gecko/intl/unicharutil/util/nsUnicharUtils.cpp
Justin Lebar ext:(%2C%20Kyle%20Huey%20%3Cme%40kylehuey.com%3E) 8b20bfbcec Bug 145975 - Implement nsCaseInsensitiveUTF8StringComparator r=smontagu
--HG--
extra : rebase_source : 8e5d63a6a5ca50b6e95a80421ad96a1d4a52ae77
2010-08-31 18:03:40 -07:00

543 lines
15 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Unicode case conversion helpers.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corp..
* Portions created by the Initial Developer are Copyright (C) 2002
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Alec Flett <alecf@netscape.com>
* Benjamin Smedberg <benjamin@smedbergs.us>
* Ben Turner <mozilla@songbirdnest.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsUnicharUtils.h"
#include "nsUnicharUtilCIID.h"
#include "nsCRT.h"
#include "nsICaseConversion.h"
#include "nsServiceManagerUtils.h"
#include "nsXPCOMStrings.h"
#include "casetable.h"
#include "nsUTF8Utils.h"
#include <ctype.h>
// For gUpperToTitle
enum {
kUpperIdx =0,
kTitleIdx
};
// For gUpperToTitle
enum {
kLowIdx =0,
kSizeEveryIdx,
kDiffIdx
};
#define IS_ASCII(u) ((u) < 0x80)
#define IS_ASCII_UPPER(u) (('A' <= (u)) && ( (u) <= 'Z' ))
#define IS_ASCII_LOWER(u) (('a' <= (u)) && ( (u) <= 'z'))
#define IS_ASCII_ALPHA(u) (IS_ASCII_UPPER(u) || IS_ASCII_LOWER(u))
#define IS_ASCII_SPACE(u) ( ' ' == (u) )
#define IS_NOCASE_CHAR(u) (0==(1&(gCaseBlocks[(u)>>13]>>(0x001F&((u)>>8)))))
// Size of Tables
// Changing these numbers may break UTF-8 caching. Be careful!
#define CASE_MAP_CACHE_SIZE 0x100
#define CASE_MAP_CACHE_MASK 0xFF
struct nsCompressedMap {
const PRUnichar *mTable;
PRUint32 mSize;
PRUint32 mCache[CASE_MAP_CACHE_SIZE];
PRUint32 mLastBase;
PRUnichar Map(PRUnichar aChar)
{
// We don't need explicit locking here since the cached values are int32s,
// which are read and written atomically. The following code is threadsafe
// because we never access bits from mCache directly -- we always first
// read the entire entry into a local variable and then mask off the bits
// we're interested in.
// Check the 256-byte cache first and bail with our answer if we can.
PRUint32 cachedData = mCache[aChar & CASE_MAP_CACHE_MASK];
if (aChar == ((cachedData >> 16) & 0x0000FFFF))
return cachedData & 0x0000FFFF;
// Now try the last index we looked up, storing it into a local variable
// for thread-safety.
PRUint32 base = mLastBase;
PRUnichar res = 0;
// Does this character fit in the slot?
if ((aChar <= ((mTable[base+kSizeEveryIdx] >> 8) +
mTable[base+kLowIdx])) &&
(mTable[base+kLowIdx] <= aChar)) {
// This character uses the same base as our last lookup, so the
// conversion is easy.
if (((mTable[base+kSizeEveryIdx] & 0x00FF) > 0) &&
(0 != ((aChar - mTable[base+kLowIdx]) %
(mTable[base+kSizeEveryIdx] & 0x00FF))))
{
res = aChar;
} else {
res = aChar + mTable[base+kDiffIdx];
}
} else {
// Do the full lookup.
res = this->Lookup(0, mSize/2, mSize-1, aChar);
}
// Cache the result and return.
mCache[aChar & CASE_MAP_CACHE_MASK] =
((aChar << 16) & 0xFFFF0000) | (0x0000FFFF & res);
return res;
}
// Takes as arguments the left bound, middle, right bound, and character to
// search for. Executes a binary search.
PRUnichar Lookup(PRUint32 l,
PRUint32 m,
PRUint32 r,
PRUnichar aChar)
{
PRUint32 base = m*3; // Every line in the table is 3 units wide.
// Is aChar past the top of the current table entry? (The upper byte of
// the 'every' entry contains the offset to the end of this entry.)
if (aChar > ((mTable[base+kSizeEveryIdx] >> 8) +
mTable[base+kLowIdx]))
{
if (l > m || l == r)
return aChar;
// Advance one round.
PRUint32 newm = (m+r+1)/2;
if (newm == m)
newm++;
return this->Lookup(m+1, newm, r, aChar);
// Is aChar below the bottom of the current table entry?
} else if (mTable[base+kLowIdx] > aChar) {
if (r < m || l == r)
return aChar;
// Advance one round
PRUint32 newm = (l+m-1)/2;
if(newm == m)
newm++;
return this->Lookup(l, newm, m-1, aChar);
// We've found the entry aChar should live in.
} else {
// Determine if aChar falls in a gap. (The lower byte of the 'every'
// entry contains n for which every nth character from the base is a
// character of interest.)
if (((mTable[base+kSizeEveryIdx] & 0x00FF) > 0) &&
(0 != ((aChar - mTable[base+kLowIdx]) %
(mTable[base+kSizeEveryIdx] & 0x00FF))))
{
return aChar;
}
// If aChar doesn't fall in the gap, cache and convert.
mLastBase = base;
return aChar + mTable[base+kDiffIdx];
}
}
};
static nsCompressedMap gUpperMap = {
reinterpret_cast<const PRUnichar*>(&gToUpper[0]),
gToUpperItems
};
static nsCompressedMap gLowerMap = {
reinterpret_cast<const PRUnichar*>(&gToLower[0]),
gToLowerItems
};
// We want ToLowerCase(PRUnichar) and ToLowerCaseASCII(PRUnichar) to be fast
// when they're called from within the case-insensitive comparators, so we
// define inlined versions.
static NS_ALWAYS_INLINE PRUnichar
ToLowerCase_inline(PRUnichar aChar)
{
if (IS_ASCII(aChar)) {
return gASCIIToLower[aChar];
} else if (IS_NOCASE_CHAR(aChar)) {
return aChar;
}
return gLowerMap.Map(aChar);
}
static NS_ALWAYS_INLINE PRUnichar
ToLowerCaseASCII_inline(const PRUnichar aChar)
{
if (IS_ASCII(aChar))
return gASCIIToLower[aChar];
return aChar;
}
void
ToLowerCase(nsAString& aString)
{
PRUnichar *buf = aString.BeginWriting();
ToLowerCase(buf, buf, aString.Length());
}
void
ToLowerCase(const nsAString& aSource,
nsAString& aDest)
{
const PRUnichar *in;
PRUnichar *out;
PRUint32 len = NS_StringGetData(aSource, &in);
NS_StringGetMutableData(aDest, len, &out);
NS_ASSERTION(out, "Uh...");
ToLowerCase(in, out, len);
}
PRUnichar
ToLowerCaseASCII(const PRUnichar aChar)
{
return ToLowerCaseASCII_inline(aChar);
}
void
ToUpperCase(nsAString& aString)
{
PRUnichar *buf = aString.BeginWriting();
ToUpperCase(buf, buf, aString.Length());
}
void
ToUpperCase(const nsAString& aSource,
nsAString& aDest)
{
const PRUnichar *in;
PRUnichar *out;
PRUint32 len = NS_StringGetData(aSource, &in);
NS_StringGetMutableData(aDest, len, &out);
NS_ASSERTION(out, "Uh...");
ToUpperCase(in, out, len);
}
#ifdef MOZILLA_INTERNAL_API
PRInt32
nsCaseInsensitiveStringComparator::operator()(const PRUnichar* lhs,
const PRUnichar* rhs,
PRUint32 lLength,
PRUint32 rLength) const
{
return (lLength == rLength) ? CaseInsensitiveCompare(lhs, rhs, lLength) :
(lLength > rLength) ? 1 : -1;
}
PRInt32
nsCaseInsensitiveUTF8StringComparator::operator()(const char* lhs,
const char* rhs,
PRUint32 lLength,
PRUint32 rLength) const
{
return CaseInsensitiveCompare(lhs, rhs, lLength, rLength);
}
PRInt32
nsASCIICaseInsensitiveStringComparator::operator()(const PRUnichar* lhs,
const PRUnichar* rhs,
PRUint32 lLength,
PRUint32 rLength) const
{
if (lLength != rLength) {
if (lLength > rLength)
return 1;
return -1;
}
while (rLength) {
PRUnichar l = *lhs++;
PRUnichar r = *rhs++;
if (l != r) {
l = ToLowerCaseASCII_inline(l);
r = ToLowerCaseASCII_inline(r);
if (l > r)
return 1;
else if (r > l)
return -1;
}
rLength--;
}
return 0;
}
#endif // MOZILLA_INTERNAL_API
PRUnichar
ToLowerCase(PRUnichar aChar)
{
return ToLowerCase_inline(aChar);
}
void
ToLowerCase(const PRUnichar *aIn, PRUnichar *aOut, PRUint32 aLen)
{
for (PRUint32 i = 0; i < aLen; i++) {
aOut[i] = ToLowerCase(aIn[i]);
}
}
PRUnichar
ToUpperCase(PRUnichar aChar)
{
if (IS_ASCII(aChar)) {
if (IS_ASCII_LOWER(aChar))
return aChar - 0x20;
else
return aChar;
} else if (IS_NOCASE_CHAR(aChar)) {
return aChar;
}
return gUpperMap.Map(aChar);
}
void
ToUpperCase(const PRUnichar *aIn, PRUnichar *aOut, PRUint32 aLen)
{
for (PRUint32 i = 0; i < aLen; i++) {
aOut[i] = ToUpperCase(aIn[i]);
}
}
PRUnichar
ToTitleCase(PRUnichar aChar)
{
if (IS_ASCII(aChar)) {
return ToUpperCase(aChar);
} else if (IS_NOCASE_CHAR(aChar)) {
return aChar;
}
// First check for uppercase characters whose titlecase mapping is
// different, like U+01F1 DZ: they must remain unchanged.
if (0x01C0 == (aChar & 0xFFC0)) {
for (PRUint32 i = 0; i < gUpperToTitleItems; i++) {
if (aChar == gUpperToTitle[(i*2)+kUpperIdx]) {
return aChar;
}
}
}
PRUnichar upper = gUpperMap.Map(aChar);
if (0x01C0 == ( upper & 0xFFC0)) {
for (PRUint32 i = 0 ; i < gUpperToTitleItems; i++) {
if (upper == gUpperToTitle[(i*2)+kUpperIdx]) {
return gUpperToTitle[(i*2)+kTitleIdx];
}
}
}
return upper;
}
PRInt32
CaseInsensitiveCompare(const PRUnichar *a,
const PRUnichar *b,
PRUint32 len)
{
NS_ASSERTION(a && b, "Do not pass in invalid pointers!");
if (len) {
do {
PRUnichar c1 = *a++;
PRUnichar c2 = *b++;
if (c1 != c2) {
c1 = ToLowerCase_inline(c1);
c2 = ToLowerCase_inline(c2);
if (c1 != c2) {
if (c1 < c2) {
return -1;
}
return 1;
}
}
} while (--len != 0);
}
return 0;
}
// Calculates the codepoint of the UTF8 sequence starting at aStr. Sets aNext
// to the byte following the end of the sequence.
//
// If the sequence is invalid, or if computing the codepoint would take us off
// the end of the string (as marked by aEnd), returns -1 and does not set
// aNext. Note that this function doesn't check that aStr < aEnd -- it assumes
// you've done that already.
static NS_ALWAYS_INLINE PRUint32
GetLowerUTF8Codepoint(const char* aStr, const char* aEnd, const char **aNext)
{
// Convert to unsigned char so that stuffing chars into PRUint32s doesn't
// sign extend.
const unsigned char *str = (unsigned char*)aStr;
if (UTF8traits::isASCII(str[0])) {
// It's ASCII; just convert to lower-case and return it.
*aNext = aStr + 1;
return gASCIIToLower[*str];
}
if (UTF8traits::is2byte(str[0]) && NS_LIKELY(aStr + 1 < aEnd)) {
// It's a two-byte sequence, so it looks like
// 110XXXXX 10XXXXXX.
// This is definitely in the BMP, so we can store straightaway into a
// PRUint16.
PRUint16 c;
c = (str[0] & 0x1F) << 6;
c += (str[1] & 0x3F);
if (!IS_NOCASE_CHAR(c))
c = gLowerMap.Map(c);
*aNext = aStr + 2;
return c;
}
if (UTF8traits::is3byte(str[0]) && NS_LIKELY(aStr + 2 < aEnd)) {
// It's a three-byte sequence, so it looks like
// 1110XXXX 10XXXXXX 10XXXXXX.
// This will just barely fit into 16-bits, so store into a PRUint16.
PRUint16 c;
c = (str[0] & 0x0F) << 12;
c += (str[1] & 0x3F) << 6;
c += (str[2] & 0x3F);
if (!IS_NOCASE_CHAR(c))
c = gLowerMap.Map(c);
*aNext = aStr + 3;
return c;
}
if (UTF8traits::is4byte(str[0]) && NS_LIKELY(aStr + 3 < aEnd)) {
// It's a four-byte sequence, so it looks like
// 11110XXX 10XXXXXX 10XXXXXX 10XXXXXX.
// Unless this is an overlong sequence, the codepoint it encodes definitely
// isn't in the BMP, so we don't bother trying to convert it to lower-case.
PRUint32 c;
c = (str[0] & 0x07) << 18;
c += (str[1] & 0x3F) << 12;
c += (str[2] & 0x3F) << 6;
c += (str[3] & 0x3F);
*aNext = aStr + 4;
return c;
}
// Hm, we don't understand this sequence.
return -1;
}
PRInt32 CaseInsensitiveCompare(const char *aLeft,
const char *aRight,
PRUint32 aLeftBytes,
PRUint32 aRightBytes)
{
const char *leftEnd = aLeft + aLeftBytes;
const char *rightEnd = aRight + aRightBytes;
while (aLeft < leftEnd && aRight < rightEnd) {
PRUint32 leftChar = GetLowerUTF8Codepoint(aLeft, leftEnd, &aLeft);
if (NS_UNLIKELY(leftChar == PRUint32(-1)))
return -1;
PRUint32 rightChar = GetLowerUTF8Codepoint(aRight, rightEnd, &aRight);
if (NS_UNLIKELY(rightChar == PRUint32(-1)))
return -1;
// Now leftChar and rightChar are lower-case, so we can compare them.
if (leftChar != rightChar) {
if (leftChar > rightChar)
return 1;
return -1;
}
}
// Make sure that if one string is longer than the other we return the
// correct result.
if (aLeft < leftEnd)
return 1;
if (aRight < rightEnd)
return -1;
return 0;
}
PRBool
CaseInsensitiveUTF8CharsEqual(const char* aLeft, const char* aRight,
const char* aLeftEnd, const char* aRightEnd,
const char** aLeftNext, const char** aRightNext,
PRBool* aErr)
{
NS_ASSERTION(aLeftNext, "Out pointer shouldn't be null.");
NS_ASSERTION(aRightNext, "Out pointer shouldn't be null.");
NS_ASSERTION(aErr, "Out pointer shouldn't be null.");
NS_ASSERTION(aLeft < aLeftEnd, "aLeft must be less than aLeftEnd.");
NS_ASSERTION(aRight < aRightEnd, "aRight must be less than aRightEnd.");
PRUint32 leftChar = GetLowerUTF8Codepoint(aLeft, aLeftEnd, aLeftNext);
if (NS_UNLIKELY(leftChar == PRUint32(-1))) {
*aErr = PR_TRUE;
return PR_FALSE;
}
PRUint32 rightChar = GetLowerUTF8Codepoint(aRight, aRightEnd, aRightNext);
if (NS_UNLIKELY(rightChar == PRUint32(-1))) {
*aErr = PR_TRUE;
return PR_FALSE;
}
// Can't have an error past this point.
*aErr = PR_FALSE;
return leftChar == rightChar;
}