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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
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Add m-esr52 at 52.6.0
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diff --git a/intl/icu/source/i18n/csrucode.cpp b/intl/icu/source/i18n/csrucode.cpp
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+// Copyright (C) 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+ **********************************************************************
+ * Copyright (C) 2005-2013, International Business Machines
+ * Corporation and others. All Rights Reserved.
+ **********************************************************************
+ */
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_CONVERSION
+
+#include "csrucode.h"
+#include "csmatch.h"
+
+U_NAMESPACE_BEGIN
+
+CharsetRecog_Unicode::~CharsetRecog_Unicode()
+{
+ // nothing to do
+}
+
+CharsetRecog_UTF_16_BE::~CharsetRecog_UTF_16_BE()
+{
+ // nothing to do
+}
+
+const char *CharsetRecog_UTF_16_BE::getName() const
+{
+ return "UTF-16BE";
+}
+
+// UTF-16 confidence calculation. Very simple minded, but better than nothing.
+// Any 8 bit non-control characters bump the confidence up. These have a zero high byte,
+// and are very likely to be UTF-16, although they could also be part of a UTF-32 code.
+// NULs are a contra-indication, they will appear commonly if the actual encoding is UTF-32.
+// NULs should be rare in actual text.
+
+static int32_t adjustConfidence(UChar codeUnit, int32_t confidence) {
+ if (codeUnit == 0) {
+ confidence -= 10;
+ } else if ((codeUnit >= 0x20 && codeUnit <= 0xff) || codeUnit == 0x0a) {
+ confidence += 10;
+ }
+ if (confidence < 0) {
+ confidence = 0;
+ } else if (confidence > 100) {
+ confidence = 100;
+ }
+ return confidence;
+}
+
+
+UBool CharsetRecog_UTF_16_BE::match(InputText* textIn, CharsetMatch *results) const
+{
+ const uint8_t *input = textIn->fRawInput;
+ int32_t confidence = 10;
+ int32_t length = textIn->fRawLength;
+
+ int32_t bytesToCheck = (length > 30) ? 30 : length;
+ for (int32_t charIndex=0; charIndex<bytesToCheck-1; charIndex+=2) {
+ UChar codeUnit = (input[charIndex] << 8) | input[charIndex + 1];
+ if (charIndex == 0 && codeUnit == 0xFEFF) {
+ confidence = 100;
+ break;
+ }
+ confidence = adjustConfidence(codeUnit, confidence);
+ if (confidence == 0 || confidence == 100) {
+ break;
+ }
+ }
+ if (bytesToCheck < 4 && confidence < 100) {
+ confidence = 0;
+ }
+ results->set(textIn, this, confidence);
+ return (confidence > 0);
+}
+
+CharsetRecog_UTF_16_LE::~CharsetRecog_UTF_16_LE()
+{
+ // nothing to do
+}
+
+const char *CharsetRecog_UTF_16_LE::getName() const
+{
+ return "UTF-16LE";
+}
+
+UBool CharsetRecog_UTF_16_LE::match(InputText* textIn, CharsetMatch *results) const
+{
+ const uint8_t *input = textIn->fRawInput;
+ int32_t confidence = 10;
+ int32_t length = textIn->fRawLength;
+
+ int32_t bytesToCheck = (length > 30) ? 30 : length;
+ for (int32_t charIndex=0; charIndex<bytesToCheck-1; charIndex+=2) {
+ UChar codeUnit = input[charIndex] | (input[charIndex + 1] << 8);
+ if (charIndex == 0 && codeUnit == 0xFEFF) {
+ confidence = 100; // UTF-16 BOM
+ if (length >= 4 && input[2] == 0 && input[3] == 0) {
+ confidence = 0; // UTF-32 BOM
+ }
+ break;
+ }
+ confidence = adjustConfidence(codeUnit, confidence);
+ if (confidence == 0 || confidence == 100) {
+ break;
+ }
+ }
+ if (bytesToCheck < 4 && confidence < 100) {
+ confidence = 0;
+ }
+ results->set(textIn, this, confidence);
+ return (confidence > 0);
+}
+
+CharsetRecog_UTF_32::~CharsetRecog_UTF_32()
+{
+ // nothing to do
+}
+
+UBool CharsetRecog_UTF_32::match(InputText* textIn, CharsetMatch *results) const
+{
+ const uint8_t *input = textIn->fRawInput;
+ int32_t limit = (textIn->fRawLength / 4) * 4;
+ int32_t numValid = 0;
+ int32_t numInvalid = 0;
+ bool hasBOM = FALSE;
+ int32_t confidence = 0;
+
+ if (limit > 0 && getChar(input, 0) == 0x0000FEFFUL) {
+ hasBOM = TRUE;
+ }
+
+ for(int32_t i = 0; i < limit; i += 4) {
+ int32_t ch = getChar(input, i);
+
+ if (ch < 0 || ch >= 0x10FFFF || (ch >= 0xD800 && ch <= 0xDFFF)) {
+ numInvalid += 1;
+ } else {
+ numValid += 1;
+ }
+ }
+
+
+ // Cook up some sort of confidence score, based on presense of a BOM
+ // and the existence of valid and/or invalid multi-byte sequences.
+ if (hasBOM && numInvalid==0) {
+ confidence = 100;
+ } else if (hasBOM && numValid > numInvalid*10) {
+ confidence = 80;
+ } else if (numValid > 3 && numInvalid == 0) {
+ confidence = 100;
+ } else if (numValid > 0 && numInvalid == 0) {
+ confidence = 80;
+ } else if (numValid > numInvalid*10) {
+ // Probably corruput UTF-32BE data. Valid sequences aren't likely by chance.
+ confidence = 25;
+ }
+
+ results->set(textIn, this, confidence);
+ return (confidence > 0);
+}
+
+CharsetRecog_UTF_32_BE::~CharsetRecog_UTF_32_BE()
+{
+ // nothing to do
+}
+
+const char *CharsetRecog_UTF_32_BE::getName() const
+{
+ return "UTF-32BE";
+}
+
+int32_t CharsetRecog_UTF_32_BE::getChar(const uint8_t *input, int32_t index) const
+{
+ return input[index + 0] << 24 | input[index + 1] << 16 |
+ input[index + 2] << 8 | input[index + 3];
+}
+
+CharsetRecog_UTF_32_LE::~CharsetRecog_UTF_32_LE()
+{
+ // nothing to do
+}
+
+const char *CharsetRecog_UTF_32_LE::getName() const
+{
+ return "UTF-32LE";
+}
+
+int32_t CharsetRecog_UTF_32_LE::getChar(const uint8_t *input, int32_t index) const
+{
+ return input[index + 3] << 24 | input[index + 2] << 16 |
+ input[index + 1] << 8 | input[index + 0];
+}
+
+U_NAMESPACE_END
+#endif
+