import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

intl/icu/source/i18n/visibledigits.cpp

@@ -0,0 +1,186 @@
+// Copyright (C) 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+ * Copyright (C) 2016, International Business Machines
+ * Corporation and others.  All Rights Reserved.
+ *
+ * file name: visibledigits.cpp
+ */
+
+#include <math.h>
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "cstring.h"
+#include "decNumber.h"
+#include "digitlst.h"
+#include "uassert.h"
+#include "visibledigits.h"
+
+static const int32_t kNegative = 1;
+static const int32_t kInfinite = 2;
+static const int32_t kNaN = 4;
+
+U_NAMESPACE_BEGIN
+
+void VisibleDigits::setNegative() {
+    fFlags |= kNegative;
+}
+
+void VisibleDigits::setNaN() {
+    fFlags |= kNaN;
+}
+
+void VisibleDigits::setInfinite() {
+    fFlags |= kInfinite;
+}
+
+void VisibleDigits::clear() {
+    fInterval.clear();
+    fDigits.clear();
+    fExponent = 0;
+    fFlags = 0;
+    fAbsIntValue = 0LL;
+    fAbsIntValueSet = FALSE;
+    fAbsDoubleValue = 0.0;
+    fAbsDoubleValueSet = FALSE;
+}
+
+UBool VisibleDigits::isNegative() const {
+    return (fFlags & kNegative);
+}
+
+UBool VisibleDigits::isNaN() const {
+    return (fFlags & kNaN);
+}
+
+UBool VisibleDigits::isInfinite() const {
+    return (fFlags & kInfinite);
+}
+
+int32_t VisibleDigits::getDigitByExponent(int32_t digitPos) const {
+    if (digitPos < fExponent || digitPos >= fExponent + fDigits.length()) {
+        return 0;
+    }
+    const char *ptr = fDigits.data();
+    return ptr[digitPos - fExponent];
+}
+
+UBool VisibleDigits::isOverMaxDigits() const {
+    return (fExponent + fDigits.length() > fInterval.getMostSignificantExclusive());
+}
+
+UBool VisibleDigits::isNaNOrInfinity() const {
+    return (fFlags & (kInfinite | kNaN)) != 0;
+}
+
+double VisibleDigits::computeAbsDoubleValue() const {
+    // Take care of NaN and infinity
+    if (isNaN()) {
+        return uprv_getNaN();
+    }
+    if (isInfinite()) {
+        return uprv_getInfinity();
+    }
+
+    // stack allocate a decNumber to hold MAX_DBL_DIGITS+3 significant digits
+    struct {
+        decNumber  decNum;
+        char       digits[MAX_DBL_DIGITS+3];
+    } decNumberWithStorage;
+    decNumber *numberPtr = &decNumberWithStorage.decNum;
+
+    int32_t mostSig = fInterval.getMostSignificantExclusive();
+    int32_t mostSigNonZero = fExponent + fDigits.length();
+    int32_t end = mostSig > mostSigNonZero ? mostSigNonZero : mostSig;
+    int32_t leastSig = fInterval.getLeastSignificantInclusive();
+    int32_t start = leastSig > fExponent ? leastSig : fExponent;
+    if (end <= start) {
+        return 0.0;
+    }
+    if (start < end - (MAX_DBL_DIGITS+3)) {
+        start = end - (MAX_DBL_DIGITS+3);
+    }
+    uint8_t *pos = numberPtr->lsu;
+    const char *src = &(fDigits.data()[start - fExponent]);
+    for (int32_t i = start; i < end; ++i) {
+        *pos++ = (uint8_t) (*src++);
+    }
+    numberPtr->exponent = start;
+    numberPtr->bits = 0;
+    numberPtr->digits = end - start;
+    char str[MAX_DBL_DIGITS+18];
+    uprv_decNumberToString(numberPtr, str);
+    U_ASSERT(uprv_strlen(str) < MAX_DBL_DIGITS+18);
+    char *unused = NULL;
+    return DigitList::decimalStrToDouble(str, &unused);
+}
+
+void VisibleDigits::getFixedDecimal(
+    double &source, int64_t &intValue, int64_t &f, int64_t &t, int32_t &v, UBool &hasIntValue) const {
+    source = 0.0;
+    intValue = 0;
+    f = 0;
+    t = 0;
+    v = 0;
+    hasIntValue = FALSE;
+    if (isNaNOrInfinity()) {
+        return;
+    }
+
+    // source
+    if (fAbsDoubleValueSet) {
+        source = fAbsDoubleValue;
+    } else {
+        source = computeAbsDoubleValue();
+    }
+
+    // visible decimal digits
+    v = fInterval.getFracDigitCount();
+
+    // intValue
+
+    // If we initialized from an int64 just use that instead of
+    // calculating
+    if (fAbsIntValueSet) {
+        intValue = fAbsIntValue;
+    } else {
+        int32_t startPos = fInterval.getMostSignificantExclusive();
+        if (startPos > 18) {
+            startPos = 18;
+        }
+        // process the integer digits
+        for (int32_t i = startPos - 1; i >= 0; --i) {
+            intValue = intValue * 10LL + getDigitByExponent(i);
+        }
+        if (intValue == 0LL && startPos > 0) {
+            intValue = 100000000000000000LL;
+        }
+    }
+
+    // f (decimal digits)
+    // skip over any leading 0's in fraction digits.
+    int32_t idx = -1;
+    for (; idx >= -v && getDigitByExponent(idx) == 0; --idx)
+      ;
+
+    // Only process up to first 18 non zero fraction digits for decimalDigits
+    // since that is all we can fit into an int64.
+    for (int32_t i = idx; i >= -v && i > idx - 18; --i) {
+        f = f * 10LL + getDigitByExponent(i);
+    }
+
+    // If we have no decimal digits, we don't have an integer value
+    hasIntValue = (f == 0LL);
+
+    // t (decimal digits without trailing zeros)
+   t = f;
+    while (t > 0 && t % 10LL == 0) {
+        t /= 10;
+    }
+}
+
+U_NAMESPACE_END
+#endif /* #if !UCONFIG_NO_FORMATTING */