diff --git a/examples/create-database.rs b/examples/create-database.rs
index 5c6e81d1d..07ffeb931 100644
--- a/examples/create-database.rs
+++ b/examples/create-database.rs
@@ -59,10 +59,10 @@ fn index(schema: Schema, database_path: &Path, csv_data_path: &Path) -> Result<D
             }
         };
 
-        update.update_document(&document).unwrap();
+        update.update_document(&document, &tokenizer_builder)?;
     }
 
-    let mut update = update.build()?;
+    let update = update.build()?;
     database.ingest_update_file(update)?;
 
     Ok(database)
diff --git a/src/data/doc_ids.rs b/src/data/doc_ids.rs
index 9c7eac2ff..9c4ea6474 100644
--- a/src/data/doc_ids.rs
+++ b/src/data/doc_ids.rs
@@ -1,62 +1,53 @@
+use std::io::{self, Cursor, BufRead};
 use std::slice::from_raw_parts;
-use std::sync::Arc;
-use std::{io, mem};
+use std::mem::size_of;
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use sdset::Set;
 
 use crate::DocumentId;
 use crate::data::SharedData;
+use super::into_u8_slice;
 
 #[derive(Default, Clone)]
-pub struct DocIds {
-    data: SharedData,
-}
+pub struct DocIds(SharedData);
 
 impl DocIds {
-    pub fn empty() -> Self {
-        DocIds { data: SharedData::empty() }
+    pub fn new(ids: &Set<DocumentId>) -> DocIds {
+        let bytes = unsafe { into_u8_slice(ids.as_slice()) };
+        let data = SharedData::from_bytes(bytes.to_vec());
+        DocIds(data)
     }
 
-    pub fn from_bytes(vec: Vec<u8>) -> io::Result<Self> {
-        let len = vec.len();
-        DocIds::from_shared_bytes(Arc::new(vec), 0, len)
-    }
+    pub fn from_cursor(cursor: &mut Cursor<SharedData>) -> io::Result<DocIds> {
+        let len = cursor.read_u64::<LittleEndian>()? as usize;
+        let offset = cursor.position() as usize;
+        let doc_ids = cursor.get_ref().range(offset, len);
+        cursor.consume(len);
 
-    pub fn from_shared_bytes(bytes: Arc<Vec<u8>>, offset: usize, len: usize) -> io::Result<Self> {
-        let data = SharedData { bytes, offset, len };
-        DocIds::from_data(data)
-    }
-
-    pub fn as_bytes(&self) -> &[u8] {
-        &self.data
-    }
-
-    fn from_data(data: SharedData) -> io::Result<Self> {
-        let len = data.as_ref().read_u64::<LittleEndian>()?;
-        let data = data.range(mem::size_of::<u64>(), len as usize);
-        Ok(DocIds { data })
-    }
-
-    pub fn from_raw(vec: Vec<DocumentId>) -> Self {
-        DocIds::from_bytes(unsafe { mem::transmute(vec) }).unwrap()
+        Ok(DocIds(doc_ids))
     }
 
     pub fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
-        let len = self.data.len() as u64;
+        let len = self.0.len() as u64;
         bytes.write_u64::<LittleEndian>(len).unwrap();
-        bytes.extend_from_slice(&self.data);
+        bytes.extend_from_slice(&self.0);
     }
 
-    pub fn contains(&self, doc: DocumentId) -> bool {
-        // FIXME prefer using the sdset::exponential_search function
-        self.doc_ids().binary_search(&doc).is_ok()
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
     }
 
-    pub fn doc_ids(&self) -> &Set<DocumentId> {
-        let slice = &self.data;
+    pub fn as_bytes(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+impl AsRef<Set<DocumentId>> for DocIds {
+    fn as_ref(&self) -> &Set<DocumentId> {
+        let slice = &self.0;
         let ptr = slice.as_ptr() as *const DocumentId;
-        let len = slice.len() / mem::size_of::<DocumentId>();
+        let len = slice.len() / size_of::<DocumentId>();
         let slice = unsafe { from_raw_parts(ptr, len) };
         Set::new_unchecked(slice)
     }
diff --git a/src/data/doc_indexes.rs b/src/data/doc_indexes.rs
index 21627cb0d..b760765bf 100644
--- a/src/data/doc_indexes.rs
+++ b/src/data/doc_indexes.rs
@@ -1,5 +1,5 @@
+use std::io::{self, Write, Cursor, BufRead};
 use std::slice::from_raw_parts;
-use std::io::{self, Write};
 use std::mem::size_of;
 use std::ops::Index;
 use std::sync::Arc;
@@ -9,6 +9,7 @@ use sdset::Set;
 
 use crate::DocIndex;
 use crate::data::SharedData;
+use super::into_u8_slice;
 
 #[derive(Debug)]
 #[repr(C)]
@@ -24,40 +25,36 @@ pub struct DocIndexes {
 }
 
 impl DocIndexes {
-    pub fn from_bytes(vec: Vec<u8>) -> io::Result<DocIndexes> {
-        let len = vec.len();
-        DocIndexes::from_shared_bytes(Arc::new(vec), 0, len)
+    pub fn from_bytes(bytes: Vec<u8>) -> io::Result<DocIndexes> {
+        let bytes = Arc::new(bytes);
+        let len = bytes.len();
+        let data = SharedData::new(bytes, 0, len);
+        let mut  cursor = Cursor::new(data);
+        DocIndexes::from_cursor(&mut cursor)
     }
 
-    pub fn from_shared_bytes(bytes: Arc<Vec<u8>>, offset: usize, len: usize) -> io::Result<DocIndexes> {
-        let data = SharedData { bytes, offset, len };
-        DocIndexes::from_data(data)
-    }
+    pub fn from_cursor(cursor: &mut Cursor<SharedData>) -> io::Result<DocIndexes> {
+        let len = cursor.read_u64::<LittleEndian>()? as usize;
+        let offset = cursor.position() as usize;
+        let ranges = cursor.get_ref().range(offset, len);
+        cursor.consume(len);
 
-    fn from_data(data: SharedData) -> io::Result<DocIndexes> {
-        let ranges_len_offset = data.len() - size_of::<u64>();
-        let ranges_len = (&data[ranges_len_offset..]).read_u64::<LittleEndian>()?;
-        let ranges_len = ranges_len as usize;
-
-        let ranges_offset = ranges_len_offset - ranges_len;
-        let ranges = data.range(ranges_offset, ranges_len);
-
-        let indexes = data.range(0, ranges_offset);
+        let len = cursor.read_u64::<LittleEndian>()? as usize;
+        let offset = cursor.position() as usize;
+        let indexes = cursor.get_ref().range(offset, len);
+        cursor.consume(len);
 
         Ok(DocIndexes { ranges, indexes })
     }
 
     pub fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
         let ranges_len = self.ranges.len() as u64;
-        let indexes_len = self.indexes.len() as u64;
-        let u64_size = size_of::<u64>() as u64;
-        let len = indexes_len + ranges_len + u64_size;
-
-        let _ = bytes.write_u64::<LittleEndian>(len);
-
-        bytes.extend_from_slice(&self.indexes);
-        bytes.extend_from_slice(&self.ranges);
         let _ = bytes.write_u64::<LittleEndian>(ranges_len);
+        bytes.extend_from_slice(&self.ranges);
+
+        let indexes_len = self.indexes.len() as u64;
+        let _ = bytes.write_u64::<LittleEndian>(indexes_len);
+        bytes.extend_from_slice(&self.indexes);
     }
 
     pub fn get(&self, index: usize) -> Option<&Set<DocIndex>> {
@@ -97,12 +94,17 @@ impl Index<usize> for DocIndexes {
 
 pub struct DocIndexesBuilder<W> {
     ranges: Vec<Range>,
+    indexes: Vec<DocIndex>,
     wtr: W,
 }
 
 impl DocIndexesBuilder<Vec<u8>> {
     pub fn memory() -> Self {
-        DocIndexesBuilder::new(Vec::new())
+        DocIndexesBuilder {
+            ranges: Vec::new(),
+            indexes: Vec::new(),
+            wtr: Vec::new(),
+        }
     }
 }
 
@@ -110,19 +112,18 @@ impl<W: Write> DocIndexesBuilder<W> {
     pub fn new(wtr: W) -> Self {
         DocIndexesBuilder {
             ranges: Vec::new(),
+            indexes: Vec::new(),
             wtr: wtr,
         }
     }
 
-    pub fn insert(&mut self, indexes: &Set<DocIndex>) -> io::Result<()> {
+    pub fn insert(&mut self, indexes: &Set<DocIndex>) {
         let len = indexes.len() as u64;
         let start = self.ranges.last().map(|r| r.end).unwrap_or(0);
         let range = Range { start, end: start + len };
         self.ranges.push(range);
 
-        // write the values
-        let indexes = unsafe { into_u8_slice(indexes) };
-        self.wtr.write_all(indexes)
+        self.indexes.extend_from_slice(indexes);
     }
 
     pub fn finish(self) -> io::Result<()> {
@@ -130,24 +131,20 @@ impl<W: Write> DocIndexesBuilder<W> {
     }
 
     pub fn into_inner(mut self) -> io::Result<W> {
-        // write the ranges
-        let ranges = unsafe { into_u8_slice(self.ranges.as_slice()) };
-        self.wtr.write_all(ranges)?;
-
-        // write the length of the ranges
+        let ranges = unsafe { into_u8_slice(&self.ranges) };
         let len = ranges.len() as u64;
         self.wtr.write_u64::<LittleEndian>(len)?;
+        self.wtr.write_all(ranges)?;
+
+        let indexes = unsafe { into_u8_slice(&self.indexes) };
+        let len = indexes.len() as u64;
+        self.wtr.write_u64::<LittleEndian>(len)?;
+        self.wtr.write_all(indexes)?;
 
         Ok(self.wtr)
     }
 }
 
-unsafe fn into_u8_slice<T>(slice: &[T]) -> &[u8] {
-    let ptr = slice.as_ptr() as *const u8;
-    let len = slice.len() * size_of::<T>();
-    from_raw_parts(ptr, len)
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -177,9 +174,9 @@ mod tests {
 
         let mut builder = DocIndexesBuilder::memory();
 
-        builder.insert(Set::new(&[a])?)?;
-        builder.insert(Set::new(&[a, b, c])?)?;
-        builder.insert(Set::new(&[a, c])?)?;
+        builder.insert(Set::new(&[a])?);
+        builder.insert(Set::new(&[a, b, c])?);
+        builder.insert(Set::new(&[a, c])?);
 
         let bytes = builder.into_inner()?;
         let docs = DocIndexes::from_bytes(bytes)?;
@@ -212,18 +209,17 @@ mod tests {
 
         let mut builder = DocIndexesBuilder::memory();
 
-        builder.insert(Set::new(&[a])?)?;
-        builder.insert(Set::new(&[a, b, c])?)?;
-        builder.insert(Set::new(&[a, c])?)?;
+        builder.insert(Set::new(&[a])?);
+        builder.insert(Set::new(&[a, b, c])?);
+        builder.insert(Set::new(&[a, c])?);
 
         let builder_bytes = builder.into_inner()?;
         let docs = DocIndexes::from_bytes(builder_bytes.clone())?;
 
         let mut bytes = Vec::new();
         docs.write_to_bytes(&mut bytes);
-        let len = size_of::<u64>();
 
-        assert_eq!(builder_bytes, &bytes[len..]);
+        assert_eq!(builder_bytes, bytes);
 
         Ok(())
     }
diff --git a/src/data/mod.rs b/src/data/mod.rs
index 69888dfcf..0e0b0e2c4 100644
--- a/src/data/mod.rs
+++ b/src/data/mod.rs
@@ -1,26 +1,30 @@
 mod doc_ids;
 mod doc_indexes;
 
+use std::slice::from_raw_parts;
+use std::mem::size_of;
 use std::ops::Deref;
 use std::sync::Arc;
 
 pub use self::doc_ids::DocIds;
 pub use self::doc_indexes::{DocIndexes, DocIndexesBuilder};
 
-#[derive(Clone)]
-struct SharedData {
-    bytes: Arc<Vec<u8>>,
-    offset: usize,
-    len: usize,
+#[derive(Default, Clone)]
+pub struct SharedData {
+    pub bytes: Arc<Vec<u8>>,
+    pub offset: usize,
+    pub len: usize,
 }
 
 impl SharedData {
-    pub fn empty() -> SharedData {
-        SharedData {
-            bytes: Arc::default(),
-            offset: 0,
-            len: 0,
-        }
+    pub fn from_bytes(vec: Vec<u8>) -> SharedData {
+        let len = vec.len();
+        let bytes = Arc::new(vec);
+        SharedData::new(bytes, 0, len)
+    }
+
+    pub fn new(bytes: Arc<Vec<u8>>, offset: usize, len: usize) -> SharedData {
+        SharedData { bytes, offset, len }
     }
 
     pub fn range(&self, offset: usize, len: usize) -> SharedData {
@@ -33,12 +37,6 @@ impl SharedData {
     }
 }
 
-impl Default for SharedData {
-    fn default() -> SharedData {
-        SharedData::empty()
-    }
-}
-
 impl Deref for SharedData {
     type Target = [u8];
 
@@ -52,3 +50,9 @@ impl AsRef<[u8]> for SharedData {
         &self.bytes[self.offset..self.offset + self.len]
     }
 }
+
+unsafe fn into_u8_slice<T: Sized>(slice: &[T]) -> &[u8] {
+    let ptr = slice.as_ptr() as *const u8;
+    let len = slice.len() * size_of::<T>();
+    from_raw_parts(ptr, len)
+}
diff --git a/src/database/database.rs b/src/database/database.rs
index 9b3d76f15..225059300 100644
--- a/src/database/database.rs
+++ b/src/database/database.rs
@@ -7,7 +7,7 @@ use rocksdb::rocksdb::{Writable, Snapshot};
 use rocksdb::{DB, DBVector, MergeOperands};
 use crossbeam::atomic::ArcCell;
 
-use crate::database::index::{self, Index, Positive};
+use crate::database::index::Index;
 use crate::database::{DatabaseView, Update, Schema};
 use crate::database::{DATA_INDEX, DATA_SCHEMA};
 
@@ -86,7 +86,7 @@ impl Database {
             };
 
             let path = update.path().to_string_lossy();
-            let mut options = IngestExternalFileOptions::new();
+            let options = IngestExternalFileOptions::new();
             // options.move_files(move_update);
 
             let cf_handle = db.cf_handle("default").expect("\"default\" column family not found");
@@ -182,7 +182,6 @@ mod tests {
         };
 
         let database = Database::create(&rocksdb_path, schema.clone())?;
-        let tokenizer_builder = DefaultBuilder::new();
 
         let update_path = dir.path().join("update.sst");
 
@@ -201,11 +200,12 @@ mod tests {
 
         let docid0;
         let docid1;
-        let mut update = {
+        let update = {
+            let tokenizer_builder = DefaultBuilder::new();
             let mut builder = UpdateBuilder::new(update_path, schema);
 
-            docid0 = builder.update_document(&doc0).unwrap();
-            docid1 = builder.update_document(&doc1).unwrap();
+            docid0 = builder.update_document(&doc0, &tokenizer_builder)?;
+            docid1 = builder.update_document(&doc1, &tokenizer_builder)?;
 
             builder.build()?
         };
diff --git a/src/database/index/mod.rs b/src/database/index/mod.rs
index 0098c5fd2..f9964f1f5 100644
--- a/src/database/index/mod.rs
+++ b/src/database/index/mod.rs
@@ -4,18 +4,16 @@ mod positive;
 pub(crate) use self::negative::Negative;
 pub(crate) use self::positive::{Positive, PositiveBuilder};
 
-use std::sync::Arc;
 use std::error::Error;
-use std::io::{Cursor, BufRead};
+use std::io::Cursor;
+use std::sync::Arc;
 
-use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use fst::{IntoStreamer, Streamer};
 use sdset::duo::DifferenceByKey;
 use sdset::{Set, SetOperation};
-use fst::raw::Fst;
 use fst::Map;
 
-use crate::data::{DocIds, DocIndexes};
+use crate::data::{SharedData, DocIndexes};
 
 #[derive(Default)]
 pub struct Index {
@@ -35,8 +33,11 @@ impl Index {
         len: usize,
     ) -> Result<Index, Box<Error>>
     {
-        let (negative, neg_offset) = Negative::from_shared_bytes(bytes.clone(), offset, len)?;
-        let (positive, _) = Positive::from_shared_bytes(bytes, offset + neg_offset, len)?;
+        let data = SharedData::new(bytes, offset, len);
+        let mut cursor = Cursor::new(data);
+
+        let negative = Negative::from_cursor(&mut cursor)?;
+        let positive = Positive::from_cursor(&mut cursor)?;
         Ok(Index { negative, positive })
     }
 
@@ -71,7 +72,7 @@ impl Index {
             let (map, indexes) = builder.into_inner()?;
             let map = Map::from_bytes(map)?;
             let indexes = DocIndexes::from_bytes(indexes)?;
-            Positive { map, indexes }
+            Positive::new(map, indexes)
         };
 
         let negative = Negative::default();
diff --git a/src/database/index/negative.rs b/src/database/index/negative.rs
index e9c30abfc..822c99d20 100644
--- a/src/database/index/negative.rs
+++ b/src/database/index/negative.rs
@@ -1,46 +1,36 @@
-use std::io::{Cursor, BufRead};
 use std::error::Error;
-use std::mem::size_of;
+use std::io::Cursor;
 use std::ops::Deref;
-use std::sync::Arc;
 
 use sdset::Set;
-use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
+use byteorder::{LittleEndian, WriteBytesExt};
 
+use crate::data::SharedData;
 use crate::data::DocIds;
 use crate::DocumentId;
 
 #[derive(Default)]
-pub struct Negative {
-    pub doc_ids: DocIds,
-}
+pub struct Negative(DocIds);
 
 impl Negative {
-    pub fn from_shared_bytes(
-        bytes: Arc<Vec<u8>>,
-        offset: usize,
-        len: usize,
-    ) -> Result<(Negative, usize), Box<Error>>
-    {
-        let mut cursor = Cursor::new(&bytes[..len]);
-        cursor.consume(offset);
+    pub fn new(doc_ids: DocIds) -> Negative {
+        Negative(doc_ids)
+    }
 
-        let len = cursor.read_u64::<LittleEndian>()? as usize;
-        let offset = cursor.position() as usize;
-        let doc_ids = DocIds::from_shared_bytes(bytes, offset, len)?;
-
-        Ok((Negative { doc_ids }, offset + len))
+    pub fn from_cursor(cursor: &mut Cursor<SharedData>) -> Result<Negative, Box<Error>> {
+        let doc_ids = DocIds::from_cursor(cursor)?;
+        Ok(Negative(doc_ids))
     }
 
     pub fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
-        let slice = self.doc_ids.as_bytes();
+        let slice = self.0.as_bytes();
         let len = slice.len() as u64;
         let _ = bytes.write_u64::<LittleEndian>(len);
         bytes.extend_from_slice(slice);
     }
 
     pub fn is_empty(&self) -> bool {
-        self.doc_ids.doc_ids().is_empty()
+        self.0.is_empty()
     }
 }
 
@@ -48,6 +38,6 @@ impl Deref for Negative {
     type Target = Set<DocumentId>;
 
     fn deref(&self) -> &Self::Target {
-        self.doc_ids.doc_ids()
+        self.0.as_ref()
     }
 }
diff --git a/src/database/index/positive.rs b/src/database/index/positive.rs
index f72cb94de..d6c3bf3d5 100644
--- a/src/database/index/positive.rs
+++ b/src/database/index/positive.rs
@@ -1,7 +1,5 @@
 use std::io::{Write, BufRead, Cursor};
-use std::mem::size_of;
 use std::error::Error;
-use std::sync::Arc;
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use fst::{map, Map, Streamer, IntoStreamer};
@@ -10,51 +8,51 @@ use sdset::duo::Union;
 use fst::raw::Fst;
 
 use crate::data::{DocIndexes, DocIndexesBuilder};
+use crate::data::SharedData;
 use crate::DocIndex;
 
 #[derive(Default)]
 pub struct Positive {
-    pub map: Map,
-    pub indexes: DocIndexes,
+    map: Map,
+    indexes: DocIndexes,
 }
 
 impl Positive {
-    pub fn from_shared_bytes(
-        bytes: Arc<Vec<u8>>,
-        offset: usize,
-        len: usize,
-    ) -> Result<(Positive, usize), Box<Error>>
-    {
-        let mut cursor = Cursor::new(&bytes[..len]);
-        cursor.consume(offset);
+    pub fn new(map: Map, indexes: DocIndexes) -> Positive {
+        Positive { map, indexes }
+    }
 
-        let map_len = cursor.read_u64::<LittleEndian>()? as usize;
-        let map_offset = cursor.position() as usize;
-        let fst = Fst::from_shared_bytes(bytes.clone(), map_offset, map_len)?;
+    pub fn from_cursor(cursor: &mut Cursor<SharedData>) -> Result<Positive, Box<Error>> {
+        let len = cursor.read_u64::<LittleEndian>()? as usize;
+        let offset = cursor.position() as usize;
+        let data = cursor.get_ref().range(offset, len);
+
+        let fst = Fst::from_shared_bytes(data.bytes, data.offset, data.len)?;
         let map = Map::from(fst);
+        cursor.consume(len);
 
-        cursor.consume(map_len);
-        let indexes_len = cursor.read_u64::<LittleEndian>()? as usize;
-        let indexes_offset = cursor.position() as usize;
-        let indexes = DocIndexes::from_shared_bytes(bytes, indexes_offset, indexes_len)?;
+        let indexes = DocIndexes::from_cursor(cursor)?;
 
-        let positive = Positive { map, indexes };
-        let len = indexes_offset + indexes_len;
-
-        Ok((positive, len))
+        Ok(Positive { map, indexes})
     }
 
     pub fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
-        // indexes
         let slice = self.map.as_fst().as_bytes();
         let len = slice.len() as u64;
         let _ = bytes.write_u64::<LittleEndian>(len);
         bytes.extend_from_slice(slice);
 
-        // map
         self.indexes.write_to_bytes(bytes);
     }
 
+    pub fn map(&self) -> &Map {
+        &self.map
+    }
+
+    pub fn indexes(&self) -> &DocIndexes {
+        &self.indexes
+    }
+
     pub fn union(&self, other: &Positive) -> Result<Positive, Box<Error>> {
         let mut builder = PositiveBuilder::memory();
         let mut stream = map::OpBuilder::new().add(&self.map).add(&other.map).union();
@@ -155,15 +153,11 @@ impl<W: Write, X: Write> PositiveBuilder<W, X> {
     where K: AsRef<[u8]>,
     {
         self.map.insert(key, self.value)?;
-        self.indexes.insert(indexes)?;
+        self.indexes.insert(indexes);
         self.value += 1;
         Ok(())
     }
 
-    pub fn finish(self) -> Result<(), Box<Error>> {
-        self.into_inner().map(drop)
-    }
-
     pub fn into_inner(self) -> Result<(W, X), Box<Error>> {
         let map = self.map.into_inner()?;
         let indexes = self.indexes.into_inner()?;
diff --git a/src/database/schema.rs b/src/database/schema.rs
index 5f622e003..60a258824 100644
--- a/src/database/schema.rs
+++ b/src/database/schema.rs
@@ -141,10 +141,12 @@ impl Schema {
         attributes
     }
 
-    pub fn document_id<T>(&self, document: &T) -> Result<DocumentId, Box<Error>>
+    pub fn document_id<T>(&self, document: T) -> Result<DocumentId, SerializerError>
     where T: Serialize,
     {
-        unimplemented!()
+        let id_attribute_name = &self.inner.identifier;
+        let serializer = FindDocumentIdSerializer { id_attribute_name };
+        document.serialize(serializer)
     }
 
     pub fn props(&self, attr: SchemaAttr) -> SchemaProps {
diff --git a/src/database/serde/indexer_serializer.rs b/src/database/serde/indexer_serializer.rs
index bfb0118ed..0bfb6e44a 100644
--- a/src/database/serde/indexer_serializer.rs
+++ b/src/database/serde/indexer_serializer.rs
@@ -1,4 +1,4 @@
-use crate::database::update::UnorderedPositiveBlobBuilder;
+use crate::database::update::RawUpdateBuilder;
 use crate::database::schema::SchemaAttr;
 use crate::database::serde::SerializerError;
 use crate::tokenizer::TokenizerBuilder;
@@ -10,7 +10,7 @@ use serde::ser;
 
 pub struct IndexerSerializer<'a, B> {
     pub tokenizer_builder: &'a B,
-    pub builder: &'a mut UnorderedPositiveBlobBuilder<Vec<u8>, Vec<u8>>,
+    pub builder: &'a mut RawUpdateBuilder,
     pub document_id: DocumentId,
     pub attribute: SchemaAttr,
 }
@@ -72,10 +72,10 @@ where B: TokenizerBuilder
             // and the unidecoded lowercased version
             let word_unidecoded = unidecode::unidecode(word).to_lowercase();
             if word_lower != word_unidecoded {
-                self.builder.insert(word_unidecoded, doc_index);
+                self.builder.insert_doc_index(word_unidecoded.into_bytes(), doc_index);
             }
 
-            self.builder.insert(word_lower, doc_index);
+            self.builder.insert_doc_index(word_lower.into_bytes(), doc_index);
         }
         Ok(())
     }
diff --git a/src/database/serde/serializer.rs b/src/database/serde/serializer.rs
index d2faed2db..48c58fd0d 100644
--- a/src/database/serde/serializer.rs
+++ b/src/database/serde/serializer.rs
@@ -1,24 +1,20 @@
-use std::collections::BTreeMap;
-
 use serde::Serialize;
 use serde::ser;
 
 use crate::database::serde::indexer_serializer::IndexerSerializer;
 use crate::database::serde::key_to_string::KeyToStringSerializer;
-use crate::database::update::UnorderedPositiveBlobBuilder;
 use crate::database::document_key::DocumentKeyAttr;
-use crate::database::update::NewState;
-use crate::database::Schema;
+use crate::database::update::RawUpdateBuilder;
 use crate::database::serde::SerializerError;
 use crate::tokenizer::TokenizerBuilder;
+use crate::database::schema::Schema;
 use crate::DocumentId;
 
 pub struct Serializer<'a, B> {
     pub schema: &'a Schema,
-    pub tokenizer_builder: &'a B,
     pub document_id: DocumentId,
-    pub builder: &'a mut UnorderedPositiveBlobBuilder<Vec<u8>, Vec<u8>>,
-    pub new_states: &'a mut BTreeMap<DocumentKeyAttr, NewState>,
+    pub tokenizer_builder: &'a B,
+    pub builder: &'a mut RawUpdateBuilder,
 }
 
 impl<'a, B> ser::Serializer for Serializer<'a, B>
@@ -145,7 +141,6 @@ where B: TokenizerBuilder
             document_id: self.document_id,
             current_key_name: None,
             builder: self.builder,
-            new_states: self.new_states,
         })
     }
 
@@ -160,7 +155,6 @@ where B: TokenizerBuilder
             tokenizer_builder: self.tokenizer_builder,
             document_id: self.document_id,
             builder: self.builder,
-            new_states: self.new_states,
         })
     }
 
@@ -181,8 +175,7 @@ pub struct MapSerializer<'a, B> {
     pub tokenizer_builder: &'a B,
     pub document_id: DocumentId,
     pub current_key_name: Option<String>,
-    pub builder: &'a mut UnorderedPositiveBlobBuilder<Vec<u8>, Vec<u8>>,
-    pub new_states: &'a mut BTreeMap<DocumentKeyAttr, NewState>,
+    pub builder: &'a mut RawUpdateBuilder,
 }
 
 impl<'a, B> ser::SerializeMap for MapSerializer<'a, B>
@@ -220,7 +213,7 @@ where B: TokenizerBuilder
             if props.is_stored() {
                 let value = bincode::serialize(value).unwrap();
                 let key = DocumentKeyAttr::new(self.document_id, attr);
-                self.new_states.insert(key, NewState::Updated { value });
+                self.builder.insert_attribute_value(key, value);
             }
             if props.is_indexed() {
                 let serializer = IndexerSerializer {
@@ -243,10 +236,9 @@ where B: TokenizerBuilder
 
 pub struct StructSerializer<'a, B> {
     pub schema: &'a Schema,
-    pub tokenizer_builder: &'a B,
     pub document_id: DocumentId,
-    pub builder: &'a mut UnorderedPositiveBlobBuilder<Vec<u8>, Vec<u8>>,
-    pub new_states: &'a mut BTreeMap<DocumentKeyAttr, NewState>,
+    pub tokenizer_builder: &'a B,
+    pub builder: &'a mut RawUpdateBuilder,
 }
 
 impl<'a, B> ser::SerializeStruct for StructSerializer<'a, B>
@@ -267,7 +259,7 @@ where B: TokenizerBuilder
             if props.is_stored() {
                 let value = bincode::serialize(value).unwrap();
                 let key = DocumentKeyAttr::new(self.document_id, attr);
-                self.new_states.insert(key, NewState::Updated { value });
+                self.builder.insert_attribute_value(key, value);
             }
             if props.is_indexed() {
                 let serializer = IndexerSerializer {
diff --git a/src/database/update/builder.rs b/src/database/update/builder.rs
index c3bdf59fc..344eb84e4 100644
--- a/src/database/update/builder.rs
+++ b/src/database/update/builder.rs
@@ -1,95 +1,60 @@
-use std::collections::{BTreeMap, BTreeSet};
 use std::path::PathBuf;
 use std::error::Error;
 
-use fst::map::{Map, MapBuilder};
-use rocksdb::rocksdb_options;
 use serde::Serialize;
-use sdset::Set;
 
-use crate::database::index::{Index, Positive, PositiveBuilder, Negative};
-use crate::database::{DATA_INDEX, Schema, DocumentKeyAttr};
-use crate::data::{DocIds, DocIndexes};
-use crate::{DocumentId, DocIndex};
-use super::Update;
+use crate::database::serde::serializer::Serializer;
+use crate::database::serde::SerializerError;
+use crate::tokenizer::TokenizerBuilder;
+use crate::database::Schema;
 
-type Token = Vec<u8>; // TODO could be replaced by a SmallVec
-type Value = Vec<u8>;
+use crate::DocumentId;
+use super::{Update, RawUpdateBuilder};
 
 pub struct UpdateBuilder {
-    sst_file: PathBuf,
     schema: Schema,
-    removed_documents: BTreeSet<DocumentId>,
-    words_indexes: BTreeMap<Token, Vec<DocIndex>>,
-    keys_values: BTreeMap<DocumentKeyAttr, Value>,
+    raw_builder: RawUpdateBuilder,
 }
 
 impl UpdateBuilder {
     pub fn new(path: PathBuf, schema: Schema) -> UpdateBuilder {
         UpdateBuilder {
-            sst_file: path,
             schema: schema,
-            removed_documents: BTreeSet::new(),
-            words_indexes: BTreeMap::new(),
-            keys_values: BTreeMap::new(),
+            raw_builder: RawUpdateBuilder::new(path),
         }
     }
 
-    pub fn update_document<T>(&mut self, document: T) -> Result<DocumentId, Box<Error>>
+    pub fn update_document<T, B>(
+        &mut self,
+        document: T,
+        tokenizer_builder: &B,
+    ) -> Result<DocumentId, SerializerError>
     where T: Serialize,
+          B: TokenizerBuilder,
     {
-        unimplemented!()
+        let document_id = self.schema.document_id(&document)?;
+
+        let serializer = Serializer {
+            schema: &self.schema,
+            document_id: document_id,
+            tokenizer_builder: tokenizer_builder,
+            builder: &mut self.raw_builder,
+        };
+
+        document.serialize(serializer)?;
+
+        Ok(document_id)
     }
 
-    pub fn remove_document<T>(&mut self, document: T) -> Result<DocumentId, Box<Error>>
+    pub fn remove_document<T>(&mut self, document: T) -> Result<DocumentId, SerializerError>
     where T: Serialize,
     {
-        unimplemented!()
+        let document_id = self.schema.document_id(&document)?;
+        self.raw_builder.remove_document(document_id);
+        Ok(document_id)
     }
 
     pub fn build(self) -> Result<Update, Box<Error>> {
-        let tree = {
-            let negative = {
-                let documents_ids = self.removed_documents.into_iter().collect();
-                let doc_ids = DocIds::from_raw(documents_ids);
-                Negative { doc_ids }
-            };
-
-            let positive = {
-                let mut builder = PositiveBuilder::memory();
-
-                for (key, mut indexes) in self.words_indexes {
-                    indexes.sort_unstable();
-                    let indexes = Set::new_unchecked(&indexes);
-                    builder.insert(key, indexes);
-                }
-
-                let (map, indexes) = builder.into_inner()?;
-                let map = Map::from_bytes(map)?;
-                let indexes = DocIndexes::from_bytes(indexes)?;
-                Positive { map, indexes }
-            };
-
-            Index { negative, positive }
-        };
-
-        let env_options = rocksdb_options::EnvOptions::new();
-        let column_family_options = rocksdb_options::ColumnFamilyOptions::new();
-        let mut file_writer = rocksdb::SstFileWriter::new(env_options, column_family_options);
-        file_writer.open(&self.sst_file.to_string_lossy())?;
-
-        // write the data-index
-        let mut bytes = Vec::new();
-        tree.write_to_bytes(&mut bytes);
-        file_writer.merge(DATA_INDEX, &bytes)?;
-
-        // write all the documents attributes updates
-        for (key, value) in self.keys_values {
-            file_writer.put(key.as_ref(), &value)?;
-        }
-
-        file_writer.finish()?;
-
-        Ok(Update { sst_file: self.sst_file })
+        self.raw_builder.build()
     }
 }
diff --git a/src/database/update/mod.rs b/src/database/update/mod.rs
index 7bdda9949..3e3eb8cca 100644
--- a/src/database/update/mod.rs
+++ b/src/database/update/mod.rs
@@ -1,8 +1,10 @@
 use std::path::{Path, PathBuf};
 
 mod builder;
+mod raw_builder;
 
 pub use self::builder::UpdateBuilder;
+pub use self::raw_builder::RawUpdateBuilder;
 
 pub struct Update {
     sst_file: PathBuf,
diff --git a/src/database/update/raw_builder.rs b/src/database/update/raw_builder.rs
new file mode 100644
index 000000000..e7e65a5fc
--- /dev/null
+++ b/src/database/update/raw_builder.rs
@@ -0,0 +1,93 @@
+use std::collections::{BTreeMap, BTreeSet};
+use std::path::PathBuf;
+use std::error::Error;
+
+use rocksdb::rocksdb_options;
+use fst::map::Map;
+use sdset::Set;
+
+use crate::database::index::{Index, Positive, PositiveBuilder, Negative};
+use crate::database::{DATA_INDEX, DocumentKeyAttr};
+use crate::data::{DocIds, DocIndexes};
+use crate::{DocumentId, DocIndex};
+use super::Update;
+
+type Token = Vec<u8>; // TODO could be replaced by a SmallVec
+type Value = Vec<u8>;
+
+pub struct RawUpdateBuilder {
+    sst_file: PathBuf,
+    removed_documents: BTreeSet<DocumentId>,
+    words_indexes: BTreeMap<Token, Vec<DocIndex>>,
+    keys_values: BTreeMap<DocumentKeyAttr, Value>,
+}
+
+impl RawUpdateBuilder {
+    pub fn new(path: PathBuf) -> RawUpdateBuilder {
+        RawUpdateBuilder {
+            sst_file: path,
+            removed_documents: BTreeSet::new(),
+            words_indexes: BTreeMap::new(),
+            keys_values: BTreeMap::new(),
+        }
+    }
+
+    pub fn insert_doc_index(&mut self, token: Vec<u8>, doc_index: DocIndex) {
+        self.words_indexes.entry(token).or_insert_with(Vec::new).push(doc_index)
+    }
+
+    pub fn insert_attribute_value(&mut self, key_attr: DocumentKeyAttr, value: Vec<u8>) -> Option<Vec<u8>> {
+        self.keys_values.insert(key_attr, value)
+    }
+
+    pub fn remove_document(&mut self, id: DocumentId) {
+        self.removed_documents.insert(id);
+    }
+
+    pub fn build(self) -> Result<Update, Box<Error>> {
+        let tree = {
+            let negative = {
+                let documents_ids: Vec<_> = self.removed_documents.into_iter().collect();
+                let documents_ids = Set::new_unchecked(&documents_ids);
+                let doc_ids = DocIds::new(documents_ids);
+                Negative::new(doc_ids)
+            };
+
+            let positive = {
+                let mut builder = PositiveBuilder::memory();
+
+                for (key, mut indexes) in self.words_indexes {
+                    indexes.sort_unstable();
+                    let indexes = Set::new_unchecked(&indexes);
+                    builder.insert(key, indexes)?;
+                }
+
+                let (map, indexes) = builder.into_inner()?;
+                let map = Map::from_bytes(map)?;
+                let indexes = DocIndexes::from_bytes(indexes)?;
+                Positive::new(map, indexes)
+            };
+
+            Index { negative, positive }
+        };
+
+        let env_options = rocksdb_options::EnvOptions::new();
+        let column_family_options = rocksdb_options::ColumnFamilyOptions::new();
+        let mut file_writer = rocksdb::SstFileWriter::new(env_options, column_family_options);
+        file_writer.open(&self.sst_file.to_string_lossy())?;
+
+        // write the data-index
+        let mut bytes = Vec::new();
+        tree.write_to_bytes(&mut bytes);
+        file_writer.merge(DATA_INDEX, &bytes)?;
+
+        // write all the documents attributes updates
+        for (key, value) in self.keys_values {
+            file_writer.put(key.as_ref(), &value)?;
+        }
+
+        file_writer.finish()?;
+
+        Ok(Update { sst_file: self.sst_file })
+    }
+}
diff --git a/src/rank/query_builder.rs b/src/rank/query_builder.rs
index a5bbdf885..5e4ee0d11 100644
--- a/src/rank/query_builder.rs
+++ b/src/rank/query_builder.rs
@@ -86,7 +86,7 @@ where D: Deref<Target=DB>,
         let mut stream = {
             let mut op_builder = fst::map::OpBuilder::new();
             for automaton in &automatons {
-                let stream = self.view.index().positive.map.search(automaton);
+                let stream = self.view.index().positive.map().search(automaton);
                 op_builder.push(stream);
             }
             op_builder.union()
@@ -100,7 +100,7 @@ where D: Deref<Target=DB>,
                 let distance = automaton.eval(input).to_u8();
                 let is_exact = distance == 0 && input.len() == automaton.query_len();
 
-                let doc_indexes = &self.view.index().positive.indexes;
+                let doc_indexes = &self.view.index().positive.indexes();
                 let doc_indexes = &doc_indexes[iv.value as usize];
 
                 for doc_index in doc_indexes {