Xapian::Compactor Class Reference

Compact a database, or merge and compact several. More...

#include <compactor.h>

Inheritance diagram for Xapian::Compactor:

Collaboration diagram for Xapian::Compactor:

List of all members.

Classes

class Internal

Public Types

enum compaction_level { STANDARD, FULL, FULLER }

Public Member Functions

Compactor ()

virtual ~Compactor ()

void set_block_size (size_t block_size)

Set the block size to use for tables in the output database.

void set_renumber (bool renumber)

Set whether to preserve existing document id values.

void set_multipass (bool multipass)

Set whether to merge postlists in multiple passes.

void set_compaction_level (compaction_level compaction)

Set the compaction level.

void set_destdir (const std::string &destdir)

Set where to write the output.

void add_source (const std::string &srcdir)

Add a source database.

void compact ()

Perform the actual compaction/merging operation.

virtual void set_status (const std::string &table, const std::string &status)

Update progress.

virtual std::string resolve_duplicate_metadata (const std::string &key, size_t num_tags, const std::string tags[])

Resolve multiple user metadata entries with the same key.

Private Attributes

Xapian::Internal::RefCntPtr
< Internal > internal

Detailed Description

Compact a database, or merge and compact several.

Definition at line 34 of file compactor.h.

Member Enumeration Documentation

enum Xapian::Compactor::compaction_level

Enumerator:

STANDARD
FULL
FULLER

Definition at line 39 of file compactor.h.

Constructor & Destructor Documentation

Xapian::Compactor::Compactor ( )

Definition at line 123 of file compactor.cc.

Xapian::Compactor::~Compactor ( ) [virtual]

Definition at line 125 of file compactor.cc.

Member Function Documentation

void Xapian::Compactor::add_source ( const std::string & srcdir )

Add a source database.

Parameters:

srcdir

The path to the source database to add.

Definition at line 158 of file compactor.cc.

Referenced by DEFINE_TESTCASE(), and main().

void Xapian::Compactor::compact ( )

Perform the actual compaction/merging operation.

Definition at line 164 of file compactor.cc.

Referenced by DEFINE_TESTCASE(), and main().

string Xapian::Compactor::resolve_duplicate_metadata	(	const std::string &	key,
		size_t	num_tags,
		const std::string	tags[]
	)			`[virtual]`

Resolve multiple user metadata entries with the same key.

When merging, if the same user metadata key is set in more than one input, then this method is called to allow this to be resolving in an appropriate way.

The default implementation just returns tags[0].

For multipass this will currently get called multiple times for the same key if there are duplicates to resolve in each pass, but this may change in the future.

Parameters:

	key	The metadata key with duplicate entries.
	num_tags	How many tags there are.
	tags	An array of num_tags strings containing the tags to merge.

Reimplemented in MyCompactor.

Definition at line 177 of file compactor.cc.

Referenced by FlintCompact::merge_postlists(), ChertCompact::merge_postlists(), and BrassCompact::merge_postlists().

void Xapian::Compactor::set_block_size ( size_t block_size )

Set the block size to use for tables in the output database.

Parameters:

block_size

The block size to use. Valid block sizes are currently powers of two between 2048 and 65536, with the default being 8192, but the valid sizes and default may change in the future.

Definition at line 128 of file compactor.cc.

Referenced by main().

void Xapian::Compactor::set_compaction_level ( compaction_level compaction )

Set the compaction level.

Parameters:

compaction

Available values are: - Xapian::Compactor::STANDARD - Don't split items unnecessarily. - Xapian::Compactor::FULL - Split items whenever it saves space (the default). - Xapian::Compactor::FULLER - Allow oversize items to save more space (not recommended if you ever plan to update the compacted database).

Definition at line 146 of file compactor.cc.

Referenced by main().

void Xapian::Compactor::set_destdir ( const std::string & destdir )

Set where to write the output.

Parameters:

destdir

Output path. This can be the same as an input if that input is a stub database (in which case the database(s) listed in the stub will be compacted to a new database and then the stub will be atomically updated to point to this new database).

Definition at line 152 of file compactor.cc.

Referenced by DEFINE_TESTCASE(), and main().

void Xapian::Compactor::set_multipass ( bool multipass )

Set whether to merge postlists in multiple passes.

Parameters:

multipass

If true and merging more than 3 databases, merge the postlists in multiple passes, which is generally faster but requires more disk space for temporary files. By default we don't do this.

Definition at line 140 of file compactor.cc.

Referenced by main().

void Xapian::Compactor::set_renumber ( bool renumber )

Set whether to preserve existing document id values.

Parameters:

renumber

The default is true, which means that document ids will be renumbered - currently by applying the same offset to all the document ids in a particular source database.

If false, then the document ids must be unique over all source databases. Currently the ranges of document ids in each source must not overlap either, though this restriction may be removed in the future.

Definition at line 134 of file compactor.cc.

Referenced by DEFINE_TESTCASE(), and main().

void Xapian::Compactor::set_status	(	const std::string &	table,
		const std::string &	status
	)			`[virtual]`

Update progress.

Subclass this method if you want to get progress updates during compaction. This is called for each table first with empty status, And then one or more times with non-empty status.

The default implementation does nothing.

Parameters:

	table	The table currently being compacted.
	status	A status message.

Reimplemented in MyCompactor.

Definition at line 170 of file compactor.cc.

Referenced by compact_brass(), compact_chert(), and compact_flint().

Member Data Documentation

Xapian::Internal::RefCntPtr<Internal> Xapian::Compactor::internal [private]

For internal use only.

Reference counted internals.

Definition at line 43 of file compactor.h.

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

include/xapian/compactor.h
api/compactor.cc


Classes
class	Internal
Public Types
enum	compaction_level { STANDARD, FULL, FULLER }
Public Member Functions
	Compactor ()
virtual	~Compactor ()
void	set_block_size (size_t block_size)
	Set the block size to use for tables in the output database.
void	set_renumber (bool renumber)
	Set whether to preserve existing document id values.
void	set_multipass (bool multipass)
	Set whether to merge postlists in multiple passes.
void	set_compaction_level (compaction_level compaction)
	Set the compaction level.
void	set_destdir (const std::string &destdir)
	Set where to write the output.
void	add_source (const std::string &srcdir)
	Add a source database.
void	compact ()
	Perform the actual compaction/merging operation.
virtual void	set_status (const std::string &table, const std::string &status)
	Update progress.
virtual std::string	resolve_duplicate_metadata (const std::string &key, size_t num_tags, const std::string tags[])
	Resolve multiple user metadata entries with the same key.
Private Attributes
Xapian::Internal::RefCntPtr < Internal >	internal