db random sort

1 files changed, 36 insertions, 2 deletions

diff --git a/database/src/kv/index.rs b/database/src/kv/index.rs
index 7a3a5b1..60d291c 100644
--- a/database/src/kv/index.rs
+++ b/database/src/kv/index.rs
@@ -15,6 +15,7 @@ use crate::{
 };
 use anyhow::Result;
 use jellyobject::Object;
+use std::iter::empty;
 
 pub fn update_index(
     txn: &mut dyn jellykv::Transaction,
@@ -37,6 +38,16 @@ pub fn update_index(
                 }
             }
         }
+        SortKey::Random => {
+            for mut k in ks {
+                k.extend(randomize(row).to_be_bytes());
+                if remove {
+                    txn.del(&k)?;
+                } else {
+                    txn.set(&k, &row.to_be_bytes())?;
+                }
+            }
+        }
         SortKey::Count => {
             for k in ks {
                 let mut c = read_counter(txn, &k, 0)?;
@@ -62,7 +73,7 @@ pub fn update_index(
                 }
             }
         }
-        SortKey::Text(path) => {}
+        SortKey::Text(_) => todo!(),
     }
     Ok(())
 }
@@ -91,6 +102,20 @@ pub fn iter_index<'a>(
                 })
             }),
         ),
+        Sort::Random(seed) => {
+            let mut k = prefix.clone();
+            k.extend(randomize(*seed).to_be_bytes());
+            let Some(it) = txn.iter(&k, false)?.next() else {
+                return Ok(Box::new(empty()));
+            };
+            let res = it?;
+            if !res.starts_with(&prefix) {
+                return Ok(Box::new(empty()));
+            }
+            let r = txn.get(&res)?.unwrap();
+            let row = RowNum::from_be_bytes(r.try_into().unwrap());
+            Box::new([Ok((row, vec![]))].into_iter())
+        }
         Sort::Value(value_sort) => {
             assert!(value_sort.offset.is_none(), "TODO");
             Box::new(
@@ -111,7 +136,7 @@ pub fn iter_index<'a>(
                 }),
             )
         }
-        Sort::TextSearch(path, _) => todo!(),
+        Sort::TextSearch(_, _) => todo!(),
     })
 }
 
@@ -125,3 +150,12 @@ fn prefix_end(mut prefix: Vec<u8>) -> Vec<u8> {
     }
     prefix
 }
+
+fn randomize(mut x: u64) -> u64 {
+    for _ in 0..15 {
+        x ^= x << 13;
+        x ^= x >> 7;
+        x ^= x << 17;
+    }
+    x
+}