From 439719732c636e3f4b0802a2bd97c5bea78e9d16 Mon Sep 17 00:00:00 2001
From: Tpt <thomas@pellissier-tanon.fr>
Date: Mon, 10 Sep 2018 14:42:45 +0200
Subject: [PATCH] Adds method to get the size of a Graph or a Dataset

---
 Cargo.toml         |  1 +
 src/store/mod.rs   |  8 ++++++++
 src/store/store.rs | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index 0e791141..2cd5faf6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,6 +20,7 @@ lazy_static = "1"
 rocksdb = "0.10"
 url = "1"
 uuid = { version = "0.6", features = ["v4"] }
+bzip2 = "0.3"
 byteorder = "1"
 
 [build-dependencies]
diff --git a/src/store/mod.rs b/src/store/mod.rs
index adec5b03..bd3fa28b 100644
--- a/src/store/mod.rs
+++ b/src/store/mod.rs
@@ -57,6 +57,10 @@ pub trait Graph {
     fn insert(&self, triple: &Triple) -> Result<()>;
 
     fn remove(&self, triple: &Triple) -> Result<()>;
+
+    fn len(&self) -> Result<usize>;
+
+    fn is_empty(&self) -> Result<bool>;
 }
 
 pub trait NamedGraph: Graph {
@@ -128,4 +132,8 @@ pub trait Dataset {
     fn insert(&self, quad: &Quad) -> Result<()>;
 
     fn remove(&self, quad: &Quad) -> Result<()>;
+
+    fn len(&self) -> Result<usize>;
+
+    fn is_empty(&self) -> Result<bool>;
 }
diff --git a/src/store/store.rs b/src/store/store.rs
index 7d4b37ce..280d1610 100644
--- a/src/store/store.rs
+++ b/src/store/store.rs
@@ -266,6 +266,14 @@ impl<S: EncodedQuadsStore> Dataset for StoreDataset<S> {
     fn remove(&self, quad: &Quad) -> Result<()> {
         self.store.remove(&self.store.encoder().encode_quad(quad)?)
     }
+
+    fn len(&self) -> Result<usize> {
+        Ok(self.store.quads()?.count())
+    }
+
+    fn is_empty(&self) -> Result<bool> {
+        Ok(self.store.quads()?.any(|_| true))
+    }
 }
 
 pub struct StoreNamedGraph<S: EncodedQuadsStore> {
@@ -403,6 +411,17 @@ impl<S: EncodedQuadsStore> Graph for StoreNamedGraph<S> {
                 .encode_triple_in_graph(triple, self.encoded_name.clone())?,
         )
     }
+
+    fn len(&self) -> Result<usize> {
+        Ok(self.store.quads_for_graph(&self.encoded_name)?.count())
+    }
+
+    fn is_empty(&self) -> Result<bool> {
+        Ok(self
+            .store
+            .quads_for_graph(&self.encoded_name)?
+            .any(|_| true))
+    }
 }
 
 impl<S: EncodedQuadsStore> NamedGraph for StoreNamedGraph<S> {
@@ -530,6 +549,14 @@ impl<S: EncodedQuadsStore> Graph for StoreDefaultGraph<S> {
         self.store
             .remove(&self.store.encoder().encode_triple_in_graph(triple, None)?)
     }
+
+    fn len(&self) -> Result<usize> {
+        Ok(self.store.quads_for_graph(&None)?.count())
+    }
+
+    fn is_empty(&self) -> Result<bool> {
+        Ok(self.store.quads_for_graph(&None)?.any(|_| true))
+    }
 }
 
 pub struct StoreUnionGraph<S: EncodedQuadsStore> {
@@ -650,6 +677,14 @@ impl<S: EncodedQuadsStore> Graph for StoreUnionGraph<S> {
     fn remove(&self, triple: &Triple) -> Result<()> {
         unimplemented!()
     }
+
+    fn len(&self) -> Result<usize> {
+        Ok(self.store.quads()?.count())
+    }
+
+    fn is_empty(&self) -> Result<bool> {
+        Ok(self.store.quads()?.any(|_| true))
+    }
 }
 
 pub struct DelegatingBytesStore<'a, S: 'a + BytesStore + Sized>(&'a S);