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/*
Copyright(C) 2011-2016 Brazil
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#pragma once
#include "dat.hpp"
namespace grn {
namespace dat {
class GRN_DAT_API Block {
public:
Block() : next_(0), prev_(0), first_phantom_(0), num_phantoms_(0) {}
// Blocks in the same level are stored in a doubly-linked list which is
// represented by the following next() and prev().
UInt32 next() const {
return next_ / BLOCK_SIZE;
}
UInt32 prev() const {
return prev_ / BLOCK_SIZE;
}
// A level indicates how easyily find_offset() can find a good offset in that
// block. It is easier in lower level blocks.
UInt32 level() const {
return next_ & BLOCK_MASK;
}
// A block level rises when find_offset() fails to find a good offset
// MAX_FAILURE_COUNT times in that block.
UInt32 failure_count() const {
return prev_ & BLOCK_MASK;
}
UInt32 first_phantom() const {
return first_phantom_;
}
UInt32 num_phantoms() const {
return num_phantoms_;
}
void set_next(UInt32 x) {
GRN_DAT_DEBUG_THROW_IF(x > MAX_BLOCK_ID);
next_ = (next_ & BLOCK_MASK) | (x * BLOCK_SIZE);
}
void set_prev(UInt32 x) {
GRN_DAT_DEBUG_THROW_IF(x > MAX_BLOCK_ID);
prev_ = (prev_ & BLOCK_MASK) | (x * BLOCK_SIZE);
}
void set_level(UInt32 x) {
GRN_DAT_DEBUG_THROW_IF(x > MAX_BLOCK_LEVEL);
GRN_DAT_DEBUG_THROW_IF(x > BLOCK_MASK);
next_ = (next_ & ~BLOCK_MASK) | x;
}
void set_failure_count(UInt32 x) {
GRN_DAT_DEBUG_THROW_IF(x > MAX_FAILURE_COUNT);
GRN_DAT_DEBUG_THROW_IF(x > BLOCK_MASK);
prev_ = (prev_ & ~BLOCK_MASK) | x;
}
void set_first_phantom(UInt32 x) {
GRN_DAT_DEBUG_THROW_IF(x >= BLOCK_SIZE);
first_phantom_ = (UInt16)x;
}
void set_num_phantoms(UInt32 x) {
GRN_DAT_DEBUG_THROW_IF(x > BLOCK_SIZE);
num_phantoms_ = (UInt16)x;
}
private:
UInt32 next_;
UInt32 prev_;
UInt16 first_phantom_;
UInt16 num_phantoms_;
};
} // namespace dat
} // namespace grn
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