rgbisect 0.1.0

The recursive graph bisection algorithm suite compresses indexes or graphs via identifier reassignment.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172

use log::*;

pub mod proto;

pub enum CiffRecord {
    PostingsList(proto::PostingsList),
    Document {
        doc_id: u32,
        external_id: String,
        length: u32,
    },
}

pub struct Reader<'a> {
    input: protobuf::CodedInputStream<'a>,
    average_doc_len: f64,
    num_records: usize,
    num_docs: usize,
    num_postings_lists: usize,
    postings_left: usize,
    docs_left: usize,
    header: proto::Header,
}

impl<'a> Reader<'a> {
    pub fn new<T: 'a + std::io::BufRead>(input: &'a mut T) -> anyhow::Result<Reader<'a>> {
        let mut input = protobuf::CodedInputStream::from_buffered_reader(input);
        let header = input.read_message::<proto::Header>()?;
        Ok(Reader {
            input,
            average_doc_len: header.get_average_doclength(),
            postings_left: header.get_num_postings_lists() as usize,
            docs_left: header.get_num_docs() as usize,
            num_docs: header.get_num_docs() as usize,
            num_postings_lists: header.get_num_postings_lists() as usize,
            num_records: header.get_num_postings_lists() as usize + header.get_num_docs() as usize,
            header,
        })
    }

    pub fn header(&self) -> &proto::Header {
        &self.header
    }

    pub fn num_docs(&self) -> usize {
        self.num_docs
    }

    pub fn num_postings_lists(&self) -> usize {
        self.num_postings_lists
    }

    pub fn avg_doc_len(&self) -> f64 {
        self.average_doc_len
    }
}

impl<'a> ExactSizeIterator for Reader<'a> {
    fn len(&self) -> usize {
        self.num_records
    }
}

impl<'a> Iterator for Reader<'a> {
    type Item = CiffRecord;

    fn next(&mut self) -> Option<CiffRecord> {
        if self.postings_left != 0 {
            self.postings_left -= 1;
            return match self.input.read_message::<proto::PostingsList>() {
                Ok(record) => Some(CiffRecord::PostingsList(record)),
                Err(e) => {
                    error!("Error parsing CIFF postingslist: {}", e);
                    None
                }
            };
        }
        if self.docs_left != 0 {
            self.docs_left -= 1;
            return match self.input.read_message::<proto::DocRecord>() {
                Ok(record) => {
                    Some(CiffRecord::Document {
                        doc_id: record.get_docid() as u32, // todo fix this...
                        external_id: record.get_collection_docid().to_string(),
                        length: record.get_doclength() as u32, // todo fix this...
                    })
                }
                Err(e) => {
                    error!("Error parsing CIFF document: {}", e);
                    None
                }
            };
        }
        None
    }
}


pub struct Writer<'a> {
    output: protobuf::CodedOutputStream<'a>,
}

impl<'a> Writer<'a> {
    pub fn from_reader<T: 'a + std::io::Write>(output: &'a mut T,reader: &Reader<'a>,description: &str) -> Result<Writer<'a>, protobuf::ProtobufError> {
        let header = reader.header();
        let description = format!("{} {}",header.get_description(),description);
        Self::new(
            output,
            header.get_num_postings_lists(),
            header.get_total_postings_lists(),
            header.get_total_terms_in_collection(),
            header.get_num_docs(),
            header.get_total_docs(),
            header.get_average_doclength(),
            &description
        )
    }

    pub fn new<T: 'a + std::io::Write>(
        output: &'a mut T,
        num_postings_lists: i32,
        total_postings_lists: i32,
        total_terms_in_collection: i64,
        num_docs: i32,
        total_docs: i32,
        avg_doc_len: f64,
        description: &str,
    ) -> Result<Writer<'a>, protobuf::ProtobufError> {
        let mut writer = Writer {
            output: protobuf::CodedOutputStream::new(output),
        };

        // write the header
        let mut header = proto::Header::default();
        header.set_version(1);
        header.set_description(description.into());
        header.set_num_postings_lists(num_postings_lists);
        header.set_total_postings_lists(total_postings_lists);
        header.set_total_terms_in_collection(total_terms_in_collection);
        header.set_num_docs(num_docs);
        header.set_total_docs(total_docs);
        header.set_average_doclength(avg_doc_len);

        writer.output.write_message_no_tag(&header)?;

        Ok(writer)
    }

    pub fn write_document(
        &mut self,
        docid: i32,
        external_id: String,
        len: i32,
    ) -> Result<(), protobuf::ProtobufError> {
        let mut document = proto::DocRecord::default();
        document.set_docid(docid);
        document.set_collection_docid(external_id);
        document.set_doclength(len);
        self.output.write_message_no_tag(&document)
    }

    pub fn write_postingslist(
        &mut self,
        postings_list: proto::PostingsList,
    ) -> Result<(), protobuf::ProtobufError> {
        self.output.write_message_no_tag(&postings_list)
    }

    pub fn flush(&mut self) -> Result<(), protobuf::ProtobufError> {
        self.output.flush()
    }
}