ClickHouse/dbms/src/Disks/DiskLocal.h
2019-12-16 23:19:50 +02:00

124 lines
3.1 KiB
C++

#pragma once
#include <Disks/IDisk.h>
#include <IO/ReadBufferFromFile.h>
#include <IO/WriteBufferFromFile.h>
#include <mutex>
#include <Poco/DirectoryIterator.h>
#include <Poco/File.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
}
class DiskLocalReservation;
class DiskLocal : public IDisk
{
public:
friend class DiskLocalReservation;
DiskLocal(const String & name_, const String & path_, UInt64 keep_free_space_bytes_)
: name(name_), disk_path(path_), keep_free_space_bytes(keep_free_space_bytes_)
{
if (disk_path.back() != '/')
throw Exception("Disk path must ends with '/', but '" + disk_path + "' doesn't.", ErrorCodes::LOGICAL_ERROR);
}
const String & getName() const override { return name; }
const String & getPath() const override { return disk_path; }
ReservationPtr reserve(UInt64 bytes) override;
UInt64 getTotalSpace() const override;
UInt64 getAvailableSpace() const override;
UInt64 getUnreservedSpace() const override;
UInt64 getKeepingFreeSpace() const override { return keep_free_space_bytes; }
bool exists(const String & path) const override;
bool isFile(const String & path) const override;
bool isDirectory(const String & path) const override;
void createDirectory(const String & path) override;
void createDirectories(const String & path) override;
DiskDirectoryIteratorPtr iterateDirectory(const String & path) override;
void moveFile(const String & from_path, const String & to_path) override;
void copyFile(const String & from_path, const String & to_path) override;
std::unique_ptr<ReadBuffer> readFile(const String & path) const override;
std::unique_ptr<WriteBuffer> writeFile(const String & path) override;
private:
bool tryReserve(UInt64 bytes);
private:
const String name;
const String disk_path;
const UInt64 keep_free_space_bytes;
/// Used for reservation counters modification
static std::mutex mutex;
UInt64 reserved_bytes = 0;
UInt64 reservation_count = 0;
};
using DiskLocalPtr = std::shared_ptr<DiskLocal>;
class DiskLocalDirectoryIterator : public IDiskDirectoryIterator
{
public:
explicit DiskLocalDirectoryIterator(const String & path) : iter(path) {}
void next() override { ++iter; }
bool isValid() const override { return iter != Poco::DirectoryIterator(); }
String name() const override { return iter.name(); }
private:
Poco::DirectoryIterator iter;
};
class DiskLocalReservation : public IReservation
{
public:
DiskLocalReservation(const DiskLocalPtr & disk_, UInt64 size_)
: disk(disk_), size(size_), metric_increment(CurrentMetrics::DiskSpaceReservedForMerge, size_)
{
}
UInt64 getSize() const override { return size; }
DiskPtr getDisk() const override { return disk; }
void update(UInt64 new_size) override;
~DiskLocalReservation() override;
private:
DiskLocalPtr disk;
UInt64 size;
CurrentMetrics::Increment metric_increment;
};
class DiskFactory;
void registerDiskLocal(DiskFactory & factory);
}