cfsa1_impl.hpp
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/*
* File: cfsa1_impl.hpp
* Author: mlenart
*
* Created on November 4, 2013, 1:08 PM
*/
#ifndef CFSA1_IMPL_HPP
#define CFSA1_IMPL_HPP
#include <vector>
#include "fsa.hpp"
#include "../deserializationUtils.hpp"
using namespace std;
static const unsigned char CFSA1_ACCEPTING_FLAG = 128;
static const unsigned char CFSA1_ARRAY_FLAG = 64;
static const unsigned char CFSA1_TRANSITIONS_NUM_MASK = 63;
static const unsigned char CFSA1_OFFSET_SIZE_MASK = 3;
static const unsigned int CFSA1_INITIAL_ARRAY_STATE_OFFSET = 257;
struct StateData2 {
unsigned int transitionsNum;
// bool isArray;
bool isAccepting;
};
struct TransitionData2 {
unsigned int offsetSize;
unsigned int shortLabel;
};
static inline StateData2 readStateData(const unsigned char*& ptr) {
StateData2 res;
unsigned char firstByte = readInt8(ptr);
// res.isArray = firstByte & CFSA1_ARRAY_FLAG;
res.isAccepting = firstByte & CFSA1_ACCEPTING_FLAG;
res.transitionsNum = firstByte & CFSA1_TRANSITIONS_NUM_MASK;
if (res.transitionsNum == CFSA1_TRANSITIONS_NUM_MASK) {
res.transitionsNum = readInt8(ptr);
}
return res;
}
static inline TransitionData2 readTransitionFirstByte(const unsigned char*& ptr) {
TransitionData2 res;
unsigned char firstByte = readInt8(ptr);
res.offsetSize = firstByte & CFSA1_OFFSET_SIZE_MASK;
res.shortLabel = firstByte >> 2;
return res;
}
template <class T>
vector<unsigned char> CompressedFSA1<T>::initializeChar2PopularCharIdx(const unsigned char* ptr) {
return vector<unsigned char>(ptr, ptr + CFSA1_INITIAL_ARRAY_STATE_OFFSET);
}
template <class T>
CompressedFSA1<T>::CompressedFSA1(const unsigned char* ptr, const Deserializer<T>& deserializer)
: FSA<T>(ptr + CFSA1_INITIAL_ARRAY_STATE_OFFSET, deserializer),
label2ShortLabel(initializeChar2PopularCharIdx(ptr)) {
}
template <class T>
CompressedFSA1<T>::~CompressedFSA1() {
}
template <class T>
void CompressedFSA1<T>::reallyDoProceed(
const unsigned char* statePtr,
State<T>& state) const {
const unsigned char* currPtr = statePtr;
const StateData2 sd = readStateData(currPtr);
if (sd.isAccepting) {
T value;
long valueSize = this->deserializer.deserialize(currPtr, value);
state.setNext(statePtr - this->initialStatePtr, value, valueSize);
}
else {
state.setNext(statePtr - this->initialStatePtr);
}
}
template <class T>
void CompressedFSA1<T>::proceedToNext(const char c, State<T>& state) const {
const unsigned char* currPtr = this->initialStatePtr + state.getOffset();
unsigned char shortLabel = this->label2ShortLabel[(const unsigned char) c];
const StateData2 sd = readStateData(currPtr);
if (state.isAccepting()) {
currPtr += state.getValueSize();
}
bool found = false;
TransitionData2 td;
for (unsigned int i = 0; i < sd.transitionsNum; i++) {
td = readTransitionFirstByte(currPtr);
if (td.shortLabel == shortLabel) {
if (shortLabel == 0) {
char label = static_cast<char> (readInt8(currPtr));
if (label == c) {
found = true;
break;
}
else {
currPtr += td.offsetSize;
}
}
else {
found = true;
break;
}
}
else {
if (td.shortLabel == 0) {
currPtr++;
}
currPtr += td.offsetSize;
}
}
if (!found) {
state.setNextAsSink();
}
else {
uint32_t offset;
switch (td.offsetSize) {
case 0:
offset = 0;
break;
case 1:
offset = readInt8(currPtr);
break;
case 2:
offset = readInt16(currPtr);
break;
case 3:
offset = readInt24(currPtr);
break;
default:
cerr << "Offset size = " << td.offsetSize << endl;
throw FileFormatException("Invalid file format");
}
currPtr += offset;
reallyDoProceed(currPtr, state);
}
}
#endif /* CFSA1_IMPL_HPP */