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02ccdeb94e
This comment explains this patch and the associated patches that should be folded into it. This paragraph should be removed when the patches are folded after review. This change significantly improves ledger sync and fetch times while reducing memory consumption. The change affects the code from that begins with SHAMap::getMissingNodes and runs through to Database::threadEntry. The existing code issues a number of async fetches which are then handed off to the Database's pool of read threads to execute. The results of each read are placed in the Database's positive and negative caches. The caller waits for all reads to complete and then retrieves the results out of these caches. Among other issues, this means that the results of the first read cannot be processed until the last read completes. Additionally, all the results must sit in memory. This patch changes the behavior so that each read operation has a completion handler associated with it. The completion of the read calls the handler, allowing the results of each read to be processed as it completes. As this was the only reason the negative and positive caches were needed, they can now be removed. The read generation code is also no longer needed and is removed. The batch fetch logic was never implemented or supported and is removed.
60 lines
2.1 KiB
C++
60 lines
2.1 KiB
C++
//------------------------------------------------------------------------------
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/*
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This file is part of rippled: https://github.com/ripple/rippled
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Copyright (c) 2012, 2013 Ripple Labs Inc.
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Permission to use, copy, modify, and/or 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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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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//==============================================================================
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#ifndef RIPPLE_NODESTORE_DATABASEROTATING_H_INCLUDED
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#define RIPPLE_NODESTORE_DATABASEROTATING_H_INCLUDED
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#include <ripple/nodestore/Database.h>
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namespace ripple {
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namespace NodeStore {
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/* This class has two key-value store Backend objects for persisting SHAMap
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* records. This facilitates online deletion of data. New backends are
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* rotated in. Old ones are rotated out and deleted.
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*/
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class DatabaseRotating : public Database
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{
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public:
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DatabaseRotating(
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std::string const& name,
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Stoppable& parent,
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Scheduler& scheduler,
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int readThreads,
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Section const& config,
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beast::Journal journal)
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: Database(name, parent, scheduler, readThreads, config, journal)
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{
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}
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/** Rotates the backends.
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@param f A function executed before the rotation and under the same lock
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*/
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virtual void
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rotateWithLock(std::function<std::unique_ptr<NodeStore::Backend>(
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std::string const& writableBackendName)> const& f) = 0;
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};
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} // namespace NodeStore
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} // namespace ripple
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#endif
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