gStore/VSTree/EntryBuffer.cpp

99 lines
1.9 KiB
C++

/*
* EntryBuffer.cpp
*
* Created on: 2014-7-3
* Author: hanshuo
*/
#include"EntryBuffer.h"
using namespace std;
int EntryBuffer::DEFAULT_CAPACITY = 2*1000*1000;
EntryBuffer::EntryBuffer(int _capacity)
{
this->capacity = _capacity;
this->num = 0;
this->elems = new SigEntry[this->capacity];
}
EntryBuffer::~EntryBuffer()
{
delete [] this->elems;
}
int EntryBuffer::getCapacity()const
{
return this->capacity;
}
int EntryBuffer::getNum()const
{
return this->num;
}
bool EntryBuffer::isEmpty()const
{
return (this->num == 0);
}
bool EntryBuffer::isFull()const
{
return (this->num == this->capacity);
}
SigEntry* EntryBuffer::getElem(int _i)
{
return &this->elems[_i];
}
bool EntryBuffer::insert(const SigEntry& _entry)
{
if (this->isFull())
{
cerr << "error, entry buffer is full, can not insert now in EntryBuffer::insert." << endl;
return false;
}
this->elems[this->num ++] = _entry;
return true;
}
/* clear the entry buffer and fill it from the entry file until the buffer is full or the file ends. */
int EntryBuffer::fillElemsFromFile(FILE* _p_file)
{
this->clear();
SigEntry entry;
// bug here! if we read an entry, we must put it into buffer. Otherwise this entry will be missed.
// fread((char *)&entry, sizeof(SigEntry), 1, _p_file);
// while (!this->isFull() && !feof(_p_file))
// {
// this->insert(entry);
// fread((char *)&entry, sizeof(SigEntry), 1, _p_file);
// }
while (!this->isFull())
{
bool is_reach_EOF = feof(_p_file);
bool is_entry_read = (fread((char *)&entry, sizeof(SigEntry), 1, _p_file) == 1);
if (is_reach_EOF || !is_entry_read)
{
break;
}
this->insert(entry);
}
return this->num;
}
void EntryBuffer::clear()
{
this->num = 0;
}