michael@0: /*
michael@0: *******************************************************************************
michael@0: *   Copyright (C) 2010-2011, International Business Machines
michael@0: *   Corporation and others.  All Rights Reserved.
michael@0: *******************************************************************************
michael@0: *   file name:  ucharstrie.h
michael@0: *   encoding:   US-ASCII
michael@0: *   tab size:   8 (not used)
michael@0: *   indentation:4
michael@0: *
michael@0: *   created on: 2010nov14
michael@0: *   created by: Markus W. Scherer
michael@0: */
michael@0: 
michael@0: #include "unicode/utypes.h"
michael@0: #include "unicode/appendable.h"
michael@0: #include "unicode/ucharstrie.h"
michael@0: #include "unicode/uobject.h"
michael@0: #include "unicode/utf16.h"
michael@0: #include "cmemory.h"
michael@0: #include "uassert.h"
michael@0: 
michael@0: U_NAMESPACE_BEGIN
michael@0: 
michael@0: UCharsTrie::~UCharsTrie() {
michael@0:     uprv_free(ownedArray_);
michael@0: }
michael@0: 
michael@0: UStringTrieResult
michael@0: UCharsTrie::current() const {
michael@0:     const UChar *pos=pos_;
michael@0:     if(pos==NULL) {
michael@0:         return USTRINGTRIE_NO_MATCH;
michael@0:     } else {
michael@0:         int32_t node;
michael@0:         return (remainingMatchLength_<0 && (node=*pos)>=kMinValueLead) ?
michael@0:                 valueResult(node) : USTRINGTRIE_NO_VALUE;
michael@0:     }
michael@0: }
michael@0: 
michael@0: UStringTrieResult
michael@0: UCharsTrie::firstForCodePoint(UChar32 cp) {
michael@0:     return cp<=0xffff ?
michael@0:         first(cp) :
michael@0:         (USTRINGTRIE_HAS_NEXT(first(U16_LEAD(cp))) ?
michael@0:             next(U16_TRAIL(cp)) :
michael@0:             USTRINGTRIE_NO_MATCH);
michael@0: }
michael@0: 
michael@0: UStringTrieResult
michael@0: UCharsTrie::nextForCodePoint(UChar32 cp) {
michael@0:     return cp<=0xffff ?
michael@0:         next(cp) :
michael@0:         (USTRINGTRIE_HAS_NEXT(next(U16_LEAD(cp))) ?
michael@0:             next(U16_TRAIL(cp)) :
michael@0:             USTRINGTRIE_NO_MATCH);
michael@0: }
michael@0: 
michael@0: UStringTrieResult
michael@0: UCharsTrie::branchNext(const UChar *pos, int32_t length, int32_t uchar) {
michael@0:     // Branch according to the current unit.
michael@0:     if(length==0) {
michael@0:         length=*pos++;
michael@0:     }
michael@0:     ++length;
michael@0:     // The length of the branch is the number of units to select from.
michael@0:     // The data structure encodes a binary search.
michael@0:     while(length>kMaxBranchLinearSubNodeLength) {
michael@0:         if(uchar<*pos++) {
michael@0:             length>>=1;
michael@0:             pos=jumpByDelta(pos);
michael@0:         } else {
michael@0:             length=length-(length>>1);
michael@0:             pos=skipDelta(pos);
michael@0:         }
michael@0:     }
michael@0:     // Drop down to linear search for the last few units.
michael@0:     // length>=2 because the loop body above sees length>kMaxBranchLinearSubNodeLength>=3
michael@0:     // and divides length by 2.
michael@0:     do {
michael@0:         if(uchar==*pos++) {
michael@0:             UStringTrieResult result;
michael@0:             int32_t node=*pos;
michael@0:             if(node&kValueIsFinal) {
michael@0:                 // Leave the final value for getValue() to read.
michael@0:                 result=USTRINGTRIE_FINAL_VALUE;
michael@0:             } else {
michael@0:                 // Use the non-final value as the jump delta.
michael@0:                 ++pos;
michael@0:                 // int32_t delta=readValue(pos, node);
michael@0:                 int32_t delta;
michael@0:                 if(node<kMinTwoUnitValueLead) {
michael@0:                     delta=node;
michael@0:                 } else if(node<kThreeUnitValueLead) {
michael@0:                     delta=((node-kMinTwoUnitValueLead)<<16)|*pos++;
michael@0:                 } else {
michael@0:                     delta=(pos[0]<<16)|pos[1];
michael@0:                     pos+=2;
michael@0:                 }
michael@0:                 // end readValue()
michael@0:                 pos+=delta;
michael@0:                 node=*pos;
michael@0:                 result= node>=kMinValueLead ? valueResult(node) : USTRINGTRIE_NO_VALUE;
michael@0:             }
michael@0:             pos_=pos;
michael@0:             return result;
michael@0:         }
michael@0:         --length;
michael@0:         pos=skipValue(pos);
michael@0:     } while(length>1);
michael@0:     if(uchar==*pos++) {
michael@0:         pos_=pos;
michael@0:         int32_t node=*pos;
michael@0:         return node>=kMinValueLead ? valueResult(node) : USTRINGTRIE_NO_VALUE;
michael@0:     } else {
michael@0:         stop();
michael@0:         return USTRINGTRIE_NO_MATCH;
michael@0:     }
michael@0: }
michael@0: 
michael@0: UStringTrieResult
michael@0: UCharsTrie::nextImpl(const UChar *pos, int32_t uchar) {
michael@0:     int32_t node=*pos++;
michael@0:     for(;;) {
michael@0:         if(node<kMinLinearMatch) {
michael@0:             return branchNext(pos, node, uchar);
michael@0:         } else if(node<kMinValueLead) {
michael@0:             // Match the first of length+1 units.
michael@0:             int32_t length=node-kMinLinearMatch;  // Actual match length minus 1.
michael@0:             if(uchar==*pos++) {
michael@0:                 remainingMatchLength_=--length;
michael@0:                 pos_=pos;
michael@0:                 return (length<0 && (node=*pos)>=kMinValueLead) ?
michael@0:                         valueResult(node) : USTRINGTRIE_NO_VALUE;
michael@0:             } else {
michael@0:                 // No match.
michael@0:                 break;
michael@0:             }
michael@0:         } else if(node&kValueIsFinal) {
michael@0:             // No further matching units.
michael@0:             break;
michael@0:         } else {
michael@0:             // Skip intermediate value.
michael@0:             pos=skipNodeValue(pos, node);
michael@0:             node&=kNodeTypeMask;
michael@0:         }
michael@0:     }
michael@0:     stop();
michael@0:     return USTRINGTRIE_NO_MATCH;
michael@0: }
michael@0: 
michael@0: UStringTrieResult
michael@0: UCharsTrie::next(int32_t uchar) {
michael@0:     const UChar *pos=pos_;
michael@0:     if(pos==NULL) {
michael@0:         return USTRINGTRIE_NO_MATCH;
michael@0:     }
michael@0:     int32_t length=remainingMatchLength_;  // Actual remaining match length minus 1.
michael@0:     if(length>=0) {
michael@0:         // Remaining part of a linear-match node.
michael@0:         if(uchar==*pos++) {
michael@0:             remainingMatchLength_=--length;
michael@0:             pos_=pos;
michael@0:             int32_t node;
michael@0:             return (length<0 && (node=*pos)>=kMinValueLead) ?
michael@0:                     valueResult(node) : USTRINGTRIE_NO_VALUE;
michael@0:         } else {
michael@0:             stop();
michael@0:             return USTRINGTRIE_NO_MATCH;
michael@0:         }
michael@0:     }
michael@0:     return nextImpl(pos, uchar);
michael@0: }
michael@0: 
michael@0: UStringTrieResult
michael@0: UCharsTrie::next(const UChar *s, int32_t sLength) {
michael@0:     if(sLength<0 ? *s==0 : sLength==0) {
michael@0:         // Empty input.
michael@0:         return current();
michael@0:     }
michael@0:     const UChar *pos=pos_;
michael@0:     if(pos==NULL) {
michael@0:         return USTRINGTRIE_NO_MATCH;
michael@0:     }
michael@0:     int32_t length=remainingMatchLength_;  // Actual remaining match length minus 1.
michael@0:     for(;;) {
michael@0:         // Fetch the next input unit, if there is one.
michael@0:         // Continue a linear-match node without rechecking sLength<0.
michael@0:         int32_t uchar;
michael@0:         if(sLength<0) {
michael@0:             for(;;) {
michael@0:                 if((uchar=*s++)==0) {
michael@0:                     remainingMatchLength_=length;
michael@0:                     pos_=pos;
michael@0:                     int32_t node;
michael@0:                     return (length<0 && (node=*pos)>=kMinValueLead) ?
michael@0:                             valueResult(node) : USTRINGTRIE_NO_VALUE;
michael@0:                 }
michael@0:                 if(length<0) {
michael@0:                     remainingMatchLength_=length;
michael@0:                     break;
michael@0:                 }
michael@0:                 if(uchar!=*pos) {
michael@0:                     stop();
michael@0:                     return USTRINGTRIE_NO_MATCH;
michael@0:                 }
michael@0:                 ++pos;
michael@0:                 --length;
michael@0:             }
michael@0:         } else {
michael@0:             for(;;) {
michael@0:                 if(sLength==0) {
michael@0:                     remainingMatchLength_=length;
michael@0:                     pos_=pos;
michael@0:                     int32_t node;
michael@0:                     return (length<0 && (node=*pos)>=kMinValueLead) ?
michael@0:                             valueResult(node) : USTRINGTRIE_NO_VALUE;
michael@0:                 }
michael@0:                 uchar=*s++;
michael@0:                 --sLength;
michael@0:                 if(length<0) {
michael@0:                     remainingMatchLength_=length;
michael@0:                     break;
michael@0:                 }
michael@0:                 if(uchar!=*pos) {
michael@0:                     stop();
michael@0:                     return USTRINGTRIE_NO_MATCH;
michael@0:                 }
michael@0:                 ++pos;
michael@0:                 --length;
michael@0:             }
michael@0:         }
michael@0:         int32_t node=*pos++;
michael@0:         for(;;) {
michael@0:             if(node<kMinLinearMatch) {
michael@0:                 UStringTrieResult result=branchNext(pos, node, uchar);
michael@0:                 if(result==USTRINGTRIE_NO_MATCH) {
michael@0:                     return USTRINGTRIE_NO_MATCH;
michael@0:                 }
michael@0:                 // Fetch the next input unit, if there is one.
michael@0:                 if(sLength<0) {
michael@0:                     if((uchar=*s++)==0) {
michael@0:                         return result;
michael@0:                     }
michael@0:                 } else {
michael@0:                     if(sLength==0) {
michael@0:                         return result;
michael@0:                     }
michael@0:                     uchar=*s++;
michael@0:                     --sLength;
michael@0:                 }
michael@0:                 if(result==USTRINGTRIE_FINAL_VALUE) {
michael@0:                     // No further matching units.
michael@0:                     stop();
michael@0:                     return USTRINGTRIE_NO_MATCH;
michael@0:                 }
michael@0:                 pos=pos_;  // branchNext() advanced pos and wrote it to pos_ .
michael@0:                 node=*pos++;
michael@0:             } else if(node<kMinValueLead) {
michael@0:                 // Match length+1 units.
michael@0:                 length=node-kMinLinearMatch;  // Actual match length minus 1.
michael@0:                 if(uchar!=*pos) {
michael@0:                     stop();
michael@0:                     return USTRINGTRIE_NO_MATCH;
michael@0:                 }
michael@0:                 ++pos;
michael@0:                 --length;
michael@0:                 break;
michael@0:             } else if(node&kValueIsFinal) {
michael@0:                 // No further matching units.
michael@0:                 stop();
michael@0:                 return USTRINGTRIE_NO_MATCH;
michael@0:             } else {
michael@0:                 // Skip intermediate value.
michael@0:                 pos=skipNodeValue(pos, node);
michael@0:                 node&=kNodeTypeMask;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: const UChar *
michael@0: UCharsTrie::findUniqueValueFromBranch(const UChar *pos, int32_t length,
michael@0:                                       UBool haveUniqueValue, int32_t &uniqueValue) {
michael@0:     while(length>kMaxBranchLinearSubNodeLength) {
michael@0:         ++pos;  // ignore the comparison unit
michael@0:         if(NULL==findUniqueValueFromBranch(jumpByDelta(pos), length>>1, haveUniqueValue, uniqueValue)) {
michael@0:             return NULL;
michael@0:         }
michael@0:         length=length-(length>>1);
michael@0:         pos=skipDelta(pos);
michael@0:     }
michael@0:     do {
michael@0:         ++pos;  // ignore a comparison unit
michael@0:         // handle its value
michael@0:         int32_t node=*pos++;
michael@0:         UBool isFinal=(UBool)(node>>15);
michael@0:         node&=0x7fff;
michael@0:         int32_t value=readValue(pos, node);
michael@0:         pos=skipValue(pos, node);
michael@0:         if(isFinal) {
michael@0:             if(haveUniqueValue) {
michael@0:                 if(value!=uniqueValue) {
michael@0:                     return NULL;
michael@0:                 }
michael@0:             } else {
michael@0:                 uniqueValue=value;
michael@0:                 haveUniqueValue=TRUE;
michael@0:             }
michael@0:         } else {
michael@0:             if(!findUniqueValue(pos+value, haveUniqueValue, uniqueValue)) {
michael@0:                 return NULL;
michael@0:             }
michael@0:             haveUniqueValue=TRUE;
michael@0:         }
michael@0:     } while(--length>1);
michael@0:     return pos+1;  // ignore the last comparison unit
michael@0: }
michael@0: 
michael@0: UBool
michael@0: UCharsTrie::findUniqueValue(const UChar *pos, UBool haveUniqueValue, int32_t &uniqueValue) {
michael@0:     int32_t node=*pos++;
michael@0:     for(;;) {
michael@0:         if(node<kMinLinearMatch) {
michael@0:             if(node==0) {
michael@0:                 node=*pos++;
michael@0:             }
michael@0:             pos=findUniqueValueFromBranch(pos, node+1, haveUniqueValue, uniqueValue);
michael@0:             if(pos==NULL) {
michael@0:                 return FALSE;
michael@0:             }
michael@0:             haveUniqueValue=TRUE;
michael@0:             node=*pos++;
michael@0:         } else if(node<kMinValueLead) {
michael@0:             // linear-match node
michael@0:             pos+=node-kMinLinearMatch+1;  // Ignore the match units.
michael@0:             node=*pos++;
michael@0:         } else {
michael@0:             UBool isFinal=(UBool)(node>>15);
michael@0:             int32_t value;
michael@0:             if(isFinal) {
michael@0:                 value=readValue(pos, node&0x7fff);
michael@0:             } else {
michael@0:                 value=readNodeValue(pos, node);
michael@0:             }
michael@0:             if(haveUniqueValue) {
michael@0:                 if(value!=uniqueValue) {
michael@0:                     return FALSE;
michael@0:                 }
michael@0:             } else {
michael@0:                 uniqueValue=value;
michael@0:                 haveUniqueValue=TRUE;
michael@0:             }
michael@0:             if(isFinal) {
michael@0:                 return TRUE;
michael@0:             }
michael@0:             pos=skipNodeValue(pos, node);
michael@0:             node&=kNodeTypeMask;
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: int32_t
michael@0: UCharsTrie::getNextUChars(Appendable &out) const {
michael@0:     const UChar *pos=pos_;
michael@0:     if(pos==NULL) {
michael@0:         return 0;
michael@0:     }
michael@0:     if(remainingMatchLength_>=0) {
michael@0:         out.appendCodeUnit(*pos);  // Next unit of a pending linear-match node.
michael@0:         return 1;
michael@0:     }
michael@0:     int32_t node=*pos++;
michael@0:     if(node>=kMinValueLead) {
michael@0:         if(node&kValueIsFinal) {
michael@0:             return 0;
michael@0:         } else {
michael@0:             pos=skipNodeValue(pos, node);
michael@0:             node&=kNodeTypeMask;
michael@0:         }
michael@0:     }
michael@0:     if(node<kMinLinearMatch) {
michael@0:         if(node==0) {
michael@0:             node=*pos++;
michael@0:         }
michael@0:         out.reserveAppendCapacity(++node);
michael@0:         getNextBranchUChars(pos, node, out);
michael@0:         return node;
michael@0:     } else {
michael@0:         // First unit of the linear-match node.
michael@0:         out.appendCodeUnit(*pos);
michael@0:         return 1;
michael@0:     }
michael@0: }
michael@0: 
michael@0: void
michael@0: UCharsTrie::getNextBranchUChars(const UChar *pos, int32_t length, Appendable &out) {
michael@0:     while(length>kMaxBranchLinearSubNodeLength) {
michael@0:         ++pos;  // ignore the comparison unit
michael@0:         getNextBranchUChars(jumpByDelta(pos), length>>1, out);
michael@0:         length=length-(length>>1);
michael@0:         pos=skipDelta(pos);
michael@0:     }
michael@0:     do {
michael@0:         out.appendCodeUnit(*pos++);
michael@0:         pos=skipValue(pos);
michael@0:     } while(--length>1);
michael@0:     out.appendCodeUnit(*pos);
michael@0: }
michael@0: 
michael@0: U_NAMESPACE_END