/*
*******************************************************************************
*
* Copyright (C) 1999-2015, 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::LEVEL_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::LEVEL_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 */
for(int32_t length=4; length>middleLength; --length) {
if(lower[length].count>0 && upper[length].count>0) {
// Note: The lowerEnd and upperStart weights are versions of
// lowerLimit and upperLimit (which are lowerLimit<upperLimit),
// truncated (still less-or-equal)
// and then with their last bytes changed to the
// maxByte (for lowerEnd) or minByte (for upperStart).
const uint32_t lowerEnd=lower[length].end;
const uint32_t upperStart=upper[length].start;
UBool merged=FALSE;
if(lowerEnd>upperStart) {
// These two lower and upper ranges collide.
// Since lowerLimit<upperLimit and lowerEnd and upperStart
// are versions with only their last bytes modified
// (and following ones removed/reset to 0),
// lowerEnd>upperStart is only possible
// if the leading bytes are equal
// and lastByte(lowerEnd)>lastByte(upperStart).
U_ASSERT(truncateWeight(lowerEnd, length-1)==
truncateWeight(upperStart, length-1));
// Intersect these two ranges.
lower[length].end=upper[length].end;
lower[length].count=
(int32_t)getWeightTrail(lower[length].end, length)-
(int32_t)getWeightTrail(lower[length].start, length)+1;
// count might be <=0 in which case there is no room,
// and the range-collecting code below will ignore this range.
merged=TRUE;
} else if(lowerEnd==upperStart) {
// Not possible, unless minByte==maxByte which is not allowed.
U_ASSERT(minBytes[length]<maxBytes[length]);
} else /* lowerEnd<upperStart */ {
if(incWeight(lowerEnd, length)==upperStart) {
// Merge adjacent ranges.
lower[length].end=upper[length].end;
lower[length].count+=upper[length].count; // might be >countBytes
merged=TRUE;
}
}
if(merged) {
// Remove all shorter ranges.
// There was no room available for them between the ranges we just merged.
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 */