You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
152 lines
5.2 KiB
152 lines
5.2 KiB
// © 2019 and later: Unicode, Inc. and others.
|
|
// License & terms of use: http://www.unicode.org/copyright.html
|
|
|
|
// locdistance.h
|
|
// created: 2019may08 Markus W. Scherer
|
|
|
|
#ifndef __LOCDISTANCE_H__
|
|
#define __LOCDISTANCE_H__
|
|
|
|
#include "unicode/utypes.h"
|
|
#include "unicode/bytestrie.h"
|
|
#include "unicode/localematcher.h"
|
|
#include "unicode/locid.h"
|
|
#include "unicode/uobject.h"
|
|
#include "lsr.h"
|
|
|
|
U_NAMESPACE_BEGIN
|
|
|
|
struct LocaleDistanceData;
|
|
|
|
/**
|
|
* Offline-built data for LocaleMatcher.
|
|
* Mostly but not only the data for mapping locales to their maximized forms.
|
|
*/
|
|
class LocaleDistance final : public UMemory {
|
|
public:
|
|
static const LocaleDistance *getSingleton(UErrorCode &errorCode);
|
|
|
|
static int32_t shiftDistance(int32_t distance) {
|
|
return distance << DISTANCE_SHIFT;
|
|
}
|
|
|
|
static int32_t getShiftedDistance(int32_t indexAndDistance) {
|
|
return indexAndDistance & DISTANCE_MASK;
|
|
}
|
|
|
|
static double getDistanceDouble(int32_t indexAndDistance) {
|
|
double shiftedDistance = getShiftedDistance(indexAndDistance);
|
|
return shiftedDistance / (1 << DISTANCE_SHIFT);
|
|
}
|
|
|
|
static int32_t getDistanceFloor(int32_t indexAndDistance) {
|
|
return (indexAndDistance & DISTANCE_MASK) >> DISTANCE_SHIFT;
|
|
}
|
|
|
|
static int32_t getIndex(int32_t indexAndDistance) {
|
|
// assert indexAndDistance >= 0;
|
|
return indexAndDistance >> INDEX_SHIFT;
|
|
}
|
|
|
|
/**
|
|
* Finds the supported LSR with the smallest distance from the desired one.
|
|
* Equivalent LSR subtags must be normalized into a canonical form.
|
|
*
|
|
* <p>Returns the index of the lowest-distance supported LSR in the high bits
|
|
* (negative if none has a distance below the threshold),
|
|
* and its distance (0..ABOVE_THRESHOLD) in the low bits.
|
|
*/
|
|
int32_t getBestIndexAndDistance(const LSR &desired,
|
|
const LSR **supportedLSRs, int32_t supportedLSRsLength,
|
|
int32_t shiftedThreshold,
|
|
ULocMatchFavorSubtag favorSubtag,
|
|
ULocMatchDirection direction) const;
|
|
|
|
UBool isParadigmLSR(const LSR &lsr) const;
|
|
|
|
int32_t getDefaultScriptDistance() const {
|
|
return defaultScriptDistance;
|
|
}
|
|
|
|
int32_t getDefaultDemotionPerDesiredLocale() const {
|
|
return defaultDemotionPerDesiredLocale;
|
|
}
|
|
|
|
private:
|
|
// The distance is shifted left to gain some fraction bits.
|
|
static constexpr int32_t DISTANCE_SHIFT = 3;
|
|
static constexpr int32_t DISTANCE_FRACTION_MASK = 7;
|
|
// 7 bits for 0..100
|
|
static constexpr int32_t DISTANCE_INT_SHIFT = 7;
|
|
static constexpr int32_t INDEX_SHIFT = DISTANCE_INT_SHIFT + DISTANCE_SHIFT;
|
|
static constexpr int32_t DISTANCE_MASK = 0x3ff;
|
|
// tic constexpr int32_t MAX_INDEX = 0x1fffff; // avoids sign bit
|
|
static constexpr int32_t INDEX_NEG_1 = 0xfffffc00;
|
|
|
|
LocaleDistance(const LocaleDistanceData &data, const XLikelySubtags &likely);
|
|
LocaleDistance(const LocaleDistance &other) = delete;
|
|
LocaleDistance &operator=(const LocaleDistance &other) = delete;
|
|
|
|
static void initLocaleDistance(UErrorCode &errorCode);
|
|
|
|
UBool isMatch(const LSR &desired, const LSR &supported,
|
|
int32_t shiftedThreshold, ULocMatchFavorSubtag favorSubtag) const {
|
|
const LSR *pSupp = &supported;
|
|
return getBestIndexAndDistance(
|
|
desired, &pSupp, 1,
|
|
shiftedThreshold, favorSubtag, ULOCMATCH_DIRECTION_WITH_ONE_WAY) >= 0;
|
|
}
|
|
|
|
static int32_t getDesSuppScriptDistance(BytesTrie &iter, uint64_t startState,
|
|
const char *desired, const char *supported);
|
|
|
|
static int32_t getRegionPartitionsDistance(
|
|
BytesTrie &iter, uint64_t startState,
|
|
const char *desiredPartitions, const char *supportedPartitions,
|
|
int32_t threshold);
|
|
|
|
static int32_t getFallbackRegionDistance(BytesTrie &iter, uint64_t startState);
|
|
|
|
static int32_t trieNext(BytesTrie &iter, const char *s, bool wantValue);
|
|
|
|
const char *partitionsForRegion(const LSR &lsr) const {
|
|
// ill-formed region -> one non-matching string
|
|
int32_t pIndex = regionToPartitionsIndex[lsr.regionIndex];
|
|
return partitionArrays[pIndex];
|
|
}
|
|
|
|
int32_t getDefaultRegionDistance() const {
|
|
return defaultRegionDistance;
|
|
}
|
|
|
|
const XLikelySubtags &likelySubtags;
|
|
|
|
// The trie maps each dlang+slang+dscript+sscript+dregion+sregion
|
|
// (encoded in ASCII with bit 7 set on the last character of each subtag) to a distance.
|
|
// There is also a trie value for each subsequence of whole subtags.
|
|
// One '*' is used for a (desired, supported) pair of "und", "Zzzz"/"", or "ZZ"/"".
|
|
BytesTrie trie;
|
|
|
|
/**
|
|
* Maps each region to zero or more single-character partitions.
|
|
*/
|
|
const uint8_t *regionToPartitionsIndex;
|
|
const char **partitionArrays;
|
|
|
|
/**
|
|
* Used to get the paradigm region for a cluster, if there is one.
|
|
*/
|
|
const LSR *paradigmLSRs;
|
|
int32_t paradigmLSRsLength;
|
|
|
|
int32_t defaultLanguageDistance;
|
|
int32_t defaultScriptDistance;
|
|
int32_t defaultRegionDistance;
|
|
int32_t minRegionDistance;
|
|
int32_t defaultDemotionPerDesiredLocale;
|
|
};
|
|
|
|
U_NAMESPACE_END
|
|
|
|
#endif // __LOCDISTANCE_H__
|