forked from continuwuation/rocksdb
1585f2240c
Summary: The current seek key validation is too strict. This change relaxes it at block iterator level, and add additional check at DB iterator level. The new contract is that when MultiScan is used, after prepared is called, each following seek must seek the start key of the prepared scan range in order. Otherwise, the iterator is set with error status. Pull Request resolved: https://github.com/facebook/rocksdb/pull/14040 Test Plan: Unit test Reviewed By: anand1976 Differential Revision: D84292297 Pulled By: xingbowang fbshipit-source-id: 7b31f727e67e7c0bfc53c2f9a6552e0c3d324869
76 lines
2.7 KiB
C++
76 lines
2.7 KiB
C++
// Copyright (c) Meta Platforms, Inc. and affiliates.
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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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#include "rocksdb/db.h"
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namespace ROCKSDB_NAMESPACE {
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using MultiScanIterator = MultiScan::MultiScanIterator;
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MultiScan::MultiScan(const ReadOptions& read_options,
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const MultiScanArgs& scan_opts, DB* db,
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ColumnFamilyHandle* cfh)
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: read_options_(read_options), scan_opts_(scan_opts), db_(db), cfh_(cfh) {
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bool slow_path = false;
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// Setup read_options with iterate_uuper_bound based on the first scan.
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// Subsequent scans will update and allocate a new DB iterator as necessary
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if (scan_opts.GetScanRanges()[0].range.limit) {
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upper_bound_ = *scan_opts.GetScanRanges()[0].range.limit;
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read_options_.iterate_upper_bound = &upper_bound_;
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} else {
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read_options_.iterate_upper_bound = nullptr;
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}
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for (const auto& opts : scan_opts.GetScanRanges()) {
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// Check that all the ScanOptions either specify an upper bound or not. If
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// its mixed we take the slow path which avoids calling Prepare: we have to
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// reallocate the Iterator with updated read_options everytime we switch
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// between upper bound or no upper bound, which complicates Prepare.
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if (opts.range.limit.has_value() !=
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scan_opts.GetScanRanges()[0].range.limit.has_value()) {
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slow_path = true;
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break;
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}
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}
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db_iter_.reset(db->NewIterator(read_options_, cfh));
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if (!slow_path) {
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db_iter_->Prepare(scan_opts);
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}
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}
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MultiScanIterator& MultiScanIterator::operator++() {
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status_ = db_iter_->status();
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if (!status_.ok()) {
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throw MultiScanException(status_);
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}
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if (idx_ >= scan_opts_.size()) {
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throw std::logic_error("Index out of range");
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}
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idx_++;
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if (idx_ < scan_opts_.size()) {
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// Check if we need to update read_options_
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if (scan_opts_[idx_].range.limit.has_value() !=
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(read_options_.iterate_upper_bound != nullptr)) {
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if (scan_opts_[idx_].range.limit) {
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*upper_bound_ = *scan_opts_[idx_].range.limit;
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read_options_.iterate_upper_bound = upper_bound_;
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} else {
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read_options_.iterate_upper_bound = nullptr;
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}
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db_iter_.reset(db_->NewIterator(read_options_, cfh_));
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scan_.Reset(db_iter_.get());
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} else if (scan_opts_[idx_].range.limit) {
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*upper_bound_ = *scan_opts_[idx_].range.limit;
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}
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db_iter_->Seek(*scan_opts_[idx_].range.start);
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status_ = db_iter_->status();
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if (!status_.ok()) {
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throw MultiScanException(status_);
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}
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}
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return *this;
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}
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} // namespace ROCKSDB_NAMESPACE
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