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-rw-r--r--xpcom/string/nsCharTraits.h487
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+/* -*- 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 <stdint.h> // for |uint32_t|
+#include <string.h> // for |memcpy|, et al
+#include "mozilla/MemoryChecking.h"
+
+// 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)
+// Easier to type than NS_IS_HIGH_SURROGATE && NS_IS_LOW_SURROGATE
+#define NS_IS_SURROGATE_PAIR(h, l) \
+ (NS_IS_HIGH_SURROGATE(h) && NS_IS_LOW_SURROGATE(l))
+// 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;
+
+ // 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 void uninitialize(char_type* aStr, size_t aN) {
+#ifdef DEBUG
+ memset(aStr, 0xE4, aN * sizeof(char_type));
+#endif
+ MOZ_MAKE_MEM_UNDEFINED(aStr, 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 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;
+ }
+
+ static bool equalsLatin1(const char_type* aStr1, const char* aStr2,
+ const size_t aN) {
+ for (size_t i = aN; i > 0; --i, ++aStr1, ++aStr2) {
+ if (*aStr1 != static_cast<char_type>(*aStr2)) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
+ // 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;
+
+ // 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 void uninitialize(char_type* aStr, size_t aN) {
+#ifdef DEBUG
+ memset(aStr, 0xE4, aN * sizeof(char_type));
+#endif
+ MOZ_MAKE_MEM_UNDEFINED(aStr, aN * sizeof(char_type));
+ }
+
+ static char_type* copyASCII(char_type* aStr1, const char* aStr2, size_t aN) {
+ return copy(aStr1, aStr2, 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);
+ }
+
+ static bool equalsLatin1(const char_type* aStr1, const char* aStr2,
+ size_t aN) {
+ return memcmp(aStr1, aStr2, aN) == 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) {
+ // 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___)
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