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1186192ed1
Summary: Replace include/leveldb with include/rocksdb. Test Plan: make clean; make check make clean; make release Differential Revision: https://reviews.facebook.net/D12489
105 lines
3.1 KiB
C++
105 lines
3.1 KiB
C++
/**
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* @author Deon Nicholas (dnicholas@fb.com)
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* Copyright 2013 Facebook
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*/
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#include "stringappend2.h"
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#include <memory>
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#include <assert.h>
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#include "rocksdb/slice.h"
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#include "rocksdb/merge_operator.h"
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#include "utilities/merge_operators.h"
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namespace leveldb {
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// Constructor: also specify the delimiter character.
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StringAppendTESTOperator::StringAppendTESTOperator(char delim_char)
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: delim_(delim_char) {
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}
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// Implementation for the merge operation (concatenates two strings)
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bool StringAppendTESTOperator::FullMerge(
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const Slice& key,
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const Slice* existing_value,
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const std::deque<std::string>& operands,
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std::string* new_value,
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Logger* logger) const {
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// Clear the *new_value for writing.
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assert(new_value);
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new_value->clear();
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// Compute the space needed for the final result.
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int numBytes = 0;
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for(auto it = operands.begin(); it != operands.end(); ++it) {
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numBytes += it->size() + 1; // Plus 1 for the delimiter
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}
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// Only print the delimiter after the first entry has been printed
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bool printDelim = false;
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// Prepend the *existing_value if one exists.
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if (existing_value) {
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new_value->reserve(numBytes + existing_value->size());
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new_value->append(existing_value->data(), existing_value->size());
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printDelim = true;
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} else if (numBytes) {
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new_value->reserve(numBytes-1); // Minus 1 since we have one less delimiter
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}
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// Concatenate the sequence of strings (and add a delimiter between each)
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for(auto it = operands.begin(); it != operands.end(); ++it) {
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if (printDelim) {
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new_value->append(1,delim_);
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}
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new_value->append(*it);
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printDelim = true;
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}
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return true;
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}
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bool StringAppendTESTOperator::PartialMerge(const Slice& key,
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const Slice& left_operand,
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const Slice& right_operand,
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std::string* new_value,
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Logger* logger) const {
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return false;
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}
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// A version of PartialMerge that actually performs "partial merging".
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// Use this to simulate the exact behaviour of the StringAppendOperator.
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bool StringAppendTESTOperator::_AssocPartialMerge(const Slice& key,
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const Slice& left_operand,
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const Slice& right_operand,
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std::string* new_value,
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Logger* logger) const {
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// Clear the *new_value for writing.
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assert(new_value);
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new_value->clear();
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// Generic append
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// Reserve correct size for *new_value, and apply concatenation.
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new_value->reserve(left_operand.size() + 1 + right_operand.size());
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new_value->assign(left_operand.data(), left_operand.size());
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new_value->append(1,delim_);
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new_value->append(right_operand.data(), right_operand.size());
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return true;
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}
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const char* StringAppendTESTOperator::Name() const {
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return "StringAppendTESTOperator";
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}
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std::shared_ptr<MergeOperator>
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MergeOperators::CreateStringAppendTESTOperator() {
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return std::make_shared<StringAppendTESTOperator>(',');
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}
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} // namespace leveldb
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