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1 /*
2 *******************************************************************************
3 * Copyright (C) 2013-2014, International Business Machines
4 * Corporation and others.  All Rights Reserved.
5 *******************************************************************************
6 * collationrootelements.h
7 *
8 * created on: 2013mar01
9 * created by: Markus W. Scherer
10 */
11 
12 #ifndef __COLLATIONROOTELEMENTS_H__
13 #define __COLLATIONROOTELEMENTS_H__
14 
15 #include "unicode/utypes.h"
16 
17 #if !UCONFIG_NO_COLLATION
18 
19 #include "unicode/uobject.h"
20 #include "collation.h"
21 
22 U_NAMESPACE_BEGIN
23 
24 /**
25  * Container and access methods for collation elements and weights
26  * that occur in the root collator.
27  * Needed for finding boundaries for building a tailoring.
28  *
29  * This class takes and returns 16-bit secondary and tertiary weights.
30  */
31 class U_I18N_API CollationRootElements : public UMemory {
32 public:
CollationRootElements(const uint32_t * rootElements,int32_t rootElementsLength)33     CollationRootElements(const uint32_t *rootElements, int32_t rootElementsLength)
34             : elements(rootElements), length(rootElementsLength) {}
35 
36     /**
37      * Higher than any root primary.
38      */
39     static const uint32_t PRIMARY_SENTINEL = 0xffffff00;
40 
41     /**
42      * Flag in a root element, set if the element contains secondary & tertiary weights,
43      * rather than a primary.
44      */
45     static const uint32_t SEC_TER_DELTA_FLAG = 0x80;
46     /**
47      * Mask for getting the primary range step value from a primary-range-end element.
48      */
49     static const uint8_t PRIMARY_STEP_MASK = 0x7f;
50 
51     enum {
52         /**
53          * Index of the first CE with a non-zero tertiary weight.
54          * Same as the start of the compact root elements table.
55          */
56         IX_FIRST_TERTIARY_INDEX,
57         /**
58          * Index of the first CE with a non-zero secondary weight.
59          */
60         IX_FIRST_SECONDARY_INDEX,
61         /**
62          * Index of the first CE with a non-zero primary weight.
63          */
64         IX_FIRST_PRIMARY_INDEX,
65         /**
66          * Must match Collation::COMMON_SEC_AND_TER_CE.
67          */
68         IX_COMMON_SEC_AND_TER_CE,
69         /**
70          * Secondary & tertiary boundaries.
71          * Bits 31..24: [fixed last secondary common byte 45]
72          * Bits 23..16: [fixed first ignorable secondary byte 80]
73          * Bits 15.. 8: reserved, 0
74          * Bits  7.. 0: [fixed first ignorable tertiary byte 3C]
75          */
76         IX_SEC_TER_BOUNDARIES,
77         /**
78          * The current number of indexes.
79          * Currently the same as elements[IX_FIRST_TERTIARY_INDEX].
80          */
81         IX_COUNT
82     };
83 
84     /**
85      * Returns the boundary between tertiary weights of primary/secondary CEs
86      * and those of tertiary CEs.
87      * This is the upper limit for tertiaries of primary/secondary CEs.
88      * This minus one is the lower limit for tertiaries of tertiary CEs.
89      */
getTertiaryBoundary()90     uint32_t getTertiaryBoundary() const {
91         return (elements[IX_SEC_TER_BOUNDARIES] << 8) & 0xff00;
92     }
93 
94     /**
95      * Returns the first assigned tertiary CE.
96      */
getFirstTertiaryCE()97     uint32_t getFirstTertiaryCE() const {
98         return elements[elements[IX_FIRST_TERTIARY_INDEX]] & ~SEC_TER_DELTA_FLAG;
99     }
100 
101     /**
102      * Returns the last assigned tertiary CE.
103      */
getLastTertiaryCE()104     uint32_t getLastTertiaryCE() const {
105         return elements[elements[IX_FIRST_SECONDARY_INDEX] - 1] & ~SEC_TER_DELTA_FLAG;
106     }
107 
108     /**
109      * Returns the last common secondary weight.
110      * This is the lower limit for secondaries of primary CEs.
111      */
getLastCommonSecondary()112     uint32_t getLastCommonSecondary() const {
113         return (elements[IX_SEC_TER_BOUNDARIES] >> 16) & 0xff00;
114     }
115 
116     /**
117      * Returns the boundary between secondary weights of primary CEs
118      * and those of secondary CEs.
119      * This is the upper limit for secondaries of primary CEs.
120      * This minus one is the lower limit for secondaries of secondary CEs.
121      */
getSecondaryBoundary()122     uint32_t getSecondaryBoundary() const {
123         return (elements[IX_SEC_TER_BOUNDARIES] >> 8) & 0xff00;
124     }
125 
126     /**
127      * Returns the first assigned secondary CE.
128      */
getFirstSecondaryCE()129     uint32_t getFirstSecondaryCE() const {
130         return elements[elements[IX_FIRST_SECONDARY_INDEX]] & ~SEC_TER_DELTA_FLAG;
131     }
132 
133     /**
134      * Returns the last assigned secondary CE.
135      */
getLastSecondaryCE()136     uint32_t getLastSecondaryCE() const {
137         return elements[elements[IX_FIRST_PRIMARY_INDEX] - 1] & ~SEC_TER_DELTA_FLAG;
138     }
139 
140     /**
141      * Returns the first assigned primary weight.
142      */
getFirstPrimary()143     uint32_t getFirstPrimary() const {
144         return elements[elements[IX_FIRST_PRIMARY_INDEX]];  // step=0: cannot be a range end
145     }
146 
147     /**
148      * Returns the first assigned primary CE.
149      */
getFirstPrimaryCE()150     int64_t getFirstPrimaryCE() const {
151         return Collation::makeCE(getFirstPrimary());
152     }
153 
154     /**
155      * Returns the last root CE with a primary weight before p.
156      * Intended only for reordering group boundaries.
157      */
158     int64_t lastCEWithPrimaryBefore(uint32_t p) const;
159 
160     /**
161      * Returns the first root CE with a primary weight of at least p.
162      * Intended only for reordering group boundaries.
163      */
164     int64_t firstCEWithPrimaryAtLeast(uint32_t p) const;
165 
166     /**
167      * Returns the primary weight before p.
168      * p must be greater than the first root primary.
169      */
170     uint32_t getPrimaryBefore(uint32_t p, UBool isCompressible) const;
171 
172     /** Returns the secondary weight before [p, s]. */
173     uint32_t getSecondaryBefore(uint32_t p, uint32_t s) const;
174 
175     /** Returns the tertiary weight before [p, s, t]. */
176     uint32_t getTertiaryBefore(uint32_t p, uint32_t s, uint32_t t) const;
177 
178     /**
179      * Finds the index of the input primary.
180      * p must occur as a root primary, and must not be 0.
181      */
182     int32_t findPrimary(uint32_t p) const;
183 
184     /**
185      * Returns the primary weight after p where index=findPrimary(p).
186      * p must be at least the first root primary.
187      */
188     uint32_t getPrimaryAfter(uint32_t p, int32_t index, UBool isCompressible) const;
189     /**
190      * Returns the secondary weight after [p, s] where index=findPrimary(p)
191      * except use index=0 for p=0.
192      *
193      * Must return a weight for every root [p, s] as well as for every weight
194      * returned by getSecondaryBefore(). If p!=0 then s can be BEFORE_WEIGHT16.
195      *
196      * Exception: [0, 0] is handled by the CollationBuilder:
197      * Both its lower and upper boundaries are special.
198      */
199     uint32_t getSecondaryAfter(int32_t index, uint32_t s) const;
200     /**
201      * Returns the tertiary weight after [p, s, t] where index=findPrimary(p)
202      * except use index=0 for p=0.
203      *
204      * Must return a weight for every root [p, s, t] as well as for every weight
205      * returned by getTertiaryBefore(). If s!=0 then t can be BEFORE_WEIGHT16.
206      *
207      * Exception: [0, 0, 0] is handled by the CollationBuilder:
208      * Both its lower and upper boundaries are special.
209      */
210     uint32_t getTertiaryAfter(int32_t index, uint32_t s, uint32_t t) const;
211 
212 private:
213     /**
214      * Returns the first secondary & tertiary weights for p where index=findPrimary(p)+1.
215      */
216     uint32_t getFirstSecTerForPrimary(int32_t index) const;
217 
218     /**
219      * Finds the largest index i where elements[i]<=p.
220      * Requires first primary<=p<0xffffff00 (PRIMARY_SENTINEL).
221      * Does not require that p is a root collator primary.
222      */
223     int32_t findP(uint32_t p) const;
224 
isEndOfPrimaryRange(uint32_t q)225     static inline UBool isEndOfPrimaryRange(uint32_t q) {
226         return (q & SEC_TER_DELTA_FLAG) == 0 && (q & PRIMARY_STEP_MASK) != 0;
227     }
228 
229     /**
230      * Data structure:
231      *
232      * The first few entries are indexes, up to elements[IX_FIRST_TERTIARY_INDEX].
233      * See the comments on the IX_ constants.
234      *
235      * All other elements are a compact form of the root collator CEs
236      * in mostly collation order.
237      *
238      * A sequence of one or more root CEs with the same primary weight is stored as
239      * one element with the primary weight, with the SEC_TER_DELTA_FLAG flag not set,
240      * followed by elements with only the secondary/tertiary weights,
241      * each with that flag set.
242      * If the lowest secondary/tertiary combination is Collation::COMMON_SEC_AND_TER_CE,
243      * then the element for that combination is omitted.
244      *
245      * Note: If the first actual secondary/tertiary combination is higher than
246      * Collation::COMMON_SEC_AND_TER_CE (which is unusual),
247      * the runtime code will assume anyway that Collation::COMMON_SEC_AND_TER_CE is present.
248      *
249      * A range of only-primary CEs with a consistent "step" increment
250      * from each primary to the next may be stored as a range.
251      * Only the first and last primary are stored, and the last has the step
252      * value in the low bits (PRIMARY_STEP_MASK).
253      *
254      * An range-end element may also either start a new range or be followed by
255      * elements with secondary/tertiary deltas.
256      *
257      * A primary element that is not a range end has zero step bits.
258      *
259      * There is no element for the completely ignorable CE (all weights 0).
260      *
261      * Before elements[IX_FIRST_PRIMARY_INDEX], all elements are secondary/tertiary deltas,
262      * for all of the ignorable root CEs.
263      *
264      * There are no elements for unassigned-implicit primary CEs.
265      * All primaries stored here are at most 3 bytes long.
266      */
267     const uint32_t *elements;
268     int32_t length;
269 };
270 
271 U_NAMESPACE_END
272 
273 #endif  // !UCONFIG_NO_COLLATION
274 #endif  // __COLLATIONROOTELEMENTS_H__
275