Fixes and simplifies RocksDB store quads lookup

lib/src/store/rocksdb.rs

@@ -245,35 +245,29 @@ impl<'a> StoreConnection for RocksDbStoreConnection<'a> {
 }
 
 impl<'a> RocksDbStoreConnection<'a> {
-    fn quads(&self) -> Result<SPOGIndexIterator> {
-        let mut iter = self.store.db.raw_iterator_cf(self.spog_cf)?;
-        iter.seek_to_first();
-        Ok(SPOGIndexIterator { iter })
+    fn quads(&self) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.spog_quads(b"", EncodedQuadPattern::new(None, None, None, None))
     }
 
     fn quads_for_subject(
         &self,
         subject: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<SPOGIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.spog_cf)?;
-        iter.seek(&encode_term(subject)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: SPOGIndexIterator { iter },
-            filter: EncodedQuadPattern::new(Some(subject), None, None, None),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.spog_quads(
+            &encode_term(subject)?,
+            EncodedQuadPattern::new(Some(subject), None, None, None),
+        )
     }
 
     fn quads_for_subject_predicate(
         &self,
         subject: EncodedTerm,
         predicate: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<SPOGIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.spog_cf)?;
-        iter.seek(&encode_term_pair(subject, predicate)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: SPOGIndexIterator { iter },
-            filter: EncodedQuadPattern::new(Some(subject), Some(predicate), None, None),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.spog_quads(
+            &encode_term_pair(subject, predicate)?,
+            EncodedQuadPattern::new(Some(subject), Some(predicate), None, None),
+        )
     }
 
     fn quads_for_subject_predicate_object(
@@ -281,88 +275,74 @@ impl<'a> RocksDbStoreConnection<'a> {
         subject: EncodedTerm,
         predicate: EncodedTerm,
         object: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<SPOGIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.spog_cf)?;
-        iter.seek(&encode_term_triple(subject, predicate, object)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: SPOGIndexIterator { iter },
-            filter: EncodedQuadPattern::new(Some(subject), Some(predicate), Some(object), None),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.spog_quads(
+            &encode_term_triple(subject, predicate, object)?,
+            EncodedQuadPattern::new(Some(subject), Some(predicate), Some(object), None),
+        )
     }
 
     fn quads_for_subject_object(
         &self,
         subject: EncodedTerm,
         object: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<OSPGIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.spog_cf)?;
-        iter.seek(&encode_term_pair(object, subject)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: OSPGIndexIterator { iter },
-            filter: EncodedQuadPattern::new(Some(subject), None, Some(object), None),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.ospg_quads(
+            &encode_term_pair(object, subject)?,
+            EncodedQuadPattern::new(Some(subject), None, Some(object), None),
+        )
     }
 
     fn quads_for_predicate(
         &self,
         predicate: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<POSGIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.posg_cf)?;
-        iter.seek(&encode_term(predicate)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: POSGIndexIterator { iter },
-            filter: EncodedQuadPattern::new(None, Some(predicate), None, None),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.posg_quads(
+            &encode_term(predicate)?,
+            EncodedQuadPattern::new(None, Some(predicate), None, None),
+        )
     }
 
     fn quads_for_predicate_object(
         &self,
         predicate: EncodedTerm,
         object: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<POSGIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.spog_cf)?;
-        iter.seek(&encode_term_pair(predicate, object)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: POSGIndexIterator { iter },
-            filter: EncodedQuadPattern::new(None, Some(predicate), Some(object), None),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.posg_quads(
+            &encode_term_pair(predicate, object)?,
+            EncodedQuadPattern::new(None, Some(predicate), Some(object), None),
+        )
     }
 
     fn quads_for_object(
         &self,
         object: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<OSPGIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.ospg_cf)?;
-        iter.seek(&encode_term(object)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: OSPGIndexIterator { iter },
-            filter: EncodedQuadPattern::new(None, None, Some(object), None),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.ospg_quads(
+            &encode_term(object)?,
+            EncodedQuadPattern::new(None, None, Some(object), None),
+        )
     }
 
     fn quads_for_graph(
         &self,
         graph_name: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<GSPOIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.gspo_cf)?;
-        iter.seek(&encode_term(graph_name)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: GSPOIndexIterator { iter },
-            filter: EncodedQuadPattern::new(None, None, None, Some(graph_name)),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.gspo_quads(
+            &encode_term(graph_name)?,
+            EncodedQuadPattern::new(None, None, None, Some(graph_name)),
+        )
     }
 
     fn quads_for_subject_graph(
         &self,
         subject: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<GSPOIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.gspo_cf)?;
-        iter.seek(&encode_term_pair(graph_name, subject)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: GSPOIndexIterator { iter },
-            filter: EncodedQuadPattern::new(Some(subject), None, None, Some(graph_name)),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.gspo_quads(
+            &encode_term_pair(graph_name, subject)?,
+            EncodedQuadPattern::new(Some(subject), None, None, Some(graph_name)),
+        )
     }
 
     fn quads_for_subject_predicate_graph(
@@ -370,13 +350,11 @@ impl<'a> RocksDbStoreConnection<'a> {
         subject: EncodedTerm,
         predicate: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<GSPOIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.spog_cf)?;
-        iter.seek(&encode_term_triple(graph_name, subject, predicate)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: GSPOIndexIterator { iter },
-            filter: EncodedQuadPattern::new(Some(subject), Some(predicate), None, Some(graph_name)),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.gspo_quads(
+            &encode_term_triple(graph_name, subject, predicate)?,
+            EncodedQuadPattern::new(Some(subject), Some(predicate), None, Some(graph_name)),
+        )
     }
 
     fn quads_for_subject_object_graph(
@@ -384,26 +362,22 @@ impl<'a> RocksDbStoreConnection<'a> {
         subject: EncodedTerm,
         object: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<GOSPIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.gosp_cf)?;
-        iter.seek(&encode_term_triple(graph_name, object, subject)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: GOSPIndexIterator { iter },
-            filter: EncodedQuadPattern::new(Some(subject), None, Some(object), Some(graph_name)),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.gosp_quads(
+            &encode_term_triple(graph_name, object, subject)?,
+            EncodedQuadPattern::new(Some(subject), None, Some(object), Some(graph_name)),
+        )
     }
 
     fn quads_for_predicate_graph(
         &self,
         predicate: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<GPOSIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.gpos_cf)?;
-        iter.seek(&encode_term_pair(graph_name, predicate)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: GPOSIndexIterator { iter },
-            filter: EncodedQuadPattern::new(None, Some(predicate), None, Some(graph_name)),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.gpos_quads(
+            &encode_term_pair(graph_name, predicate)?,
+            EncodedQuadPattern::new(None, Some(predicate), None, Some(graph_name)),
+        )
     }
 
     fn quads_for_predicate_object_graph(
@@ -411,25 +385,114 @@ impl<'a> RocksDbStoreConnection<'a> {
         predicate: EncodedTerm,
         object: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<GPOSIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.gosp_cf)?;
-        iter.seek(&encode_term_triple(graph_name, predicate, object)?);
-        Ok(FilteringEncodedQuadsIterator {
-            iter: GPOSIndexIterator { iter },
-            filter: EncodedQuadPattern::new(None, Some(predicate), Some(object), Some(graph_name)),
-        })
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.gpos_quads(
+            &encode_term_triple(graph_name, predicate, object)?,
+            EncodedQuadPattern::new(None, Some(predicate), Some(object), Some(graph_name)),
+        )
     }
 
     fn quads_for_object_graph(
         &self,
         object: EncodedTerm,
         graph_name: EncodedTerm,
-    ) -> Result<FilteringEncodedQuadsIterator<GOSPIndexIterator>> {
-        let mut iter = self.store.db.raw_iterator_cf(self.gosp_cf)?;
-        iter.seek(&encode_term_pair(graph_name, object)?);
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.gosp_quads(
+            &encode_term_pair(graph_name, object)?,
+            EncodedQuadPattern::new(None, None, Some(object), Some(graph_name)),
+        )
+    }
+
+    fn spog_quads(
+        &self,
+        start: &[u8],
+        filter: EncodedQuadPattern,
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.inner_quads(
+            self.spog_cf,
+            &start,
+            |buffer| Cursor::new(buffer).read_spog_quad(),
+            filter,
+        )
+    }
+
+    fn posg_quads(
+        &self,
+        start: &[u8],
+        filter: EncodedQuadPattern,
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.inner_quads(
+            self.posg_cf,
+            &start,
+            |buffer| Cursor::new(buffer).read_posg_quad(),
+            filter,
+        )
+    }
+
+    fn ospg_quads(
+        &self,
+        start: &[u8],
+        filter: EncodedQuadPattern,
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.inner_quads(
+            self.ospg_cf,
+            &start,
+            |buffer| Cursor::new(buffer).read_ospg_quad(),
+            filter,
+        )
+    }
+
+    fn gspo_quads(
+        &self,
+        start: &[u8],
+        filter: EncodedQuadPattern,
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.inner_quads(
+            self.gspo_cf,
+            &start,
+            |buffer| Cursor::new(buffer).read_gspo_quad(),
+            filter,
+        )
+    }
+
+    fn gpos_quads(
+        &self,
+        start: &[u8],
+        filter: EncodedQuadPattern,
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.inner_quads(
+            self.gpos_cf,
+            &start,
+            |buffer| Cursor::new(buffer).read_gpos_quad(),
+            filter,
+        )
+    }
+
+    fn gosp_quads(
+        &self,
+        start: &[u8],
+        filter: EncodedQuadPattern,
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        self.inner_quads(
+            self.gosp_cf,
+            &start,
+            |buffer| Cursor::new(buffer).read_gosp_quad(),
+            filter,
+        )
+    }
+
+    fn inner_quads(
+        &self,
+        cf: ColumnFamily,
+        start: &[u8],
+        decode: impl Fn(&[u8]) -> Result<EncodedQuad> + 'a,
+        filter: EncodedQuadPattern,
+    ) -> Result<impl Iterator<Item = Result<EncodedQuad>> + 'a> {
+        let mut iter = self.store.db.raw_iterator_cf(cf)?;
+        iter.seek(&start);
         Ok(FilteringEncodedQuadsIterator {
-            iter: GOSPIndexIterator { iter },
-            filter: EncodedQuadPattern::new(None, None, Some(object), Some(graph_name)),
+            iter: DecodingIndexIterator { iter, decode },
+            filter,
         })
     }
 }
@@ -617,110 +680,21 @@ fn encode_term_triple(t1: EncodedTerm, t2: EncodedTerm, t3: EncodedTerm) -> Resu
     Ok(vec)
 }
 
-struct GSPOIndexIterator<'a> {
+struct DecodingIndexIterator<'a, F: Fn(&[u8]) -> Result<EncodedQuad>> {
     iter: DBRawIterator<'a>,
+    decode: F,
 }
 
-impl<'a> Iterator for GSPOIndexIterator<'a> {
+impl<'a, F: Fn(&[u8]) -> Result<EncodedQuad>> Iterator for DecodingIndexIterator<'a, F> {
     type Item = Result<EncodedQuad>;
 
     fn next(&mut self) -> Option<Result<EncodedQuad>> {
-        self.iter.next();
-        unsafe {
-            //This is safe because we are not keeping the buffer
-            self.iter
-                .key_inner()
-                .map(|buffer| Cursor::new(buffer).read_gspo_quad())
-        }
-    }
-}
-
-struct GPOSIndexIterator<'a> {
-    iter: DBRawIterator<'a>,
-}
-
-impl<'a> Iterator for GPOSIndexIterator<'a> {
-    type Item = Result<EncodedQuad>;
-
-    fn next(&mut self) -> Option<Result<EncodedQuad>> {
-        self.iter.next();
-        unsafe {
-            //This is safe because we are not keeping the buffer
-            self.iter
-                .key_inner()
-                .map(|buffer| Cursor::new(buffer).read_gpos_quad())
-        }
-    }
-}
-
-struct GOSPIndexIterator<'a> {
-    iter: DBRawIterator<'a>,
-}
-
-impl<'a> Iterator for GOSPIndexIterator<'a> {
-    type Item = Result<EncodedQuad>;
-
-    fn next(&mut self) -> Option<Result<EncodedQuad>> {
-        self.iter.next();
-        unsafe {
-            //This is safe because we are not keeping the buffer
-            self.iter
-                .key_inner()
-                .map(|buffer| Cursor::new(buffer).read_gosp_quad())
-        }
-    }
-}
-
-struct SPOGIndexIterator<'a> {
-    iter: DBRawIterator<'a>,
-}
-
-impl<'a> Iterator for SPOGIndexIterator<'a> {
-    type Item = Result<EncodedQuad>;
-
-    fn next(&mut self) -> Option<Result<EncodedQuad>> {
-        self.iter.next();
-        unsafe {
-            //This is safe because we are not keeping the buffer
-            self.iter
-                .key_inner()
-                .map(|buffer| Cursor::new(buffer).read_spog_quad())
-        }
-    }
-}
-
-struct POSGIndexIterator<'a> {
-    iter: DBRawIterator<'a>,
-}
-
-impl<'a> Iterator for POSGIndexIterator<'a> {
-    type Item = Result<EncodedQuad>;
-
-    fn next(&mut self) -> Option<Result<EncodedQuad>> {
-        self.iter.next();
-        unsafe {
-            //This is safe because we are not keeping the buffer
-            self.iter
-                .key_inner()
-                .map(|buffer| Cursor::new(buffer).read_posg_quad())
-        }
-    }
-}
-
-struct OSPGIndexIterator<'a> {
-    iter: DBRawIterator<'a>,
-}
-
-impl<'a> Iterator for OSPGIndexIterator<'a> {
-    type Item = Result<EncodedQuad>;
-
-    fn next(&mut self) -> Option<Result<EncodedQuad>> {
-        self.iter.next();
-        unsafe {
-            //This is safe because we are not keeping the buffer
-            self.iter
-                .key_inner()
-                .map(|buffer| Cursor::new(buffer).read_ospg_quad())
+        if self.iter.valid() {
+            let result = unsafe { self.iter.key_inner().map(|buffer| (self.decode)(buffer)) };
+            self.iter.next();
+            result
+        } else {
+            None
         }
     }
 }
@@ -764,3 +738,116 @@ impl From<RocksString> for String {
         val.deref().to_owned()
     }
 }
+
+#[test]
+fn repository() -> Result<()> {
+    use crate::model::*;
+    use crate::repository::RepositoryConnection;
+    use rand::random;
+    use std::env::temp_dir;
+    use std::fs::remove_dir_all;
+
+    let main_s = NamedOrBlankNode::from(BlankNode::default());
+    let main_p = NamedNode::parse("http://example.com")?;
+    let main_o = Term::from(Literal::from(1));
+
+    let main_quad = Quad::new(main_s.clone(), main_p.clone(), main_o.clone(), None);
+
+    let mut repo_path = temp_dir();
+    repo_path.push(random::<u128>().to_string());
+
+    {
+        let repository = RocksDbRepository::open(&repo_path)?;
+        let mut connection = repository.connection()?;
+        connection.insert(&main_quad)?;
+
+        let target = vec![main_quad];
+        assert_eq!(
+            connection
+                .quads_for_pattern(None, None, None, None)
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(Some(&main_s), None, None, None)
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(Some(&main_s), Some(&main_p), None, None)
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(Some(&main_s), Some(&main_p), Some(&main_o), None)
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(Some(&main_s), Some(&main_p), Some(&main_o), Some(None))
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(Some(&main_s), Some(&main_p), None, Some(None))
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(Some(&main_s), None, Some(&main_o), None)
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(Some(&main_s), None, Some(&main_o), Some(None))
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(Some(&main_s), None, None, Some(None))
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(None, Some(&main_p), None, None)
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(None, Some(&main_p), Some(&main_o), None)
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(None, None, Some(&main_o), None)
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(None, None, None, Some(None))
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+        assert_eq!(
+            connection
+                .quads_for_pattern(None, Some(&main_p), Some(&main_o), Some(None))
+                .collect::<Result<Vec<_>>>()?,
+            target
+        );
+    }
+
+    remove_dir_all(&repo_path)?;
+    Ok(())
+}