1 // Copyright (C) 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
4 *******************************************************************************
5 * Copyright (C) 2010-2012,2014, International Business Machines
6 * Corporation and others. All Rights Reserved.
7 *******************************************************************************
8 * file name: stringtriebuilder.h
10 * tab size: 8 (not used)
13 * created on: 2010dec24
14 * created by: Markus W. Scherer
17 #ifndef __STRINGTRIEBUILDER_H__
18 #define __STRINGTRIEBUILDER_H__
20 #include "unicode/utypes.h"
21 #include "unicode/uobject.h"
25 * \brief C++ API: Builder API for trie builders
28 // Forward declaration.
30 typedef struct UHashtable UHashtable;
33 * Build options for BytesTrieBuilder and CharsTrieBuilder.
36 enum UStringTrieBuildOption {
38 * Builds a trie quickly.
41 USTRINGTRIE_BUILD_FAST,
43 * Builds a trie more slowly, attempting to generate
44 * a shorter but equivalent serialization.
45 * This build option also uses more memory.
47 * This option can be effective when many integer values are the same
48 * and string/byte sequence suffixes can be shared.
49 * Runtime speed is not expected to improve.
52 USTRINGTRIE_BUILD_SMALL
58 * Base class for string trie builder classes.
60 * This class is not intended for public subclassing.
63 class U_COMMON_API StringTrieBuilder : public UObject {
65 #ifndef U_HIDE_INTERNAL_API
67 static UBool hashNode(const void *node);
69 static UBool equalNodes(const void *left, const void *right);
70 #endif /* U_HIDE_INTERNAL_API */
73 // Do not enclose the protected default constructor with #ifndef U_HIDE_INTERNAL_API
74 // or else the compiler will create a public default constructor.
78 virtual ~StringTrieBuilder();
80 #ifndef U_HIDE_INTERNAL_API
82 void createCompactBuilder(int32_t sizeGuess, UErrorCode &errorCode);
84 void deleteCompactBuilder();
87 void build(UStringTrieBuildOption buildOption, int32_t elementsLength, UErrorCode &errorCode);
90 int32_t writeNode(int32_t start, int32_t limit, int32_t unitIndex);
92 int32_t writeBranchSubNode(int32_t start, int32_t limit, int32_t unitIndex, int32_t length);
93 #endif /* U_HIDE_INTERNAL_API */
97 #ifndef U_HIDE_INTERNAL_API
99 Node *makeNode(int32_t start, int32_t limit, int32_t unitIndex, UErrorCode &errorCode);
101 Node *makeBranchSubNode(int32_t start, int32_t limit, int32_t unitIndex,
102 int32_t length, UErrorCode &errorCode);
103 #endif /* U_HIDE_INTERNAL_API */
106 virtual int32_t getElementStringLength(int32_t i) const = 0;
108 virtual UChar getElementUnit(int32_t i, int32_t unitIndex) const = 0;
110 virtual int32_t getElementValue(int32_t i) const = 0;
112 // Finds the first unit index after this one where
113 // the first and last element have different units again.
115 virtual int32_t getLimitOfLinearMatch(int32_t first, int32_t last, int32_t unitIndex) const = 0;
117 // Number of different units at unitIndex.
119 virtual int32_t countElementUnits(int32_t start, int32_t limit, int32_t unitIndex) const = 0;
121 virtual int32_t skipElementsBySomeUnits(int32_t i, int32_t unitIndex, int32_t count) const = 0;
123 virtual int32_t indexOfElementWithNextUnit(int32_t i, int32_t unitIndex, UChar unit) const = 0;
126 virtual UBool matchNodesCanHaveValues() const = 0;
129 virtual int32_t getMaxBranchLinearSubNodeLength() const = 0;
131 virtual int32_t getMinLinearMatch() const = 0;
133 virtual int32_t getMaxLinearMatchLength() const = 0;
135 #ifndef U_HIDE_INTERNAL_API
136 // max(BytesTrie::kMaxBranchLinearSubNodeLength, UCharsTrie::kMaxBranchLinearSubNodeLength).
138 static const int32_t kMaxBranchLinearSubNodeLength=5;
140 // Maximum number of nested split-branch levels for a branch on all 2^16 possible UChar units.
141 // log2(2^16/kMaxBranchLinearSubNodeLength) rounded up.
143 static const int32_t kMaxSplitBranchLevels=14;
146 * Makes sure that there is only one unique node registered that is
147 * equivalent to newNode.
148 * @param newNode Input node. The builder takes ownership.
149 * @param errorCode ICU in/out UErrorCode.
150 Set to U_MEMORY_ALLOCATION_ERROR if it was success but newNode==NULL.
151 * @return newNode if it is the first of its kind, or
152 * an equivalent node if newNode is a duplicate.
155 Node *registerNode(Node *newNode, UErrorCode &errorCode);
157 * Makes sure that there is only one unique FinalValueNode registered
159 * Avoids creating a node if the value is a duplicate.
160 * @param value A final value.
161 * @param errorCode ICU in/out UErrorCode.
162 Set to U_MEMORY_ALLOCATION_ERROR if it was success but newNode==NULL.
163 * @return A FinalValueNode with the given value.
166 Node *registerFinalValue(int32_t value, UErrorCode &errorCode);
167 #endif /* U_HIDE_INTERNAL_API */
171 * registerNode() and registerFinalValue() take ownership of their input nodes,
172 * and only return owned nodes.
173 * If they see a failure UErrorCode, they will delete the input node.
174 * If they get a NULL pointer, they will record a U_MEMORY_ALLOCATION_ERROR.
175 * If there is a failure, they return NULL.
177 * NULL Node pointers can be safely passed into other Nodes because
178 * they call the static Node::hashCode() which checks for a NULL pointer first.
180 * Therefore, as long as builder functions register a new node,
181 * they need to check for failures only before explicitly dereferencing
182 * a Node pointer, or before setting a new UErrorCode.
185 // Hash set of nodes, maps from nodes to integer 1.
189 // Do not conditionalize the following with #ifndef U_HIDE_INTERNAL_API,
190 // it is needed for layout of other objects.
192 class Node : public UObject {
194 Node(int32_t initialHash) : hash(initialHash), offset(0) {}
195 inline int32_t hashCode() const { return hash; }
196 // Handles node==NULL.
197 static inline int32_t hashCode(const Node *node) { return node==NULL ? 0 : node->hashCode(); }
198 // Base class operator==() compares the actual class types.
199 virtual UBool operator==(const Node &other) const;
200 inline UBool operator!=(const Node &other) const { return !operator==(other); }
202 * Traverses the Node graph and numbers branch edges, with rightmost edges first.
203 * This is to avoid writing a duplicate node twice.
205 * Branch nodes in this trie data structure are not symmetric.
206 * Most branch edges "jump" to other nodes but the rightmost branch edges
207 * just continue without a jump.
208 * Therefore, write() must write the rightmost branch edge last
209 * (trie units are written backwards), and must write it at that point even if
210 * it is a duplicate of a node previously written elsewhere.
212 * This function visits and marks right branch edges first.
213 * Edges are numbered with increasingly negative values because we share the
214 * offset field which gets positive values when nodes are written.
215 * A branch edge also remembers the first number for any of its edges.
217 * When a further-left branch edge has a number in the range of the rightmost
218 * edge's numbers, then it will be written as part of the required right edge
219 * and we can avoid writing it first.
221 * After root.markRightEdgesFirst(-1) the offsets of all nodes are negative
224 * @param edgeNumber The first edge number for this node and its sub-nodes.
225 * @return An edge number that is at least the maximum-negative
226 * of the input edge number and the numbers of this node and all of its sub-nodes.
228 virtual int32_t markRightEdgesFirst(int32_t edgeNumber);
229 // write() must set the offset to a positive value.
230 virtual void write(StringTrieBuilder &builder) = 0;
231 // See markRightEdgesFirst.
232 inline void writeUnlessInsideRightEdge(int32_t firstRight, int32_t lastRight,
233 StringTrieBuilder &builder) {
234 // Note: Edge numbers are negative, lastRight<=firstRight.
235 // If offset>0 then this node and its sub-nodes have been written already
236 // and we need not write them again.
237 // If this node is part of the unwritten right branch edge,
238 // then we wait until that is written.
239 if(offset<0 && (offset<lastRight || firstRight<offset)) {
243 inline int32_t getOffset() const { return offset; }
249 #ifndef U_HIDE_INTERNAL_API
250 // This class should not be overridden because
251 // registerFinalValue() compares a stack-allocated FinalValueNode
252 // (stack-allocated so that we don't unnecessarily create lots of duplicate nodes)
253 // with the input node, and the
254 // !Node::operator==(other) used inside FinalValueNode::operator==(other)
255 // will be false if the typeid's are different.
257 class FinalValueNode : public Node {
259 FinalValueNode(int32_t v) : Node(0x111111*37+v), value(v) {}
260 virtual UBool operator==(const Node &other) const;
261 virtual void write(StringTrieBuilder &builder);
265 #endif /* U_HIDE_INTERNAL_API */
267 // Do not conditionalize the following with #ifndef U_HIDE_INTERNAL_API,
268 // it is needed for layout of other objects.
272 class ValueNode : public Node {
274 ValueNode(int32_t initialHash) : Node(initialHash), hasValue(FALSE), value(0) {}
275 virtual UBool operator==(const Node &other) const;
276 void setValue(int32_t v) {
286 #ifndef U_HIDE_INTERNAL_API
290 class IntermediateValueNode : public ValueNode {
292 IntermediateValueNode(int32_t v, Node *nextNode)
293 : ValueNode(0x222222*37+hashCode(nextNode)), next(nextNode) { setValue(v); }
294 virtual UBool operator==(const Node &other) const;
295 virtual int32_t markRightEdgesFirst(int32_t edgeNumber);
296 virtual void write(StringTrieBuilder &builder);
300 #endif /* U_HIDE_INTERNAL_API */
302 // Do not conditionalize the following with #ifndef U_HIDE_INTERNAL_API,
303 // it is needed for layout of other objects.
307 class LinearMatchNode : public ValueNode {
309 LinearMatchNode(int32_t len, Node *nextNode)
310 : ValueNode((0x333333*37+len)*37+hashCode(nextNode)),
311 length(len), next(nextNode) {}
312 virtual UBool operator==(const Node &other) const;
313 virtual int32_t markRightEdgesFirst(int32_t edgeNumber);
319 #ifndef U_HIDE_INTERNAL_API
323 class BranchNode : public Node {
325 BranchNode(int32_t initialHash) : Node(initialHash) {}
327 int32_t firstEdgeNumber;
333 class ListBranchNode : public BranchNode {
335 ListBranchNode() : BranchNode(0x444444), length(0) {}
336 virtual UBool operator==(const Node &other) const;
337 virtual int32_t markRightEdgesFirst(int32_t edgeNumber);
338 virtual void write(StringTrieBuilder &builder);
339 // Adds a unit with a final value.
340 void add(int32_t c, int32_t value) {
341 units[length]=(UChar)c;
343 values[length]=value;
345 hash=(hash*37+c)*37+value;
347 // Adds a unit which leads to another match node.
348 void add(int32_t c, Node *node) {
349 units[length]=(UChar)c;
353 hash=(hash*37+c)*37+hashCode(node);
356 Node *equal[kMaxBranchLinearSubNodeLength]; // NULL means "has final value".
358 int32_t values[kMaxBranchLinearSubNodeLength];
359 UChar units[kMaxBranchLinearSubNodeLength];
365 class SplitBranchNode : public BranchNode {
367 SplitBranchNode(UChar middleUnit, Node *lessThanNode, Node *greaterOrEqualNode)
368 : BranchNode(((0x555555*37+middleUnit)*37+
369 hashCode(lessThanNode))*37+hashCode(greaterOrEqualNode)),
370 unit(middleUnit), lessThan(lessThanNode), greaterOrEqual(greaterOrEqualNode) {}
371 virtual UBool operator==(const Node &other) const;
372 virtual int32_t markRightEdgesFirst(int32_t edgeNumber);
373 virtual void write(StringTrieBuilder &builder);
377 Node *greaterOrEqual;
380 // Branch head node, for writing the actual node lead unit.
382 class BranchHeadNode : public ValueNode {
384 BranchHeadNode(int32_t len, Node *subNode)
385 : ValueNode((0x666666*37+len)*37+hashCode(subNode)),
386 length(len), next(subNode) {}
387 virtual UBool operator==(const Node &other) const;
388 virtual int32_t markRightEdgesFirst(int32_t edgeNumber);
389 virtual void write(StringTrieBuilder &builder);
392 Node *next; // A branch sub-node.
394 #endif /* U_HIDE_INTERNAL_API */
397 virtual Node *createLinearMatchNode(int32_t i, int32_t unitIndex, int32_t length,
398 Node *nextNode) const = 0;
401 virtual int32_t write(int32_t unit) = 0;
403 virtual int32_t writeElementUnits(int32_t i, int32_t unitIndex, int32_t length) = 0;
405 virtual int32_t writeValueAndFinal(int32_t i, UBool isFinal) = 0;
407 virtual int32_t writeValueAndType(UBool hasValue, int32_t value, int32_t node) = 0;
409 virtual int32_t writeDeltaTo(int32_t jumpTarget) = 0;
414 #endif // __STRINGTRIEBUILDER_H__