Update ICU to 54.1 step 1

source/i18n/collationweights.cpp

+/*  
+*******************************************************************************
+*
+*   Copyright (C) 1999-2014, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+*******************************************************************************
+*   file name:  collationweights.cpp
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 2001mar08 as ucol_wgt.cpp
+*   created by: Markus W. Scherer
+*
+*   This file contains code for allocating n collation element weights
+*   between two exclusive limits.
+*   It is used only internally by the collation tailoring builder.
+*/
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_COLLATION
+
+#include "cmemory.h"
+#include "collation.h"
+#include "collationweights.h"
+#include "uarrsort.h"
+#include "uassert.h"
+
+#ifdef UCOL_DEBUG
+#   include <stdio.h>
+#endif
+
+U_NAMESPACE_BEGIN
+
+/* collation element weight allocation -------------------------------------- */
+
+/* helper functions for CE weights */
+
+static inline uint32_t
+getWeightTrail(uint32_t weight, int32_t length) {
+    return (uint32_t)(weight>>(8*(4-length)))&0xff;
+}
+
+static inline uint32_t
+setWeightTrail(uint32_t weight, int32_t length, uint32_t trail) {
+    length=8*(4-length);
+    return (uint32_t)((weight&(0xffffff00<<length))|(trail<<length));
+}
+
+static inline uint32_t
+getWeightByte(uint32_t weight, int32_t idx) {
+    return getWeightTrail(weight, idx); /* same calculation */
+}
+
+static inline uint32_t
+setWeightByte(uint32_t weight, int32_t idx, uint32_t byte) {
+    uint32_t mask; /* 0xffffffff except a 00 "hole" for the index-th byte */
+
+    idx*=8;
+    if(idx<32) {
+        mask=((uint32_t)0xffffffff)>>idx;
+    } else {
+        // Do not use uint32_t>>32 because on some platforms that does not shift at all
+        // while we need it to become 0.
+        // PowerPC: 0xffffffff>>32 = 0           (wanted)
+        // x86:     0xffffffff>>32 = 0xffffffff  (not wanted)
+        //
+        // ANSI C99 6.5.7 Bitwise shift operators:
+        // "If the value of the right operand is negative
+        // or is greater than or equal to the width of the promoted left operand,
+        // the behavior is undefined."
+        mask=0;
+    }
+    idx=32-idx;
+    mask|=0xffffff00<<idx;
+    return (uint32_t)((weight&mask)|(byte<<idx));
+}
+
+static inline uint32_t
+truncateWeight(uint32_t weight, int32_t length) {
+    return (uint32_t)(weight&(0xffffffff<<(8*(4-length))));
+}
+
+static inline uint32_t
+incWeightTrail(uint32_t weight, int32_t length) {
+    return (uint32_t)(weight+(1UL<<(8*(4-length))));
+}
+
+static inline uint32_t
+decWeightTrail(uint32_t weight, int32_t length) {
+    return (uint32_t)(weight-(1UL<<(8*(4-length))));
+}
+
+CollationWeights::CollationWeights()
+        : middleLength(0), rangeIndex(0), rangeCount(0) {
+    for(int32_t i = 0; i < 5; ++i) {
+        minBytes[i] = maxBytes[i] = 0;
+    }
+}
+
+void
+CollationWeights::initForPrimary(UBool compressible) {
+    middleLength=1;
+    minBytes[1] = Collation::MERGE_SEPARATOR_BYTE + 1;
+    maxBytes[1] = Collation::TRAIL_WEIGHT_BYTE;
+    if(compressible) {
+        minBytes[2] = Collation::PRIMARY_COMPRESSION_LOW_BYTE + 1;
+        maxBytes[2] = Collation::PRIMARY_COMPRESSION_HIGH_BYTE - 1;
+    } else {
+        minBytes[2] = 2;
+        maxBytes[2] = 0xff;
+    }
+    minBytes[3] = 2;
+    maxBytes[3] = 0xff;
+    minBytes[4] = 2;
+    maxBytes[4] = 0xff;
+}
+
+void
+CollationWeights::initForSecondary() {
+    // We use only the lower 16 bits for secondary weights.
+    middleLength=3;
+    minBytes[1] = 0;
+    maxBytes[1] = 0;
+    minBytes[2] = 0;
+    maxBytes[2] = 0;
+    minBytes[3] = Collation::MERGE_SEPARATOR_BYTE + 1;
+    maxBytes[3] = 0xff;
+    minBytes[4] = 2;
+    maxBytes[4] = 0xff;
+}
+
+void
+CollationWeights::initForTertiary() {
+    // We use only the lower 16 bits for tertiary weights.
+    middleLength=3;
+    minBytes[1] = 0;
+    maxBytes[1] = 0;
+    minBytes[2] = 0;
+    maxBytes[2] = 0;
+    // We use only 6 bits per byte.
+    // The other bits are used for case & quaternary weights.
+    minBytes[3] = Collation::MERGE_SEPARATOR_BYTE + 1;
+    maxBytes[3] = 0x3f;
+    minBytes[4] = 2;
+    maxBytes[4] = 0x3f;
+}
+
+uint32_t
+CollationWeights::incWeight(uint32_t weight, int32_t length) const {
+    for(;;) {
+        uint32_t byte=getWeightByte(weight, length);
+        if(byte<maxBytes[length]) {
+            return setWeightByte(weight, length, byte+1);
+        } else {
+            // Roll over, set this byte to the minimum and increment the previous one.
+            weight=setWeightByte(weight, length, minBytes[length]);
+            --length;
+            U_ASSERT(length > 0);
+        }
+    }
+}
+
+uint32_t
+CollationWeights::incWeightByOffset(uint32_t weight, int32_t length, int32_t offset) const {
+    for(;;) {
+        offset += getWeightByte(weight, length);
+        if((uint32_t)offset <= maxBytes[length]) {
+            return setWeightByte(weight, length, offset);
+        } else {
+            // Split the offset between this byte and the previous one.
+            offset -= minBytes[length];
+            weight = setWeightByte(weight, length, minBytes[length] + offset % countBytes(length));
+            offset /= countBytes(length);
+            --length;
+            U_ASSERT(length > 0);
+        }
+    }
+}
+
+void
+CollationWeights::lengthenRange(WeightRange &range) const {
+    int32_t length=range.length+1;
+    range.start=setWeightTrail(range.start, length, minBytes[length]);
+    range.end=setWeightTrail(range.end, length, maxBytes[length]);
+    range.count*=countBytes(length);
+    range.length=length;
+}
+
+/* for uprv_sortArray: sort ranges in weight order */
+static int32_t U_CALLCONV
+compareRanges(const void * /*context*/, const void *left, const void *right) {
+    uint32_t l, r;
+
+    l=((const CollationWeights::WeightRange *)left)->start;
+    r=((const CollationWeights::WeightRange *)right)->start;
+    if(l<r) {
+        return -1;
+    } else if(l>r) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+UBool
+CollationWeights::getWeightRanges(uint32_t lowerLimit, uint32_t upperLimit) {
+    U_ASSERT(lowerLimit != 0);
+    U_ASSERT(upperLimit != 0);
+
+    /* get the lengths of the limits */
+    int32_t lowerLength=lengthOfWeight(lowerLimit);
+    int32_t upperLength=lengthOfWeight(upperLimit);
+
+#ifdef UCOL_DEBUG
+    printf("length of lower limit 0x%08lx is %ld\n", lowerLimit, lowerLength);
+    printf("length of upper limit 0x%08lx is %ld\n", upperLimit, upperLength);
+#endif
+    U_ASSERT(lowerLength>=middleLength);
+    // Permit upperLength<middleLength: The upper limit for secondaries is 0x10000.
+
+    if(lowerLimit>=upperLimit) {
+#ifdef UCOL_DEBUG
+        printf("error: no space between lower & upper limits\n");
+#endif
+        return FALSE;
+    }
+
+    /* check that neither is a prefix of the other */
+    if(lowerLength<upperLength) {
+        if(lowerLimit==truncateWeight(upperLimit, lowerLength)) {
+#ifdef UCOL_DEBUG
+            printf("error: lower limit 0x%08lx is a prefix of upper limit 0x%08lx\n", lowerLimit, upperLimit);
+#endif
+            return FALSE;
+        }
+    }
+    /* if the upper limit is a prefix of the lower limit then the earlier test lowerLimit>=upperLimit has caught it */
+
+    WeightRange lower[5], middle, upper[5]; /* [0] and [1] are not used - this simplifies indexing */
+    uprv_memset(lower, 0, sizeof(lower));
+    uprv_memset(&middle, 0, sizeof(middle));
+    uprv_memset(upper, 0, sizeof(upper));
+
+    /*
+     * With the limit lengths of 1..4, there are up to 7 ranges for allocation:
+     * range     minimum length
+     * lower[4]  4
+     * lower[3]  3
+     * lower[2]  2
+     * middle    1
+     * upper[2]  2
+     * upper[3]  3
+     * upper[4]  4
+     *
+     * We are now going to calculate up to 7 ranges.
+     * Some of them will typically overlap, so we will then have to merge and eliminate ranges.
+     */
+    uint32_t weight=lowerLimit;
+    for(int32_t length=lowerLength; length>middleLength; --length) {
+        uint32_t trail=getWeightTrail(weight, length);
+        if(trail<maxBytes[length]) {
+            lower[length].start=incWeightTrail(weight, length);
+            lower[length].end=setWeightTrail(weight, length, maxBytes[length]);
+            lower[length].length=length;
+            lower[length].count=maxBytes[length]-trail;
+        }
+        weight=truncateWeight(weight, length-1);
+    }
+    if(weight<0xff000000) {
+        middle.start=incWeightTrail(weight, middleLength);
+    } else {
+        // Prevent overflow for primary lead byte FF
+        // which would yield a middle range starting at 0.
+        middle.start=0xffffffff;  // no middle range
+    }
+
+    weight=upperLimit;
+    for(int32_t length=upperLength; length>middleLength; --length) {
+        uint32_t trail=getWeightTrail(weight, length);
+        if(trail>minBytes[length]) {
+            upper[length].start=setWeightTrail(weight, length, minBytes[length]);
+            upper[length].end=decWeightTrail(weight, length);
+            upper[length].length=length;
+            upper[length].count=trail-minBytes[length];
+        }
+        weight=truncateWeight(weight, length-1);
+    }
+    middle.end=decWeightTrail(weight, middleLength);
+
+    /* set the middle range */
+    middle.length=middleLength;
+    if(middle.end>=middle.start) {
+        middle.count=(int32_t)((middle.end-middle.start)>>(8*(4-middleLength)))+1;
+    } else {
+        /* no middle range, eliminate overlaps */
+
+        /* reduce or remove the lower ranges that go beyond upperLimit */
+        for(int32_t length=4; length>middleLength; --length) {
+            if(lower[length].count>0 && upper[length].count>0) {
+                uint32_t start=upper[length].start;
+                uint32_t end=lower[length].end;
+
+                if(end>=start || incWeight(end, length)==start) {
+                    /* lower and upper ranges collide or are directly adjacent: merge these two and remove all shorter ranges */
+                    start=lower[length].start;
+                    end=lower[length].end=upper[length].end;
+                    /*
+                     * merging directly adjacent ranges needs to subtract the 0/1 gaps in between;
+                     * it may result in a range with count>countBytes
+                     */
+                    lower[length].count=
+                        (int32_t)(getWeightTrail(end, length)-getWeightTrail(start, length)+1+
+                                  countBytes(length)*(getWeightByte(end, length-1)-getWeightByte(start, length-1)));
+                    upper[length].count=0;
+                    while(--length>middleLength) {
+                        lower[length].count=upper[length].count=0;
+                    }
+                    break;
+                }
+            }
+        }
+    }
+
+#ifdef UCOL_DEBUG
+    /* print ranges */
+    for(int32_t length=4; length>=2; --length) {
+        if(lower[length].count>0) {
+            printf("lower[%ld] .start=0x%08lx .end=0x%08lx .count=%ld\n", length, lower[length].start, lower[length].end, lower[length].count);
+        }
+    }
+    if(middle.count>0) {
+        printf("middle   .start=0x%08lx .end=0x%08lx .count=%ld\n", middle.start, middle.end, middle.count);
+    }
+    for(int32_t length=2; length<=4; ++length) {
+        if(upper[length].count>0) {
+            printf("upper[%ld] .start=0x%08lx .end=0x%08lx .count=%ld\n", length, upper[length].start, upper[length].end, upper[length].count);
+        }
+    }
+#endif
+
+    /* copy the ranges, shortest first, into the result array */
+    rangeCount=0;
+    if(middle.count>0) {
+        uprv_memcpy(ranges, &middle, sizeof(WeightRange));
+        rangeCount=1;
+    }
+    for(int32_t length=middleLength+1; length<=4; ++length) {
+        /* copy upper first so that later the middle range is more likely the first one to use */
+        if(upper[length].count>0) {
+            uprv_memcpy(ranges+rangeCount, upper+length, sizeof(WeightRange));
+            ++rangeCount;
+        }
+        if(lower[length].count>0) {
+            uprv_memcpy(ranges+rangeCount, lower+length, sizeof(WeightRange));
+            ++rangeCount;
+        }
+    }
+    return rangeCount>0;
+}
+
+UBool
+CollationWeights::allocWeightsInShortRanges(int32_t n, int32_t minLength) {
+    // See if the first few minLength and minLength+1 ranges have enough weights.
+    for(int32_t i = 0; i < rangeCount && ranges[i].length <= (minLength + 1); ++i) {
+        if(n <= ranges[i].count) {
+            // Use the first few minLength and minLength+1 ranges.
+            if(ranges[i].length > minLength) {
+                // Reduce the number of weights from the last minLength+1 range
+                // which might sort before some minLength ranges,
+                // so that we use all weights in the minLength ranges.
+                ranges[i].count = n;
+            }
+            rangeCount = i + 1;
+#ifdef UCOL_DEBUG
+            printf("take first %ld ranges\n", rangeCount);
+#endif
+
+            if(rangeCount>1) {
+                /* sort the ranges by weight values */
+                UErrorCode errorCode=U_ZERO_ERROR;
+                uprv_sortArray(ranges, rangeCount, sizeof(WeightRange),
+                               compareRanges, NULL, FALSE, &errorCode);
+                /* ignore error code: we know that the internal sort function will not fail here */
+            }
+            return TRUE;
+        }
+        n -= ranges[i].count;  // still >0
+    }
+    return FALSE;
+}
+
+UBool
+CollationWeights::allocWeightsInMinLengthRanges(int32_t n, int32_t minLength) {
+    // See if the minLength ranges have enough weights
+    // when we split one and lengthen the following ones.
+    int32_t count = 0;
+    int32_t minLengthRangeCount;
+    for(minLengthRangeCount = 0;
+            minLengthRangeCount < rangeCount &&
+                ranges[minLengthRangeCount].length == minLength;
+            ++minLengthRangeCount) {
+        count += ranges[minLengthRangeCount].count;
+    }
+
+    int32_t nextCountBytes = countBytes(minLength + 1);
+    if(n > count * nextCountBytes) { return FALSE; }
+
+    // Use the minLength ranges. Merge them, and then split again as necessary.
+    uint32_t start = ranges[0].start;
+    uint32_t end = ranges[0].end;
+    for(int32_t i = 1; i < minLengthRangeCount; ++i) {
+        if(ranges[i].start < start) { start = ranges[i].start; }
+        if(ranges[i].end > end) { end = ranges[i].end; }
+    }
+
+    // Calculate how to split the range between minLength (count1) and minLength+1 (count2).
+    // Goal:
+    //   count1 + count2 * nextCountBytes = n
+    //   count1 + count2 = count
+    // These turn into
+    //   (count - count2) + count2 * nextCountBytes = n
+    // and then into the following count1 & count2 computations.
+    int32_t count2 = (n - count) / (nextCountBytes - 1);  // number of weights to be lengthened
+    int32_t count1 = count - count2;  // number of minLength weights
+    if(count2 == 0 || (count1 + count2 * nextCountBytes) < n) {
+        // round up
+        ++count2;
+        --count1;
+        U_ASSERT((count1 + count2 * nextCountBytes) >= n);
+    }
+
+    ranges[0].start = start;
+
+    if(count1 == 0) {
+        // Make one long range.
+        ranges[0].end = end;
+        ranges[0].count = count;
+        lengthenRange(ranges[0]);
+        rangeCount = 1;
+    } else {
+        // Split the range, lengthen the second part.
+#ifdef UCOL_DEBUG
+        printf("split the range number %ld (out of %ld minLength ranges) by %ld:%ld\n",
+               splitRange, rangeCount, count1, count2);
+#endif
+
+        // Next start = start + count1. First end = 1 before that.
+        ranges[0].end = incWeightByOffset(start, minLength, count1 - 1);
+        ranges[0].count = count1;
+
+        ranges[1].start = incWeight(ranges[0].end, minLength);
+        ranges[1].end = end;
+        ranges[1].length = minLength;  // +1 when lengthened
+        ranges[1].count = count2;  // *countBytes when lengthened
+        lengthenRange(ranges[1]);
+        rangeCount = 2;
+    }
+    return TRUE;
+}
+
+/*
+ * call getWeightRanges and then determine heuristically
+ * which ranges to use for a given number of weights between (excluding)
+ * two limits
+ */
+UBool
+CollationWeights::allocWeights(uint32_t lowerLimit, uint32_t upperLimit, int32_t n) {
+#ifdef UCOL_DEBUG
+    puts("");
+#endif
+
+    if(!getWeightRanges(lowerLimit, upperLimit)) {
+#ifdef UCOL_DEBUG
+        printf("error: unable to get Weight ranges\n");
+#endif
+        return FALSE;
+    }
+
+    /* try until we find suitably large ranges */
+    for(;;) {
+        /* get the smallest number of bytes in a range */
+        int32_t minLength=ranges[0].length;
+
+        if(allocWeightsInShortRanges(n, minLength)) { break; }
+
+        if(minLength == 4) {
+#ifdef UCOL_DEBUG
+            printf("error: the maximum number of %ld weights is insufficient for n=%ld\n",
+                   minLengthCount, n);
+#endif
+            return FALSE;
+        }
+
+        if(allocWeightsInMinLengthRanges(n, minLength)) { break; }
+
+        /* no good match, lengthen all minLength ranges and iterate */
+#ifdef UCOL_DEBUG
+        printf("lengthen the short ranges from %ld bytes to %ld and iterate\n", minLength, minLength+1);
+#endif
+        for(int32_t i=0; ranges[i].length==minLength; ++i) {
+            lengthenRange(ranges[i]);
+        }
+    }
+
+#ifdef UCOL_DEBUG
+    puts("final ranges:");
+    for(int32_t i=0; i<rangeCount; ++i) {
+        printf("ranges[%ld] .start=0x%08lx .end=0x%08lx .length=%ld .count=%ld\n",
+               i, ranges[i].start, ranges[i].end, ranges[i].length, ranges[i].count);
+    }
+#endif
+
+    rangeIndex = 0;
+    return TRUE;
+}
+
+uint32_t
+CollationWeights::nextWeight() {
+    if(rangeIndex >= rangeCount) {
+        return 0xffffffff;
+    } else {
+        /* get the next weight */
+        WeightRange &range = ranges[rangeIndex];
+        uint32_t weight = range.start;
+        if(--range.count == 0) {
+            /* this range is finished */
+            ++rangeIndex;
+        } else {
+            /* increment the weight for the next value */
+            range.start = incWeight(weight, range.length);
+            U_ASSERT(range.start <= range.end);
+        }
+
+        return weight;
+    }
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_COLLATION */