108 lines
2.4 KiB
C++
108 lines
2.4 KiB
C++
/*
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* Copyright (c) 2013, 2014, 2015, 2022 Jonas 'Sortie' Termansen.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* block.cpp
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* Blocks in the filesystem.
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*/
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#include <sys/types.h>
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#include <assert.h>
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#include <stddef.h>
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#include <stdint.h>
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#include "block.h"
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#include "device.h"
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#include "ioleast.h"
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Block::Block()
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{
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this->block_data = NULL;
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}
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Block::Block(Device* device, uint32_t block_id)
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{
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Construct(device, block_id);
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}
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void Block::Construct(Device* device, uint32_t block_id)
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{
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this->prev_block = NULL;
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this->next_block = NULL;
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this->prev_hashed = NULL;
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this->next_hashed = NULL;
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this->device = device;
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this->reference_count = 1;
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this->block_id = block_id;
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}
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Block::~Block()
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{
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Destruct();
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delete[] block_data;
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}
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void Block::Destruct()
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{
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Unlink();
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}
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void Block::Refer()
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{
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reference_count++;
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}
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void Block::Unref()
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{
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if ( !--reference_count )
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{
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#if 0
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device->block_count--;
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delete this;
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#endif
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}
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}
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void Block::Use()
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{
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Unlink();
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Prelink();
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}
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void Block::Unlink()
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{
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(prev_block ? prev_block->next_block : device->mru_block) = next_block;
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(next_block ? next_block->prev_block : device->lru_block) = prev_block;
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size_t bin = block_id % DEVICE_HASH_LENGTH;
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(prev_hashed ? prev_hashed->next_hashed : device->hash_blocks[bin]) = next_hashed;
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if ( next_hashed ) next_hashed->prev_hashed = prev_hashed;
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}
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void Block::Prelink()
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{
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prev_block = NULL;
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next_block = device->mru_block;
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if ( device->mru_block )
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device->mru_block->prev_block = this;
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device->mru_block = this;
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if ( !device->lru_block )
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device->lru_block = this;
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size_t bin = block_id % DEVICE_HASH_LENGTH;
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prev_hashed = NULL;
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next_hashed = device->hash_blocks[bin];
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device->hash_blocks[bin] = this;
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if ( next_hashed )
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next_hashed->prev_hashed = this;
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}
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