0588de76bb
Reviewers: buda Reviewed By: buda Subscribers: pullbot Differential Revision: https://phabricator.memgraph.io/D526
57 lines
1.2 KiB
C++
57 lines
1.2 KiB
C++
#pragma once
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#include <memory>
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#include <vector>
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#include "utils/auto_scope.hpp"
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/* @brief Allocates blocks of block_size and stores
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* the pointers on allocated blocks inside a vector.
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*/
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template <size_t block_size>
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class BlockAllocator {
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struct Block {
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Block() { data = malloc(block_size); }
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Block(void *ptr) { data = ptr; }
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void *data;
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};
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public:
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static constexpr size_t size = block_size;
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BlockAllocator(size_t capacity = 0) {
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for (size_t i = 0; i < capacity; ++i) unused_.emplace_back();
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}
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~BlockAllocator() {
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for (auto block : unused_) free(block.data);
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unused_.clear();
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for (auto block : release_) free(block.data);
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release_.clear();
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}
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size_t unused_size() const { return unused_.size(); }
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size_t release_size() const { return release_.size(); }
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// Returns nullptr on no memory.
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void *acquire() {
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if (unused_.size() == 0) unused_.emplace_back();
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auto ptr = unused_.back().data;
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Auto(unused_.pop_back());
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return ptr;
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}
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void release(void *ptr) { release_.emplace_back(ptr); }
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private:
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// TODO: try implement with just one vector
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// but consecutive acquire release calls should work
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// TODO: measure first!
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std::vector<Block> unused_;
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std::vector<Block> release_;
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};
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