Xapian: Internal Source Documentation: xapian-core: backends/flint/flint

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Defines
#define	CASSERT(a) {char assert[(a) ? 1 : -1];(void)assert;}
	Compile time assert a condition.
#define	CASSERT_TYPE_UNSIGNED(T) CASSERT(static_cast<T>(-1) > 0)
	Compile time assert that type T is unsigned.
Typedefs
typedef unsigned char	om_byte
typedef unsigned int	om_uint32
typedef int	om_int32
Functions
template<class T>
bool	unpack_uint (const char *src, const char src_end, T *resultptr)
	Reads an unsigned integer from a string starting at a given position.
template<class T>
string	pack_uint (T value)
	Generates a packed representation of an integer.
template<>
string	pack_uint< bool > (bool value)
	Generates a packed representation of a bool.
template<class T>
bool	unpack_uint_last (const char *src, const char src_end, T *resultptr)
	Reads an unsigned integer from a string starting at a given position.
template<class T>
string	pack_uint_last (T value)
	Generates a packed representation of an integer.
template<class T>
string	pack_uint_preserving_sort (T value)
	Generate a packed representation of an integer, preserving sort order.
template<class T>
bool	unpack_uint_preserving_sort (const char *src, const char src_end, T *resultptr)
	Unpack a unsigned integer, store in sort preserving order.
bool	unpack_string (const char *src, const char src_end, string &result)
string	pack_string (string value)
string	pack_string_preserving_sort (string value)
	Pack a string into a representation which preserves sort order.
bool	unpack_string_preserving_sort (const char *src, const char src_end, string &result)
bool	unpack_bool (const char *src, const char src_end, bool *resultptr)
string	pack_bool (bool value)
string	flint_docid_to_key (Xapian::docid did)
	Convert a document id to a key (suitable when the docid is the only component of the key).

Define Documentation

#define CASSERT ( a ) {char assert[(a) ? 1 : -1];(void)assert;}

Compile time assert a condition.

Definition at line 33 of file flint_utils.h.

Referenced by QuartzRecordTable::get_doccount(), FlintRecordTable::get_doccount(), unpack_uint(), and unpack_uint_last().

#define CASSERT_TYPE_UNSIGNED ( T ) CASSERT(static_cast<T>(-1) > 0)

Compile time assert that type T is unsigned.

Definition at line 36 of file flint_utils.h.

Referenced by QuartzRecordTable::get_doccount(), FlintRecordTable::get_doccount(), pack_uint(), pack_uint_last(), pack_uint_preserving_sort(), unpack_uint(), and unpack_uint_last().

Typedef Documentation

typedef unsigned char om_byte

Definition at line 38 of file flint_utils.h.

typedef unsigned int om_uint32

Definition at line 39 of file flint_utils.h.

typedef int om_int32

Definition at line 40 of file flint_utils.h.

Function Documentation

template<class T>

bool unpack_uint	(	const char **	src,
		const char *	src_end,
		T *	resultptr
	)			`[inline]`

Reads an unsigned integer from a string starting at a given position.

Parameters:

	src	A pointer to a pointer to the data to read. The character pointer will be updated to point to the next character to read, or 0 if the method ran out of data. (It is only set to 0 in case of an error).
	src_end	A pointer to the byte after the end of the data to read the integer from.
	resultptr	A pointer to a place to store the result. If an error occurs, the value stored in this location is undefined. If this pointer is 0, the result is not stored, and the method simply skips over the result.

Returns:: True if an integer was successfully read. False if the read failed. Failure may either be due to the data running out (in which case *src will equal 0), or due to the value read overflowing the size of result (in which case *src will point to wherever the value ends, despite the overflow).

Definition at line 68 of file flint_utils.h.

References CASSERT, and CASSERT_TYPE_UNSIGNED.

Referenced by check_table(), FlintTermList::FlintTermList(), FlintTermListTable::get_doclength(), FlintAllDocsPostList::get_doclength(), QuartzRecordTable::get_lastdocid(), QuartzRecordTable::get_total_length(), main(), merge_postlists(), PositionCursor::next(), PostlistCursor::next(), QuartzTermList::next(), FlintTermList::next(), QuartzPositionList::next_internal(), FlintPositionListTable::positionlist_count(), QuartzTermList::QuartzTermList(), QuartzPositionList::read_data(), FlintPositionList::read_data(), read_did_increase(), FlintDatabase::read_metainfo(), QuartzPostList::read_number_of_entries(), FlintPostList::read_number_of_entries(), read_start_of_chunk(), read_start_of_first_chunk(), read_wdf_and_length(), test_packint2(), test_unpackint1(), QuartzValueTable::unpack_entry(), FlintValueTable::unpack_entry(), and unpack_string().

template<class T>

string pack_uint ( T value ) [inline]

Generates a packed representation of an integer.

Parameters:

value

The integer to represent.

Returns:: A string containing the representation of the integer.

Definition at line 125 of file flint_utils.h.

References CASSERT_TYPE_UNSIGNED.

Referenced by QPostlistChunkWriter::append(), PostlistChunkWriter::append(), QuartzValueTable::encode_values(), FlintValueTable::encode_values(), FlintWritableDatabase::flush_postlist_changes(), main(), make_key(), make_start_of_chunk(), make_start_of_first_chunk(), make_wdf_and_length(), merge_postlists(), PositionCursor::next(), pack_string(), QuartzTermListTable::set_entries(), QuartzPositionListTable::set_positionlist(), FlintPositionListTable::set_positionlist(), FlintTermListTable::set_termlist(), QuartzRecordTable::set_total_length_and_lastdocid(), test_packint1(), test_packint2(), and write_start_of_chunk().

template<>

string pack_uint< bool > ( bool value ) [inline]

Generates a packed representation of a bool.

This is a specialisation of the template above.

Parameters:

value

The bool to represent.

Returns:: A string containing the representation of the bool.

template<class T>

bool unpack_uint_last	(	const char **	src,
		const char *	src_end,
		T *	resultptr
	)			`[inline]`

Reads an unsigned integer from a string starting at a given position.

This encoding requires that we know the encoded length from out-of-band information (so is suitable when only one integer is encoded, or for the last integer encoded).

Parameters:

	src	A pointer to a pointer to the data to read.
	src_end	A pointer to the byte after the end of the data to read the integer from.
	resultptr	A pointer to a place to store the result. If an error occurs, the value stored in this location is undefined. If this pointer is 0, the result is not stored, and the method simply skips over the result.

Returns:: True if an integer was successfully read. False if the read failed. Failure can hapen if the value read overflows the size of result.

Definition at line 177 of file flint_utils.h.

References CASSERT, and CASSERT_TYPE_UNSIGNED.

Referenced by check_table(), FlintSpellingWordsList::get_termfreq(), QuartzRecordTable::get_total_length(), FlintSpellingTable::get_word_frequency(), main(), merge_postlists(), merge_spellings(), DocIDKeyedCursor::next(), QuartzAllDocsPostList::QuartzAllDocsPostList(), and FlintDatabase::read_metainfo().

template<class T>

string pack_uint_last ( T value ) [inline]

Generates a packed representation of an integer.

This encoding requires that we know the encoded length from out-of-band information (so is suitable when only one integer is encoded, or for the last integer encoded).

Parameters:

value

The integer to represent.

Returns:: A string containing the representation of the integer.

Definition at line 212 of file flint_utils.h.

References CASSERT_TYPE_UNSIGNED.

Referenced by FlintWritableDatabase::flush_postlist_changes(), main(), FlintSpellingTable::merge_changes(), merge_postlists(), merge_spellings(), DocIDKeyedCursor::next(), quartz_docid_to_key(), and QuartzRecordTable::set_total_length_and_lastdocid().

template<class T>

string pack_uint_preserving_sort ( T value ) [inline]

Generate a packed representation of an integer, preserving sort order.

This representation is less compact than the usual one, and has a limit of 256 bytes on the length of the integer. However, this is unlikely to ever be a problem.

Parameters:

value

The integer to represent.

Returns:: A string containing the representation of the integer.

Definition at line 237 of file flint_utils.h.

References CASSERT_TYPE_UNSIGNED.

Referenced by flint_docid_to_key(), main(), make_key(), FlintPostListTable::make_key(), FlintPositionListTable::make_key(), merge_docid_keyed(), merge_postlists(), FlintPositionListTable::positionlist_count(), FlintPositionList::read_data(), FlintAllDocsPostList::skip_to(), and test_packint3().

template<class T>

bool unpack_uint_preserving_sort	(	const char **	src,
		const char *	src_end,
		T *	resultptr
	)			`[inline]`

Unpack a unsigned integer, store in sort preserving order.

Parameters:

	src	A pointer to a pointer to the data to read. The character pointer will be updated to point to the next character to read, or 0 if the method ran out of data. (It is only set to 0 in case of an error).
	src_end	A pointer to the byte after the end of the data to read the integer from.
	resultptr	A pointer to a place to store the result. If an error occurs, the value stored in this location is undefined. If this pointer is 0, the result is not stored, and the method simply skips over the result.

Returns:: True if an integer was successfully read. False if the read failed. Failure may either be due to the data running out (in which case *src will equal 0), or due to the value read overflowing the size of result (in which case *src will point to wherever the value ends, despite the overflow).

Definition at line 273 of file flint_utils.h.

Referenced by check_table(), QPostlistChunkWriter::flush(), PostlistChunkWriter::flush(), QuartzPostListTable::get_chunk(), FlintPostListTable::get_chunk(), merge_docid_keyed(), QuartzPostList::move_to_chunk_containing(), FlintPostList::move_to_chunk_containing(), PostlistCursor::next(), QuartzPostList::next_chunk(), FlintPostList::next_chunk(), FlintAllDocsPostList::read_did_from_current_key(), and test_packint3().