Schema specification. More...

#include <Schema.h>

Collaboration diagram for Hypertable::Schema:

Public Member Functions
	Schema ()
	Default constructor. More...

	Schema (const Schema &other)
	Copy constructor. More...

	~Schema ()
	Destructor. More...

void	clear_generation ()
	Clears generation values. More...

bool	clear_generation_if_changed (Schema &original)
	Clears generation if different than `original`. More...

void	update_generation (int64_t generation)
	Updates generation and assigns column family IDs. More...

const std::string	render_xml (bool with_ids=false)
	Renders schema in XML format. More...

const std::string	render_hql (const std::string &table_name)
	Renders schema as HQL `CREATE TABLE` statement. More...

int64_t	get_generation () const
	Gets generation. More...

void	set_generation (int64_t generation)
	Sets generation. More...

int32_t	get_version () const
	Gets version number. More...

void	set_version (int32_t version)
	Sets version number. More...

int32_t	get_max_column_family_id ()
	Gets the maximum column family ID. More...

TableParts	get_table_parts ()
	Gets table parts. More...

AccessGroupSpecs &	get_access_groups ()
	Returns reference to access group vector. More...

AccessGroupSpec *	get_access_group (const std::string &name)
	Gets an access group specification given its name. More...

AccessGroupSpec *	get_access_group (const char *name)

ColumnFamilySpecs &	get_column_families ()
	Returns reference to column family vector. More...

ColumnFamilySpec *	get_column_family (const std::string &name)
	Gets a column family specification given its name. More...

ColumnFamilySpec *	get_column_family (const char *name)

ColumnFamilySpec *	remove_column_family (const std::string &name)
	Removes column family. More...

ColumnFamilySpec *	get_column_family (int32_t id, bool get_deleted=false)
	Gets a column family specification given its ID. More...

void	add_access_group (AccessGroupSpec *ag)
	Adds access group specification. More...

AccessGroupSpec *	replace_access_group (AccessGroupSpec *new_ag)
	Replaces access group specification. More...

bool	access_group_exists (const std::string &name) const
	Checks if access group exists. More...

bool	column_family_exists (int32_t id, bool get_deleted=false) const
	Checks if column family exists. More...

void	drop_column_family (const String &name)
	Drops column family. More...

void	rename_column_family (const String &old_name, const String &new_name)
	Renames a column family. More...

bool	column_is_counter (int id)
	Checks if column is a counter column. More...

void	set_group_commit_interval (int32_t interval)
	Sets group commit interval. More...

int32_t	get_group_commit_interval ()
	Gets group commit interval. More...

void	set_access_group_defaults (const AccessGroupOptions &defaults)
	Sets default access group options. More...

AccessGroupOptions &	access_group_defaults ()
	Returns reference to default access group options. More...

void	set_column_family_defaults (const ColumnFamilyOptions &defaults)
	Sets default column family options. More...

ColumnFamilyOptions &	column_family_defaults ()
	Returns reference to default column family options. More...

void	validate ()
	Validates schema and reconstructs data structures. More...

Static Public Member Functions
static Schema *	new_instance (const std::string &buf)
	Creates schema object from XML schema string. More...

Private Types
typedef PageArenaAllocator < const char * >	CstrAlloc

typedef std::map< const char , AccessGroupSpec , LtCstr, CstrAlloc >	CstrAccessGroupMap
	Map of access group specifications. More...

typedef std::map< const char , ColumnFamilySpec , LtCstr, CstrAlloc >	CstrColumnFamilyMap
	Map of column family specifications (key == name) More...

Private Member Functions
void	merge_table_defaults (ColumnFamilySpec *cf_spec)
	Merges default column family options into a column family spec. More...

void	merge_table_defaults (AccessGroupSpec *ag_spec)
	Merges default access group options into access group spec. More...

Private Attributes
CharArena	m_arena

int64_t	m_generation
	Generation. More...

int32_t	m_version {}
	Version number. More...

int32_t	m_group_commit_interval {}
	Group commit interval. More...

AccessGroupOptions	m_ag_defaults
	Default access group options. More...

ColumnFamilyOptions	m_cf_defaults
	Default column family options. More...

AccessGroupSpecs	m_access_groups
	Access group specifications. More...

CstrAccessGroupMap	m_access_group_map

ColumnFamilySpecs	m_column_families
	&Column family specifications More...

CstrColumnFamilyMap	m_column_family_map

std::map< int32_t, ColumnFamilySpec * >	m_column_family_id_map
	Map of column family specifications (key == ID) More...

std::vector< bool >	m_counter_mask
	Bitmask describing which column families are counters. More...

Detailed Description

Schema specification.

Definition at line 52 of file Schema.h.

Member Typedef Documentation

typedef std::map<const char*, AccessGroupSpec*, LtCstr, CstrAlloc> Hypertable::Schema::CstrAccessGroupMap

private

Map of access group specifications.

Definition at line 447 of file Schema.h.

typedef PageArenaAllocator<const char*> Hypertable::Schema::CstrAlloc

private

Definition at line 425 of file Schema.h.

typedef std::map<const char*, ColumnFamilySpec*, LtCstr, CstrAlloc> Hypertable::Schema::CstrColumnFamilyMap

private

Map of column family specifications (key == name)

Definition at line 454 of file Schema.h.

Constructor & Destructor Documentation

Hypertable::Schema::Schema ( )

inline

Default constructor.

Definition at line 56 of file Schema.h.

Schema::Schema ( const Schema & other )

Copy constructor.

Assumes src_schema has been checked for validity.

Copies contents of other schema into this one and then calls validate().

Parameters

other Other schema from which to copy

Definition at line 77 of file Schema.cc.

Schema::~Schema ( )

Destructor.

Deletes all access group specifications in m_access_groups

Definition at line 130 of file Schema.cc.

Member Function Documentation

AccessGroupOptions& Hypertable::Schema::access_group_defaults ( )

inline

Returns reference to default access group options.

Returns: Reference to default access group options.

Definition at line 381 of file Schema.h.

bool Schema::access_group_exists ( const std::string & name ) const

Checks if access group exists.

Looks up name in m_access_group_map and returns true if it is found.

Parameters

name	Access group name

Returns: true if access group exists, false otherwise

Definition at line 441 of file Schema.cc.

void Schema::add_access_group ( AccessGroupSpec * ag )

Adds access group specification.

Merges access group defaults (m_ag_defaults) into ag and merges column family defaults (m_cf_defaults) into each of its column family specs. Pushes ag onto the end of m_access_groups and inserts it into m_access_group_map.

Parameters

ag	Access group specification

Exceptions

Exception with code set to Error::TOO_MANY_COLUMNS if added access group pushes the number of column families past the maximum, or Error::BAD_SCHEMA if access group or any of its colums already exist.

Definition at line 354 of file Schema.cc.

void Schema::clear_generation ( )

Clears generation values.

Sets m_generation to 0 and sets the generation value of all column families within all access groups to 0.

Definition at line 216 of file Schema.cc.

bool Schema::clear_generation_if_changed ( Schema & original )

Clears generation if different than original.

Compares this object with original and if then differ, sets m_generation to 0 and returns true. Comparison of each member access group is compared with AccessGroupSpec::clear_generation_if_changed() causing the access group spec's generation to be set to 0 if they differ.

Parameters

original Original schema with which to compare

Returns: true if this object differs from original, false otherwise.

Definition at line 223 of file Schema.cc.

ColumnFamilyOptions& Hypertable::Schema::column_family_defaults ( )

inline

Returns reference to default column family options.

Returns: Reference to default column family options.

Definition at line 392 of file Schema.h.

bool Schema::column_family_exists	(	int32_t	id,
		bool	get_deleted = `false`
	)		const

Checks if column family exists.

Checks if the column family with ID, id, exists by searching for it in m_column_family_id_map. Returns true if column family exists and either a) is not deleted, or b) is deleted and the value passed in for get_deleted is true.

Parameters

id	ID of column family to search for
get_deleted	Return

Returns: true if column family exists, false otherwise.

Definition at line 431 of file Schema.cc.

bool Hypertable::Schema::column_is_counter ( int id )

inline

Checks if column is a counter column.

Returns the value of the id^th bit of m_counter_mask.

Parameters

id	Column family ID

Returns: true if column is a counter, false otherwise.

Definition at line 357 of file Schema.h.

void Schema::drop_column_family ( const String & name )

Drops column family.

Locates access group for column family name and marks it as deleted with a call to AccessGroupSpec::drop_column(), then re-inserts the column family back into m_column_family_map with its new new ("!<id>").

Parameters

name	Name of column family to drop

Definition at line 470 of file Schema.cc.

AccessGroupSpec* Hypertable::Schema::get_access_group ( const std::string & name )

inline

Gets an access group specification given its name.

Searches m_access_group_map for the access group named name, returning it if it exists or nullptr if it does not.

Parameters

name	Name of access group to return

Returns: Access group specification corresponding to name, or nullptr if it does not exist.

Definition at line 242 of file Schema.h.

AccessGroupSpec* Hypertable::Schema::get_access_group ( const char * name )

inline

Definition at line 245 of file Schema.h.

AccessGroupSpecs& Hypertable::Schema::get_access_groups ( )

inline

Returns reference to access group vector.

Returns: Reference to access group vector.

Definition at line 234 of file Schema.h.

ColumnFamilySpecs& Hypertable::Schema::get_column_families ( )

inline

Returns reference to column family vector.

Returns: Reference to column family vector.

Definition at line 254 of file Schema.h.

ColumnFamilySpec* Hypertable::Schema::get_column_family ( const std::string & name )

inline

Gets a column family specification given its name.

Searches m_column_family_map for the column family named name, returning it if it exists or nullptr if it does not.

Parameters

name	Name of column family to return

Returns: Column family specification corresponding to name, or nullptr if it does not exist.

Definition at line 262 of file Schema.h.

ColumnFamilySpec* Hypertable::Schema::get_column_family ( const char * name )

inline

Definition at line 265 of file Schema.h.

ColumnFamilySpec* Hypertable::Schema::get_column_family	(	int32_t	id,
		bool	get_deleted = `false`
	)

inline

Gets a column family specification given its ID.

Searches m_column_family_id_map for the column family with ID id, returning it if it exists and is not deleted or get_deleted is true. Otherwise, nullptr is returned.

Parameters

id	Column family ID of specification to fetch
get_deleted	Return specification even if it is deleted

Returns: Column family specification with ID id if it exists and it is not deleted or get_deleted is true. Otherwise, nullptr is returned.

Definition at line 292 of file Schema.h.

int64_t Hypertable::Schema::get_generation ( ) const

inline

Gets generation.

Returns the value of m_generation.

Returns: Generation

Definition at line 207 of file Schema.h.

int32_t Hypertable::Schema::get_group_commit_interval ( )

inline

Gets group commit interval.

Returns: Group commit interval

Definition at line 370 of file Schema.h.

int32_t Schema::get_max_column_family_id ( )

Gets the maximum column family ID.

Protected methods.

Returns: Maximum column family ID.

Definition at line 328 of file Schema.cc.

TableParts Schema::get_table_parts ( )

Gets table parts.

Returns: TableParts object describing table parts defined by this schema.

Definition at line 337 of file Schema.cc.

int32_t Hypertable::Schema::get_version ( ) const

inline

Gets version number.

Returns the value of m_version.

Returns: Version Number

Definition at line 217 of file Schema.h.

void Schema::merge_table_defaults ( ColumnFamilySpec * cf_spec )

private

Merges default column family options into a column family spec.

Parameters

cf_spec Column family spec into which table defaults are to be merged

Definition at line 540 of file Schema.cc.

void Schema::merge_table_defaults ( AccessGroupSpec * ag_spec )

private

Merges default access group options into access group spec.

Parameters

ag_spec Access group spec into which table defaults are to be merged

Definition at line 550 of file Schema.cc.

Schema * Schema::new_instance ( const std::string & buf )

static

Creates schema object from XML schema string.

Constructs a new schema from the XML specification held in buf and them calls validate().

Parameters

buf	Buffer holding XML schema string.

Returns: Pointer to newly allocated Schema object.

Definition at line 202 of file Schema.cc.

ColumnFamilySpec * Schema::remove_column_family ( const std::string & name )

Removes column family.

Removes column family named name from m_column_family_map. If column family ID is non-zero, then the column family is removed from m_column_family_id_map and the corresponding entry in m_counter_mask is set to false. If column family exists in m_column_family_map, then it is returned, otherwise, nullptr is returned.

Parameters

name	Name of column family to remove

Returns: Removed column family

Definition at line 396 of file Schema.cc.

void Schema::rename_column_family	(	const String &	old_name,
		const String &	new_name
	)

Renames a column family.

Locates column family old_name in m_column_family_map, renames it to new_name and sets its generation to 0.

Parameters

old_name	Name of existing column family to be renamed
new_name	New name for column family

Definition at line 447 of file Schema.cc.

const string Schema::render_hql ( const std::string & table_name )

Renders schema as HQL CREATE TABLE statement.

The following is example output produced by this member function with "MyTable" passed in as table_name.

CREATE TABLE MyTable (
  actions MAX_VERSIONS 3 TTL 2592000,
  language MAX_VERSIONS 2,
  checksum MAX_VERSIONS 1,
  ACCESS GROUP default (actions) BLOCKSIZE 65000,
  ACCESS GROUP meta (language, checksum) BLOCKSIZE 65000 MAX_VERSIONS 2
) GROUP_COMMIT_INTERVAL 200 BLOCKSIZE 65000

Parameters

table_name Name of table

Returns: String representation of schema as HQL CREATE TABLE statement.

Definition at line 292 of file Schema.cc.

const string Schema::render_xml ( bool with_ids = false )

Renders schema in XML format.

The name of the toplevel element of the output is Schema and contains the following child elements:

Element	Description
Generation	Generation number
GroupCommitInterval	Group commit interval
AccessGroupDefaults	Default access group options
ColumnFamilyDefaults	Default column family options
AccessGroup	Access group specification (see AccessGroupSpec::render_xml())

The following is example output produced by this member function.

<Schema>
  <Generation>42</Generation>
  <GroupCommitInterval>100</GroupCommitInterval>
  <AccessGroupDefaults>
    <BlockSize>65000</BlockSize>
  </AccessGroupDefaults>
  <ColumnFamilyDefaults>
  </ColumnFamilyDefaults>
  <AccessGroup name="default">
    <Options>
      <BlockSize>65000</BlockSize>
    </Options>
    <ColumnFamilyDefaults>
    </ColumnFamilyDefaults>
    <ColumnFamily id="1">
      <Generation>42</Generation>
      <Name>actions</Name>
      <AccessGroup>default</AccessGroup>
      <Deleted>false</Deleted>
      <Options>
        <MaxVersions>3</MaxVersions>
        <TTL>2592000</TTL>
      </Options>
    </ColumnFamily>
  </AccessGroup>
  <AccessGroup name="meta">
    <Options>
      <BlockSize>65000</BlockSize>
    </Options>
    <ColumnFamilyDefaults>
      <MaxVersions>2</MaxVersions>
    </ColumnFamilyDefaults>
    <ColumnFamily id="2">
      <Generation>42</Generation>
      <Name>language</Name>
      <AccessGroup>meta</AccessGroup>
      <Deleted>false</Deleted>
      <Options>
        <MaxVersions>2</MaxVersions>
      </Options>
    </ColumnFamily>
    <ColumnFamily id="3">
      <Generation>42</Generation>
      <Name>checksum</Name>
      <AccessGroup>meta</AccessGroup>
      <Deleted>false</Deleted>
      <Options>
        <MaxVersions>1</MaxVersions>
      </Options>
    </ColumnFamily>
  </AccessGroup>
</Schema>

Parameters

with_ids Include generation and column IDs in output

Returns: String representation of schema in XML format

Definition at line 265 of file Schema.cc.

AccessGroupSpec * Schema::replace_access_group ( AccessGroupSpec * new_ag )

Replaces access group specification.

Removes access group specification with the same name as the name of new_ag from m_access_groups and then adds new_ag with a call to add_access_group().

Parameters

new_ag Replacement access group specification

Returns: Old access group specification

Definition at line 414 of file Schema.cc.

void Hypertable::Schema::set_access_group_defaults ( const AccessGroupOptions & defaults )

inline

Sets default access group options.

Sets m_ag_defaults to defaults

Parameters

defaults Access group options to use as table defaults

Definition at line 375 of file Schema.h.

void Hypertable::Schema::set_column_family_defaults ( const ColumnFamilyOptions & defaults )

inline

Sets default column family options.

Sets m_cf_defaults to defaults

Parameters

defaults Column family options to use as table defaults

Definition at line 386 of file Schema.h.

void Hypertable::Schema::set_generation ( int64_t generation )

inline

Sets generation.

Sets m_generation to generation

Parameters

generation New generation value

Definition at line 212 of file Schema.h.

void Hypertable::Schema::set_group_commit_interval ( int32_t interval )

inline

Sets group commit interval.

Sets m_group_commit_interval to interval.

Parameters

interval New value for group commit interval

Definition at line 364 of file Schema.h.

void Hypertable::Schema::set_version ( int32_t version )

inline

Sets version number.

Sets m_version to version

Parameters

version New version number

Definition at line 222 of file Schema.h.

void Schema::update_generation ( int64_t generation )

Updates generation and assigns column family IDs.

For each column family specification that has a generation value of zero, its generation is set to generation, and if its ID is also zero, it is assigned an ID that is one larger than the maximum column family ID of all of the column families. If any column family was assigned the new generation value, generation, then m_generation is also set to generation. Lastly, validate() is called.

Parameters

generation New generation

Definition at line 244 of file Schema.cc.

void Schema::validate ( )

Validates schema and reconstructs data structures.

Reconstructs m_column_families, m_column_family_map, m_column_family_id_map, and m_counter_mask by recursing through m_access_groups. During the data structure reconstruction, validation checks are performed to make sure there aren't too many columns or there exists a column that is assigned to two different access groups.

Exceptions

Exception with code set to Error::TOO_MANY_COLUMNS if too many columns are defined, or Error::BAD_SCHEMA if the same column is assigned to two different access groups.

Definition at line 505 of file Schema.cc.

Member Data Documentation

CstrAccessGroupMap Hypertable::Schema::m_access_group_map

private

Definition at line 448 of file Schema.h.

AccessGroupSpecs Hypertable::Schema::m_access_groups

private

Access group specifications.

Definition at line 444 of file Schema.h.

AccessGroupOptions Hypertable::Schema::m_ag_defaults

private

Default access group options.

Definition at line 438 of file Schema.h.

CharArena Hypertable::Schema::m_arena

private

Definition at line 426 of file Schema.h.

ColumnFamilyOptions Hypertable::Schema::m_cf_defaults

private

Default column family options.

Definition at line 441 of file Schema.h.

ColumnFamilySpecs Hypertable::Schema::m_column_families

private

&Column family specifications

Definition at line 451 of file Schema.h.

std::map<int32_t, ColumnFamilySpec *> Hypertable::Schema::m_column_family_id_map

private

Map of column family specifications (key == ID)

Definition at line 458 of file Schema.h.

CstrColumnFamilyMap Hypertable::Schema::m_column_family_map

private

Definition at line 455 of file Schema.h.

std::vector<bool> Hypertable::Schema::m_counter_mask

private

Bitmask describing which column families are counters.

Definition at line 461 of file Schema.h.

int64_t Hypertable::Schema::m_generation

private

Generation.

Definition at line 429 of file Schema.h.

int32_t Hypertable::Schema::m_group_commit_interval {}

private

Group commit interval.

Definition at line 435 of file Schema.h.

int32_t Hypertable::Schema::m_version {}

private

Version number.

Definition at line 432 of file Schema.h.

The documentation for this class was generated from the following files:

/home/doug/src/hypertable/src/cc/Hypertable/Lib/Schema.h
/home/doug/src/hypertable/src/cc/Hypertable/Lib/Schema.cc

Public Member Functions

Static Public Member Functions

Private Types

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation