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 </pre><pre class="rust"><code><span class="kw">use </span>std::cmp::Ordering;
 <span class="kw">use </span>std::io::{<span class="self">self</span>, Write};

 <span class="kw">use </span>common::{BinarySerializable, CountingWriter, VInt};
 <span class="kw">use </span>fail::fail_point;

 <span class="kw">use </span><span class="kw">super</span>::TermInfo;
 <span class="kw">use </span><span class="kw">crate</span>::core::Segment;
 <span class="kw">use </span><span class="kw">crate</span>::directory::{CompositeWrite, WritePtr};
 <span class="kw">use </span><span class="kw">crate</span>::fieldnorm::FieldNormReader;
 <span class="kw">use </span><span class="kw">crate</span>::positions::PositionSerializer;
 <span class="kw">use </span><span class="kw">crate</span>::postings::compression::{BlockEncoder, VIntEncoder, COMPRESSION_BLOCK_SIZE};
 <span class="kw">use </span><span class="kw">crate</span>::postings::skip::SkipSerializer;
 <span class="kw">use </span><span class="kw">crate</span>::query::Bm25Weight;
 <span class="kw">use </span><span class="kw">crate</span>::schema::{Field, FieldEntry, FieldType, IndexRecordOption, Schema};
 <span class="kw">use </span><span class="kw">crate</span>::termdict::{TermDictionaryBuilder, TermOrdinal};
 <span class="kw">use crate</span>::{DocId, Score};

 <span class="doccomment">/// `InvertedIndexSerializer` is in charge of serializing
 /// postings on disk, in the
 /// * `.idx` (inverted index)
 /// * `.pos` (positions file)
 /// * `.term` (term dictionary)
 ///
 /// `PostingsWriter` are in charge of pushing the data to the
 /// serializer.
 ///
 /// The serializer expects to receive the following calls
 /// in this order :
 /// * `set_field(...)`
 /// * `new_term(...)`
 /// * `write_doc(...)`
 /// * `write_doc(...)`
 /// * `write_doc(...)`
 /// * ...
 /// * `close_term()`
 /// * `new_term(...)`
 /// * `write_doc(...)`
 /// * ...
 /// * `close_term()`
 /// * `set_field(...)`
 /// * ...
 /// * `close()`
 ///
 /// Terms have to be pushed in a lexicographically-sorted order.
 /// Within a term, documents have to be pushed in increasing order.
 ///
 /// A description of the serialization format is
 /// [available here](https://fulmicoton.gitbooks.io/tantivy-doc/content/inverted-index.html).
 </span><span class="kw">pub struct </span>InvertedIndexSerializer {
     terms_write: CompositeWrite&lt;WritePtr&gt;,
     postings_write: CompositeWrite&lt;WritePtr&gt;,
     positions_write: CompositeWrite&lt;WritePtr&gt;,
     schema: Schema,
 }

 <span class="kw">impl </span>InvertedIndexSerializer {
     <span class="doccomment">/// Open a new `InvertedIndexSerializer` for the given segment
     </span><span class="kw">pub fn </span>open(segment: <span class="kw-2">&amp;mut </span>Segment) -&gt; <span class="kw">crate</span>::Result&lt;InvertedIndexSerializer&gt; {
         <span class="kw">use </span><span class="kw">crate</span>::SegmentComponent::{Positions, Postings, Terms};
         <span class="kw">let </span>inv_index_serializer = InvertedIndexSerializer {
             terms_write: CompositeWrite::wrap(segment.open_write(Terms)<span class="question-mark">?</span>),
             postings_write: CompositeWrite::wrap(segment.open_write(Postings)<span class="question-mark">?</span>),
             positions_write: CompositeWrite::wrap(segment.open_write(Positions)<span class="question-mark">?</span>),
             schema: segment.schema(),
         };
         <span class="prelude-val">Ok</span>(inv_index_serializer)
     }

     <span class="doccomment">/// Must be called before starting pushing terms of
     /// a given field.
     ///
     /// Loads the indexing options for the given field.
     </span><span class="kw">pub fn </span>new_field(
         <span class="kw-2">&amp;mut </span><span class="self">self</span>,
         field: Field,
         total_num_tokens: u64,
         fieldnorm_reader: <span class="prelude-ty">Option</span>&lt;FieldNormReader&gt;,
     ) -&gt; io::Result&lt;FieldSerializer&gt; {
         <span class="kw">let </span>field_entry: <span class="kw-2">&amp;</span>FieldEntry = <span class="self">self</span>.schema.get_field_entry(field);
         <span class="kw">let </span>term_dictionary_write = <span class="self">self</span>.terms_write.for_field(field);
         <span class="kw">let </span>postings_write = <span class="self">self</span>.postings_write.for_field(field);
         <span class="kw">let </span>positions_write = <span class="self">self</span>.positions_write.for_field(field);
         <span class="kw">let </span>field_type: FieldType = (<span class="kw-2">*</span>field_entry.field_type()).clone();
         FieldSerializer::create(
             <span class="kw-2">&amp;</span>field_type,
             total_num_tokens,
             term_dictionary_write,
             postings_write,
             positions_write,
             fieldnorm_reader,
         )
     }

     <span class="doccomment">/// Closes the serializer.
     </span><span class="kw">pub fn </span>close(<span class="self">self</span>) -&gt; io::Result&lt;()&gt; {
         <span class="self">self</span>.terms_write.close()<span class="question-mark">?</span>;
         <span class="self">self</span>.postings_write.close()<span class="question-mark">?</span>;
         <span class="self">self</span>.positions_write.close()<span class="question-mark">?</span>;
         <span class="prelude-val">Ok</span>(())
     }
 }

 <span class="doccomment">/// The field serializer is in charge of
 /// the serialization of a specific field.
 </span><span class="kw">pub struct </span>FieldSerializer&lt;<span class="lifetime">&#39;a</span>&gt; {
     term_dictionary_builder: TermDictionaryBuilder&lt;<span class="kw-2">&amp;</span><span class="lifetime">&#39;a </span><span class="kw-2">mut </span>CountingWriter&lt;WritePtr&gt;&gt;,
     postings_serializer: PostingsSerializer&lt;<span class="kw-2">&amp;</span><span class="lifetime">&#39;a </span><span class="kw-2">mut </span>CountingWriter&lt;WritePtr&gt;&gt;,
     positions_serializer_opt: <span class="prelude-ty">Option</span>&lt;PositionSerializer&lt;<span class="kw-2">&amp;</span><span class="lifetime">&#39;a </span><span class="kw-2">mut </span>CountingWriter&lt;WritePtr&gt;&gt;&gt;,
     current_term_info: TermInfo,
     term_open: bool,
     num_terms: TermOrdinal,
 }

 <span class="kw">impl</span>&lt;<span class="lifetime">&#39;a</span>&gt; FieldSerializer&lt;<span class="lifetime">&#39;a</span>&gt; {
     <span class="kw">fn </span>create(
         field_type: <span class="kw-2">&amp;</span>FieldType,
         total_num_tokens: u64,
         term_dictionary_write: <span class="kw-2">&amp;</span><span class="lifetime">&#39;a </span><span class="kw-2">mut </span>CountingWriter&lt;WritePtr&gt;,
         postings_write: <span class="kw-2">&amp;</span><span class="lifetime">&#39;a </span><span class="kw-2">mut </span>CountingWriter&lt;WritePtr&gt;,
         positions_write: <span class="kw-2">&amp;</span><span class="lifetime">&#39;a </span><span class="kw-2">mut </span>CountingWriter&lt;WritePtr&gt;,
         fieldnorm_reader: <span class="prelude-ty">Option</span>&lt;FieldNormReader&gt;,
     ) -&gt; io::Result&lt;FieldSerializer&lt;<span class="lifetime">&#39;a</span>&gt;&gt; {
         total_num_tokens.serialize(postings_write)<span class="question-mark">?</span>;
         <span class="kw">let </span>index_record_option = field_type
             .index_record_option()
             .unwrap_or(IndexRecordOption::Basic);
         <span class="kw">let </span>term_dictionary_builder = TermDictionaryBuilder::create(term_dictionary_write)<span class="question-mark">?</span>;
         <span class="kw">let </span>average_fieldnorm = fieldnorm_reader
             .as_ref()
             .map(|ff_reader| (total_num_tokens <span class="kw">as </span>Score / ff_reader.num_docs() <span class="kw">as </span>Score))
             .unwrap_or(<span class="number">0.0</span>);
         <span class="kw">let </span>postings_serializer = PostingsSerializer::new(
             postings_write,
             average_fieldnorm,
             index_record_option,
             fieldnorm_reader,
         );
         <span class="kw">let </span>positions_serializer_opt = <span class="kw">if </span>index_record_option.has_positions() {
             <span class="prelude-val">Some</span>(PositionSerializer::new(positions_write))
         } <span class="kw">else </span>{
             <span class="prelude-val">None
         </span>};

         <span class="prelude-val">Ok</span>(FieldSerializer {
             term_dictionary_builder,
             postings_serializer,
             positions_serializer_opt,
             current_term_info: TermInfo::default(),
             term_open: <span class="bool-val">false</span>,
             num_terms: TermOrdinal::default(),
         })
     }

     <span class="kw">fn </span>current_term_info(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; TermInfo {
         <span class="kw">let </span>positions_start =
             <span class="kw">if let </span><span class="prelude-val">Some</span>(positions_serializer) = <span class="self">self</span>.positions_serializer_opt.as_ref() {
                 positions_serializer.written_bytes()
             } <span class="kw">else </span>{
                 <span class="number">0u64
             </span>} <span class="kw">as </span>usize;
         <span class="kw">let </span>addr = <span class="self">self</span>.postings_serializer.written_bytes() <span class="kw">as </span>usize;
         TermInfo {
             doc_freq: <span class="number">0</span>,
             postings_range: addr..addr,
             positions_range: positions_start..positions_start,
         }
     }

     <span class="doccomment">/// Starts the postings for a new term.
     /// * term - the term. It needs to come after the previous term according to the lexicographical
     ///   order.
     /// * term_doc_freq - return the number of document containing the term.
     </span><span class="kw">pub fn </span>new_term(<span class="kw-2">&amp;mut </span><span class="self">self</span>, term: <span class="kw-2">&amp;</span>[u8], term_doc_freq: u32) -&gt; io::Result&lt;TermOrdinal&gt; {
         <span class="macro">assert!</span>(
             !<span class="self">self</span>.term_open,
             <span class="string">&quot;Called new_term, while the previous term was not closed.&quot;
         </span>);

         <span class="self">self</span>.term_open = <span class="bool-val">true</span>;
         <span class="self">self</span>.postings_serializer.clear();
         <span class="self">self</span>.current_term_info = <span class="self">self</span>.current_term_info();
         <span class="self">self</span>.term_dictionary_builder.insert_key(term)<span class="question-mark">?</span>;
         <span class="kw">let </span>term_ordinal = <span class="self">self</span>.num_terms;
         <span class="self">self</span>.num_terms += <span class="number">1</span>;
         <span class="self">self</span>.postings_serializer.new_term(term_doc_freq);
         <span class="prelude-val">Ok</span>(term_ordinal)
     }

     <span class="doccomment">/// Serialize the information that a document contains for the current term:
     /// its term frequency, and the position deltas.
     ///
     /// At this point, the positions are already `delta-encoded`.
     /// For instance, if the positions are `2, 3, 17`,
     /// `position_deltas` is `2, 1, 14`
     ///
     /// Term frequencies and positions may be ignored by the serializer depending
     /// on the configuration of the field in the `Schema`.
     </span><span class="kw">pub fn </span>write_doc(<span class="kw-2">&amp;mut </span><span class="self">self</span>, doc_id: DocId, term_freq: u32, position_deltas: <span class="kw-2">&amp;</span>[u32]) {
         <span class="self">self</span>.current_term_info.doc_freq += <span class="number">1</span>;
         <span class="self">self</span>.postings_serializer.write_doc(doc_id, term_freq);
         <span class="kw">if let </span><span class="prelude-val">Some</span>(<span class="kw-2">ref mut </span>positions_serializer) = <span class="self">self</span>.positions_serializer_opt.as_mut() {
             <span class="macro">assert_eq!</span>(term_freq <span class="kw">as </span>usize, position_deltas.len());
             positions_serializer.write_positions_delta(position_deltas);
         }
     }

     <span class="doccomment">/// Finish the serialization for this term postings.
     ///
     /// If the current block is incomplete, it needs to be encoded
     /// using `VInt` encoding.
     </span><span class="kw">pub fn </span>close_term(<span class="kw-2">&amp;mut </span><span class="self">self</span>) -&gt; io::Result&lt;()&gt; {
         <span class="macro">fail_point!</span>(<span class="string">&quot;FieldSerializer::close_term&quot;</span>, |msg: <span class="prelude-ty">Option</span>&lt;String&gt;| {
             <span class="prelude-val">Err</span>(io::Error::new(io::ErrorKind::Other, <span class="macro">format!</span>(<span class="string">&quot;{:?}&quot;</span>, msg)))
         });
         <span class="kw">if </span><span class="self">self</span>.term_open {
             <span class="self">self</span>.postings_serializer
                 .close_term(<span class="self">self</span>.current_term_info.doc_freq)<span class="question-mark">?</span>;
             <span class="self">self</span>.current_term_info.postings_range.end =
                 <span class="self">self</span>.postings_serializer.written_bytes() <span class="kw">as </span>usize;

             <span class="kw">if let </span><span class="prelude-val">Some</span>(positions_serializer) = <span class="self">self</span>.positions_serializer_opt.as_mut() {
                 positions_serializer.close_term()<span class="question-mark">?</span>;
                 <span class="self">self</span>.current_term_info.positions_range.end =
                     positions_serializer.written_bytes() <span class="kw">as </span>usize;
             }
             <span class="self">self</span>.term_dictionary_builder
                 .insert_value(<span class="kw-2">&amp;</span><span class="self">self</span>.current_term_info)<span class="question-mark">?</span>;
             <span class="self">self</span>.term_open = <span class="bool-val">false</span>;
         }
         <span class="prelude-val">Ok</span>(())
     }

     <span class="doccomment">/// Closes the current field.
     </span><span class="kw">pub fn </span>close(<span class="kw-2">mut </span><span class="self">self</span>) -&gt; io::Result&lt;()&gt; {
         <span class="self">self</span>.close_term()<span class="question-mark">?</span>;
         <span class="kw">if let </span><span class="prelude-val">Some</span>(positions_serializer) = <span class="self">self</span>.positions_serializer_opt {
             positions_serializer.close()<span class="question-mark">?</span>;
         }
         <span class="self">self</span>.postings_serializer.close()<span class="question-mark">?</span>;
         <span class="self">self</span>.term_dictionary_builder.finish()<span class="question-mark">?</span>;
         <span class="prelude-val">Ok</span>(())
     }
 }

 <span class="kw">struct </span>Block {
     doc_ids: [DocId; COMPRESSION_BLOCK_SIZE],
     term_freqs: [u32; COMPRESSION_BLOCK_SIZE],
     len: usize,
 }

 <span class="kw">impl </span>Block {
     <span class="kw">fn </span>new() -&gt; <span class="self">Self </span>{
         Block {
             doc_ids: [<span class="number">0u32</span>; COMPRESSION_BLOCK_SIZE],
             term_freqs: [<span class="number">0u32</span>; COMPRESSION_BLOCK_SIZE],
             len: <span class="number">0</span>,
         }
     }

     <span class="kw">fn </span>doc_ids(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="kw-2">&amp;</span>[DocId] {
         <span class="kw-2">&amp;</span><span class="self">self</span>.doc_ids[..<span class="self">self</span>.len]
     }

     <span class="kw">fn </span>term_freqs(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="kw-2">&amp;</span>[u32] {
         <span class="kw-2">&amp;</span><span class="self">self</span>.term_freqs[..<span class="self">self</span>.len]
     }

     <span class="kw">fn </span>clear(<span class="kw-2">&amp;mut </span><span class="self">self</span>) {
         <span class="self">self</span>.len = <span class="number">0</span>;
     }

     <span class="kw">fn </span>append_doc(<span class="kw-2">&amp;mut </span><span class="self">self</span>, doc: DocId, term_freq: u32) {
         <span class="kw">let </span>len = <span class="self">self</span>.len;
         <span class="self">self</span>.doc_ids[len] = doc;
         <span class="self">self</span>.term_freqs[len] = term_freq;
         <span class="self">self</span>.len = len + <span class="number">1</span>;
     }

     <span class="kw">fn </span>is_full(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; bool {
         <span class="self">self</span>.len == COMPRESSION_BLOCK_SIZE
     }

     <span class="kw">fn </span>is_empty(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; bool {
         <span class="self">self</span>.len == <span class="number">0
     </span>}

     <span class="kw">fn </span>last_doc(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; DocId {
         <span class="macro">assert_eq!</span>(<span class="self">self</span>.len, COMPRESSION_BLOCK_SIZE);
         <span class="self">self</span>.doc_ids[COMPRESSION_BLOCK_SIZE - <span class="number">1</span>]
     }
 }

 <span class="kw">pub struct </span>PostingsSerializer&lt;W: Write&gt; {
     output_write: CountingWriter&lt;W&gt;,
     last_doc_id_encoded: u32,

     block_encoder: BlockEncoder,
     block: Box&lt;Block&gt;,

     postings_write: Vec&lt;u8&gt;,
     skip_write: SkipSerializer,

     mode: IndexRecordOption,
     fieldnorm_reader: <span class="prelude-ty">Option</span>&lt;FieldNormReader&gt;,

     bm25_weight: <span class="prelude-ty">Option</span>&lt;Bm25Weight&gt;,
     avg_fieldnorm: Score, <span class="comment">/* Average number of term in the field for that segment.
                            * this value is used to compute the block wand information. */
 </span>}

 <span class="kw">impl</span>&lt;W: Write&gt; PostingsSerializer&lt;W&gt; {
     <span class="kw">pub fn </span>new(
         write: W,
         avg_fieldnorm: Score,
         mode: IndexRecordOption,
         fieldnorm_reader: <span class="prelude-ty">Option</span>&lt;FieldNormReader&gt;,
     ) -&gt; PostingsSerializer&lt;W&gt; {
         PostingsSerializer {
             output_write: CountingWriter::wrap(write),

             block_encoder: BlockEncoder::new(),
             block: Box::new(Block::new()),

             postings_write: Vec::new(),
             skip_write: SkipSerializer::new(),

             last_doc_id_encoded: <span class="number">0u32</span>,
             mode,

             fieldnorm_reader,
             bm25_weight: <span class="prelude-val">None</span>,
             avg_fieldnorm,
         }
     }

     <span class="kw">pub fn </span>new_term(<span class="kw-2">&amp;mut </span><span class="self">self</span>, term_doc_freq: u32) {
         <span class="self">self</span>.bm25_weight = <span class="prelude-val">None</span>;

         <span class="kw">if </span>!<span class="self">self</span>.mode.has_freq() {
             <span class="kw">return</span>;
         }

         <span class="kw">let </span>num_docs_in_segment: u64 =
             <span class="kw">if let </span><span class="prelude-val">Some</span>(fieldnorm_reader) = <span class="self">self</span>.fieldnorm_reader.as_ref() {
                 fieldnorm_reader.num_docs() <span class="kw">as </span>u64
             } <span class="kw">else </span>{
                 <span class="kw">return</span>;
             };

         <span class="kw">if </span>num_docs_in_segment == <span class="number">0 </span>{
             <span class="kw">return</span>;
         }

         <span class="self">self</span>.bm25_weight = <span class="prelude-val">Some</span>(Bm25Weight::for_one_term(
             term_doc_freq <span class="kw">as </span>u64,
             num_docs_in_segment,
             <span class="self">self</span>.avg_fieldnorm,
         ));
     }

     <span class="kw">fn </span>write_block(<span class="kw-2">&amp;mut </span><span class="self">self</span>) {
         {
             <span class="comment">// encode the doc ids
             </span><span class="kw">let </span>(num_bits, block_encoded): (u8, <span class="kw-2">&amp;</span>[u8]) = <span class="self">self
                 </span>.block_encoder
                 .compress_block_sorted(<span class="self">self</span>.block.doc_ids(), <span class="self">self</span>.last_doc_id_encoded);
             <span class="self">self</span>.last_doc_id_encoded = <span class="self">self</span>.block.last_doc();
             <span class="self">self</span>.skip_write
                 .write_doc(<span class="self">self</span>.last_doc_id_encoded, num_bits);
             <span class="comment">// last el block 0, offset block 1,
             </span><span class="self">self</span>.postings_write.extend(block_encoded);
         }
         <span class="kw">if </span><span class="self">self</span>.mode.has_freq() {
             <span class="kw">let </span>(num_bits, block_encoded): (u8, <span class="kw-2">&amp;</span>[u8]) = <span class="self">self
                 </span>.block_encoder
                 .compress_block_unsorted(<span class="self">self</span>.block.term_freqs());
             <span class="self">self</span>.postings_write.extend(block_encoded);
             <span class="self">self</span>.skip_write.write_term_freq(num_bits);
             <span class="kw">if </span><span class="self">self</span>.mode.has_positions() {
                 <span class="comment">// We serialize the sum of term freqs within the skip information
                 // in order to navigate through positions.
                 </span><span class="kw">let </span>sum_freq = <span class="self">self</span>.block.term_freqs().iter().cloned().sum();
                 <span class="self">self</span>.skip_write.write_total_term_freq(sum_freq);
             }
             <span class="kw">let </span><span class="kw-2">mut </span>blockwand_params = (<span class="number">0u8</span>, <span class="number">0u32</span>);
             <span class="kw">if let </span><span class="prelude-val">Some</span>(bm25_weight) = <span class="self">self</span>.bm25_weight.as_ref() {
                 <span class="kw">if let </span><span class="prelude-val">Some</span>(fieldnorm_reader) = <span class="self">self</span>.fieldnorm_reader.as_ref() {
                     <span class="kw">let </span>docs = <span class="self">self</span>.block.doc_ids().iter().cloned();
                     <span class="kw">let </span>term_freqs = <span class="self">self</span>.block.term_freqs().iter().cloned();
                     <span class="kw">let </span>fieldnorms = docs.map(|doc| fieldnorm_reader.fieldnorm_id(doc));
                     blockwand_params = fieldnorms
                         .zip(term_freqs)
                         .max_by(
                             |(left_fieldnorm_id, left_term_freq),
                              (right_fieldnorm_id, right_term_freq)| {
                                 <span class="kw">let </span>left_score =
                                     bm25_weight.tf_factor(<span class="kw-2">*</span>left_fieldnorm_id, <span class="kw-2">*</span>left_term_freq);
                                 <span class="kw">let </span>right_score =
                                     bm25_weight.tf_factor(<span class="kw-2">*</span>right_fieldnorm_id, <span class="kw-2">*</span>right_term_freq);
                                 left_score
                                     .partial_cmp(<span class="kw-2">&amp;</span>right_score)
                                     .unwrap_or(Ordering::Equal)
                             },
                         )
                         .unwrap();
                 }
             }
             <span class="kw">let </span>(fieldnorm_id, term_freq) = blockwand_params;
             <span class="self">self</span>.skip_write.write_blockwand_max(fieldnorm_id, term_freq);
         }
         <span class="self">self</span>.block.clear();
     }

     <span class="kw">pub fn </span>write_doc(<span class="kw-2">&amp;mut </span><span class="self">self</span>, doc_id: DocId, term_freq: u32) {
         <span class="self">self</span>.block.append_doc(doc_id, term_freq);
         <span class="kw">if </span><span class="self">self</span>.block.is_full() {
             <span class="self">self</span>.write_block();
         }
     }

     <span class="kw">fn </span>close(<span class="kw-2">mut </span><span class="self">self</span>) -&gt; io::Result&lt;()&gt; {
         <span class="self">self</span>.postings_write.flush()
     }

     <span class="kw">pub fn </span>close_term(<span class="kw-2">&amp;mut </span><span class="self">self</span>, doc_freq: u32) -&gt; io::Result&lt;()&gt; {
         <span class="kw">if </span>!<span class="self">self</span>.block.is_empty() {
             <span class="comment">// we have doc ids waiting to be written
             // this happens when the number of doc ids is
             // not a perfect multiple of our block size.
             //
             // In that case, the remaining part is encoded
             // using variable int encoding.
             </span>{
                 <span class="kw">let </span>block_encoded = <span class="self">self
                     </span>.block_encoder
                     .compress_vint_sorted(<span class="self">self</span>.block.doc_ids(), <span class="self">self</span>.last_doc_id_encoded);
                 <span class="self">self</span>.postings_write.write_all(block_encoded)<span class="question-mark">?</span>;
             }
             <span class="comment">// ... Idem for term frequencies
             </span><span class="kw">if </span><span class="self">self</span>.mode.has_freq() {
                 <span class="kw">let </span>block_encoded = <span class="self">self
                     </span>.block_encoder
                     .compress_vint_unsorted(<span class="self">self</span>.block.term_freqs());
                 <span class="self">self</span>.postings_write.write_all(block_encoded)<span class="question-mark">?</span>;
             }
             <span class="self">self</span>.block.clear();
         }
         <span class="kw">if </span>doc_freq &gt;= COMPRESSION_BLOCK_SIZE <span class="kw">as </span>u32 {
             <span class="kw">let </span>skip_data = <span class="self">self</span>.skip_write.data();
             VInt(skip_data.len() <span class="kw">as </span>u64).serialize(<span class="kw-2">&amp;mut </span><span class="self">self</span>.output_write)<span class="question-mark">?</span>;
             <span class="self">self</span>.output_write.write_all(skip_data)<span class="question-mark">?</span>;
         }
         <span class="self">self</span>.output_write.write_all(<span class="kw-2">&amp;</span><span class="self">self</span>.postings_write[..])<span class="question-mark">?</span>;
         <span class="self">self</span>.skip_write.clear();
         <span class="self">self</span>.postings_write.clear();
         <span class="self">self</span>.bm25_weight = <span class="prelude-val">None</span>;
         <span class="prelude-val">Ok</span>(())
     }

     <span class="doccomment">/// Returns the number of bytes written in the postings write object
     /// at this point.
     /// When called before writing the postings of a term, this value is used as
     /// start offset.
     /// When called after writing the postings of a term, this value is used as a
     /// end offset.
     </span><span class="kw">fn </span>written_bytes(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; u64 {
         <span class="self">self</span>.output_write.written_bytes() <span class="kw">as </span>u64
     }

     <span class="kw">fn </span>clear(<span class="kw-2">&amp;mut </span><span class="self">self</span>) {
         <span class="self">self</span>.block.clear();
         <span class="self">self</span>.last_doc_id_encoded = <span class="number">0</span>;
     }
 }
 </code></pre></div>
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