blip

src/core/skip.rs

@@ -1,5 +1,9 @@
 use std::io::Write;
 use std::io::BufWriter;
+use std::io::Read;
+use std::io::Cursor;
+use std::io::SeekFrom;
+use std::io::Seek;
 use core::DocId;
 use std::ops::DerefMut;
 use serde::Serialize;
@@ -10,9 +14,6 @@ use core::error;
 use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
 
 
-
-// writer
-
 struct LayerBuilder {
     period: usize,
     buffer: Vec<u8>,
@@ -69,7 +70,6 @@ pub struct SkipListBuilder {
     layers: Vec<LayerBuilder>,
 }
 
-
 enum InsertResult {
     SkipPointer(usize),
     NoNeedForSkip,
@@ -128,3 +128,47 @@ impl SkipListBuilder {
         Ok(())
     }
 }
+
+
+// ---------------------------
+
+
+struct Layer<R: Read + Seek> {
+    reader: R,
+    num_items: u32,
+}
+
+impl<R: Read + Seek + Clone> Layer<R> {
+    fn read(reader: &mut R) -> Layer<R> {
+        // TODO error handling?
+        let num_items = reader.read_u32::<BigEndian>().unwrap() as u32;
+        let num_bytes = reader.read_u32::<BigEndian>().unwrap() as u32;
+        let reader_clone = reader.clone();
+        reader.seek(SeekFrom::Current(num_bytes as i64));
+        Layer {
+            reader: reader_clone,
+            num_items: num_items,
+        }
+    }
+}
+
+pub struct SkipList<R: Read + Seek> {
+    layers: Vec<Layer<R>>,
+}
+
+impl<R: Read + Seek> SkipList<R> {
+
+    pub fn read(data: &[u8]) -> SkipList<Cursor<&[u8]>> {
+        let mut cursor = Cursor::new(data);
+        // TODO error handling?
+        let num_layers = cursor.read_u8().unwrap();
+        let mut layers = Vec::new();
+        for _ in (0..num_layers) {
+            layers.push(Layer::read(&mut cursor));
+        }
+        SkipList {
+            layers: layers
+        }
+    }
+
+}

tests/skip.rs

@@ -35,3 +35,16 @@ fn test_skip_list_builder() {
         assert_eq!(output[0], 3);
     }
 }
+
+
+#[test]
+fn test_skip_list_builder() {
+    {
+        let mut output: Vec<u8> = Vec::new();
+        let mut skip_list_builder: SkipListBuilder = SkipListBuilder::new(10);
+        skip_list_builder.insert(2, 3);
+        skip_list_builder.write::<Vec<u8>>(&mut output);
+        let skip_list = SkipList::read(output.as_slice());
+    }
+
+}