use less memory in builders (#132)

* complete builder rewrite for better memory behavior

* dedup while adding triples to the simple builder

* use archive store for the builder benchmarks

* change loop strategy for iterator

benches/builder/main.rs

@@ -12,7 +12,7 @@ use data::*;
 #[bench]
 fn build_empty_base_layer(b: &mut Bencher) {
     let dir = tempdir().unwrap();
-    let store = terminus_store::open_sync_directory_store(dir.path());
+    let store = terminus_store::open_sync_archive_store(dir.path(), 512);
 
     b.iter(|| {
         let builder = store.create_base_layer().unwrap();
@@ -23,7 +23,7 @@ fn build_empty_base_layer(b: &mut Bencher) {
 #[bench]
 fn build_base_layer_1000(b: &mut Bencher) {
     let dir = tempdir().unwrap();
-    let store = terminus_store::open_sync_directory_store(dir.path());
+    let store = terminus_store::open_sync_archive_store(dir.path(), 512);
 
     let seed = b"the quick brown fox jumped over ";
     let rand = StdRng::from_seed(*seed);
@@ -48,7 +48,7 @@ fn build_base_layer_1000(b: &mut Bencher) {
 #[bench]
 fn build_empty_child_layer_on_empty_base_layer(b: &mut Bencher) {
     let dir = tempdir().unwrap();
-    let store = terminus_store::open_sync_directory_store(dir.path());
+    let store = terminus_store::open_sync_archive_store(dir.path(), 512);
     let builder = store.create_base_layer().unwrap();
     let base_layer = builder.commit().unwrap();
 
@@ -61,7 +61,7 @@ fn build_empty_child_layer_on_empty_base_layer(b: &mut Bencher) {
 #[bench]
 fn build_nonempty_child_layer_on_empty_base_layer(b: &mut Bencher) {
     let dir = tempdir().unwrap();
-    let store = terminus_store::open_sync_directory_store(dir.path());
+    let store = terminus_store::open_sync_archive_store(dir.path(), 512);
     let builder = store.create_base_layer().unwrap();
     let base_layer = builder.commit().unwrap();
 
@@ -88,7 +88,7 @@ fn build_nonempty_child_layer_on_empty_base_layer(b: &mut Bencher) {
 #[bench]
 fn build_nonempty_child_layer_on_nonempty_base_layer(b: &mut Bencher) {
     let dir = tempdir().unwrap();
-    let store = terminus_store::open_sync_directory_store(dir.path());
+    let store = terminus_store::open_sync_archive_store(dir.path(), 512);
 
     let seed = b"the quick brown fox jumped over ";
     let rand = StdRng::from_seed(*seed);