/*
*******************************************************************************
* Copyright (C) 2010-2012, International Business Machines
* Corporation and others. All Rights Reserved.
*******************************************************************************
* file name: bytestriebuilder.cpp
* encoding: US-ASCII
* tab size: 8 (not used)
* indentation:4
*
* created on: 2010sep25
* created by: Markus W. Scherer
*/
#include "unicode/utypes.h"
#include "unicode/bytestrie.h"
#include "unicode/bytestriebuilder.h"
#include "unicode/stringpiece.h"
#include "charstr.h"
#include "cmemory.h"
#include "uhash.h"
#include "uarrsort.h"
#include "uassert.h"
#include "ustr_imp.h"
U_NAMESPACE_BEGIN
/*
* Note: This builder implementation stores (bytes, value) pairs with full copies
* of the byte sequences, until the BytesTrie is built.
* It might(!) take less memory if we collected the data in a temporary, dynamic trie.
*/
class BytesTrieElement : public UMemory {
public:
// Use compiler's default constructor, initializes nothing.
void setTo(const StringPiece &s, int32_t val, CharString &strings, UErrorCode &errorCode);
StringPiece getString(const CharString &strings) const {
int32_t offset=stringOffset;
int32_t length;
if(offset>=0) {
length=(uint8_t)strings[offset++];
} else {
offset=~offset;
length=((int32_t)(uint8_t)strings[offset]<<8)|(uint8_t)strings[offset+1];
offset+=2;
}
return StringPiece(strings.data()+offset, length);
}
int32_t getStringLength(const CharString &strings) const {
int32_t offset=stringOffset;
if(offset>=0) {
return (uint8_t)strings[offset];
} else {
offset=~offset;
return ((int32_t)(uint8_t)strings[offset]<<8)|(uint8_t)strings[offset+1];
}
}
char charAt(int32_t index, const CharString &strings) const { return data(strings)[index]; }
int32_t getValue() const { return value; }
int32_t compareStringTo(const BytesTrieElement &o, const CharString &strings) const;
private:
const char *data(const CharString &strings) const {
int32_t offset=stringOffset;
if(offset>=0) {
++offset;
} else {
offset=~offset+2;
}
return strings.data()+offset;
}
// If the stringOffset is non-negative, then the first strings byte contains
// the string length.
// If the stringOffset is negative, then the first two strings bytes contain
// the string length (big-endian), and the offset needs to be bit-inverted.
// (Compared with a stringLength field here, this saves 3 bytes per string for most strings.)
int32_t stringOffset;
int32_t value;
};
void
BytesTrieElement::setTo(const StringPiece &s, int32_t val,
CharString &strings, UErrorCode &errorCode) {
if(U_FAILURE(errorCode)) {
return;
}
int32_t length=s.length();
if(length>0xffff) {
// Too long: We store the length in 1 or 2 bytes.
errorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return;
}
int32_t offset=strings.length();
if(length>0xff) {
offset=~offset;
strings.append((char)(length>>8), errorCode);
}
strings.append((char)length, errorCode);
stringOffset=offset;
value=val;
strings.append(s, errorCode);
}
int32_t
BytesTrieElement::compareStringTo(const BytesTrieElement &other, const CharString &strings) const {
// TODO: add StringPiece::compare(), see ticket #8187
StringPiece thisString=getString(strings);
StringPiece otherString=other.getString(strings);
int32_t lengthDiff=thisString.length()-otherString.length();
int32_t commonLength;
if(lengthDiff<=0) {
commonLength=thisString.length();
} else {
commonLength=otherString.length();
}
int32_t diff=uprv_memcmp(thisString.data(), otherString.data(), commonLength);
return diff!=0 ? diff : lengthDiff;
}
BytesTrieBuilder::BytesTrieBuilder(UErrorCode &errorCode)
: strings(NULL), elements(NULL), elementsCapacity(0), elementsLength(0),
bytes(NULL), bytesCapacity(0), bytesLength(0) {
if(U_FAILURE(errorCode)) {
return;
}
strings=new CharString();
if(strings==NULL) {
errorCode=U_MEMORY_ALLOCATION_ERROR;
}
}
BytesTrieBuilder::~BytesTrieBuilder() {
delete strings;
delete[] elements;
uprv_free(bytes);
}
BytesTrieBuilder &
BytesTrieBuilder::add(const StringPiece &s, int32_t value, UErrorCode &errorCode) {
if(U_FAILURE(errorCode)) {
return *this;
}
if(bytesLength>0) {
// Cannot add elements after building.
errorCode=U_NO_WRITE_PERMISSION;
return *this;
}
if(elementsLength==elementsCapacity) {
int32_t newCapacity;
if(elementsCapacity==0) {
newCapacity=1024;
} else {
newCapacity=4*elementsCapacity;
}
BytesTrieElement *newElements=new BytesTrieElement[newCapacity];
if(newElements==NULL) {
errorCode=U_MEMORY_ALLOCATION_ERROR;
return *this; // error instead of dereferencing null
}
if(elementsLength>0) {
uprv_memcpy(newElements, elements, elementsLength*sizeof(BytesTrieElement));
}
delete[] elements;
elements=newElements;
elementsCapacity=newCapacity;
}
elements[elementsLength++].setTo(s, value, *strings, errorCode);
return *this;
}
U_CDECL_BEGIN
static int32_t U_CALLCONV
compareElementStrings(const void *context, const void *left, const void *right) {
const CharString *strings=static_cast<const CharString *>(context);
const BytesTrieElement *leftElement=static_cast<const BytesTrieElement *>(left);
const BytesTrieElement *rightElement=static_cast<const BytesTrieElement *>(right);
return leftElement->compareStringTo(*rightElement, *strings);
}
U_CDECL_END
BytesTrie *
BytesTrieBuilder::build(UStringTrieBuildOption buildOption, UErrorCode &errorCode) {
buildBytes(buildOption, errorCode);
BytesTrie *newTrie=NULL;
if(U_SUCCESS(errorCode)) {
newTrie=new BytesTrie(bytes, bytes+(bytesCapacity-bytesLength));
if(newTrie==NULL) {
errorCode=U_MEMORY_ALLOCATION_ERROR;
} else {
bytes=NULL; // The new trie now owns the array.
bytesCapacity=0;
}
}
return newTrie;
}
StringPiece
BytesTrieBuilder::buildStringPiece(UStringTrieBuildOption buildOption, UErrorCode &errorCode) {
buildBytes(buildOption, errorCode);
StringPiece result;
if(U_SUCCESS(errorCode)) {
result.set(bytes+(bytesCapacity-bytesLength), bytesLength);
}
return result;
}
void
BytesTrieBuilder::buildBytes(UStringTrieBuildOption buildOption, UErrorCode &errorCode) {
if(U_FAILURE(errorCode)) {
return;
}
if(bytes!=NULL && bytesLength>0) {
// Already built.
return;
}
if(bytesLength==0) {
if(elementsLength==0) {
errorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return;
}
uprv_sortArray(elements, elementsLength, (int32_t)sizeof(BytesTrieElement),
compareElementStrings, strings,
FALSE, // need not be a stable sort
&errorCode);
if(U_FAILURE(errorCode)) {
return;
}
// Duplicate strings are not allowed.
StringPiece prev=elements[0].getString(*strings);
for(int32_t i=1; i<elementsLength; ++i) {
StringPiece current=elements[i].getString(*strings);
if(prev==current) {
errorCode=U_ILLEGAL_ARGUMENT_ERROR;
return;
}
prev=current;
}
}
// Create and byte-serialize the trie for the elements.
bytesLength=0;
int32_t capacity=strings->length();
if(capacity<1024) {
capacity=1024;
}
if(bytesCapacity<capacity) {
uprv_free(bytes);
bytes=static_cast<char *>(uprv_malloc(capacity));
if(bytes==NULL) {
errorCode=U_MEMORY_ALLOCATION_ERROR;
bytesCapacity=0;
return;
}
bytesCapacity=capacity;
}
StringTrieBuilder::build(buildOption, elementsLength, errorCode);
if(bytes==NULL) {
errorCode=U_MEMORY_ALLOCATION_ERROR;
}
}
BytesTrieBuilder &
BytesTrieBuilder::clear() {
strings->clear();
elementsLength=0;
bytesLength=0;
return *this;
}
int32_t
BytesTrieBuilder::getElementStringLength(int32_t i) const {
return elements[i].getStringLength(*strings);
}
UChar
BytesTrieBuilder::getElementUnit(int32_t i, int32_t byteIndex) const {
return (uint8_t)elements[i].charAt(byteIndex, *strings);
}
int32_t
BytesTrieBuilder::getElementValue(int32_t i) const {
return elements[i].getValue();
}
int32_t
BytesTrieBuilder::getLimitOfLinearMatch(int32_t first, int32_t last, int32_t byteIndex) const {
const BytesTrieElement &firstElement=elements[first];
const BytesTrieElement &lastElement=elements[last];
int32_t minStringLength=firstElement.getStringLength(*strings);
while(++byteIndex<minStringLength &&
firstElement.charAt(byteIndex, *strings)==
lastElement.charAt(byteIndex, *strings)) {}
return byteIndex;
}
int32_t
BytesTrieBuilder::countElementUnits(int32_t start, int32_t limit, int32_t byteIndex) const {
int32_t length=0; // Number of different bytes at byteIndex.
int32_t i=start;
do {
char byte=elements[i++].charAt(byteIndex, *strings);
while(i<limit && byte==elements[i].charAt(byteIndex, *strings)) {
++i;
}
++length;
} while(i<limit);
return length;
}
int32_t
BytesTrieBuilder::skipElementsBySomeUnits(int32_t i, int32_t byteIndex, int32_t count) const {
do {
char byte=elements[i++].charAt(byteIndex, *strings);
while(byte==elements[i].charAt(byteIndex, *strings)) {
++i;
}
} while(--count>0);
return i;
}
int32_t
BytesTrieBuilder::indexOfElementWithNextUnit(int32_t i, int32_t byteIndex, UChar byte) const {
char b=(char)byte;
while(b==elements[i].charAt(byteIndex, *strings)) {
++i;
}
return i;
}
BytesTrieBuilder::BTLinearMatchNode::BTLinearMatchNode(const char *bytes, int32_t len, Node *nextNode)
: LinearMatchNode(len, nextNode), s(bytes) {
hash=hash*37+ustr_hashCharsN(bytes, len);
}
UBool
BytesTrieBuilder::BTLinearMatchNode::operator==(const Node &other) const {
if(this==&other) {
return TRUE;
}
if(!LinearMatchNode::operator==(other)) {
return FALSE;
}
const BTLinearMatchNode &o=(const BTLinearMatchNode &)other;
return 0==uprv_memcmp(s, o.s, length);
}
void
BytesTrieBuilder::BTLinearMatchNode::write(StringTrieBuilder &builder) {
BytesTrieBuilder &b=(BytesTrieBuilder &)builder;
next->write(builder);
b.write(s, length);
offset=b.write(b.getMinLinearMatch()+length-1);
}
StringTrieBuilder::Node *
BytesTrieBuilder::createLinearMatchNode(int32_t i, int32_t byteIndex, int32_t length,
Node *nextNode) const {
return new BTLinearMatchNode(
elements[i].getString(*strings).data()+byteIndex,
length,
nextNode);
}
UBool
BytesTrieBuilder::ensureCapacity(int32_t length) {
if(bytes==NULL) {
return FALSE; // previous memory allocation had failed
}
if(length>bytesCapacity) {
int32_t newCapacity=bytesCapacity;
do {
newCapacity*=2;
} while(newCapacity<=length);
char *newBytes=static_cast<char *>(uprv_malloc(newCapacity));
if(newBytes==NULL) {
// unable to allocate memory
uprv_free(bytes);
bytes=NULL;
bytesCapacity=0;
return FALSE;
}
uprv_memcpy(newBytes+(newCapacity-bytesLength),
bytes+(bytesCapacity-bytesLength), bytesLength);
uprv_free(bytes);
bytes=newBytes;
bytesCapacity=newCapacity;
}
return TRUE;
}
int32_t
BytesTrieBuilder::write(int32_t byte) {
int32_t newLength=bytesLength+1;
if(ensureCapacity(newLength)) {
bytesLength=newLength;
bytes[bytesCapacity-bytesLength]=(char)byte;
}
return bytesLength;
}
int32_t
BytesTrieBuilder::write(const char *b, int32_t length) {
int32_t newLength=bytesLength+length;
if(ensureCapacity(newLength)) {
bytesLength=newLength;
uprv_memcpy(bytes+(bytesCapacity-bytesLength), b, length);
}
return bytesLength;
}
int32_t
BytesTrieBuilder::writeElementUnits(int32_t i, int32_t byteIndex, int32_t length) {
return write(elements[i].getString(*strings).data()+byteIndex, length);
}
int32_t
BytesTrieBuilder::writeValueAndFinal(int32_t i, UBool isFinal) {
if(0<=i && i<=BytesTrie::kMaxOneByteValue) {
return write(((BytesTrie::kMinOneByteValueLead+i)<<1)|isFinal);
}
char intBytes[5];
int32_t length=1;
if(i<0 || i>0xffffff) {
intBytes[0]=(char)BytesTrie::kFiveByteValueLead;
intBytes[1]=(char)((uint32_t)i>>24);
intBytes[2]=(char)((uint32_t)i>>16);
intBytes[3]=(char)((uint32_t)i>>8);
intBytes[4]=(char)i;
length=5;
// } else if(i<=BytesTrie::kMaxOneByteValue) {
// intBytes[0]=(char)(BytesTrie::kMinOneByteValueLead+i);
} else {
if(i<=BytesTrie::kMaxTwoByteValue) {
intBytes[0]=(char)(BytesTrie::kMinTwoByteValueLead+(i>>8));
} else {
if(i<=BytesTrie::kMaxThreeByteValue) {
intBytes[0]=(char)(BytesTrie::kMinThreeByteValueLead+(i>>16));
} else {
intBytes[0]=(char)BytesTrie::kFourByteValueLead;
intBytes[1]=(char)(i>>16);
length=2;
}
intBytes[length++]=(char)(i>>8);
}
intBytes[length++]=(char)i;
}
intBytes[0]=(char)((intBytes[0]<<1)|isFinal);
return write(intBytes, length);
}
int32_t
BytesTrieBuilder::writeValueAndType(UBool hasValue, int32_t value, int32_t node) {
int32_t offset=write(node);
if(hasValue) {
offset=writeValueAndFinal(value, FALSE);
}
return offset;
}
int32_t
BytesTrieBuilder::writeDeltaTo(int32_t jumpTarget) {
int32_t i=bytesLength-jumpTarget;
U_ASSERT(i>=0);
if(i<=BytesTrie::kMaxOneByteDelta) {
return write(i);
}
char intBytes[5];
int32_t length;
if(i<=BytesTrie::kMaxTwoByteDelta) {
intBytes[0]=(char)(BytesTrie::kMinTwoByteDeltaLead+(i>>8));
length=1;
} else {
if(i<=BytesTrie::kMaxThreeByteDelta) {
intBytes[0]=(char)(BytesTrie::kMinThreeByteDeltaLead+(i>>16));
length=2;
} else {
if(i<=0xffffff) {
intBytes[0]=(char)BytesTrie::kFourByteDeltaLead;
length=3;
} else {
intBytes[0]=(char)BytesTrie::kFiveByteDeltaLead;
intBytes[1]=(char)(i>>24);
length=4;
}
intBytes[1]=(char)(i>>16);
}
intBytes[1]=(char)(i>>8);
}
intBytes[length++]=(char)i;
return write(intBytes, length);
}
U_NAMESPACE_END