c368c6afe8
Summary: * Mostly, remove `sample_for_compression` from CompressionInfo because it's not used by the core function it serves, `CompressData()`. Confusing (and inefficient), especially in db_bench where it appears to use `FLAGS_sample_for_compression` in places where it is actually ignored. * Various clarifying comments, clean-ups, and tiny optimizations * Prepare some structures like `CompressionDict` for more usage * Some TODOs and FIXMEs about some things I've noticed are amiss, confusing, or excessive * A notable optimization opportunity that might become a "pay as you go" improvement for the potential indirection costs of customizable compression: use C++23's resize_and_overwrite() in compress functions to avoid zeroing the string buffer contents before populating it. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13539 Test Plan: existing tests / CI Reviewed By: hx235 Differential Revision: D73451273 Pulled By: pdillinger fbshipit-source-id: 0373627466d695043d21146ce34d52f189ae9432
47 lines
1.3 KiB
C++
47 lines
1.3 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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#pragma once
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#include <algorithm>
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#include "rocksdb/memory_allocator.h"
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namespace ROCKSDB_NAMESPACE {
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struct CustomDeleter {
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CustomDeleter(MemoryAllocator* a = nullptr) : allocator(a) {}
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void operator()(char* ptr) const {
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if (allocator) {
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allocator->Deallocate(ptr);
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} else {
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delete[] ptr;
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}
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}
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MemoryAllocator* allocator;
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};
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using CacheAllocationPtr = std::unique_ptr<char[], CustomDeleter>;
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inline CacheAllocationPtr AllocateBlock(size_t size,
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MemoryAllocator* allocator) {
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if (allocator) {
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auto block = static_cast<char*>(allocator->Allocate(size));
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return CacheAllocationPtr(block, allocator);
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}
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return CacheAllocationPtr(new char[size]);
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}
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inline CacheAllocationPtr AllocateAndCopyBlock(const Slice& data,
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MemoryAllocator* allocator) {
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CacheAllocationPtr cap = AllocateBlock(data.size(), allocator);
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std::copy_n(data.data(), data.size(), cap.get());
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return cap;
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}
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} // namespace ROCKSDB_NAMESPACE
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