Struct tantivy::collector::HistogramCollector

pub struct HistogramCollector { /* private fields */ }

Histogram builds an histogram of the values of a fastfield for the collected DocSet.

At construction, it is given parameters that define a partition of an interval [min_val, max_val) into N buckets with the same width. The ith bucket is then defined by [min_val + i * bucket_width, min_val + (i+1) * bucket_width)

An histogram is then defined as a Vec<u64> of length num_buckets, that contains a count of documents for each value bucket.

See also HistogramCollector::new().

Warning

f64 fields are not supported.

Implementations

impl HistogramCollector

pub fn new<TFastValue: FastValue>( field: String, min_value: TFastValue, bucket_width: u64, num_buckets: usize ) -> HistogramCollector

Builds a new HistogramCollector.

The scale/range of the histogram is not dynamic. It is required to define it by supplying following parameter:

• min_value: the minimum value that can be recorded in the histogram.
• bucket_width: the length of the interval that is associated with each buckets.
• num_buckets: The overall number of buckets.

Together, this parameters define a partition of [min_value, min_value + num_buckets * bucket_width) into num_buckets intervals of width bucket that we call bucket.

Disclaimer

This function panics if the field given is of type f64.

Trait Implementations

impl Clone for HistogramCollector

fn clone(&self) -> HistogramCollector

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Collector for HistogramCollector

type Fruit = Vec<u64>

Fruit is the type for the result of our collection. e.g. usize for the Count collector.

type Child = SegmentHistogramCollector

Type of the SegmentCollector associated with this collector.

fn for_segment( &self, _segment_local_id: SegmentOrdinal, segment: &SegmentReader ) -> Result<Self::Child>

set_segment is called before beginning to enumerate on this segment.

fn requires_scoring(&self) -> bool

Returns true iff the collector requires to compute scores for documents.

fn merge_fruits(&self, child_histograms: Vec<Vec<u64>>) -> Result<Vec<u64>>

Combines the fruit associated with the collection of each segments into one fruit.

fn collect_segment( &self, weight: &dyn Weight, segment_ord: u32, reader: &SegmentReader ) -> Result<<Self::Child as SegmentCollector>::Fruit>

Created a segment collector and