16_t(uint32_t(c) >> 10) + \
+                                char16_t(0xD7C0))
+// where it's to be noted that 0xD7C0 is not bitwise-OR'd
+// but added.
+
+// Since 0x10000 & 0x03FF == 0,
+// (c - 0x10000) & 0x03FF == c & 0x03FF so that
+// ((c - 0x10000) & 0x03FF) | 0xDC00 is equivalent to
+#define L_SURROGATE(c) char16_t(char16_t(uint32_t(c) & uint32_t(0x03FF)) | \
+                                 char16_t(0xDC00))
+
+#define IS_IN_BMP(ucs) (uint32_t(ucs) < PLANE1_BASE)
+#define UCS2_REPLACEMENT_CHAR char16_t(0xFFFD)
+
+#define UCS_END uint32_t(0x00110000)
+#define IS_VALID_CHAR(c) ((uint32_t(c) < UCS_END) && !IS_SURROGATE(c))
+#define ENSURE_VALID_CHAR(c) (IS_VALID_CHAR(c) ? (c) : UCS2_REPLACEMENT_CHAR)
+
+template <class CharT>
+struct nsCharTraits
+{
+};
+
+template <>
+struct nsCharTraits<char16_t>
+{
+  typedef char16_t char_type;
+  typedef uint16_t  unsigned_char_type;
+  typedef char      incompatible_char_type;
+
+  static char_type* const sEmptyBuffer;
+
+  static void
+  assign(char_type& aLhs, char_type aRhs)
+  {
+    aLhs = aRhs;
+  }
+
+
+  // integer representation of characters:
+  typedef int int_type;
+
+  static char_type
+  to_char_type(int_type aChar)
+  {
+    return char_type(aChar);
+  }
+
+  static int_type
+  to_int_type(char_type aChar)
+  {
+    return int_type(static_cast<unsigned_char_type>(aChar));
+  }
+
+  static bool
+  eq_int_type(int_type aLhs, int_type aRhs)
+  {
+    return aLhs == aRhs;
+  }
+
+
+  // |char_type| comparisons:
+
+  static bool
+  eq(char_type aLhs, char_type aRhs)
+  {
+    return aLhs == aRhs;
+  }
+
+  static bool
+  lt(char_type aLhs, char_type aRhs)
+  {
+    return aLhs < aRhs;
+  }
+
+
+  // operations on s[n] arrays:
+
+  static char_type*
+  move(char_type* aStr1, const char_type* aStr2, size_t aN)
+  {
+    return static_cast<char_type*>(memmove(aStr1, aStr2,
+                                           aN * sizeof(char_type)));
+  }
+
+  static char_type*
+  copy(char_type* aStr1, const char_type* aStr2, size_t aN)
+  {
+    return static_cast<char_type*>(memcpy(aStr1, aStr2,
+                                          aN * sizeof(char_type)));
+  }
+
+  static char_type*
+  copyASCII(char_type* aStr1, const char* aStr2, size_t aN)
+  {
+    for (char_type* s = aStr1; aN--; ++s, ++aStr2) {
+      NS_ASSERTION(!(*aStr2 & ~0x7F), "Unexpected non-ASCII character");
+      *s = static_cast<char_type>(*aStr2);
+    }
+    return aStr1;
+  }
+
+  static char_type*
+  assign(char_type* aStr, size_t aN, char_type aChar)
+  {
+    char_type* result = aStr;
+    while (aN--) {
+      assign(*aStr++, aChar);
+    }
+    return result;
+  }
+
+  static int
+  compare(const char_type* aStr1, const char_type* aStr2, size_t aN)
+  {
+    for (; aN--; ++aStr1, ++aStr2) {
+      if (!eq(*aStr1, *aStr2)) {
+        return to_int_type(*aStr1) - to_int_type(*aStr2);
+      }
+    }
+
+    return 0;
+  }
+
+  static int
+  compareASCII(const char_type* aStr1, const char* aStr2, size_t aN)
+  {
+    for (; aN--; ++aStr1, ++aStr2) {
+      NS_ASSERTION(!(*aStr2 & ~0x7F), "Unexpected non-ASCII character");
+      if (!eq_int_type(to_int_type(*aStr1),
+                       to_int_type(static_cast<char_type>(*aStr2)))) {
+        return to_int_type(*aStr1) -
+               to_int_type(static_cast<char_type>(*aStr2));
+      }
+    }
+
+    return 0;
+  }
+
+  // this version assumes that s2 is null-terminated and s1 has length n.
+  // if s1 is shorter than s2 then we return -1; if s1 is longer than s2,
+  // we return 1.
+  static int
+  compareASCIINullTerminated(const char_type* aStr1, size_t aN,
+                             const char* aStr2)
+  {
+    for (; aN--; ++aStr1, ++aStr2) {
+      if (!*aStr2) {
+        return 1;
+      }
+      NS_ASSERTION(!(*aStr2 & ~0x7F), "Unexpected non-ASCII character");
+      if (!eq_int_type(to_int_type(*aStr1),
+                       to_int_type(static_cast<char_type>(*aStr2)))) {
+        return to_int_type(*aStr1) -
+               to_int_type(static_cast<char_type>(*aStr2));
+      }
+    }
+
+    if (*aStr2) {
+      return -1;
+    }
+
+    return 0;
+  }
+
+  /**
+   * Convert c to its lower-case form, but only if c is in the ASCII
+   * range. Otherwise leave it alone.
+   */
+  static char_type
+  ASCIIToLower(char_type aChar)
+  {
+    if (aChar >= 'A' && aChar <= 'Z') {
+      return char_type(aChar + ('a' - 'A'));
+    }
+
+    return aChar;
+  }
+
+  static int
+  compareLowerCaseToASCII(const char_type* aStr1, const char* aStr2, size_t aN)
+  {
+    for (; aN--; ++aStr1, ++aStr2) {
+      NS_ASSERTION(!(*aStr2 & ~0x7F), "Unexpected non-ASCII character");
+      NS_ASSERTION(!(*aStr2 >= 'A' && *aStr2 <= 'Z'),
+                   "Unexpected uppercase character");
+      char_type lower_s1 = ASCIIToLower(*aStr1);
+      if (lower_s1 != static_cast<char_type>(*aStr2)) {
+        return to_int_type(lower_s1) -
+               to_int_type(static_cast<char_type>(*aStr2));
+      }
+    }
+
+    return 0;
+  }
+
+  // this version assumes that s2 is null-terminated and s1 has length n.
+  // if s1 is shorter than s2 then we return -1; if s1 is longer than s2,
+  // we return 1.
+  static int
+  compareLowerCaseToASCIINullTerminated(const char_type* aStr1,
+                                        size_t aN, const char* aStr2)
+  {
+    for (; aN--; ++aStr1, ++aStr2) {
+      if (!*aStr2) {
+        return 1;
+      }
+      NS_ASSERTION(!(*aStr2 & ~0x7F), "Unexpected non-ASCII character");
+      NS_ASSERTION(!(*aStr2 >= 'A' && *aStr2 <= 'Z'),
+                   "Unexpected uppercase character");
+      char_type lower_s1 = ASCIIToLower(*aStr1);
+      if (lower_s1 != static_cast<char_type>(*aStr2)) {
+        return to_int_type(lower_s1) -
+               to_int_type(static_cast<char_type>(*aStr2));
+      }
+    }
+
+    if (*aStr2) {
+      return -1;
+    }
+
+    return 0;
+  }
+
+  static size_t
+  length(const char_type* aStr)
+  {
+    size_t result = 0;
+    while (!eq(*aStr++, char_type(0))) {
+      ++result;
+    }
+    return result;
+  }
+
+  static const char_type*
+  find(const char_type* aStr, size_t aN, char_type aChar)
+  {
+    while (aN--) {
+      if (eq(*aStr, aChar)) {
+        return aStr;
+      }
+      ++aStr;
+    }
+
+    return 0;
+  }
+};
+
+template <>
+struct nsCharTraits<char>
+{
+  typedef char           char_type;
+  typedef unsigned char  unsigned_char_type;
+  typedef char16_t      incompatible_char_type;
+
+  static char_type* const sEmptyBuffer;
+
+  static void
+  assign(char_type& aLhs, char_type aRhs)
+  {
+    aLhs = aRhs;
+  }
+
+
+  // integer representation of characters:
+
+  typedef int int_type;
+
+  static char_type
+  to_char_type(int_type aChar)
+  {
+    return char_type(aChar);
+  }
+
+  static int_type
+  to_int_type(char_type aChar)
+  {
+    return int_type(static_cast<unsigned_char_type>(aChar));
+  }
+
+  static bool
+  eq_int_type(int_type aLhs, int_type aRhs)
+  {
+    return aLhs == aRhs;
+  }
+
+
+  // |char_type| comparisons:
+
+  static bool eq(char_type aLhs, char_type aRhs)
+  {
+    return aLhs == aRhs;
+  }
+
+  static bool
+  lt(char_type aLhs, char_type aRhs)
+  {
+    return aLhs < aRhs;
+  }
+
+
+  // operations on s[n] arrays:
+
+  static char_type*
+  move(char_type* aStr1, const char_type* aStr2, size_t aN)
+  {
+    return static_cast<char_type*>(memmove(aStr1, aStr2,
+                                           aN * sizeof(char_type)));
+  }
+
+  static char_type*
+  copy(char_type* aStr1, const char_type* aStr2, size_t aN)
+  {
+    return static_cast<char_type*>(memcpy(aStr1, aStr2,
+                                          aN * sizeof(char_type)));
+  }
+
+  static char_type*
+  copyASCII(char_type* aStr1, const char* aStr2, size_t aN)
+  {
+    return copy(aStr1, aStr2, aN);
+  }
+
+  static char_type*
+  assign(char_type* aStr, size_t aN, char_type aChar)
+  {
+    return static_cast<char_type*>(memset(aStr, to_int_type(aChar), aN));
+  }
+
+  static int
+  compare(const char_type* aStr1, const char_type* aStr2, size_t aN)
+  {
+    return memcmp(aStr1, aStr2, aN);
+  }
+
+  static int
+  compareASCII(const char_type* aStr1, const char* aStr2, size_t aN)
+  {
+#ifdef DEBUG
+    for (size_t i = 0; i < aN; ++i) {
+      NS_ASSERTION(!(aStr2[i] & ~0x7F), "Unexpected non-ASCII character");
+    }
+#endif
+    return compare(aStr1, aStr2, aN);
+  }
+
+  // this version assumes that s2 is null-terminated and s1 has length n.
+  // if s1 is shorter than s2 then we return -1; if s1 is longer than s2,
+  // we return 1.
+  static int
+  compareASCIINullTerminated(const char_type* aStr1, size_t aN,
+                             const char* aStr2)
+  {
+    // can't use strcmp here because we don't want to stop when aStr1
+    // contains a null
+    for (; aN--; ++aStr1, ++aStr2) {
+      if (!*aStr2) {
+        return 1;
+      }
+      NS_ASSERTION(!(*aStr2 & ~0x7F), "Unexpected non-ASCII character");
+      if (*aStr1 != *aStr2) {
+        return to_int_type(*aStr1) - to_int_type(*aStr2);
+      }
+    }
+
+    if (*aStr2) {
+      return -1;
+    }
+
+    return 0;
+  }
+
+  /**
+   * Convert c to its lower-case form, but only if c is ASCII.
+   */
+  static char_type
+  ASCIIToLower(char_type aChar)
+  {
+    if (aChar >= 'A' && aChar <= 'Z') {
+      return char_type(aChar + ('a' - 'A'));
+    }
+
+    return aChar;
+  }
+
+  static int
+  compareLowerCaseToASCII(const char_type* aStr1, const char* aStr2, size_t aN)
+  {
+    for (; aN--; ++aStr1, ++aStr2) {
+      NS_ASSERTION(!(*aStr2 & ~0x7F), "Unexpected non-ASCII character");
+      NS_ASSERTION(!(*aStr2 >= 'A' && *aStr2 <= 'Z'),
+                   "Unexpected uppercase character");
+      char_type lower_s1 = ASCIIToLower(*aStr1);
+      if (lower_s1 != *aStr2) {
+        return to_int_type(lower_s1) - to_int_type(*aStr2);
+      }
+    }
+    return 0;
+  }
+
+  // this version assumes that s2 is null-terminated and s1 has length n.
+  // if s1 is shorter than s2 then we return -1; if s1 is longer than s2,
+  // we return 1.
+  static int
+  compareLowerCaseToASCIINullTerminated(const char_type* aStr1, size_t aN,
+                                        const char* aStr2)
+  {
+    for (; aN--; ++aStr1, ++aStr2) {
+      if (!*aStr2) {
+        return 1;
+      }
+      NS_ASSERTION(!(*aStr2 & ~0x7F), "Unexpected non-ASCII character");
+      NS_ASSERTION(!(*aStr2 >= 'A' && *aStr2 <= 'Z'),
+                   "Unexpected uppercase character");
+      char_type lower_s1 = ASCIIToLower(*aStr1);
+      if (lower_s1 != *aStr2) {
+        return to_int_type(lower_s1) - to_int_type(*aStr2);
+      }
+    }
+
+    if (*aStr2) {
+      return -1;
+    }
+
+    return 0;
+  }
+
+  static size_t
+  length(const char_type* aStr)
+  {
+    return strlen(aStr);
+  }
+
+  static const char_type*
+  find(const char_type* aStr, size_t aN, char_type aChar)
+  {
+    return reinterpret_cast<const char_type*>(memchr(aStr, to_int_type(aChar),
+                                                     aN));
+  }
+};
+
+template <class InputIterator>
+struct nsCharSourceTraits
+{
+  typedef typename InputIterator::difference_type difference_type;
+
+  static uint32_t
+  readable_distance(const InputIterator& aFirst, const InputIterator& aLast)
+  {
+    // assumes single fragment
+    return uint32_t(aLast.get() - aFirst.get());
+  }
+
+  static const typename InputIterator::value_type*
+  read(const InputIterator& aIter)
+  {
+    return aIter.get();
+  }
+
+  static void
+  advance(InputIterator& aStr, difference_type aN)
+  {
+    aStr.advance(aN);
+  }
+};
+
+template <class CharT>
+struct nsCharSourceTraits<CharT*>
+{
+  typedef ptrdiff_t difference_type;
+
+  static uint32_t
+  readable_distance(CharT* aStr)
+  {
+    return uint32_t(nsCharTraits<CharT>::length(aStr));
+    // return numeric_limits<uint32_t>::max();
+  }
+
+  static uint32_t
+  readable_distance(CharT* aFirst, CharT* aLast)
+  {
+    return uint32_t(aLast - aFirst);
+  }
+
+  static const CharT*
+  read(CharT* aStr)
+  {
+    return aStr;
+  }
+
+  static void
+  advance(CharT*& aStr, difference_type aN)
+  {
+    aStr += aN;
+  }
+};
+
+template <class OutputIterator>
+struct nsCharSinkTraits
+{
+  static void
+  write(OutputIterator& aIter, const typename OutputIterator::value_type* aStr,
+        uint32_t aN)
+  {
+    aIter.write(aStr, aN);
+  }
+};
+
+template <class CharT>
+struct nsCharSinkTraits<CharT*>
+{
+  static void
+  write(CharT*& aIter, const CharT* aStr, uint32_t aN)
+  {
+    nsCharTraits<CharT>::move(aIter, aStr, aN);
+    aIter += aN;
+  }
+};
+
+#endif // !defined(nsCharTraits_h___)