84 lines
2.4 KiB
Go
84 lines
2.4 KiB
Go
// Copyright (c) 2014 Couchbase, Inc.
|
|
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
|
|
// except in compliance with the License. You may obtain a copy of the License at
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
// Unless required by applicable law or agreed to in writing, software distributed under the
|
|
// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
|
|
// either express or implied. See the License for the specific language governing permissions
|
|
// and limitations under the License.
|
|
|
|
package analysis
|
|
|
|
// TokenLocation represents one occurrence of a term at a particular location in
|
|
// a field. Start, End and Position have the same meaning as in analysis.Token.
|
|
// Field and ArrayPositions identify the field value in the source document.
|
|
// See document.Field for details.
|
|
type TokenLocation struct {
|
|
Field string
|
|
ArrayPositions []uint64
|
|
Start int
|
|
End int
|
|
Position int
|
|
}
|
|
|
|
// TokenFreq represents all the occurrences of a term in all fields of a
|
|
// document.
|
|
type TokenFreq struct {
|
|
Term []byte
|
|
Locations []*TokenLocation
|
|
}
|
|
|
|
func (tf *TokenFreq) Frequency() int {
|
|
return len(tf.Locations)
|
|
}
|
|
|
|
// TokenFrequencies maps document terms to their combined frequencies from all
|
|
// fields.
|
|
type TokenFrequencies map[string]*TokenFreq
|
|
|
|
func (tfs TokenFrequencies) MergeAll(remoteField string, other TokenFrequencies) {
|
|
// walk the new token frequencies
|
|
for tfk, tf := range other {
|
|
// set the remoteField value in incoming token freqs
|
|
for _, l := range tf.Locations {
|
|
l.Field = remoteField
|
|
}
|
|
existingTf, exists := tfs[tfk]
|
|
if exists {
|
|
existingTf.Locations = append(existingTf.Locations, tf.Locations...)
|
|
} else {
|
|
tfs[tfk] = tf
|
|
}
|
|
}
|
|
}
|
|
|
|
func TokenFrequency(tokens TokenStream, arrayPositions []uint64) TokenFrequencies {
|
|
rv := make(map[string]*TokenFreq, len(tokens))
|
|
|
|
tls := make([]TokenLocation, len(tokens))
|
|
tlNext := 0
|
|
|
|
for _, token := range tokens {
|
|
tls[tlNext] = TokenLocation{
|
|
ArrayPositions: arrayPositions,
|
|
Start: token.Start,
|
|
End: token.End,
|
|
Position: token.Position,
|
|
}
|
|
|
|
curr, ok := rv[string(token.Term)]
|
|
if ok {
|
|
curr.Locations = append(curr.Locations, &tls[tlNext])
|
|
} else {
|
|
rv[string(token.Term)] = &TokenFreq{
|
|
Term: token.Term,
|
|
Locations: []*TokenLocation{&tls[tlNext]},
|
|
}
|
|
}
|
|
|
|
tlNext++
|
|
}
|
|
|
|
return rv
|
|
}
|