feat: new text embedding for sparse vector

Signed-off-by: cutecutecat <junyuchen@tensorchord.ai>

Author: cutecutecat

src/datatype/text_svecf32.rs

@@ -10,13 +10,13 @@ use std::ffi::{CStr, CString};
 
 #[pgrx::pg_extern(immutable, strict, parallel_safe)]
 fn _vectors_svecf32_in(input: &CStr, _oid: Oid, typmod: i32) -> SVecf32Output {
-    use crate::utils::parse::parse_vector;
+    use crate::utils::parse::parse_pgvector_svector;
     let reserve = Typmod::parse_from_i32(typmod)
         .unwrap()
         .dims()
         .map(|x| x.get())
         .unwrap_or(0);
-    let v = parse_vector(input.to_bytes(), reserve as usize, |s| {
+    let v = parse_pgvector_svector(input.to_bytes(), reserve as usize, |s| {
         s.parse::<F32>().ok()
     });
     match v {
@@ -40,16 +40,20 @@ fn _vectors_svecf32_in(input: &CStr, _oid: Oid, typmod: i32) -> SVecf32Output {
 
 #[pgrx::pg_extern(immutable, strict, parallel_safe)]
 fn _vectors_svecf32_out(vector: SVecf32Input<'_>) -> CString {
+    let dims = vector.for_borrow().dims();
     let mut buffer = String::new();
-    buffer.push('[');
-    let vec = vector.for_borrow().to_vec();
-    let mut iter = vec.iter();
-    if let Some(x) = iter.next() {
-        buffer.push_str(format!("{}", x).as_str());
-    }
-    for x in iter {
-        buffer.push_str(format!(", {}", x).as_str());
+    buffer.push('{');
+    let svec = vector.for_borrow();
+    let mut need_splitter = true;
+    for (&index, &value) in svec.indexes().iter().zip(svec.values().iter()) {
+        match need_splitter {
+            true => {
+                buffer.push_str(format!("{}:{}", index + 1, value).as_str());
+                need_splitter = false;
+            }
+            false => buffer.push_str(format!(", {}:{}", index + 1, value).as_str()),
+        }
     }
-    buffer.push(']');
+    buffer.push_str(format!("}}/{}", dims).as_str());
     CString::new(buffer).unwrap()
 }

src/utils/parse.rs

@@ -1,3 +1,4 @@
+use num_traits::Zero;
 use thiserror::Error;
 
 #[derive(Debug, Error)]
@@ -83,3 +84,105 @@ where
     }
     Ok(vector)
 }
+
+#[inline(always)]
+pub fn parse_pgvector_svector<T: Zero + Clone, F>(
+    input: &[u8],
+    reserve: usize,
+    f: F,
+) -> Result<Vec<T>, ParseVectorError>
+where
+    F: Fn(&str) -> Option<T>,
+{
+    use arrayvec::ArrayVec;
+    if input.is_empty() {
+        return Err(ParseVectorError::EmptyString {});
+    }
+    let left = 'a: {
+        for position in 0..input.len() - 1 {
+            match input[position] {
+                b'{' => break 'a position,
+                b' ' => continue,
+                _ => return Err(ParseVectorError::BadCharacter { position }),
+            }
+        }
+        return Err(ParseVectorError::BadParentheses { character: '{' });
+    };
+    let mut token: ArrayVec<u8, 48> = ArrayVec::new();
+    let mut capacity = reserve;
+    let right = 'a: {
+        for position in (1..input.len()).rev() {
+            match input[position] {
+                b'0'..=b'9' => {
+                    if token.try_push(input[position]).is_err() {
+                        return Err(ParseVectorError::TooLongNumber { position });
+                    }
+                }
+                b'/' => {
+                    token.reverse();
+                    let s = unsafe { std::str::from_utf8_unchecked(&token[..]) };
+                    capacity = s
+                        .parse::<usize>()
+                        .map_err(|_| ParseVectorError::BadParsing { position })?;
+                }
+                b'}' => {
+                    token.clear();
+                    break 'a position;
+                }
+                b' ' => continue,
+                _ => return Err(ParseVectorError::BadCharacter { position }),
+            }
+        }
+        return Err(ParseVectorError::BadParentheses { character: '}' });
+    };
+    let mut vector = vec![T::zero(); capacity];
+    let mut index: usize = 0;
+    for position in left + 1..right {
+        let c = input[position];
+        match c {
+            b'0'..=b'9' | b'a'..=b'z' | b'A'..=b'Z' | b'.' | b'+' | b'-' => {
+                if token.is_empty() {
+                    token.push(b'$');
+                }
+                if token.try_push(c).is_err() {
+                    return Err(ParseVectorError::TooLongNumber { position });
+                }
+            }
+            b',' => {
+                if !token.is_empty() {
+                    // Safety: all bytes in `token` are ascii characters
+                    let s = unsafe { std::str::from_utf8_unchecked(&token[1..]) };
+                    let num = f(s).ok_or(ParseVectorError::BadParsing { position })?;
+                    vector[index] = num;
+                    token.clear();
+                } else {
+                    return Err(ParseVectorError::TooShortNumber { position });
+                }
+            }
+            b':' => {
+                if !token.is_empty() {
+                    // Safety: all bytes in `token` are ascii characters
+                    let s = unsafe { std::str::from_utf8_unchecked(&token[1..]) };
+                    index = s
+                        .parse::<usize>()
+                        .map_err(|_| ParseVectorError::BadParsing { position })?
+                        - 1;
+                    token.clear();
+                } else {
+                    return Err(ParseVectorError::TooShortNumber { position });
+                }
+            }
+            b' ' => (),
+            _ => return Err(ParseVectorError::BadCharacter { position }),
+        }
+    }
+    if !token.is_empty() {
+        let position = right;
+        // Safety: all bytes in `token` are ascii characters
+        let s = unsafe { std::str::from_utf8_unchecked(&token[1..]) };
+        let num = f(s).ok_or(ParseVectorError::BadParsing { position })?;
+        vector[index] = num;
+        token.clear();
+    }
+    Ok(vector)
+}

tests/sqllogictest/sparse.slt

@@ -20,17 +20,17 @@ CREATE INDEX ON t USING vectors (val svector_cos_ops)
 WITH (options = "[indexing.hnsw]");
 
 query I
-SELECT COUNT(1) FROM (SELECT 1 FROM t ORDER BY val <-> '[0.5,0.5,0.5,0.5,0.5,0.5]'::svector limit 10) t2;
+SELECT COUNT(1) FROM (SELECT 1 FROM t ORDER BY val <-> '{1:3,2:1}/6'::svector limit 10) t2;
 ----
 10
 
 query I
-SELECT COUNT(1) FROM (SELECT 1 FROM t ORDER BY val <=> '[0.5,0.5,0.5,0.5,0.5,0.5]'::svector limit 10) t2;
+SELECT COUNT(1) FROM (SELECT 1 FROM t ORDER BY val <=> '{1:3,2:1}/6'::svector limit 10) t2;
 ----
 10
 
 query I
-SELECT COUNT(1) FROM (SELECT 1 FROM t ORDER BY val <#> '[0.5,0.5,0.5,0.5,0.5,0.5]'::svector limit 10) t2;
+SELECT COUNT(1) FROM (SELECT 1 FROM t ORDER BY val <#> '{1:3,2:1}/6'::svector limit 10) t2;
 ----
 10
 
@@ -40,7 +40,7 @@ DROP TABLE t;
 query I
 SELECT to_svector(5, '{1,2}', '{1,2}');
 ----
-[0, 1, 2, 0, 0]
+{2:1, 3:2}/5
 
 query I
 SELECT to_svector(5, '{1,2}', '{1,1}') * to_svector(5, '{1,3}', '{2,2}');
@@ -53,8 +53,5 @@ SELECT to_svector(5, '{1,2,3}', '{1,2}');
 statement error Duplicated index.
 SELECT to_svector(5, '{1,1}', '{1,2}');
 
-statement ok
-SELECT replace(replace(array_agg(RANDOM())::real[]::text, '{', '['), '}', ']')::svector FROM generate_series(1, 100000);
-
 statement ok
 SELECT to_svector(200000, array_agg(val)::integer[], array_agg(val)::real[]) FROM generate_series(1, 100000) AS VAL;

tests/sqllogictest/svector_subscript.slt

@@ -2,87 +2,87 @@ statement ok
 SET search_path TO pg_temp, vectors;
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[3:6];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[3:6];
 ----
-[3, 4, 5]
+{1:3, 2:4, 3:5}/3
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[:4];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[:4];
 ----
-[0, 1, 2, 3]
+{2:1, 3:2, 4:3}/4
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[5:];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[5:];
 ----
-[5, 6, 7]
+{1:5, 2:6, 3:7}/3
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[1:8];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[1:8];
 ----
-[1, 2, 3, 4, 5, 6, 7]
+{1:1, 2:2, 3:3, 4:4, 5:5, 6:6, 7:7}/7
 
 statement error type svector does only support one subscript
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[3:3][1:1];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[3:3][1:1];
 
 statement error type svector does only support slice fetch
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[3];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[3];
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[5:4];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[5:4];
 ----
 NULL
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[9:];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[9:];
 ----
 NULL
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[:0];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[:0];
 ----
 NULL
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[:-1];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[:-1];
 ----
 NULL
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[NULL:NULL];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[NULL:NULL];
 ----
 NULL
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[NULL:8];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[NULL:8];
 ----
 NULL
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[1:NULL];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[1:NULL];
 ----
 NULL
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[NULL:];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[NULL:];
 ----
 NULL
 
 query I
-SELECT ('[0, 1, 2, 3, 4, 5, 6, 7]'::svector)[:NULL];
+SELECT ('{2:1, 3:2, 4:3, 5:4, 6:5, 7:6, 8:7}/8'::svector)[:NULL];
 ----
 NULL
 
 query I
-SELECT ('[0, 0, 2, 0, 4, 0, 0, 7]'::svector)[3:7];
+SELECT ('{3:2, 5:4, 8:7}/8'::svector)[3:7];
 ----
-[0, 4, 0, 0]
+{2:4}/4
 
 query I
-SELECT ('[0, 0, 2, 0, 4, 0, 0, 7]'::svector)[5:7];
+SELECT ('{3:2, 5:4, 8:7}/8'::svector)[5:7];
 ----
-[0, 0]
+{}/2
 
 query I
-SELECT ('[0, 0, 0, 0, 0, 0, 0, 0]'::svector)[5:7];
+SELECT ('{}/8'::svector)[5:7];
 ----
-[0, 0]
+{}/2