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use Result;
use core::Segment;
use core::SegmentId;
use core::SegmentComponent;
use schema::Term;
use store::StoreReader;
use schema::Document;
use directory::ReadOnlySource;
use DocId;
use std::io;
use std::str;
use postings::TermInfo;
use datastruct::FstMap;
use std::fmt;
use rustc_serialize::json;
use core::SegmentInfo;
use schema::Field;
use postings::SegmentPostingsOption;
use postings::SegmentPostings;
use fastfield::{U32FastFieldsReader, U32FastFieldReader};
use schema::Schema;
use schema::FieldType;
use postings::FreqHandler;
use schema::TextIndexingOptions;
use error::Error;
pub struct SegmentReader {
segment_info: SegmentInfo,
segment_id: SegmentId,
term_infos: FstMap<TermInfo>,
postings_data: ReadOnlySource,
store_reader: StoreReader,
fast_fields_reader: U32FastFieldsReader,
fieldnorms_reader: U32FastFieldsReader,
positions_data: ReadOnlySource,
schema: Schema,
}
impl SegmentReader {
pub fn max_doc(&self) -> DocId {
self.segment_info.max_doc
}
pub fn num_docs(&self) -> DocId {
self.segment_info.max_doc
}
pub fn get_fast_field_reader(&self, field: Field) -> io::Result<U32FastFieldReader> {
let field_entry = self.schema.get_field_entry(field);
match *field_entry.field_type() {
FieldType::Str(_) => {
Err(io::Error::new(io::ErrorKind::Other, "fast field are not yet supported for text fields."))
},
FieldType::U32(_) => {
self.fast_fields_reader.get_field(field)
},
}
}
pub fn get_fieldnorms_reader(&self, field: Field) -> io::Result<U32FastFieldReader> {
self.fieldnorms_reader.get_field(field)
}
pub fn doc_freq(&self, term: &Term) -> u32 {
match self.get_term_info(term) {
Some(term_info) => term_info.doc_freq,
None => 0,
}
}
pub fn get_store_reader(&self) -> &StoreReader {
&self.store_reader
}
pub fn open(segment: Segment) -> Result<SegmentReader> {
let segment_info_reader = try!(segment.open_read(SegmentComponent::INFO));
let segment_info_data = try!(
str::from_utf8(&*segment_info_reader)
.map_err(|err| {
let segment_info_filepath = segment.relative_path(SegmentComponent::INFO);
Error::CorruptedFile(segment_info_filepath, Box::new(err))
})
);
let segment_info: SegmentInfo = try!(
json::decode(&segment_info_data)
.map_err(|err| {
let file_path = segment.relative_path(SegmentComponent::INFO);
Error::CorruptedFile(file_path, Box::new(err))
})
);
let source = try!(segment.open_read(SegmentComponent::TERMS));
let term_infos = try!(FstMap::from_source(source));
let store_reader = StoreReader::from(try!(segment.open_read(SegmentComponent::STORE)));
let postings_shared_mmap = try!(segment.open_read(SegmentComponent::POSTINGS));
let fast_field_data = try!(segment.open_read(SegmentComponent::FASTFIELDS));
let fast_fields_reader = try!(U32FastFieldsReader::open(fast_field_data));
let fieldnorms_data = try!(segment.open_read(SegmentComponent::FIELDNORMS));
let fieldnorms_reader = try!(U32FastFieldsReader::open(fieldnorms_data));
let positions_data = segment
.open_read(SegmentComponent::POSITIONS)
.unwrap_or_else(|_| ReadOnlySource::empty());
let schema = segment.schema();
Ok(SegmentReader {
segment_info: segment_info,
postings_data: postings_shared_mmap,
term_infos: term_infos,
segment_id: segment.id(),
store_reader: store_reader,
fast_fields_reader: fast_fields_reader,
fieldnorms_reader: fieldnorms_reader,
positions_data: positions_data,
schema: schema,
})
}
pub fn term_infos(&self) -> &FstMap<TermInfo> {
&self.term_infos
}
pub fn doc(&self, doc_id: DocId) -> Result<Document> {
self.store_reader.get(doc_id)
}
pub fn read_postings(&self, term: &Term, option: SegmentPostingsOption) -> Option<SegmentPostings> {
let field = term.field();
let field_entry = self.schema.get_field_entry(field);
let term_info = get!(self.get_term_info(&term));
let offset = term_info.postings_offset as usize;
let postings_data = &self.postings_data[offset..];
let freq_handler = match *field_entry.field_type() {
FieldType::Str(ref options) => {
let indexing_options = options.get_indexing_options();
match option {
SegmentPostingsOption::NoFreq => {
FreqHandler::new_without_freq()
}
SegmentPostingsOption::Freq => {
if indexing_options.is_termfreq_enabled() {
FreqHandler::new_with_freq()
}
else {
FreqHandler::new_without_freq()
}
}
SegmentPostingsOption::FreqAndPositions => {
if indexing_options == TextIndexingOptions::TokenizedWithFreqAndPosition {
let offseted_position_data = &self.positions_data[term_info.positions_offset as usize ..];
FreqHandler::new_with_freq_and_position(offseted_position_data)
}
else if indexing_options.is_termfreq_enabled()
{
FreqHandler::new_with_freq()
}
else {
FreqHandler::new_without_freq()
}
}
}
}
_ => {
FreqHandler::new_without_freq()
}
};
Some(SegmentPostings::from_data(term_info.doc_freq, postings_data, freq_handler))
}
pub fn read_postings_all_info(&self, term: &Term) -> Option<SegmentPostings> {
let field_entry = self.schema.get_field_entry(term.field());
let segment_posting_option = match *field_entry.field_type() {
FieldType::Str(ref text_options) => {
match text_options.get_indexing_options() {
TextIndexingOptions::TokenizedWithFreq => SegmentPostingsOption::Freq,
TextIndexingOptions::TokenizedWithFreqAndPosition => SegmentPostingsOption::FreqAndPositions,
_ => SegmentPostingsOption::NoFreq,
}
}
FieldType::U32(_) => SegmentPostingsOption::NoFreq
};
self.read_postings(term, segment_posting_option)
}
pub fn get_term_info(&self, term: &Term) -> Option<TermInfo> {
self.term_infos.get(term.as_slice())
}
}
impl fmt::Debug for SegmentReader {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "SegmentReader({:?})", self.segment_id)
}
}