ChertTable Class Reference

Class managing a Btree table in a Chert database. More...

#include <chert_table.h>

Inheritance diagram for ChertTable:

[legend]

Collaboration diagram for ChertTable:

[legend]

List of all members.

Public Member Functions
	ChertTable (const char *tablename_, const std::string &path_, bool readonly_, int compress_strategy_=DONT_COMPRESS, bool lazy=false)
	Create a new Btree object.
	~ChertTable ()
	Close the Btree.
void	close (bool permanent=false)
	Close the Btree.
bool	exists () const
	Determine whether the btree exists on disk.
void	open ()
	Open the btree at the latest revision.
bool	open (chert_revision_number_t revision_)
	Open the btree at a given revision.
bool	is_open () const
	Return true if this table is open.
void	flush_db ()
	Flush any outstanding changes to the DB file of the table.
void	commit (chert_revision_number_t revision, int changes_fd=-1, const std::string *changes_tail=NULL)
	Commit any outstanding changes to the table.
void	write_changed_blocks (int changes_fd)
	Append the list of blocks changed to a changeset file.
void	cancel ()
	Cancel any outstanding changes.
bool	get_exact_entry (const std::string &key, std::string &tag) const
	Read an entry from the table, if and only if it is exactly that being asked for.
bool	key_exists (const std::string &key) const
	Check if a key exists in the Btree.
bool	read_tag (Cursor *C_, std::string *tag, bool keep_compressed) const
	Read the tag value for the key pointed to by cursor C_.
void	add (const std::string &key, std::string tag, bool already_compressed=false)
	Add a key/tag pair to the table, replacing any existing pair with the same key.
bool	del (const std::string &key)
	Delete an entry from the table.
void	erase ()
	Erase this table from disk.
void	set_block_size (unsigned int block_size_)
	Set the block size.
unsigned int	get_block_size () const
	Get the block size.
void	create_and_open (unsigned int blocksize)
	Create a new empty btree structure on disk and open it at the initial revision.
void	set_full_compaction (bool parity)
chert_revision_number_t	get_latest_revision_number () const
	Get the latest revision number stored in this table.
chert_revision_number_t	get_open_revision_number () const
	Get the revision number at which this table is currently open.
chert_tablesize_t	get_entry_count () const
	Return a count of the number of entries in the table.
bool	empty () const
	Return true if there are no entries in the table.
ChertCursor *	cursor_get () const
	Get a cursor for reading from the table.
bool	is_modified () const
	Determine whether the object contains uncommitted modifications.
void	set_max_item_size (size_t block_capacity)
	Set the maximum item size given the block capacity.
	XAPIAN_NORETURN (static void throw_database_closed())
	Throw an exception indicating that the database is closed.
Protected Member Functions
bool	do_open_to_read (bool revision_supplied, chert_revision_number_t revision_)
	Perform the opening operation to read.
bool	do_open_to_write (bool revision_supplied, chert_revision_number_t revision_, bool create_db=false)
	Perform the opening operation to write.
bool	basic_open (bool revision_supplied, chert_revision_number_t revision)
bool	find (Cursor *) const
	find(C_) searches for the key of B->kt in the B-tree.
int	delete_kt ()
void	read_block (uint4 n, byte *p) const
	read_block(n, p) reads block n of the DB file to address p.
void	write_block (uint4 n, const byte *p) const
	write_block(n, p) writes block n in the DB file from address p.
	XAPIAN_NORETURN (void set_overwritten() const)
void	block_to_cursor (Cursor *C_, int j, uint4 n) const
void	alter ()
	Btree::alter(); is called when the B-tree is to be altered.
void	compact (byte *p)
	compact(p) compact the block at p by shuffling all the items up to the end.
void	enter_key (int j, Key prevkey, Key newkey)
	enter_key(j, prevkey, newkey) is called after a block split.
int	mid_point (byte *p)
	mid_point(p) finds the directory entry in c that determines the approximate mid point of the data in the block at p.
void	add_item_to_block (byte *p, Item_wr kt, int c)
	add_item_to_block(p, kt_, c) adds item kt_ to the block at p.
void	add_item (Item_wr kt, int j)
	ChertTable::add_item(kt_, j) adds item kt_ to the block at cursor level C[j].
void	delete_item (int j, bool repeatedly)
	ChertTable::delete_item(j, repeatedly) is (almost) the converse of add_item.
int	add_kt (bool found)
	add_kt(found) adds the item (key-tag pair) at B->kt into the B-tree, using cursor C.
void	read_root ()
void	split_root (uint4 split_n)
	Btree needs to gain a new level to insert more items: so split root block and construct a new one.
void	form_key (const std::string &key) const
char	other_base_letter () const
void	lazy_alloc_deflate_zstream () const
	Allocate the zstream for deflating, if not already allocated.
void	lazy_alloc_inflate_zstream () const
	Allocate the zstream for inflating, if not already allocated.
bool	prev (Cursor *C_, int j) const
bool	next (Cursor *C_, int j) const
bool	prev_default (Cursor *C_, int j) const
bool	next_default (Cursor *C_, int j) const
bool	prev_for_sequential (Cursor *C_, int dummy) const
bool	next_for_sequential (Cursor *C_, int dummy) const
Static Protected Member Functions
static int	find_in_block (const byte *p, Key key, bool leaf, int c)
	find_in_block(p, key, leaf, c) searches for the key in the block at p.
static uint4	block_given_by (const byte *p, int c)
	block_given_by(p, c) finds the item at block address p, directory offset c, and returns its tag value as an integer.
Protected Attributes
const char *	tablename
	The name of the table (used when writing changesets).
chert_revision_number_t	revision_number
	revision number of the opened B-tree.
chert_tablesize_t	item_count
	keeps a count of the number of items in the B-tree.
unsigned int	block_size
	block size of the B tree in bytes
chert_revision_number_t	latest_revision_number
	Revision number of the other base, or zero if there is only one base file.
bool	both_bases
	set to true if baseA and baseB both exist as valid bases.
char	base_letter
	the value 'A' or 'B' of the current base
bool	faked_root_block
	true if the root block is faked (not written to disk).
bool	sequential
	true iff the data has been written in a single write in sequential order.
int	handle
	File descriptor of the table.
int	level
	number of levels, counting from 0
uint4	root
	the root block of the B-tree
Item_wr	kt
	buffer of size block_size for making up key-tag items
byte *	buffer
	buffer of size block_size for reforming blocks
ChertTable_base	base
	For writing back as file baseA or baseB.
std::string	name
	The path name of the B tree.
int	seq_count
	count of the number of successive instances of purely sequential addition, starting at SEQ_START_POINT (neg) and going up to zero.
uint4	changed_n
	the last block to be changed by an addition
int	changed_c
	directory offset corresponding to last block to be changed by an addition
size_t	max_item_size
	maximum size of an item (key-tag pair)
bool	Btree_modified
	Set to true the first time the B-tree is modified.
bool	full_compaction
	set to true when full compaction is to be achieved
bool	writable
	Set to true when the database is opened to write.
bool	cursor_created_since_last_modification
	Flag for tracking when cursors need to rebuild.
unsigned long	cursor_version
	Version count for tracking when cursors need to rebuild.
Cursor	C [BTREE_CURSOR_LEVELS]
byte *	split_p
	Buffer used when splitting a block.
int	compress_strategy
	DONT_COMPRESS or Z_DEFAULT_STRATEGY, Z_FILTERED, Z_HUFFMAN_ONLY, Z_RLE.
z_stream *	deflate_zstream
	Zlib state object for deflating.
z_stream *	inflate_zstream
	Zlib state object for inflating.
bool	lazy
	If true, don't create the table until it's needed.
Private Member Functions
	ChertTable (const ChertTable &)
	Copying not allowed.
ChertTable &	operator= (const ChertTable &)
	Assignment not allowed.
bool	really_empty () const
	Return true if there are no entries in the table.
Friends
class	ChertCursor

---

Detailed Description

Class managing a Btree table in a Chert database.

A table is a store holding a set of key/tag pairs.

A key is used to access a block of data in a chert table.

Keys are of limited length.

Keys may not be empty (each Btree has a special empty key for internal use).

A tag is a piece of data associated with a given key. The contents of the tag are opaque to the Btree.

Tags may be of arbitrary length (the Btree imposes a very large limit). Note though that they will be loaded into memory in their entirety, so should not be permitted to grow without bound in normal usage.

Tags which are null strings _are_ valid, and are different from a tag simply not being in the table.

Definition at line 289 of file chert_table.h.

---

Constructor & Destructor Documentation

ChertTable::ChertTable

(

const ChertTable &

)

[private]

Copying not allowed.

ChertTable::ChertTable	(	const char *	tablename_,
		const std::string &	path_,
		bool	readonly_,
		int	compress_strategy_ = DONT_COMPRESS,
		bool	lazy = false
	)

Create a new Btree object.

This does not create the table on disk - the create_and_open() method must be called to create the table on disk.

This also does not open the table - either the create_and_open() or open() methods must be called before use is made of the table.

Parameters:

	tablename_	The name of the table (used in changesets).
	path_	Path at which the table is stored.
	readonly_	whether to open the table for read only access.
	compress_strategy_	DONT_COMPRESS, Z_DEFAULT_STRATEGY, Z_FILTERED, Z_HUFFMAN_ONLY, or Z_RLE.
	lazy	If true, don't create the table until it's needed.

Definition at line 1552 of file chert_table.cc.

References LOGCALL_CTOR.

ChertTable::~ChertTable

(

)

Close the Btree.

Any outstanding changes (ie, changes made without commit() having subsequently been called) will be lost.

Definition at line 1741 of file chert_table.cc.

References close(), deflate_zstream, inflate_zstream, and LOGCALL_DTOR.

---

Member Function Documentation

void ChertTable::add	(	const std::string &	key,
		std::string	tag,
		bool	already_compressed = false
	)

Add a key/tag pair to the table, replacing any existing pair with the same key.

If an error occurs during the operation, an exception will be thrown.

If key is empty, then the null item is replaced.

e.g. btree.add("TODAY", "Mon 9 Oct 2000");

Parameters:

	key	The key to store in the table.
	tag	The tag to store in the table.
	already_compressed	true if tag is already compressed, for example because it is being opaquely copied (default: false).

Definition at line 1019 of file chert_table.cc.

References add_kt(), Assert, block_size, Btree_modified, BYTE_PAIR_RANGE, C, C2, CompileTimeAssert, COMPRESS_MIN, compress_strategy, create_and_open(), cursor_created_since_last_modification, cursor_version, D2, deflate_zstream, delete_kt(), DONT_COMPRESS, find(), form_key(), full_compaction, handle, I2, item_count, K1, Item_base< T >::key(), kt, lazy_alloc_deflate_zstream(), Key::length(), LOGCALL_VOID, max_item_size, Cursor::p, Item_wr::set_component_of(), Item_wr::set_components_of(), Item_wr::set_tag(), TOTAL_FREE, and writable.

Referenced by copy_docid_keyed(), copy_position(), copy_postlist(), copy_termlist(), copy_unchanged(), Chert::PostlistChunkWriter::flush(), ChertValueManager::merge_changes(), ChertSynonymTable::merge_changes(), ChertSpellingTable::merge_changes(), ChertPostListTable::merge_changes(), ChertCompact::merge_docid_keyed(), ChertCompact::merge_postlists(), ChertCompact::merge_spellings(), ChertCompact::merge_synonyms(), ChertRecordTable::replace_record(), ChertWritableDatabase::set_metadata(), ChertPositionListTable::set_positionlist(), ChertTermListTable::set_termlist(), ChertValueManager::set_value_stats(), ChertDatabaseStats::write(), and ValueUpdater::write_tag().

void ChertTable::add_item	(	Item_wr	kt_,
		int	j
	)			[protected]

ChertTable::add_item(kt_, j) adds item kt_ to the block at cursor level C[j].

If there is not enough room the block splits and the item is then added to the appropriate half.

Definition at line 718 of file chert_table.cc.

References add_item_to_block(), Assert, AssertRel, base, block_size, Cursor::c, C, changed_c, changed_n, compact(), D2, DIR_END, DIR_START, enter_key(), level, LOGCALL_VOID, MAX_FREE, mid_point(), Cursor::n, ChertTable_base::next_free_block(), Cursor::p, seq_count, SET_DIR_END, Item_base< T >::size(), split_p, split_root(), TOTAL_FREE, writable, and write_block().

Referenced by add_kt(), enter_key(), and split_root().

void ChertTable::add_item_to_block	(	byte *	p,
		Item_wr	kt_,
		int	c
	)			[protected]

add_item_to_block(p, kt_, c) adds item kt_ to the block at p.

c is the offset in the directory that needs to be expanded to accommodate the new entry for the item. We know before this is called that there is enough contiguous room for the item in the block, so it's just a matter of shuffling up any directory entries after where we're inserting and copying in the item.

Definition at line 683 of file chert_table.cc.

References Assert, AssertRel, D2, DIR_END, Item_base< T >::get_address(), LOGCALL_VOID, MAX_FREE, SET_DIR_END, SET_MAX_FREE, SET_TOTAL_FREE, setD, Item_base< T >::size(), TOTAL_FREE, and writable.

Referenced by add_item().

int ChertTable::add_kt

(

bool

found

)

[protected]

add_kt(found) adds the item (key-tag pair) at B->kt into the B-tree, using cursor C.

found == find() is handed over as a parameter from Btree::add. Btree::alter() prepares for the alteration to the B-tree. Then there are a number of cases to consider:

If an item with the same key is in the B-tree (found is true), the new kt replaces it.

If then kt is smaller, or the same size as, the item it replaces, kt is put in the same place as the item it replaces, and the TOTAL_FREE measure is reduced.

If kt is larger than the item it replaces it is put in the MAX_FREE space if there is room, and the directory entry and space counts are adjusted accordingly.

• But if there is not room we do it the long way: the old item is deleted with delete_item and kt is added in with add_item.

If the key of kt is not in the B-tree (found is false), the new kt is added in with add_item.

Definition at line 889 of file chert_table.cc.

References add_item(), alter(), Assert, Cursor::c, C, changed_c, changed_n, Item_base< T >::components_of(), D2, delete_item(), DIR_END, Item_base< T >::get_address(), kt, LOGCALL, MAX_FREE, Cursor::p, RETURN, seq_count, SEQ_START_POINT, sequential, SET_MAX_FREE, SET_TOTAL_FREE, setD, Item_base< T >::size(), TOTAL_FREE, and writable.

Referenced by add().

void ChertTable::alter

(

)

[protected]

Btree::alter(); is called when the B-tree is to be altered.

It causes new blocks to be forced for the current set of blocks in the cursor.

The point is that if a block at level 0 is to be altered it may get a new number. Then the pointer to this block from level 1 will need changing. So the block at level 1 needs altering and may get a new block number. Then the pointer to this block from level 2 will need changing ... and so on back to the root.

The clever bit here is spotting the cases when we can make an early exit from this process. If C[j].rewrite is true, C[j+k].rewrite will be true for k = 1,2 ... We have been through all this before, and there is no need to do it again. If C[j].n was free at the start of the transaction, we can copy it back to the same place without violating the integrity of the B-tree. We don't then need a new n and can return. The corresponding C[j].rewrite may be true or false in that case.

Definition at line 413 of file chert_table.cc.

References Assert, base, ChertTable_base::block_free_at_start(), C, ChertTable_base::free_block(), latest_revision_number, level, LOGCALL_VOID, Cursor::n, ChertTable_base::next_free_block(), Cursor::p, REVISION, Cursor::rewrite, SET_REVISION, and writable.

Referenced by add_kt(), and delete_kt().

bool ChertTable::basic_open	(	bool	revision_supplied,
		chert_revision_number_t	revision
	)			[protected]

Definition at line 1322 of file chert_table.cc.

References Assert, base, base_letter, BLOCK_CAPACITY, block_size, both_bases, close(), faked_root_block, ChertTable_base::get_block_size(), ChertTable_base::get_have_fakeroot(), ChertTable_base::get_item_count(), ChertTable_base::get_level(), ChertTable_base::get_revision(), ChertTable_base::get_root(), ChertTable_base::get_sequential(), handle, item_count, kt, latest_revision_number, level, LOGCALL, LOGLINE, ChertTable_base::read(), RETURN, revision_number, root, sequential, set_max_item_size(), ChertTable_base::swap(), writable, and zeroed_new().

Referenced by do_open_to_read(), and do_open_to_write().

static uint4 ChertTable::block_given_by	(	const byte *	p,
		int	c
	)			[static, protected]

block_given_by(p, c) finds the item at block address p, directory offset c, and returns its tag value as an integer.

Referenced by ChertTableCheck::block_check(), find(), next_default(), and prev_default().

void ChertTable::block_to_cursor	(	Cursor *	C_,
		int	j,
		uint4	n
	)			const [protected]

Definition at line 347 of file chert_table.cc.

References Assert, block_size, C, GET_LEVEL, level, LOGCALL_VOID, Cursor::n, Cursor::p, rare, read_block(), REVISION, Cursor::rewrite, Xapian::Internal::str(), writable, and write_block().

Referenced by ChertTableCheck::block_check(), delete_item(), find(), next_default(), prev_default(), and read_root().

void ChertTable::cancel

(

)

Cancel any outstanding changes.

This will discard any modifications which haven't been committed by calling commit().

Reimplemented in ChertSpellingTable, and ChertSynonymTable.

Definition at line 1955 of file chert_table.cc.

References Assert, base, base_letter, BLK_UNUSED, block_size, Btree_modified, C, changed_c, changed_n, DIR_START, faked_root_block, ChertTable_base::get_block_size(), ChertTable_base::get_have_fakeroot(), ChertTable_base::get_item_count(), ChertTable_base::get_level(), ChertTable_base::get_revision(), ChertTable_base::get_root(), ChertTable_base::get_sequential(), handle, item_count, latest_revision_number, level, LOGCALL_VOID, Cursor::n, ChertTable_base::read(), read_root(), revision_number, Cursor::rewrite, root, seq_count, SEQ_START_POINT, sequential, and writable.

Referenced by ChertDatabase::cancel().

void ChertTable::close

(

bool

permanent = false

)

Close the Btree.

This closes and frees any of the btree structures which have been created and opened.

Parameters:

permanent

If true, the Btree will not reopen on demand.

Definition at line 1760 of file chert_table.cc.

References buffer, C, Item_base< T >::get_address(), handle, kt, level, LOGCALL_VOID, Cursor::p, and split_p.

Referenced by basic_open(), ChertDatabase::close(), commit(), create_and_open(), do_open_to_read(), do_open_to_write(), erase(), open(), and ~ChertTable().

void ChertTable::commit	(	chert_revision_number_t	revision,
		int	changes_fd = -1,
		const std::string *	changes_tail = NULL
	)

Commit any outstanding changes to the table.

Commit changes made by calling add() and del() to the Btree.

If an error occurs during the operation, this will be signalled by an exception. In case of error, changes made will not be committed to the Btree - they will be discarded.

Parameters:

	new_revision	The new revision number to store. This must be greater than the latest revision number (see get_latest_revision_number()), or an exception will be thrown.
	changes_fd	The file descriptor to write changes to. Defaults to -1, meaning no changes will be written.

Definition at line 1813 of file chert_table.cc.

References Assert, base, base_letter, BLK_UNUSED, both_bases, BTREE_CURSOR_LEVELS, Btree_modified, Cursor::c, C, changed_c, changed_n, ChertTable_base::clear_bit_map(), close(), ChertTable_base::commit(), DIR_START, faked_root_block, handle, io_sync(), item_count, latest_revision_number, level, LOGCALL_VOID, msvc_posix_rename(), Cursor::n, other_base_letter(), read_root(), revision_number, Cursor::rewrite, root, seq_count, SEQ_START_POINT, sequential, ChertTable_base::set_have_fakeroot(), ChertTable_base::set_item_count(), ChertTable_base::set_level(), ChertTable_base::set_revision(), ChertTable_base::set_root(), ChertTable_base::set_sequential(), tablename, unlink(), writable, and ChertTable_base::write_to_file().

Referenced by compact_chert(), main(), ChertCompact::multimerge_postlists(), and ChertDatabase::set_revision_number().

void ChertTable::compact

(

byte *

p

)

[protected]

compact(p) compact the block at p by shuffling all the items up to the end.

MAX_FREE(p) is then maximized, and is equal to TOTAL_FREE(p).

Definition at line 522 of file chert_table.cc.

References Assert, block_size, buffer, D2, DIR_END, DIR_START, Item_base< T >::get_address(), LOGCALL_VOID, SET_MAX_FREE, SET_TOTAL_FREE, setD, Item_base< T >::size(), and writable.

Referenced by add_item(), and split_root().

void ChertTable::create_and_open

(

unsigned int

blocksize

)

Create a new empty btree structure on disk and open it at the initial revision.

The table must be writable - it doesn't make sense to create a table that is read-only!

The block size must be less than 64K, where K = 1024. It is unwise to use a small block size (less than 1024 perhaps), so we enforce a minimum block size of 2K.

Example:

Btree btree("X-"); btree.create_and_open(8192); // Files will be X-DB, X-baseA (and X-baseB).

Parameters:

blocksize

- Size of blocks to use.

Exceptions:

	Xapian::DatabaseCreateError	if the table can't be created.
	Xapian::InvalidArgumentError	if the requested blocksize is unsuitable.

Reimplemented in ChertLazyTable, and ChertTermListTable.

Definition at line 1708 of file chert_table.cc.

References Assert, close(), do_open_to_write(), handle, io_unlink(), LOGCALL_VOID, revision_number, ChertTable_base::set_block_size(), set_block_size(), ChertTable_base::set_have_fakeroot(), ChertTable_base::set_revision(), ChertTable_base::set_sequential(), writable, and ChertTable_base::write_to_file().

Referenced by add(), compact_chert(), ChertDatabase::create_and_open_tables(), main(), and ChertCompact::multimerge_postlists().

ChertCursor * ChertTable::cursor_get

(

)

const

Get a cursor for reading from the table.

The cursor is owned by the caller - it is the caller's responsibility to ensure that it is deleted.

Definition at line 1307 of file chert_table.cc.

References ChertCursor, handle, LOGCALL, and RETURN.

Referenced by check_chert_table(), Chert::PostlistChunkWriter::flush(), ChertPostListTable::get_chunk(), ChertValueManager::get_chunk_containing_did(), ChertDatabase::get_postlist_cursor(), ChertDatabase::open_metadata_keylist(), ChertDatabase::open_spelling_wordlist(), ChertDatabase::open_synonym_keylist(), and ValueUpdater::update().

bool ChertTable::del

(

const std::string &

key

)

Delete an entry from the table.

The entry will be removed from the table, if it exists. If it does not exist, no action will be taken. The item with an empty key can't be removed, and false is returned.

If an error occurs during the operation, this will be signalled by an exception.

e.g. bool deleted = btree.del("TODAY")

Parameters:

key

The key to remove from the table.

Returns:

true if an entry was removed; false if it did not exist.

Definition at line 1141 of file chert_table.cc.

References Assert, Btree_modified, CHERT_BTREE_MAX_KEY_LEN, cursor_created_since_last_modification, cursor_version, delete_kt(), form_key(), handle, item_count, kt, LOGCALL, RETURN, Item_wr::set_component_of(), and writable.

Referenced by ChertPositionListTable::delete_positionlist(), ChertRecordTable::delete_record(), ChertTermListTable::delete_termlist(), Chert::PostlistChunkWriter::flush(), ChertValueManager::merge_changes(), ChertSynonymTable::merge_changes(), ChertSpellingTable::merge_changes(), ChertPostListTable::merge_changes(), ChertWritableDatabase::set_metadata(), ChertValueManager::set_value_stats(), and ValueUpdater::write_tag().

void ChertTable::delete_item	(	int	j,
		bool	repeatedly
	)			[protected]

ChertTable::delete_item(j, repeatedly) is (almost) the converse of add_item.

If repeatedly is true, the process repeats at the next level when a block has been completely emptied, freeing the block and taking out the pointer to it. Emptied root blocks are also removed, which reduces the number of levels in the B-tree.

Definition at line 816 of file chert_table.cc.

References Assert, base, BLK_UNUSED, block_to_cursor(), Cursor::c, C, D2, DIR_END, DIR_START, ChertTable_base::free_block(), level, LOGCALL_VOID, MAX_FREE, Cursor::n, Cursor::p, Cursor::rewrite, SET_DIR_END, SET_MAX_FREE, SET_TOTAL_FREE, TOTAL_FREE, and writable.

Referenced by add_kt(), and delete_kt().

int ChertTable::delete_kt

(

)

[protected]

Definition at line 955 of file chert_table.cc.

References alter(), Assert, C, delete_item(), find(), LOGCALL, RETURN, seq_count, SEQ_START_POINT, sequential, and writable.

Referenced by add(), and del().

bool ChertTable::do_open_to_read	(	bool	revision_supplied,
		chert_revision_number_t	revision_
	)			[protected]

Perform the opening operation to read.

Return true iff the open succeeded.

Definition at line 2002 of file chert_table.cc.

References basic_open(), BLK_UNUSED, block_size, C, close(), handle, lazy, level, LOGCALL, Cursor::n, O_BINARY, open(), Cursor::p, read_root(), RETURN, and revision_number.

Referenced by open().

bool ChertTable::do_open_to_write	(	bool	revision_supplied,
		chert_revision_number_t	revision_,
		bool	create_db = false
	)			[protected]

Perform the opening operation to write.

Return true iff the open succeeded.

Definition at line 1491 of file chert_table.cc.

References basic_open(), BLK_UNUSED, block_size, buffer, C, changed_c, changed_n, close(), DIR_START, handle, lazy, level, LOGCALL, Cursor::n, O_BINARY, open(), Cursor::p, read_root(), RETURN, revision_number, seq_count, SEQ_START_POINT, split_p, writable, and zeroed_new().

Referenced by create_and_open(), and open().

bool ChertTable::empty

(

)

const [inline]

Return true if there are no entries in the table.

Definition at line 568 of file chert_table.h.

References ChertCursor::level.

Referenced by ChertDatabase::has_positions(), ChertCompact::merge_docid_keyed(), ChertCompact::merge_postlists(), ChertCompact::merge_spellings(), and ChertCompact::merge_synonyms().

void ChertTable::enter_key	(	int	j,
		Key	prevkey,
		Key	newkey
	)			[protected]

enter_key(j, prevkey, newkey) is called after a block split.

It enters in the block at level C[j] a separating key for the block at level C[j - 1]. The key itself is newkey. prevkey is the preceding key, and at level 1 newkey can be trimmed down to the first point of difference to prevkey for entry in C[j].

This code looks longer than it really is. If j exceeds the number of B-tree levels the root block has split and we have to construct a new one, but this is a rare event.

The key is constructed in b, with block number C[j - 1].n as tag, and this is added in with add_item. add_item may itself cause a block split, with a further call to enter_key. Hence the recursion.

Definition at line 591 of file chert_table.cc.

References add_item(), Assert, AssertRel, Cursor::c, C, C2, D2, find_in_block(), Key::get_address(), getint4(), I2, K1, Item_base< T >::key(), Key::length(), LOGCALL_VOID, Cursor::n, Cursor::p, Cursor::rewrite, Item_wr::set_key_and_block(), SET_TOTAL_FREE, TOTAL_FREE, and writable.

Referenced by add_item().

void ChertTable::erase

(

)

Erase this table from disk.

Definition at line 1685 of file chert_table.cc.

References close(), io_unlink(), and LOGCALL_VOID.

Referenced by compact_chert(), ChertLazyTable::create_and_open(), and main().

bool ChertTable::exists

(

)

const

Determine whether the btree exists on disk.

Definition at line 1678 of file chert_table.cc.

References file_exists(), and LOGCALL.

Referenced by ChertDatabase::database_exists().

bool ChertTable::find

(

Cursor *

C_

)

const [protected]

find(C_) searches for the key of B->kt in the B-tree.

Result is true if found, false otherwise. When false, the B_tree cursor is positioned at the last key in the B-tree <= the search key. Goes to first (null) item in B-tree when key length == 0.

Definition at line 488 of file chert_table.cc.

References block_given_by(), block_to_cursor(), DIR_START, find_in_block(), Item_base< T >::key(), kt, level, LOGCALL, Key::p, and RETURN.

Referenced by add(), delete_kt(), ChertCursor::find_entry(), ChertCursor::find_entry_ge(), get_exact_entry(), and key_exists().

int ChertTable::find_in_block	(	const byte *	p,
		Key	key,
		bool	leaf,
		int	c
	)			[static, protected]

find_in_block(p, key, leaf, c) searches for the key in the block at p.

leaf is true for a data block, and false for an index block (when the first key is dummy and never needs to be tested). What we get is the directory entry to the last key <= the key being searched for.

The lookup is by binary chop, with i and j set to the left and right ends of the search area. In sequential addition, c will often be the answer, so we test the keys round c and move i and j towards c if possible.

Definition at line 458 of file chert_table.cc.

References D2, DIR_END, DIR_START, Key::get_address(), LOGCALL_STATIC, and RETURN.

Referenced by enter_key(), and find().

void ChertTable::flush_db

(

)

Flush any outstanding changes to the DB file of the table.

This must be called before commit, to ensure that the DB file is ready to be switched to a new version by the commit.

Reimplemented in ChertSpellingTable, and ChertSynonymTable.

Definition at line 1790 of file chert_table.cc.

References Assert, Btree_modified, C, faked_root_block, handle, level, LOGCALL_VOID, writable, and write_block().

Referenced by compact_chert(), main(), ChertCompact::multimerge_postlists(), and ChertDatabase::set_revision_number().

void ChertTable::form_key

(

const std::string &

key

)

const [protected]

Definition at line 989 of file chert_table.cc.

References Item_wr::form_key(), kt, and LOGCALL_VOID.

Referenced by add(), del(), ChertCursor::find_entry(), ChertCursor::find_entry_ge(), get_exact_entry(), and key_exists().

unsigned int ChertTable::get_block_size

(

)

const [inline]

Get the block size.

Definition at line 499 of file chert_table.h.

Referenced by ChertDatabase::open_tables(), and ChertDatabase::open_tables_consistent().

chert_tablesize_t ChertTable::get_entry_count

(

)

const [inline]

Return a count of the number of entries in the table.

The count does not include the ever-present item with null key.

Use empty() if you only want to know if the table is empty or not.

Returns:

The number of entries in the table.

Definition at line 563 of file chert_table.h.

Referenced by ChertRecordTable::get_doccount().

bool ChertTable::get_exact_entry	(	const std::string &	key,
		std::string &	tag
	)			const

Read an entry from the table, if and only if it is exactly that being asked for.

If the key is found in the table, then the tag is copied to tag. If the key is not found tag is left unchanged.

The result is true iff the specified key is found in the Btree.

Parameters:

	key	The key to look for in the table.
	tag	A tag object to fill with the value if found.

Returns:

true if key is found in table, false if key is not found in table.

Definition at line 1177 of file chert_table.cc.

References Assert, C, CHERT_BTREE_MAX_KEY_LEN, find(), form_key(), handle, LOGCALL, read_tag(), and RETURN.

Referenced by ChertSynonymTable::add_synonym(), ChertSpellingTable::add_word(), ChertValueManager::delete_document(), Chert::PostlistChunkWriter::flush(), ChertValueManager::get_all_values(), ChertPostListTable::get_collection_freq(), ChertDatabase::get_metadata(), ChertRecordTable::get_record(), ChertPostListTable::get_termfreq(), ChertValueManager::get_value_stats(), ChertSpellingTable::get_word_frequency(), ChertSpellingTable::merge_changes(), ChertPostListTable::merge_changes(), ChertSynonymTable::open_termlist(), ChertSpellingTable::open_termlist(), ChertPositionListTable::positionlist_count(), ChertDatabaseStats::read(), ChertPositionList::read_data(), ChertSynonymTable::remove_synonym(), ChertSpellingTable::remove_word(), and ChertPositionListTable::set_positionlist().

chert_revision_number_t ChertTable::get_latest_revision_number

(

)

const [inline]

Get the latest revision number stored in this table.

This gives the higher of the revision numbers held in the base files of the B-tree, or just the revision number if there's only one base file.

It is possible that there are other, older, revisions of this table available, and indeed that the revision currently open is one of these older revisions.

Definition at line 538 of file chert_table.h.

Referenced by ChertDatabase::ChertDatabase(), and ChertDatabase::get_next_revision_number().

chert_revision_number_t ChertTable::get_open_revision_number

(

)

const [inline]

Get the revision number at which this table is currently open.

It is possible that there are other, more recent or older revisions available.

Returns:

the current revision number.

Definition at line 550 of file chert_table.h.

Referenced by ChertDatabaseReplicator::apply_changeset_from_conn(), ChertDatabase::ChertDatabase(), ChertDatabase::create_and_open_tables(), ChertDatabase::get_revision_number(), and ChertDatabase::open_tables_consistent().

bool ChertTable::is_modified

(

)

const [inline]

Determine whether the object contains uncommitted modifications.

Returns:

true if there have been modifications since the last the last call to commit().

Reimplemented in ChertSpellingTable, and ChertSynonymTable.

Definition at line 593 of file chert_table.h.

Referenced by ChertDatabase::apply().

bool ChertTable::is_open

(

)

const [inline]

Return true if this table is open.

NB If the table is lazy and doesn't yet exist, returns false.

Definition at line 373 of file chert_table.h.

Referenced by ChertValueManager::add_document(), ChertWritableDatabase::add_document_(), ChertValueManager::delete_document(), ChertWritableDatabase::delete_document(), ChertValueManager::get_all_values(), ChertValueManager::merge_changes(), ChertDatabase::open_term_list(), and ChertWritableDatabase::replace_document().

bool ChertTable::key_exists

(

const std::string &

key

)

const

Check if a key exists in the Btree.

This is just like get_exact_entry() except it doesn't read the tag value so is more efficient if you only want to check that the key exists.

Parameters:

key

The key to look for in the table.

Returns:

true if key is found in table, false if key is not found in table.

Definition at line 1200 of file chert_table.cc.

References Assert, C, CHERT_BTREE_MAX_KEY_LEN, find(), form_key(), LOGCALL, and RETURN.

Referenced by ChertPostListTable::merge_changes(), and ChertPostListTable::term_exists().

void ChertTable::lazy_alloc_deflate_zstream

(

)

const [protected]

Allocate the zstream for deflating, if not already allocated.

Definition at line 1603 of file chert_table.cc.

References compress_strategy, deflate_zstream, rare, Xapian::Internal::str(), and usual.

Referenced by add().

void ChertTable::lazy_alloc_inflate_zstream

(

)

const [protected]

Allocate the zstream for inflating, if not already allocated.

Definition at line 1641 of file chert_table.cc.

References inflate_zstream, rare, Xapian::Internal::str(), and usual.

Referenced by read_tag().

int ChertTable::mid_point

(

byte *

p

)

[protected]

mid_point(p) finds the directory entry in c that determines the approximate mid point of the data in the block at p.

Definition at line 653 of file chert_table.cc.

References Assert, block_size, D2, DIR_END, DIR_START, LOGCALL, RETURN, and TOTAL_FREE.

Referenced by add_item().

bool ChertTable::next	(	Cursor *	C_,
		int	j
	)			const [inline, protected]

Definition at line 754 of file chert_table.h.

Referenced by ChertCursor::find_entry_ge(), ChertCursor::next(), read_tag(), and ChertCursor::read_tag().

bool ChertTable::next_default	(	Cursor *	C_,
		int	j
	)			const [protected]

Definition at line 2219 of file chert_table.cc.

References Assert, block_given_by(), block_size, block_to_cursor(), Cursor::c, D2, DIR_END, DIR_START, level, LOGCALL, Cursor::p, and RETURN.

bool ChertTable::next_for_sequential	(	Cursor *	C_,
		int	dummy
	)			const [protected]

Definition at line 2144 of file chert_table.cc.

References Assert, AssertEq, base, block_size, C, Cursor::c, D2, DIR_END, DIR_START, ChertTable_base::get_last_block(), GET_LEVEL, latest_revision_number, level, LOGCALL, Cursor::n, Cursor::p, read_block(), RETURN, REVISION, revision_number, and writable.

bool ChertTable::open

(

chert_revision_number_t

revision_

)

Open the btree at a given revision.

Like Btree::open, but try to open at the given revision number and fail if that isn't possible.

Parameters:

revision_

- revision number to open.

Returns:

true if table is successfully opened at desired revision; false if table cannot be opened at desired revision (but table is otherwise consistent).

Exceptions:

	Xapian::DatabaseCorruptError	will be thrown if the table is in a corrupt state.
	Xapian::DatabaseOpeningError	will be thrown if the table cannot be opened (but is not corrupt - eg, permission problems, not present, etc).

Reimplemented in ChertPostListTable.

Definition at line 2065 of file chert_table.cc.

References AssertEq, close(), do_open_to_read(), do_open_to_write(), LOGCALL, LOGLINE, RETURN, revision_number, and writable.

void ChertTable::open

(

)

Open the btree at the latest revision.

Exceptions:

	Xapian::DatabaseCorruptError	will be thrown if the table is in a corrupt state.
	Xapian::DatabaseOpeningError	will be thrown if the table cannot be opened (but is not corrupt - eg, permission problems, not present, etc).

Definition at line 2048 of file chert_table.cc.

References close(), do_open_to_read(), do_open_to_write(), LOGCALL_VOID, LOGLINE, and writable.

Referenced by ChertDatabaseReplicator::apply_changeset_from_conn(), ChertTableCheck::check(), check_chert_table(), do_open_to_read(), do_open_to_write(), ChertCompact::merge_docid_keyed(), ChertCompact::merge_postlists(), ChertCompact::merge_spellings(), ChertCompact::merge_synonyms(), ChertPostListTable::open(), ChertDatabase::open_tables(), and ChertDatabase::open_tables_consistent().

ChertTable& ChertTable::operator=

(

const ChertTable &

)

[private]

Assignment not allowed.

char ChertTable::other_base_letter

(

)

const [inline, protected]

Definition at line 644 of file chert_table.h.

Referenced by commit(), and write_block().

bool ChertTable::prev	(	Cursor *	C_,
		int	j
	)			const [inline, protected]

Definition at line 749 of file chert_table.h.

Referenced by ChertCursor::find_entry(), and ChertCursor::prev().

bool ChertTable::prev_default	(	Cursor *	C_,
		int	j
	)			const [protected]

Definition at line 2197 of file chert_table.cc.

References Assert, block_given_by(), block_size, block_to_cursor(), Cursor::c, D2, DIR_END, DIR_START, level, LOGCALL, Cursor::p, and RETURN.

bool ChertTable::prev_for_sequential	(	Cursor *	C_,
		int	dummy
	)			const [protected]

Definition at line 2092 of file chert_table.cc.

References Assert, AssertEq, block_size, C, Cursor::c, D2, DIR_END, DIR_START, GET_LEVEL, latest_revision_number, level, LOGCALL, Cursor::n, Cursor::p, read_block(), RETURN, REVISION, revision_number, and writable.

void ChertTable::read_block	(	uint4	n,
		byte *	p
	)			const [protected]

read_block(n, p) reads block n of the DB file to address p.

Definition at line 189 of file chert_table.cc.

References Assert, base, block_size, ChertTable_base::get_bit_map_size(), handle, io_read(), LOGCALL_VOID, and Xapian::Internal::str().

Referenced by block_to_cursor(), next_for_sequential(), prev_for_sequential(), and write_changed_blocks().

void ChertTable::read_root

(

)

[protected]

Definition at line 1447 of file chert_table.cc.

References Assert, base, block_size, block_to_cursor(), C, C2, D2, DIR_START, faked_root_block, I2, K1, latest_revision_number, level, LOGCALL_VOID, Cursor::n, ChertTable_base::next_free_block(), Cursor::p, REVISION, revision_number, root, SET_DIR_END, SET_LEVEL, SET_MAX_FREE, SET_REVISION, SET_TOTAL_FREE, setD, and writable.

Referenced by cancel(), commit(), do_open_to_read(), and do_open_to_write().

bool ChertTable::read_tag	(	Cursor *	C_,
		std::string *	tag,
		bool	keep_compressed
	)			const

Read the tag value for the key pointed to by cursor C_.

Parameters:

keep_compressed

Don't uncompress the tag - e.g. useful if it's just being opaquely copied.

Returns:

true if current_tag holds compressed data (always false if keep_compressed was false).

Definition at line 1213 of file chert_table.cc.

References Item_base< T >::append_chunk(), C2, Item_base< T >::components_of(), Item_base< T >::get_compressed(), I2, inflate_zstream, K1, lazy_alloc_inflate_zstream(), LOGCALL, LOGLINE, max_item_size, next(), RETURN, setint4(), and Xapian::Internal::str().

Referenced by get_exact_entry(), and ChertCursor::read_tag().

bool ChertTable::really_empty

(

)

const [private]

Return true if there are no entries in the table.

Definition at line 1589 of file chert_table.cc.

References ChertCursor::find_entry(), handle, and ChertCursor::next().

void ChertTable::set_block_size

(

unsigned int

block_size_

)

Set the block size.

It's only safe to do this before the table is created.

Definition at line 1696 of file chert_table.cc.

References block_size, BYTE_PAIR_RANGE, CHERT_DEFAULT_BLOCK_SIZE, and LOGCALL_VOID.

Referenced by compact_chert(), create_and_open(), ChertLazyTable::create_and_open(), main(), ChertDatabase::open_tables(), and ChertDatabase::open_tables_consistent().

void ChertTable::set_full_compaction

(

bool

parity

)

Definition at line 1298 of file chert_table.cc.

References Assert, full_compaction, LOGCALL_VOID, seq_count, and writable.

Referenced by compact_chert(), and main().

void ChertTable::set_max_item_size

(

size_t

block_capacity

)

[inline]

Set the maximum item size given the block capacity.

At least this many items of maximum size must fit into a block. The default is BLOCK_CAPACITY (which is currently 4).

Definition at line 600 of file chert_table.h.

References BLOCK_CAPACITY, D2, and DIR_START.

Referenced by basic_open(), and compact_chert().

void ChertTable::split_root

(

uint4

split_n

)

[protected]

Btree needs to gain a new level to insert more items: so split root block and construct a new one.

Definition at line 546 of file chert_table.cc.

References add_item(), base, block_size, BTREE_CURSOR_LEVELS, Cursor::c, C, compact(), DIR_START, Item_wr::form_null_key(), latest_revision_number, level, LOGCALL_VOID, Cursor::n, ChertTable_base::next_free_block(), Cursor::p, Cursor::rewrite, SET_DIR_END, SET_LEVEL, SET_REVISION, STRINGIZE, and zeroed_new().

Referenced by add_item().

void ChertTable::write_block	(	uint4	n,
		const byte *	p
	)			const [protected]

write_block(n, p) writes block n in the DB file from address p.

When writing we check to see if the DB file has already been modified. If not (so this is the first write) the old base is deleted. This prevents the possibility of it being opened subsequently as an invalid base.

Definition at line 241 of file chert_table.cc.

References Assert, AssertEqParanoid, AssertParanoid, base, ChertTable_base::block_free_at_start(), block_size, both_bases, ChertTable_base::get_bit_map_size(), handle, io_unlink(), io_write(), latest_revision_number, LOGCALL_VOID, other_base_letter(), REVISION, revision_number, and writable.

Referenced by add_item(), block_to_cursor(), and flush_db().

void ChertTable::write_changed_blocks

(

int

changes_fd

)

Append the list of blocks changed to a changeset file.

Parameters:

changes_fd

The file descriptor to write changes to.

Definition at line 1911 of file chert_table.cc.

References Assert, base, block_size, ChertTable_base::calculate_last_block(), faked_root_block, ChertTable_base::find_changed_block(), handle, io_write(), LOGCALL_VOID, pack_string(), pack_uint(), read_block(), and tablename.

Referenced by ChertDatabase::set_revision_number().

ChertTable::XAPIAN_NORETURN

(

void set_overwritten()

const

)

[protected]

ChertTable::XAPIAN_NORETURN

(

static void

throw_database_closed()

)

Throw an exception indicating that the database is closed.

---

Friends And Related Function Documentation

friend class ChertCursor [friend]

Definition at line 290 of file chert_table.h.

Referenced by cursor_get().

---

Member Data Documentation

ChertTable_base ChertTable::base [protected]

For writing back as file baseA or baseB.

Definition at line 713 of file chert_table.h.

Referenced by add_item(), alter(), basic_open(), ChertTableCheck::block_check(), cancel(), ChertTableCheck::check(), commit(), delete_item(), next_for_sequential(), read_block(), read_root(), split_root(), write_block(), and write_changed_blocks().

char ChertTable::base_letter [protected]

the value 'A' or 'B' of the current base

Definition at line 678 of file chert_table.h.

Referenced by basic_open(), cancel(), ChertTableCheck::check(), and commit().

unsigned int ChertTable::block_size [protected]

block size of the B tree in bytes

Definition at line 664 of file chert_table.h.

Referenced by add(), add_item(), basic_open(), ChertTableCheck::block_check(), block_to_cursor(), ChertTableCheck::block_usage(), cancel(), ChertTableCheck::check(), ChertCursor::ChertCursor(), compact(), do_open_to_read(), do_open_to_write(), mid_point(), next_default(), next_for_sequential(), prev_default(), prev_for_sequential(), read_block(), read_root(), ChertCursor::rebuild(), set_block_size(), split_root(), write_block(), and write_changed_blocks().

bool ChertTable::both_bases [mutable, protected]

set to true if baseA and baseB both exist as valid bases.

The unused base is deleted as soon as a write to the Btree takes place.

Definition at line 675 of file chert_table.h.

Referenced by basic_open(), commit(), and write_block().

bool ChertTable::Btree_modified [mutable, protected]

Set to true the first time the B-tree is modified.

Definition at line 734 of file chert_table.h.

Referenced by add(), cancel(), commit(), del(), and flush_db().

byte* ChertTable::buffer [protected]

buffer of size block_size for reforming blocks

Definition at line 710 of file chert_table.h.

Referenced by close(), compact(), and do_open_to_write().

Cursor ChertTable::C[BTREE_CURSOR_LEVELS] [mutable, protected]

Definition at line 774 of file chert_table.h.

Referenced by add(), add_item(), add_kt(), alter(), block_to_cursor(), cancel(), ChertTableCheck::check(), ChertCursor::ChertCursor(), close(), commit(), delete_item(), delete_kt(), do_open_to_read(), do_open_to_write(), enter_key(), flush_db(), get_exact_entry(), key_exists(), next_for_sequential(), prev_for_sequential(), read_root(), ChertCursor::rebuild(), and split_root().

int ChertTable::changed_c [protected]

directory offset corresponding to last block to be changed by an addition

Definition at line 728 of file chert_table.h.

Referenced by add_item(), add_kt(), cancel(), commit(), and do_open_to_write().

uint4 ChertTable::changed_n [protected]

the last block to be changed by an addition

Definition at line 724 of file chert_table.h.

Referenced by add_item(), add_kt(), cancel(), commit(), and do_open_to_write().

int ChertTable::compress_strategy [protected]

DONT_COMPRESS or Z_DEFAULT_STRATEGY, Z_FILTERED, Z_HUFFMAN_ONLY, Z_RLE.

Definition at line 785 of file chert_table.h.

Referenced by add(), and lazy_alloc_deflate_zstream().

bool ChertTable::cursor_created_since_last_modification [mutable, protected]

Flag for tracking when cursors need to rebuild.

Definition at line 743 of file chert_table.h.

Referenced by add(), ChertCursor::ChertCursor(), and del().

unsigned long ChertTable::cursor_version [protected]

Version count for tracking when cursors need to rebuild.

Definition at line 746 of file chert_table.h.

Referenced by add(), del(), ChertCursor::find_entry(), ChertCursor::find_entry_ge(), ChertCursor::next(), ChertCursor::prev(), and ChertCursor::rebuild().

z_stream* ChertTable::deflate_zstream [mutable, protected]

Zlib state object for deflating.

Definition at line 788 of file chert_table.h.

Referenced by add(), lazy_alloc_deflate_zstream(), and ~ChertTable().

bool ChertTable::faked_root_block [protected]

true if the root block is faked (not written to disk).

false otherwise. This is true when the btree hasn't been modified yet.

Definition at line 684 of file chert_table.h.

Referenced by basic_open(), cancel(), ChertTableCheck::check(), commit(), flush_db(), read_root(), and write_changed_blocks().

bool ChertTable::full_compaction [protected]

set to true when full compaction is to be achieved

Definition at line 737 of file chert_table.h.

Referenced by add(), and set_full_compaction().

int ChertTable::handle [protected]

File descriptor of the table.

If the table is lazily created and doesn't yet exist, this will be -1.

If close() has been called, this will be -2.

Definition at line 698 of file chert_table.h.

Referenced by add(), basic_open(), cancel(), close(), commit(), create_and_open(), cursor_get(), del(), do_open_to_read(), do_open_to_write(), flush_db(), get_exact_entry(), read_block(), really_empty(), write_block(), and write_changed_blocks().

z_stream* ChertTable::inflate_zstream [mutable, protected]

Zlib state object for inflating.

Definition at line 791 of file chert_table.h.

Referenced by lazy_alloc_inflate_zstream(), read_tag(), and ~ChertTable().

chert_tablesize_t ChertTable::item_count [protected]

keeps a count of the number of items in the B-tree.

Definition at line 661 of file chert_table.h.

Referenced by add(), basic_open(), cancel(), ChertTableCheck::check(), commit(), and del().

Item_wr ChertTable::kt [mutable, protected]

buffer of size block_size for making up key-tag items

Definition at line 707 of file chert_table.h.

Referenced by add(), add_kt(), basic_open(), close(), del(), find(), and form_key().

chert_revision_number_t ChertTable::latest_revision_number [mutable, protected]

Revision number of the other base, or zero if there is only one base file.

Definition at line 669 of file chert_table.h.

Referenced by alter(), basic_open(), cancel(), commit(), next_for_sequential(), prev_for_sequential(), read_root(), split_root(), and write_block().

bool ChertTable::lazy [protected]

If true, don't create the table until it's needed.

Definition at line 794 of file chert_table.h.

Referenced by compact_chert(), do_open_to_read(), and do_open_to_write().

int ChertTable::level [protected]

number of levels, counting from 0

Definition at line 701 of file chert_table.h.

Referenced by add_item(), alter(), basic_open(), ChertTableCheck::block_check(), block_to_cursor(), cancel(), ChertTableCheck::check(), close(), commit(), delete_item(), do_open_to_read(), do_open_to_write(), find(), flush_db(), ChertCursor::get_key(), next_default(), next_for_sequential(), prev_default(), prev_for_sequential(), read_root(), ChertCursor::read_tag(), ChertCursor::rebuild(), ChertTableCheck::report_cursor(), and split_root().

size_t ChertTable::max_item_size [protected]

maximum size of an item (key-tag pair)

Definition at line 731 of file chert_table.h.

Referenced by add(), and read_tag().

std::string ChertTable::name [protected]

The path name of the B tree.

Definition at line 716 of file chert_table.h.

chert_revision_number_t ChertTable::revision_number [protected]

revision number of the opened B-tree.

Definition at line 658 of file chert_table.h.

Referenced by basic_open(), cancel(), ChertTableCheck::check(), commit(), create_and_open(), do_open_to_read(), do_open_to_write(), next_for_sequential(), open(), prev_for_sequential(), read_root(), and write_block().

uint4 ChertTable::root [protected]

the root block of the B-tree

Definition at line 704 of file chert_table.h.

Referenced by basic_open(), cancel(), commit(), and read_root().

int ChertTable::seq_count [protected]

count of the number of successive instances of purely sequential addition, starting at SEQ_START_POINT (neg) and going up to zero.

Definition at line 721 of file chert_table.h.

Referenced by add_item(), add_kt(), cancel(), commit(), delete_kt(), do_open_to_write(), and set_full_compaction().

bool ChertTable::sequential [protected]

true iff the data has been written in a single write in sequential order.

Definition at line 689 of file chert_table.h.

Referenced by add_kt(), basic_open(), cancel(), commit(), and delete_kt().

byte* ChertTable::split_p [protected]

Buffer used when splitting a block.

This buffer holds the split off part of the block. It's only used when updating (in ChertTable::add_item().

Definition at line 781 of file chert_table.h.

Referenced by add_item(), close(), and do_open_to_write().

const char* ChertTable::tablename [protected]

The name of the table (used when writing changesets).

Definition at line 649 of file chert_table.h.

Referenced by commit(), and write_changed_blocks().

bool ChertTable::writable [protected]

Set to true when the database is opened to write.

Definition at line 740 of file chert_table.h.

Referenced by add(), add_item(), add_item_to_block(), add_kt(), alter(), basic_open(), block_to_cursor(), cancel(), commit(), compact(), create_and_open(), del(), delete_item(), delete_kt(), do_open_to_write(), enter_key(), flush_db(), next_for_sequential(), open(), prev_for_sequential(), read_root(), set_full_compaction(), and write_block().

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

• backends/chert/chert_table.h
• backends/chert/chert_table.cc