127 lines
4.3 KiB
C++
127 lines
4.3 KiB
C++
/*
|
|
*******************************************************************************
|
|
* Copyright (C) 2010, International Business Machines
|
|
* Corporation and others. All Rights Reserved.
|
|
*******************************************************************************
|
|
* file name: bytetrieiterator.h
|
|
* encoding: US-ASCII
|
|
* tab size: 8 (not used)
|
|
* indentation:4
|
|
*
|
|
* created on: 2010nov03
|
|
* created by: Markus W. Scherer
|
|
*/
|
|
|
|
#ifndef __BYTETRIEITERATOR_H__
|
|
#define __BYTETRIEITERATOR_H__
|
|
|
|
/**
|
|
* \file
|
|
* \brief C++ API: ByteTrie iterator for all of its (byte sequence, value) pairs.
|
|
*/
|
|
|
|
// Needed if and when we change the .dat package index to a ByteTrie,
|
|
// so that icupkg can work with an input package.
|
|
|
|
#include "unicode/utypes.h"
|
|
#include "unicode/stringpiece.h"
|
|
#include "bytetrie.h"
|
|
#include "charstr.h"
|
|
#include "uvectr32.h"
|
|
|
|
U_NAMESPACE_BEGIN
|
|
|
|
/**
|
|
* Iterator for all of the (byte sequence, value) pairs in a ByteTrie.
|
|
*/
|
|
class U_TOOLUTIL_API ByteTrieIterator : public UMemory {
|
|
public:
|
|
/**
|
|
* Iterates from the root of a byte-serialized ByteTrie.
|
|
* @param trieBytes The trie bytes.
|
|
* @param maxStringLength If 0, the iterator returns full strings/byte sequences.
|
|
* Otherwise, the iterator returns strings with this maximum length.
|
|
* @param errorCode Standard ICU error code. Its input value must
|
|
* pass the U_SUCCESS() test, or else the function returns
|
|
* immediately. Check for U_FAILURE() on output or use with
|
|
* function chaining. (See User Guide for details.)
|
|
*/
|
|
ByteTrieIterator(const void *trieBytes, int32_t maxStringLength, UErrorCode &errorCode);
|
|
|
|
/**
|
|
* Iterates from the current state of the specified ByteTrie.
|
|
* @param trie The trie whose state will be copied for iteration.
|
|
* @param maxStringLength If 0, the iterator returns full strings/byte sequences.
|
|
* Otherwise, the iterator returns strings with this maximum length.
|
|
* @param errorCode Standard ICU error code. Its input value must
|
|
* pass the U_SUCCESS() test, or else the function returns
|
|
* immediately. Check for U_FAILURE() on output or use with
|
|
* function chaining. (See User Guide for details.)
|
|
*/
|
|
ByteTrieIterator(const ByteTrie &trie, int32_t maxStringLength, UErrorCode &errorCode);
|
|
|
|
/**
|
|
* Resets this iterator to its initial state.
|
|
*/
|
|
ByteTrieIterator &reset();
|
|
|
|
/**
|
|
* Finds the next (byte sequence, value) pair if there is one.
|
|
*
|
|
* If the byte sequence is truncated to the maximum length and does not
|
|
* have a real value, then the value is set to -1.
|
|
* In this case, this "not a real value" is indistinguishable from
|
|
* a real value of -1.
|
|
* @return TRUE if there is another element.
|
|
*/
|
|
UBool next(UErrorCode &errorCode);
|
|
|
|
/**
|
|
* @return TRUE if there are more elements.
|
|
*/
|
|
UBool hasNext() const { return pos_!=NULL || !stack_.isEmpty(); }
|
|
|
|
/**
|
|
* @return the NUL-terminated byte sequence for the last successful next()
|
|
*/
|
|
const StringPiece &getString() const { return sp_; }
|
|
/**
|
|
* @return the value for the last successful next()
|
|
*/
|
|
int32_t getValue() const { return value_; }
|
|
|
|
private:
|
|
UBool truncateAndStop() {
|
|
pos_=NULL;
|
|
value_=-1; // no real value for str
|
|
sp_.set(str_.data(), str_.length());
|
|
return TRUE;
|
|
}
|
|
|
|
const uint8_t *branchNext(const uint8_t *pos, int32_t length, UErrorCode &errorCode);
|
|
|
|
const uint8_t *bytes_;
|
|
const uint8_t *pos_;
|
|
const uint8_t *initialPos_;
|
|
int32_t remainingMatchLength_;
|
|
int32_t initialRemainingMatchLength_;
|
|
|
|
CharString str_;
|
|
StringPiece sp_;
|
|
int32_t maxLength_;
|
|
int32_t value_;
|
|
|
|
// The stack stores pairs of integers for backtracking to another
|
|
// outbound edge of a branch node.
|
|
// The first integer is an offset from ByteTrie.bytes.
|
|
// The second integer has the str.length() from before the node in bits 15..0,
|
|
// and the remaining branch length in bits 24..16. (Bits 31..25 are unused.)
|
|
// (We could store the remaining branch length minus 1 in bits 23..16 and not use bits 31..24,
|
|
// but the code looks more confusing that way.)
|
|
UVector32 stack_;
|
|
};
|
|
|
|
U_NAMESPACE_END
|
|
|
|
#endif // __BYTETRIEITERATOR_H__
|