BrassTable Class Reference

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

#include <brass_table.h>

Inheritance diagram for BrassTable:

[legend]

Collaboration diagram for BrassTable:

[legend]

List of all members.

Public Member Functions
	BrassTable (const char *tablename_, const std::string &path_, bool readonly_, int compress_strategy_=DONT_COMPRESS, bool lazy=false)
	Create a new Btree object.
	~BrassTable ()
	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 (brass_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 (brass_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 (Brass::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)
brass_revision_number_t	get_latest_revision_number () const
	Get the latest revision number stored in this table.
brass_revision_number_t	get_open_revision_number () const
	Get the revision number at which this table is currently open.
brass_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.
BrassCursor *	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, brass_revision_number_t revision_)
	Perform the opening operation to read.
bool	do_open_to_write (bool revision_supplied, brass_revision_number_t revision_, bool create_db=false)
	Perform the opening operation to write.
bool	basic_open (bool revision_supplied, brass_revision_number_t revision)
bool	find (Brass::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 (Brass::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, Brass::Key prevkey, Brass::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, Brass::Item_wr kt, int c)
	add_item_to_block(p, kt_, c) adds item kt_ to the block at p.
void	add_item (Brass::Item_wr kt, int j)
	BrassTable::add_item(kt_, j) adds item kt_ to the block at cursor level C[j].
void	delete_item (int j, bool repeatedly)
	BrassTable::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 (Brass::Cursor *C_, int j) const
bool	next (Brass::Cursor *C_, int j) const
bool	prev_default (Brass::Cursor *C_, int j) const
bool	next_default (Brass::Cursor *C_, int j) const
bool	prev_for_sequential (Brass::Cursor *C_, int dummy) const
bool	next_for_sequential (Brass::Cursor *C_, int dummy) const
Static Protected Member Functions
static int	find_in_block (const byte *p, Brass::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).
brass_revision_number_t	revision_number
	revision number of the opened B-tree.
brass_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
brass_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
Brass::Item_wr	kt
	buffer of size block_size for making up key-tag items
byte *	buffer
	buffer of size block_size for reforming blocks
BrassTable_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.
Brass::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
	BrassTable (const BrassTable &)
	Copying not allowed.
BrassTable &	operator= (const BrassTable &)
	Assignment not allowed.
Friends
class	BrassCursor

---

Detailed Description

Class managing a Btree table in a Brass 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 brass 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 293 of file brass_table.h.

---

Constructor & Destructor Documentation

BrassTable::BrassTable

(

const BrassTable &

)

[private]

Copying not allowed.

BrassTable::BrassTable	(	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 1549 of file brass_table.cc.

References LOGCALL_CTOR.

BrassTable::~BrassTable

(

)

Close the Btree.

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

Definition at line 1723 of file brass_table.cc.

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

---

Member Function Documentation

void BrassTable::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 1016 of file brass_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, Brass::Item_base< T >::key(), kt, lazy_alloc_deflate_zstream(), Brass::Key::length(), LOGCALL_VOID, max_item_size, Brass::Cursor::p, Brass::Item_wr::set_component_of(), Brass::Item_wr::set_components_of(), Brass::Item_wr::set_tag(), TOTAL_FREE, and writable.

Referenced by Brass::PostlistChunkWriter::flush(), BrassValueManager::merge_changes(), BrassSynonymTable::merge_changes(), BrassSpellingTable::merge_changes(), BrassPostListTable::merge_changes(), BrassCompact::merge_docid_keyed(), BrassPostListTable::merge_doclen_changes(), BrassCompact::merge_postlists(), BrassCompact::merge_spellings(), BrassCompact::merge_synonyms(), BrassRecordTable::replace_record(), BrassWritableDatabase::set_metadata(), BrassPositionListTable::set_positionlist(), BrassTermListTable::set_termlist(), BrassValueManager::set_value_stats(), BrassDatabaseStats::write(), and Brass::ValueUpdater::write_tag().

void BrassTable::add_item	(	Brass::Item_wr	kt,
		int	j
	)			[protected]

BrassTable::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 715 of file brass_table.cc.

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

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

void BrassTable::add_item_to_block	(	byte *	p,
		Brass::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 680 of file brass_table.cc.

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

Referenced by add_item().

int BrassTable::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 886 of file brass_table.cc.

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

Referenced by add().

void BrassTable::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 410 of file brass_table.cc.

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

Referenced by add_kt(), and delete_kt().

bool BrassTable::basic_open	(	bool	revision_supplied,
		brass_revision_number_t	revision
	)			[protected]

Definition at line 1319 of file brass_table.cc.

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

Referenced by do_open_to_read(), and do_open_to_write().

static uint4 BrassTable::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 BrassTableCheck::block_check(), find(), next_default(), and prev_default().

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

Definition at line 346 of file brass_table.cc.

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

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

void BrassTable::cancel

(

)

Cancel any outstanding changes.

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

Reimplemented in BrassSpellingTable, and BrassSynonymTable.

Definition at line 1936 of file brass_table.cc.

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

Referenced by BrassDatabase::cancel().

void BrassTable::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 1742 of file brass_table.cc.

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

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

void BrassTable::commit	(	brass_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 1795 of file brass_table.cc.

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

Referenced by compact_brass(), BrassCompact::multimerge_postlists(), and BrassDatabase::set_revision_number().

void BrassTable::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 519 of file brass_table.cc.

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

Referenced by add_item(), and split_root().

void BrassTable::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 BrassLazyTable, and BrassTermListTable.

Definition at line 1690 of file brass_table.cc.

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

Referenced by add(), compact_brass(), BrassDatabase::create_and_open_tables(), and BrassCompact::multimerge_postlists().

BrassCursor * BrassTable::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 1304 of file brass_table.cc.

References BrassCursor, handle, LOGCALL, and RETURN.

Referenced by check_brass_table(), Brass::PostlistChunkWriter::flush(), BrassPostListTable::get_chunk(), BrassValueManager::get_chunk_containing_did(), BrassDatabase::get_postlist_cursor(), BrassDatabase::open_metadata_keylist(), BrassDatabase::open_spelling_wordlist(), BrassDatabase::open_synonym_keylist(), and Brass::ValueUpdater::update().

bool BrassTable::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 1138 of file brass_table.cc.

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

Referenced by BrassPositionListTable::delete_positionlist(), BrassRecordTable::delete_record(), BrassTermListTable::delete_termlist(), Brass::PostlistChunkWriter::flush(), BrassValueManager::merge_changes(), BrassSynonymTable::merge_changes(), BrassSpellingTable::merge_changes(), BrassPostListTable::merge_changes(), BrassWritableDatabase::set_metadata(), BrassValueManager::set_value_stats(), and Brass::ValueUpdater::write_tag().

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

BrassTable::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 813 of file brass_table.cc.

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

Referenced by add_kt(), and delete_kt().

int BrassTable::delete_kt

(

)

[protected]

Definition at line 952 of file brass_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 BrassTable::do_open_to_read	(	bool	revision_supplied,
		brass_revision_number_t	revision_
	)			[protected]

Perform the opening operation to read.

Return true iff the open succeeded.

Definition at line 1983 of file brass_table.cc.

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

Referenced by open().

bool BrassTable::do_open_to_write	(	bool	revision_supplied,
		brass_revision_number_t	revision_,
		bool	create_db = false
	)			[protected]

Perform the opening operation to write.

Return true iff the open succeeded.

Definition at line 1488 of file brass_table.cc.

References basic_open(), BLK_UNUSED, block_size, buffer, C, changed_c, changed_n, close(), DIR_START, handle, lazy, level, LOGCALL, Brass::Cursor::n, O_BINARY, open(), Brass::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 BrassTable::empty

(

)

const [inline]

Return true if there are no entries in the table.

Definition at line 569 of file brass_table.h.

Referenced by BrassDatabase::has_positions(), BrassCompact::merge_docid_keyed(), BrassCompact::merge_postlists(), BrassCompact::merge_spellings(), and BrassCompact::merge_synonyms().

void BrassTable::enter_key	(	int	j,
		Brass::Key	prevkey,
		Brass::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 588 of file brass_table.cc.

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

Referenced by add_item().

void BrassTable::erase

(

)

Erase this table from disk.

Definition at line 1667 of file brass_table.cc.

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

Referenced by compact_brass(), and BrassLazyTable::create_and_open().

bool BrassTable::exists

(

)

const

Determine whether the btree exists on disk.

Definition at line 1660 of file brass_table.cc.

References file_exists(), and LOGCALL.

Referenced by BrassDatabase::database_exists().

bool BrassTable::find

(

Brass::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 485 of file brass_table.cc.

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

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

int BrassTable::find_in_block	(	const byte *	p,
		Brass::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 455 of file brass_table.cc.

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

Referenced by enter_key(), and find().

void BrassTable::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 BrassSpellingTable, and BrassSynonymTable.

Definition at line 1772 of file brass_table.cc.

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

Referenced by compact_brass(), BrassCompact::multimerge_postlists(), and BrassDatabase::set_revision_number().

void BrassTable::form_key

(

const std::string &

key

)

const [protected]

Definition at line 986 of file brass_table.cc.

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

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

unsigned int BrassTable::get_block_size

(

)

const [inline]

Get the block size.

Definition at line 500 of file brass_table.h.

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

brass_tablesize_t BrassTable::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 564 of file brass_table.h.

Referenced by BrassRecordTable::get_doccount().

bool BrassTable::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 1174 of file brass_table.cc.

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

Referenced by BrassSynonymTable::add_synonym(), BrassSpellingTable::add_word(), BrassValueManager::delete_document(), Brass::PostlistChunkWriter::flush(), BrassValueManager::get_all_values(), BrassPostListTable::get_collection_freq(), BrassDatabase::get_metadata(), BrassRecordTable::get_record(), BrassPostListTable::get_termfreq(), BrassValueManager::get_value_stats(), BrassSpellingTable::get_word_frequency(), BrassSpellingTable::merge_changes(), BrassPostListTable::merge_changes(), BrassSynonymTable::open_termlist(), BrassSpellingTable::open_termlist(), BrassPositionListTable::positionlist_count(), BrassDatabaseStats::read(), BrassPositionList::read_data(), BrassSynonymTable::remove_synonym(), BrassSpellingTable::remove_word(), and BrassPositionListTable::set_positionlist().

brass_revision_number_t BrassTable::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 539 of file brass_table.h.

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

brass_revision_number_t BrassTable::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 551 of file brass_table.h.

Referenced by BrassDatabaseReplicator::apply_changeset_from_conn(), BrassDatabase::BrassDatabase(), BrassDatabase::create_and_open_tables(), BrassDatabase::get_revision_number(), and BrassDatabase::open_tables_consistent().

bool BrassTable::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 BrassSpellingTable, and BrassSynonymTable.

Definition at line 585 of file brass_table.h.

Referenced by BrassDatabase::apply().

bool BrassTable::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 374 of file brass_table.h.

Referenced by BrassValueManager::add_document(), BrassWritableDatabase::add_document_(), BrassValueManager::delete_document(), BrassWritableDatabase::delete_document(), BrassValueManager::get_all_values(), BrassValueManager::merge_changes(), BrassDatabase::open_term_list(), and BrassWritableDatabase::replace_document().

bool BrassTable::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 1197 of file brass_table.cc.

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

Referenced by BrassPostListTable::merge_doclen_changes(), and BrassPostListTable::term_exists().

void BrassTable::lazy_alloc_deflate_zstream

(

)

const [protected]

Allocate the zstream for deflating, if not already allocated.

Definition at line 1586 of file brass_table.cc.

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

Referenced by add().

void BrassTable::lazy_alloc_inflate_zstream

(

)

const [protected]

Allocate the zstream for inflating, if not already allocated.

Definition at line 1624 of file brass_table.cc.

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

Referenced by read_tag().

int BrassTable::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 650 of file brass_table.cc.

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

Referenced by add_item().

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

Definition at line 746 of file brass_table.h.

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

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

Definition at line 2200 of file brass_table.cc.

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

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

Definition at line 2125 of file brass_table.cc.

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

bool BrassTable::open

(

brass_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 BrassPostListTable.

Definition at line 2046 of file brass_table.cc.

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

void BrassTable::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 2029 of file brass_table.cc.

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

Referenced by BrassDatabaseReplicator::apply_changeset_from_conn(), BrassTableCheck::check(), check_brass_table(), do_open_to_read(), do_open_to_write(), BrassCompact::merge_docid_keyed(), BrassCompact::merge_postlists(), BrassCompact::merge_spellings(), BrassCompact::merge_synonyms(), BrassPostListTable::open(), BrassDatabase::open_tables(), and BrassDatabase::open_tables_consistent().

BrassTable& BrassTable::operator=

(

const BrassTable &

)

[private]

Assignment not allowed.

char BrassTable::other_base_letter

(

)

const [inline, protected]

Definition at line 636 of file brass_table.h.

Referenced by commit(), and write_block().

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

Definition at line 741 of file brass_table.h.

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

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

Definition at line 2178 of file brass_table.cc.

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

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

Definition at line 2073 of file brass_table.cc.

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

void BrassTable::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 188 of file brass_table.cc.

References Assert, base, block_size, BrassTable_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 BrassTable::read_root

(

)

[protected]

Definition at line 1444 of file brass_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, Brass::Cursor::n, BrassTable_base::next_free_block(), Brass::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 BrassTable::read_tag	(	Brass::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 1210 of file brass_table.cc.

References Brass::Item_base< T >::append_chunk(), C2, Brass::Item_base< T >::components_of(), Brass::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 BrassCursor::read_tag().

void BrassTable::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 1678 of file brass_table.cc.

References block_size, BRASS_DEFAULT_BLOCK_SIZE, BYTE_PAIR_RANGE, and LOGCALL_VOID.

Referenced by compact_brass(), create_and_open(), BrassLazyTable::create_and_open(), BrassDatabase::open_tables(), and BrassDatabase::open_tables_consistent().

void BrassTable::set_full_compaction

(

bool

parity

)

Definition at line 1295 of file brass_table.cc.

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

Referenced by compact_brass().

void BrassTable::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 592 of file brass_table.h.

References BLOCK_CAPACITY, D2, and DIR_START.

Referenced by basic_open(), and compact_brass().

void BrassTable::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 543 of file brass_table.cc.

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

Referenced by add_item().

void BrassTable::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 240 of file brass_table.cc.

References Assert, AssertEqParanoid, AssertParanoid, base, BrassTable_base::block_free_at_start(), block_size, both_bases, BrassTable_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 BrassTable::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 1893 of file brass_table.cc.

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

Referenced by BrassDatabase::set_revision_number().

BrassTable::XAPIAN_NORETURN

(

void set_overwritten()

const

)

[protected]

BrassTable::XAPIAN_NORETURN

(

static void

throw_database_closed()

)

Throw an exception indicating that the database is closed.

---

Friends And Related Function Documentation

friend class BrassCursor [friend]

Definition at line 294 of file brass_table.h.

Referenced by cursor_get().

---

Member Data Documentation

BrassTable_base BrassTable::base [protected]

For writing back as file baseA or baseB.

Definition at line 705 of file brass_table.h.

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

char BrassTable::base_letter [protected]

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

Definition at line 670 of file brass_table.h.

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

unsigned int BrassTable::block_size [protected]

block size of the B tree in bytes

Definition at line 656 of file brass_table.h.

Referenced by add(), add_item(), basic_open(), BrassTableCheck::block_check(), block_to_cursor(), BrassTableCheck::block_usage(), BrassCursor::BrassCursor(), cancel(), BrassTableCheck::check(), 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(), BrassCursor::rebuild(), set_block_size(), split_root(), write_block(), and write_changed_blocks().

bool BrassTable::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 667 of file brass_table.h.

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

bool BrassTable::Btree_modified [mutable, protected]

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

Definition at line 726 of file brass_table.h.

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

byte* BrassTable::buffer [protected]

buffer of size block_size for reforming blocks

Definition at line 702 of file brass_table.h.

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

Brass::Cursor BrassTable::C[BTREE_CURSOR_LEVELS] [mutable, protected]

Definition at line 766 of file brass_table.h.

Referenced by add(), add_item(), add_kt(), alter(), block_to_cursor(), BrassCursor::BrassCursor(), cancel(), BrassTableCheck::check(), 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(), BrassCursor::rebuild(), and split_root().

int BrassTable::changed_c [protected]

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

Definition at line 720 of file brass_table.h.

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

uint4 BrassTable::changed_n [protected]

the last block to be changed by an addition

Definition at line 716 of file brass_table.h.

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

int BrassTable::compress_strategy [protected]

DONT_COMPRESS or Z_DEFAULT_STRATEGY, Z_FILTERED, Z_HUFFMAN_ONLY, Z_RLE.

Definition at line 777 of file brass_table.h.

Referenced by add(), and lazy_alloc_deflate_zstream().

bool BrassTable::cursor_created_since_last_modification [mutable, protected]

Flag for tracking when cursors need to rebuild.

Definition at line 735 of file brass_table.h.

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

unsigned long BrassTable::cursor_version [protected]

Version count for tracking when cursors need to rebuild.

Definition at line 738 of file brass_table.h.

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

z_stream* BrassTable::deflate_zstream [mutable, protected]

Zlib state object for deflating.

Definition at line 780 of file brass_table.h.

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

bool BrassTable::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 676 of file brass_table.h.

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

bool BrassTable::full_compaction [protected]

set to true when full compaction is to be achieved

Definition at line 729 of file brass_table.h.

Referenced by add(), and set_full_compaction().

int BrassTable::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 690 of file brass_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(), write_block(), and write_changed_blocks().

z_stream* BrassTable::inflate_zstream [mutable, protected]

Zlib state object for inflating.

Definition at line 783 of file brass_table.h.

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

brass_tablesize_t BrassTable::item_count [protected]

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

Definition at line 653 of file brass_table.h.

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

Brass::Item_wr BrassTable::kt [mutable, protected]

buffer of size block_size for making up key-tag items

Definition at line 699 of file brass_table.h.

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

brass_revision_number_t BrassTable::latest_revision_number [mutable, protected]

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

Definition at line 661 of file brass_table.h.

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

bool BrassTable::lazy [protected]

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

Definition at line 786 of file brass_table.h.

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

int BrassTable::level [protected]

number of levels, counting from 0

Definition at line 693 of file brass_table.h.

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

size_t BrassTable::max_item_size [protected]

maximum size of an item (key-tag pair)

Definition at line 723 of file brass_table.h.

Referenced by add(), and read_tag().

std::string BrassTable::name [protected]

The path name of the B tree.

Definition at line 708 of file brass_table.h.

brass_revision_number_t BrassTable::revision_number [protected]

revision number of the opened B-tree.

Definition at line 650 of file brass_table.h.

Referenced by basic_open(), cancel(), BrassTableCheck::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 BrassTable::root [protected]

the root block of the B-tree

Definition at line 696 of file brass_table.h.

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

int BrassTable::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 713 of file brass_table.h.

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

bool BrassTable::sequential [protected]

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

Definition at line 681 of file brass_table.h.

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

byte* BrassTable::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 BrassTable::add_item().

Definition at line 773 of file brass_table.h.

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

const char* BrassTable::tablename [protected]

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

Definition at line 641 of file brass_table.h.

Referenced by commit(), and write_changed_blocks().

bool BrassTable::writable [protected]

Set to true when the database is opened to write.

Definition at line 732 of file brass_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/brass/brass_table.h
• backends/brass/brass_table.cc