Introduce option flags to toggle the indexing engine

src/bin/indexer.rs

@@ -52,6 +52,14 @@ struct Opt {
     #[structopt(short, long)]
     jobs: Option<usize>,
 
+    /// MTBL max number of chunks in bytes.
+    #[structopt(long)]
+    max_nb_chunks: Option<usize>,
+
+    /// MTBL max memory in bytes.
+    #[structopt(long)]
+    max_memory: Option<usize>,
+
     /// Verbose mode (-v, -vv, -vvv, etc.)
     #[structopt(short, long, parse(from_occurrences))]
     verbose: usize,
@@ -60,6 +68,10 @@ struct Opt {
     csv_file: Option<PathBuf>,
 }
 
+fn lmdb_key_valid_size(key: &[u8]) -> bool {
+    !key.is_empty() && key.len() <= LMDB_MAX_KEY_LENGTH
+}
+
 type MergeFn = fn(&[u8], &[Vec<u8>]) -> Result<Vec<u8>, ()>;
 
 struct Store {
@@ -69,15 +81,23 @@ struct Store {
 }
 
 impl Store {
-    fn new() -> Store {
-        let sorter = Sorter::builder(merge as MergeFn)
-            .chunk_compression_type(CompressionType::Snappy)
-            .build();
+    fn new(max_nb_chunks: Option<usize>, max_memory: Option<usize>) -> Store {
+        let mut builder = Sorter::builder(merge as MergeFn);
+
+        builder.chunk_compression_type(CompressionType::Snappy);
+
+        if let Some(nb_chunks) = max_nb_chunks {
+            builder.max_nb_chunks(nb_chunks);
+        }
+
+        if let Some(memory) = max_memory {
+            builder.max_memory(memory);
+        }
 
         Store {
             word_positions: ArcCache::new(65_535),
             word_position_docids: ArcCache::new(65_535),
-            sorter,
+            sorter: builder.build(),
         }
     }
 
@@ -126,7 +146,9 @@ impl Store {
             buffer.clear();
             positions.serialize_into(&mut buffer)?;
             // that we write under the generated key into MTBL
-            sorter.insert(&key, &buffer)?;
+            if lmdb_key_valid_size(&key) {
+                sorter.insert(&key, &buffer)?;
+            }
         }
 
         Ok(())
@@ -149,7 +171,9 @@ impl Store {
             buffer.clear();
             ids.serialize_into(&mut buffer)?;
             // that we write under the generated key into MTBL
-            sorter.insert(&key, &buffer)?;
+            if lmdb_key_valid_size(&key) {
+                sorter.insert(&key, &buffer)?;
+            }
             // And cleanup the position afterward
             key.truncate(key.len() - position_bytes.len());
         }
@@ -288,11 +312,13 @@ fn index_csv(
     mut rdr: csv::Reader<File>,
     thread_index: usize,
     num_threads: usize,
+    max_nb_chunks: Option<usize>,
+    max_memory: Option<usize>,
 ) -> anyhow::Result<Reader<Mmap>>
 {
     debug!("{:?}: Indexing into an Indexed...", thread_index);
 
-    let mut store = Store::new();
+    let mut store = Store::new(max_nb_chunks, max_memory);
 
     // Write the headers into a Vec of bytes and then into the store.
     let headers = rdr.headers()?;
@@ -310,19 +336,16 @@ fn index_csv(
         if document_id % num_threads != thread_index { continue }
 
         let document_id = DocumentId::try_from(document_id).context("generated id is too big")?;
-
         if document_id % (ONE_MILLION as u32) == 0 {
             debug!("We have seen {}m documents so far.", document_id / ONE_MILLION as u32);
         }
 
         for (attr, content) in document.iter().enumerate().take(MAX_ATTRIBUTES) {
             for (pos, word) in simple_alphanumeric_tokens(&content).enumerate().take(MAX_POSITION) {
-                if !word.is_empty() && word.len() < LMDB_MAX_KEY_LENGTH {
-                    let word = word.cow_to_lowercase();
-                    let position = (attr * MAX_POSITION + pos) as u32;
-                    store.insert_word_position(&word, position)?;
-                    store.insert_word_position_docid(&word, position, document_id)?;
-                }
+                let word = word.cow_to_lowercase();
+                let position = (attr * MAX_POSITION + pos) as u32;
+                store.insert_word_position(&word, position)?;
+                store.insert_word_position_docid(&word, position, document_id)?;
             }
         }
 
@@ -407,6 +430,9 @@ fn main() -> anyhow::Result<()> {
 
     let num_threads = rayon::current_num_threads();
 
+    let max_nb_chunks = opt.max_nb_chunks;
+    let max_memory = opt.max_memory;
+
     // We duplicate the file # jobs times.
     let file = opt.csv_file.unwrap();
     let csv_readers: Vec<_> = (0..num_threads).map(|_| csv::Reader::from_path(&file)).collect::<Result<_, _>>()?;
@@ -414,7 +440,7 @@ fn main() -> anyhow::Result<()> {
     let stores: Vec<_> = csv_readers
         .into_par_iter()
         .enumerate()
-        .map(|(i, rdr)| index_csv(rdr, i, num_threads))
+        .map(|(i, rdr)| index_csv(rdr, i, num_threads, max_nb_chunks, max_memory))
         .collect::<Result<_, _>>()?;
 
     debug!("We are writing into LMDB...");