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rocksdb/util/testutil.h

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8.7 KiB

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#pragma once
#include <algorithm>
#include <string>
#include <vector>
#include "db/dbformat.h"
#include "rocksdb/env.h"
#include "rocksdb/iterator.h"
#include "rocksdb/slice.h"
#include "util/random.h"
namespace rocksdb {
class SequentialFile;
class SequentialFileReader;
namespace test {
// Store in *dst a random string of length "len" and return a Slice that
// references the generated data.
extern Slice RandomString(Random* rnd, int len, std::string* dst);
extern std::string RandomHumanReadableString(Random* rnd, int len);
// Return a random key with the specified length that may contain interesting
// characters (e.g. \x00, \xff, etc.).
extern std::string RandomKey(Random* rnd, int len);
// Store in *dst a string of length "len" that will compress to
// "N*compressed_fraction" bytes and return a Slice that references
// the generated data.
extern Slice CompressibleString(Random* rnd, double compressed_fraction,
int len, std::string* dst);
// A wrapper that allows injection of errors.
class ErrorEnv : public EnvWrapper {
public:
bool writable_file_error_;
int num_writable_file_errors_;
ErrorEnv() : EnvWrapper(Env::Default()),
writable_file_error_(false),
num_writable_file_errors_(0) { }
virtual Status NewWritableFile(const std::string& fname,
unique_ptr<WritableFile>* result,
const EnvOptions& soptions) override {
result->reset();
if (writable_file_error_) {
++num_writable_file_errors_;
return Status::IOError(fname, "fake error");
}
return target()->NewWritableFile(fname, result, soptions);
}
};
// An internal comparator that just forward comparing results from the
// user comparator in it. Can be used to test entities that have no dependency
// on internal key structure but consumes InternalKeyComparator, like
// BlockBasedTable.
class PlainInternalKeyComparator : public InternalKeyComparator {
public:
explicit PlainInternalKeyComparator(const Comparator* c)
: InternalKeyComparator(c) {}
virtual ~PlainInternalKeyComparator() {}
virtual int Compare(const Slice& a, const Slice& b) const override {
return user_comparator()->Compare(a, b);
}
virtual void FindShortestSeparator(std::string* start,
const Slice& limit) const override {
user_comparator()->FindShortestSeparator(start, limit);
}
virtual void FindShortSuccessor(std::string* key) const override {
user_comparator()->FindShortSuccessor(key);
}
};
// A test comparator which compare two strings in this way:
// (1) first compare prefix of 8 bytes in alphabet order,
// (2) if two strings share the same prefix, sort the other part of the string
// in the reverse alphabet order.
// This helps simulate the case of compounded key of [entity][timestamp] and
// latest timestamp first.
class SimpleSuffixReverseComparator : public Comparator {
public:
SimpleSuffixReverseComparator() {}
virtual const char* Name() const override {
return "SimpleSuffixReverseComparator";
}
virtual int Compare(const Slice& a, const Slice& b) const override {
Slice prefix_a = Slice(a.data(), 8);
Slice prefix_b = Slice(b.data(), 8);
int prefix_comp = prefix_a.compare(prefix_b);
if (prefix_comp != 0) {
return prefix_comp;
} else {
Slice suffix_a = Slice(a.data() + 8, a.size() - 8);
Slice suffix_b = Slice(b.data() + 8, b.size() - 8);
return -(suffix_a.compare(suffix_b));
}
}
virtual void FindShortestSeparator(std::string* start,
const Slice& limit) const override {}
virtual void FindShortSuccessor(std::string* key) const override {}
};
// Returns a user key comparator that can be used for comparing two uint64_t
// slices. Instead of comparing slices byte-wise, it compares all the 8 bytes
// at once. Assumes same endian-ness is used though the database's lifetime.
// Symantics of comparison would differ from Bytewise comparator in little
// endian machines.
extern const Comparator* Uint64Comparator();
// Iterator over a vector of keys/values
class VectorIterator : public Iterator {
public:
explicit VectorIterator(const std::vector<std::string>& keys)
: keys_(keys), current_(keys.size()) {
std::sort(keys_.begin(), keys_.end());
values_.resize(keys.size());
}
VectorIterator(const std::vector<std::string>& keys,
const std::vector<std::string>& values)
: keys_(keys), values_(values), current_(keys.size()) {
assert(keys_.size() == values_.size());
}
virtual bool Valid() const override { return current_ < keys_.size(); }
virtual void SeekToFirst() override { current_ = 0; }
virtual void SeekToLast() override { current_ = keys_.size() - 1; }
virtual void Seek(const Slice& target) override {
current_ = std::lower_bound(keys_.begin(), keys_.end(), target.ToString()) -
keys_.begin();
}
virtual void Next() override { current_++; }
virtual void Prev() override { current_--; }
virtual Slice key() const override { return Slice(keys_[current_]); }
virtual Slice value() const override { return Slice(values_[current_]); }
virtual Status status() const override { return Status::OK(); }
private:
std::vector<std::string> keys_;
std::vector<std::string> values_;
size_t current_;
};
extern WritableFileWriter* GetWritableFileWriter(WritableFile* wf);
extern RandomAccessFileReader* GetRandomAccessFileReader(RandomAccessFile* raf);
extern SequentialFileReader* GetSequentialFileReader(SequentialFile* se);
class StringSink: public WritableFile {
public:
std::string contents_;
explicit StringSink(Slice* reader_contents = nullptr) :
WritableFile(),
contents_(""),
reader_contents_(reader_contents),
last_flush_(0) {
if (reader_contents_ != nullptr) {
*reader_contents_ = Slice(contents_.data(), 0);
}
}
const std::string& contents() const { return contents_; }
virtual Status Close() override { return Status::OK(); }
virtual Status Flush() override {
if (reader_contents_ != nullptr) {
assert(reader_contents_->size() <= last_flush_);
size_t offset = last_flush_ - reader_contents_->size();
*reader_contents_ = Slice(
contents_.data() + offset,
contents_.size() - offset);
last_flush_ = contents_.size();
}
return Status::OK();
}
virtual Status Sync() override { return Status::OK(); }
virtual Status Append(const Slice& slice) override {
contents_.append(slice.data(), slice.size());
return Status::OK();
}
void Drop(size_t bytes) {
if (reader_contents_ != nullptr) {
contents_.resize(contents_.size() - bytes);
*reader_contents_ = Slice(
reader_contents_->data(), reader_contents_->size() - bytes);
last_flush_ = contents_.size();
}
}
private:
Slice* reader_contents_;
size_t last_flush_;
};
class StringSource: public RandomAccessFile {
public:
StringSource(const Slice& contents, uint64_t uniq_id = 0, bool mmap = false)
: contents_(contents.data(), contents.size()), uniq_id_(uniq_id),
mmap_(mmap) {
}
virtual ~StringSource() { }
uint64_t Size() const { return contents_.size(); }
virtual Status Read(uint64_t offset, size_t n, Slice* result,
char* scratch) const override {
if (offset > contents_.size()) {
return Status::InvalidArgument("invalid Read offset");
}
if (offset + n > contents_.size()) {
n = contents_.size() - offset;
}
if (!mmap_) {
memcpy(scratch, &contents_[offset], n);
*result = Slice(scratch, n);
} else {
*result = Slice(&contents_[offset], n);
}
return Status::OK();
}
virtual size_t GetUniqueId(char* id, size_t max_size) const override {
if (max_size < 20) {
return 0;
}
char* rid = id;
rid = EncodeVarint64(rid, uniq_id_);
rid = EncodeVarint64(rid, 0);
return static_cast<size_t>(rid-id);
}
private:
std::string contents_;
uint64_t uniq_id_;
bool mmap_;
};
class NullLogger : public Logger {
public:
using Logger::Logv;
virtual void Logv(const char* format, va_list ap) override {}
virtual size_t GetLogFileSize() const override { return 0; }
};
} // namespace test
} // namespace rocksdb