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arangodb/arangod/VocBase/collection.h

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////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_VOC_BASE_COLLECTION_H
#define ARANGOD_VOC_BASE_COLLECTION_H 1
#include "Basics/Common.h"
#include "Basics/ReadWriteLock.h"
#include "VocBase/datafile.h"
#include "VocBase/vocbase.h"
////////////////////////////////////////////////////////////////////////////////
/// Data is stored in datafiles. A set of datafiles forms a collection. A
/// datafile can be read-only and sealed or read-write. All datafiles of a
/// collection are stored in a directory. This directory contains the following
/// files:
///
/// - parameter.json: The parameters of a collection.
///
/// - datafile-NNN.db: A read-only datafile. The number NNN is the datafile
/// identifier, see @ref TRI_datafile_t.
///
/// - journal-NNN.db: A read-write datafile used as journal. All new entries
/// of a collection are appended to a journal. The number NNN is the
/// datafile identifier, see @ref TRI_datafile_t.
///
/// - index-NNN.json: An index description. The number NNN is the index
/// identifier, see @ref TRI_index_t.
////////////////////////////////////////////////////////////////////////////////
namespace arangodb {
class CollectionInfo;
namespace velocypack {
template <typename T>
class Buffer;
class Slice;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief collection version for ArangoDB >= 2.0
////////////////////////////////////////////////////////////////////////////////
#define TRI_COL_VERSION_20 (5)
////////////////////////////////////////////////////////////////////////////////
/// @brief current collection version
////////////////////////////////////////////////////////////////////////////////
#define TRI_COL_VERSION TRI_COL_VERSION_20
////////////////////////////////////////////////////////////////////////////////
/// @brief predefined collection name for users
////////////////////////////////////////////////////////////////////////////////
#define TRI_COL_NAME_USERS "_users"
////////////////////////////////////////////////////////////////////////////////
/// @brief predefined collection name for statistics
////////////////////////////////////////////////////////////////////////////////
#define TRI_COL_NAME_STATISTICS "_statistics"
////////////////////////////////////////////////////////////////////////////////
/// @brief default number of index buckets
////////////////////////////////////////////////////////////////////////////////
#define TRI_DEFAULT_INDEX_BUCKETS 8
////////////////////////////////////////////////////////////////////////////////
/// @brief collection file structure
////////////////////////////////////////////////////////////////////////////////
struct TRI_col_file_structure_t {
std::vector<std::string> journals;
std::vector<std::string> compactors;
std::vector<std::string> datafiles;
std::vector<std::string> indexes;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief state of the datafile
////////////////////////////////////////////////////////////////////////////////
enum TRI_col_state_e {
TRI_COL_STATE_CLOSED = 1, // collection is closed
TRI_COL_STATE_READ = 2, // collection is opened read only
TRI_COL_STATE_WRITE = 3, // collection is opened read/append
TRI_COL_STATE_OPEN_ERROR = 4, // an error has occurred while opening
TRI_COL_STATE_WRITE_ERROR = 5 // an error has occurred while writing
};
////////////////////////////////////////////////////////////////////////////////
/// @brief collection version
////////////////////////////////////////////////////////////////////////////////
typedef uint32_t TRI_col_version_t;
namespace arangodb {
////////////////////////////////////////////////////////////////////////////////
/// @brief collection info block saved to disk as json
////////////////////////////////////////////////////////////////////////////////
class VocbaseCollectionInfo {
private:
TRI_col_version_t _version; // collection version
TRI_col_type_e _type; // collection type
TRI_voc_rid_t _revision; // last revision id written
TRI_voc_cid_t _cid; // local collection identifier
TRI_voc_cid_t _planId; // cluster-wide collection identifier
TRI_voc_size_t _maximalSize; // maximal size of memory mapped file
int64_t _initialCount; // initial count, used when loading a collection
uint32_t _indexBuckets; // number of buckets used in hash tables for indexes
char _name[TRI_COL_PATH_LENGTH]; // name of the collection()
std::shared_ptr<arangodb::velocypack::Buffer<uint8_t> const>
_keyOptions; // options for key creation
// flags
bool _isSystem; // if true, this is a system collection
bool _deleted; // if true, collection has been deleted
bool _doCompact; // if true, collection will be compacted
bool _isVolatile; // if true, collection is memory-only
bool _waitForSync; // if true, wait for msync
public:
VocbaseCollectionInfo(){};
~VocbaseCollectionInfo(){};
explicit VocbaseCollectionInfo(CollectionInfo const&);
VocbaseCollectionInfo(TRI_vocbase_t*, char const*, TRI_col_type_e,
TRI_voc_size_t, arangodb::velocypack::Slice const&);
VocbaseCollectionInfo(TRI_vocbase_t*, char const*,
arangodb::velocypack::Slice const&);
VocbaseCollectionInfo(TRI_vocbase_t*, char const*, TRI_col_type_e,
arangodb::velocypack::Slice const&);
//////////////////////////////////////////////////////////////////////////////
/// @brief Creates a new VocbaseCollectionInfo from the json content of a file
/// This function throws if the file cannot be parsed.
///
/// You must hold the @ref TRI_READ_LOCK_STATUS_VOCBASE_COL when calling this
/// function.
//////////////////////////////////////////////////////////////////////////////
static VocbaseCollectionInfo fromFile(char const*, TRI_vocbase_t*,
char const*, bool);
// collection version
TRI_col_version_t version() const;
// collection type
TRI_col_type_e type() const;
// local collection identifier
TRI_voc_cid_t id() const;
// cluster-wide collection identifier
TRI_voc_cid_t planId() const;
// last revision id written
TRI_voc_rid_t revision() const;
// maximal size of memory mapped file
TRI_voc_size_t maximalSize() const;
// initial count, used when loading a collection
int64_t initialCount() const;
// number of buckets used in hash tables for indexes
uint32_t indexBuckets() const;
// name of the collection
std::string name() const;
// name of the collection as c string
char const* namec_str() const;
//////////////////////////////////////////////////////////////////////////////
/// @brief returns a copy of the key options
/// the caller is responsible for freeing it
//////////////////////////////////////////////////////////////////////////////
std::shared_ptr<arangodb::velocypack::Buffer<uint8_t> const> keyOptions()
const;
// If true, collection has been deleted
bool deleted() const;
// If true, collection will be compacted
bool doCompact() const;
// If true, collection is a system collection
bool isSystem() const;
// If true, collection is memory-only
bool isVolatile() const;
// If true waits for mysnc
bool waitForSync() const;
void setVersion(TRI_col_version_t);
// Changes the name. Should only be called by TRI_RenameCollection
// Use with caution!
void rename(char const*);
void setIsSystem(bool value) { _isSystem = value; }
void setRevision(TRI_voc_rid_t, bool);
void setCollectionId(TRI_voc_cid_t);
void updateCount(size_t);
void setPlanId(TRI_voc_cid_t);
void setDeleted(bool);
void clearKeyOptions();
//////////////////////////////////////////////////////////////////////////////
/// @brief saves a parameter info block to file
//////////////////////////////////////////////////////////////////////////////
int saveToFile(std::string const&, bool) const;
//////////////////////////////////////////////////////////////////////////////
/// @brief updates settings for this collection info.
/// If the second parameter is false it will only
/// update the values explicitly contained in the slice.
/// If the second parameter is true and the third is a nullptr,
/// it will use global default values for all missing options in the
/// slice.
/// If the third parameter is not nullptr and the second is true, it
/// will
/// use the defaults stored in the vocbase.
//////////////////////////////////////////////////////////////////////////////
void update(arangodb::velocypack::Slice const&, bool, TRI_vocbase_t const*);
//////////////////////////////////////////////////////////////////////////////
/// @brief updates settings for this collection info with the content of the
/// other
//////////////////////////////////////////////////////////////////////////////
void update(VocbaseCollectionInfo const&);
};
} // namespace arangodb
////////////////////////////////////////////////////////////////////////////////
/// @brief collection
////////////////////////////////////////////////////////////////////////////////
struct TRI_collection_t {
public:
TRI_collection_t(TRI_collection_t const&) = delete;
TRI_collection_t& operator=(TRI_collection_t const&) = delete;
TRI_collection_t() = delete;
explicit TRI_collection_t(TRI_vocbase_t* vocbase)
: _vocbase(vocbase), _tickMax(0), _state(TRI_COL_STATE_WRITE), _lastError(0) {}
TRI_collection_t(TRI_vocbase_t* vocbase, arangodb::VocbaseCollectionInfo const& info)
: _vocbase(vocbase), _tickMax(0), _info(info), _state(TRI_COL_STATE_WRITE), _lastError(0) {}
~TRI_collection_t() = default;
public:
void iterateIndexes(std::function<bool(std::string const&, void*)> const&, void*);
/// @brief updates the parameter info block
int updateCollectionInfo(TRI_vocbase_t* vocbase,
arangodb::velocypack::Slice const& slice, bool doSync);
// datafile management
/// @brief rotate the active journal - will do nothing if there is no journal
int rotateActiveJournal();
/// @brief sync the active journal - will do nothing if there is no journal
/// or if the journal is volatile
int syncActiveJournal();
int reserveJournalSpace(TRI_voc_tick_t tick, TRI_voc_size_t size,
char*& resultPosition, TRI_datafile_t*& resultDatafile);
/// @brief create compactor file
TRI_datafile_t* createCompactor(TRI_voc_fid_t fid, TRI_voc_size_t maximalSize);
/// @brief close an existing compactor
int closeCompactor(TRI_datafile_t* datafile);
/// @brief replace a datafile with a compactor
int replaceDatafileWithCompactor(TRI_datafile_t* datafile, TRI_datafile_t* compactor);
bool removeCompactor(TRI_datafile_t*);
bool removeDatafile(TRI_datafile_t*);
void addIndexFile(std::string const&);
int removeIndexFile(TRI_idx_iid_t);
private:
/// @brief seal a datafile
int sealDatafile(TRI_datafile_t* datafile, bool isCompactor);
/// @brief creates a datafile
TRI_datafile_t* createDatafile(TRI_voc_fid_t fid,
TRI_voc_size_t journalSize,
bool isCompactor);
public:
TRI_vocbase_t* _vocbase;
TRI_voc_tick_t _tickMax;
/// @brief a lock protecting the _info structure
arangodb::basics::ReadWriteLock _infoLock;
arangodb::VocbaseCollectionInfo _info;
TRI_col_state_e _state; // state of the collection
int _lastError; // last (critical) error
std::string _directory; // directory of the collection
arangodb::basics::ReadWriteLock _filesLock;
std::vector<TRI_datafile_t*> _datafiles; // all datafiles
std::vector<TRI_datafile_t*> _journals; // all journals
std::vector<TRI_datafile_t*> _compactors; // all compactor files
private:
std::vector<std::string> _indexFiles; // all index filenames
};
////////////////////////////////////////////////////////////////////////////////
/// @brief creates a new collection
////////////////////////////////////////////////////////////////////////////////
TRI_collection_t* TRI_CreateCollection(TRI_vocbase_t*, TRI_collection_t*,
char const*,
arangodb::VocbaseCollectionInfo const&);
////////////////////////////////////////////////////////////////////////////////
/// @brief frees the memory allocated, but does not free the pointer
///
/// Note that the collection must be closed first.
////////////////////////////////////////////////////////////////////////////////
void TRI_DestroyCollection(TRI_collection_t*);
////////////////////////////////////////////////////////////////////////////////
/// @brief frees the memory allocated and frees the pointer
////////////////////////////////////////////////////////////////////////////////
void TRI_FreeCollection(TRI_collection_t*);
////////////////////////////////////////////////////////////////////////////////
/// @brief convert a parameter info block to velocypack
////////////////////////////////////////////////////////////////////////////////
std::shared_ptr<arangodb::velocypack::Builder>
TRI_CreateVelocyPackCollectionInfo(arangodb::VocbaseCollectionInfo const&);
// Expects the builder to be in an open Object state
void TRI_CreateVelocyPackCollectionInfo(arangodb::VocbaseCollectionInfo const&,
arangodb::velocypack::Builder&);
////////////////////////////////////////////////////////////////////////////////
/// @brief renames a collection
////////////////////////////////////////////////////////////////////////////////
int TRI_RenameCollection(TRI_collection_t*, char const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief iterates over a collection
////////////////////////////////////////////////////////////////////////////////
bool TRI_IterateCollection(TRI_collection_t*, bool (*)(TRI_df_marker_t const*,
void*, TRI_datafile_t*),
void*);
////////////////////////////////////////////////////////////////////////////////
/// @brief opens an existing collection
////////////////////////////////////////////////////////////////////////////////
TRI_collection_t* TRI_OpenCollection(TRI_vocbase_t*, TRI_collection_t*,
char const*, bool);
////////////////////////////////////////////////////////////////////////////////
/// @brief closes an open collection
////////////////////////////////////////////////////////////////////////////////
int TRI_CloseCollection(TRI_collection_t*);
////////////////////////////////////////////////////////////////////////////////
/// @brief returns information about the collection files
///
/// Note that the collection must not be loaded
////////////////////////////////////////////////////////////////////////////////
TRI_col_file_structure_t TRI_FileStructureCollectionDirectory(char const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief iterate over the markers in the collection's journals
///
/// this function is called on server startup for all collections. we do this
/// to get the last tick used in a collection
////////////////////////////////////////////////////////////////////////////////
bool TRI_IterateTicksCollection(char const* const,
bool (*)(TRI_df_marker_t const*, void*,
TRI_datafile_t*),
void*);
////////////////////////////////////////////////////////////////////////////////
/// @brief determine whether a collection name is a system collection name
////////////////////////////////////////////////////////////////////////////////
bool TRI_IsSystemNameCollection(char const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief checks if a collection name is allowed
////////////////////////////////////////////////////////////////////////////////
bool TRI_IsAllowedNameCollection(bool, char const*);
#endif