From e299a0e77e554ecac033fec4b42ecaa162917898 Mon Sep 17 00:00:00 2001
From: Jussi Saurio <jussi.saurio@gmail.com>
Date: Tue, 15 Apr 2025 11:19:50 +0300
Subject: [PATCH] vdbe: add Insn::IdxRowId

---
 core/vdbe/execute.rs | 22 ++++++++++++++++++++++
 core/vdbe/explain.rs | 16 ++++++++++++++++
 core/vdbe/insn.rs    |  6 ++++++
 3 files changed, 44 insertions(+)

diff --git a/core/vdbe/execute.rs b/core/vdbe/execute.rs
index 2eafed217..0325ffae8 100644
--- a/core/vdbe/execute.rs
+++ b/core/vdbe/execute.rs
@@ -1836,6 +1836,28 @@ pub fn op_row_id(
     Ok(InsnFunctionStepResult::Step)
 }
 
+pub fn op_idx_row_id(
+    program: &Program,
+    state: &mut ProgramState,
+    insn: &Insn,
+    pager: &Rc<Pager>,
+    mv_store: Option<&Rc<MvStore>>,
+) -> Result<InsnFunctionStepResult> {
+    let Insn::IdxRowId { cursor_id, dest } = insn else {
+        unreachable!("unexpected Insn {:?}", insn)
+    };
+    let mut cursors = state.cursors.borrow_mut();
+    let cursor = cursors.get_mut(*cursor_id).unwrap().as_mut().unwrap();
+    let cursor = cursor.as_btree_mut();
+    let rowid = cursor.rowid()?;
+    state.registers[*dest] = match rowid {
+        Some(rowid) => Register::OwnedValue(OwnedValue::Integer(rowid as i64)),
+        None => Register::OwnedValue(OwnedValue::Null),
+    };
+    state.pc += 1;
+    Ok(InsnFunctionStepResult::Step)
+}
+
 pub fn op_seek_rowid(
     program: &Program,
     state: &mut ProgramState,
diff --git a/core/vdbe/explain.rs b/core/vdbe/explain.rs
index f2230d2eb..f6e1073c3 100644
--- a/core/vdbe/explain.rs
+++ b/core/vdbe/explain.rs
@@ -684,6 +684,22 @@ pub fn insn_to_str(
                         .unwrap_or(&format!("cursor {}", cursor_id))
                 ),
             ),
+            Insn::IdxRowId { cursor_id, dest } => (
+                "IdxRowId",
+                *cursor_id as i32,
+                *dest as i32,
+                0,
+                OwnedValue::build_text(""),
+                0,
+                format!(
+                    "r[{}]={}.rowid",
+                    dest,
+                    &program.cursor_ref[*cursor_id]
+                        .0
+                        .as_ref()
+                        .unwrap_or(&format!("cursor {}", cursor_id))
+                ),
+            ),
             Insn::SeekRowid {
                 cursor_id,
                 src_reg,
diff --git a/core/vdbe/insn.rs b/core/vdbe/insn.rs
index 7b30396c0..87a615aee 100644
--- a/core/vdbe/insn.rs
+++ b/core/vdbe/insn.rs
@@ -438,6 +438,11 @@ pub enum Insn {
         cursor_id: CursorID,
         dest: usize,
     },
+    /// Read the rowid of the current row from an index cursor.
+    IdxRowId {
+        cursor_id: CursorID,
+        dest: usize,
+    },
 
     /// Seek to a rowid in the cursor. If not found, jump to the given PC. Otherwise, continue to the next instruction.
     SeekRowid {
@@ -856,6 +861,7 @@ impl Insn {
             Insn::String8 { .. } => execute::op_string8,
             Insn::Blob { .. } => execute::op_blob,
             Insn::RowId { .. } => execute::op_row_id,
+            Insn::IdxRowId { .. } => execute::op_idx_row_id,
             Insn::SeekRowid { .. } => execute::op_seek_rowid,
             Insn::DeferredSeek { .. } => execute::op_deferred_seek,
             Insn::SeekGE { .. } => execute::op_seek,