NegationIterator
extends IndexBundleIterator
in package
Used to iterate over the documents which don't occur in a set of iterator results
Tags
Table of Contents
- RESULTS_PER_BLOCK = 200
- Default number of documents returned for each block (at most)
- $count_block : int
- The number of documents in the current block
- $current_block_fresh : bool
- Says whether the value in $this->count_block is up to date
- $index_bundle_iterators : array<string|int, mixed>
- An array of iterators whose intersection we get documents from
- $num_docs : int
- Estimate of the number of documents that this iterator can return
- $num_iterators : int
- Number of elements in $this->index_bundle_iterators
- $pages : array<string|int, mixed>
- Cache of what currentDocsWithWord returns
- $results_per_block : int
- Number of documents returned for each block (at most)
- $seen_docs : int
- The number of documents already iterated over
- $to_advance_index : int
- Index of the iterator amongst those we are intersecting to advance next
- $total_num_docs : int
- __construct() : mixed
- Creates a negation iterator with the given parameters.
- advance() : mixed
- Forwards the iterator one group of docs (must be size 1)
- advanceSeenDocs() : mixed
- Updates the seen_docs count during an advance() call
- currentDocsWithWord() : mixed
- Gets the current block of doc ids and score associated with the this iterators word
- currentGenDocOffsetWithWord() : mixed
- Gets the doc_offset and generation for the next document that would be return by this iterator
- findDocsWithWord() : mixed
- Hook function used by currentDocsWithWord to return the current block of docs if it is not cached
- genDocOffsetCmp() : int
- Compares two arrays each containing a (generation, offset) pair.
- getCurrentDocsForKeys() : array<string|int, mixed>
- Gets the summaries associated with the keys provided the keys can be found in the current block of docs returned by this iterator
- getDirection() : int
- Returns CrawlConstants::ASCENDING or CrawlConstants::DESCENDING depending on the direction in which this iterator ttraverse the underlying index archive bundle.
- nextDocsWithWord() : array<string|int, mixed>
- Get the current block of doc summaries for the word iterator and advances the current pointer to the next block of documents. If a doc index is the next block must be of docs after this doc_index
- plan() : string
- Returns a string representation of a plan by which the current iterator finds its results
- reset() : mixed
- Returns the iterators to the first document block that it could iterate over
- setResultsPerBlock() : mixed
- This method is supposed to set the value of the result_per_block field. This field controls the maximum number of results that can be returned in one go by currentDocsWithWord(). This method cannot be consistently implemented for this iterator and expect it to behave nicely it this iterator is used together with union_iterator. So to prevent a user for doing this, calling this method results in a user defined error
- syncGenDocOffsetsAmongstIterators() : mixed
- Finds the next generation and doc offset amongst the all docs iterator and the term to be negated iterator such that the all iterator is strictly less than the term iterator.
Constants
RESULTS_PER_BLOCK
Default number of documents returned for each block (at most)
public
int
RESULTS_PER_BLOCK
= 200
Properties
$count_block
The number of documents in the current block
public
int
$count_block
$current_block_fresh
Says whether the value in $this->count_block is up to date
public
bool
$current_block_fresh
$index_bundle_iterators
An array of iterators whose intersection we get documents from
public
array<string|int, mixed>
$index_bundle_iterators
$num_docs
Estimate of the number of documents that this iterator can return
public
int
$num_docs
$num_iterators
Number of elements in $this->index_bundle_iterators
public
int
$num_iterators
$pages
Cache of what currentDocsWithWord returns
public
array<string|int, mixed>
$pages
$results_per_block
Number of documents returned for each block (at most)
public
int
$results_per_block
= self::RESULTS_PER_BLOCK
$seen_docs
The number of documents already iterated over
public
int
$seen_docs
$to_advance_index
Index of the iterator amongst those we are intersecting to advance next
public
int
$to_advance_index
$total_num_docs
public
int
$total_num_docs
Methods
__construct()
Creates a negation iterator with the given parameters.
public
__construct(object $index_bundle_iterator) : mixed
Parameters
- $index_bundle_iterator : object
-
to use as a source of documents to iterate over
Return values
mixed —advance()
Forwards the iterator one group of docs (must be size 1)
public
advance([array<string|int, mixed> $gen_doc_offset = null ]) : mixed
Parameters
- $gen_doc_offset : array<string|int, mixed> = null
-
a generation, doc_offset pair. If set, the must be of greater than or equal generation, and if equal the next block must all have $doc_offsets larger than or equal to this value
Return values
mixed —advanceSeenDocs()
Updates the seen_docs count during an advance() call
public
advanceSeenDocs() : mixed
Return values
mixed —currentDocsWithWord()
Gets the current block of doc ids and score associated with the this iterators word
public
currentDocsWithWord() : mixed
Return values
mixed —doc ids and score if there are docs left, -1 otherwise
currentGenDocOffsetWithWord()
Gets the doc_offset and generation for the next document that would be return by this iterator
public
currentGenDocOffsetWithWord() : mixed
Return values
mixed —an array with the desired document offset and generation; -1 on fail
findDocsWithWord()
Hook function used by currentDocsWithWord to return the current block of docs if it is not cached
public
findDocsWithWord() : mixed
Return values
mixed —doc ids and rank if there are docs left, -1 otherwise
genDocOffsetCmp()
Compares two arrays each containing a (generation, offset) pair.
public
genDocOffsetCmp(array<string|int, mixed> $gen_doc1, array<string|int, mixed> $gen_doc2[, int $direction = self::ASCENDING ]) : int
Parameters
- $gen_doc1 : array<string|int, mixed>
-
first ordered pair
- $gen_doc2 : array<string|int, mixed>
-
second ordered pair
- $direction : int = self::ASCENDING
-
whether the comparison should be done for a self::ASCEDNING or a self::DESCENDING search
Return values
int —-1,0,1 depending on which is bigger
getCurrentDocsForKeys()
Gets the summaries associated with the keys provided the keys can be found in the current block of docs returned by this iterator
public
getCurrentDocsForKeys([array<string|int, mixed> $keys = null ]) : array<string|int, mixed>
Parameters
- $keys : array<string|int, mixed> = null
-
keys to try to find in the current block of returned results
Return values
array<string|int, mixed> —doc summaries that match provided keys
getDirection()
Returns CrawlConstants::ASCENDING or CrawlConstants::DESCENDING depending on the direction in which this iterator ttraverse the underlying index archive bundle.
public
getDirection() : int
Return values
int —direction traversing underlying archive bundle
nextDocsWithWord()
Get the current block of doc summaries for the word iterator and advances the current pointer to the next block of documents. If a doc index is the next block must be of docs after this doc_index
public
nextDocsWithWord([ $doc_offset = null ]) : array<string|int, mixed>
Parameters
- $doc_offset : = null
-
if set the next block must all have $doc_offsets equal to or larger than this value
Return values
array<string|int, mixed> —doc summaries matching the $this->restrict_phrases
plan()
Returns a string representation of a plan by which the current iterator finds its results
public
plan() : string
Return values
string —a representation of the current iterator and its subiterators, useful for determining how a query will be processed
reset()
Returns the iterators to the first document block that it could iterate over
public
reset() : mixed
Return values
mixed —setResultsPerBlock()
This method is supposed to set the value of the result_per_block field. This field controls the maximum number of results that can be returned in one go by currentDocsWithWord(). This method cannot be consistently implemented for this iterator and expect it to behave nicely it this iterator is used together with union_iterator. So to prevent a user for doing this, calling this method results in a user defined error
public
setResultsPerBlock(int $num) : mixed
Parameters
- $num : int
-
the maximum number of results that can be returned by a block
Return values
mixed —syncGenDocOffsetsAmongstIterators()
Finds the next generation and doc offset amongst the all docs iterator and the term to be negated iterator such that the all iterator is strictly less than the term iterator.
public
syncGenDocOffsetsAmongstIterators() : mixed