From e28c1f48968ecad092471f04c6ac4c6d89ef0a7a Mon Sep 17 00:00:00 2001
From: dimgigov <gigov@gigov.org>
Date: Thu, 30 Jul 2026 14:19:11 +0300
Subject: [PATCH] refactor(exec): extract table scans into exec/scan.nim

---
 src/barabadb/query/exec/scan.nim | 71 ++++++++++++++++++++++++++++++++
 src/barabadb/query/executor.nim  | 67 +++---------------------------
 2 files changed, 76 insertions(+), 62 deletions(-)
 create mode 100644 src/barabadb/query/exec/scan.nim

diff --git a/src/barabadb/query/exec/scan.nim b/src/barabadb/query/exec/scan.nim
new file mode 100644
index 0000000..7fb1004
--- /dev/null
+++ b/src/barabadb/query/exec/scan.nim
@@ -0,0 +1,71 @@
+## Table scans — full scans and point reads against the LSM store.
+##
+## Extracted from `executor.nim` (Task 8 of the executor split).
+import std/strutils
+import std/tables
+import ../../storage/lsm
+import types
+import values
+import helpers
+import rls
+
+# ----------------------------------------------------------------------
+# Table scan and storage
+# ----------------------------------------------------------------------
+
+proc execScan*(ctx: ExecutionContext, table: string): seq[Row] =
+  result = @[]
+  # Check CTE tables first
+  if table in ctx.cteTables:
+    return ctx.cteTables[table]
+  let prefix = table & "."
+  for (key, value) in ctx.db.scanAll():
+    if not key.startsWith(prefix): continue
+    let rest = key[prefix.len..^1]
+    var row: Row
+    row["$key"] = rest
+    let valStr = cast[string](value)
+    row["$value"] = valStr
+    # Also parse individual columns
+    for k, v in parseRowData(valStr):
+      row[k] = v
+    # Extract PK value from key
+    let eqPos = rest.find('=')
+    if eqPos >= 0:
+      row[rest[0..<eqPos]] = rest[eqPos+1..^1]
+    # RLS filter
+    if passesPolicy(ctx, table, "SELECT", row):
+      # Inject qualified columns from outerRow for correlated subqueries
+      if ctx.outerRow.len > 0:
+        var outerTables: seq[string] = @[]
+        # Try to infer outer table from qualified refs already in outerRow keys
+        for k in ctx.outerRow.keys:
+          if k.contains('.') and not k.startsWith('$'):
+            let tbl = k.split('.')[0]
+            if tbl notin outerTables: outerTables.add(tbl)
+        # If no qualified keys found, scan subquery plan for correlated refs
+        if outerTables.len == 0 and ctx.subqueryPlan != nil:
+          collectCorrelatedTablesFromPlan(ctx.subqueryPlan, outerTables)
+        # Inject qualified columns
+        for k, v in ctx.outerRow:
+          if k.startsWith('$'): continue
+          if k.contains('.'): continue  # already qualified
+          for tbl in outerTables:
+            row[tbl & "." & k] = v
+      result.add(row)
+
+proc execPointRead*(ctx: ExecutionContext, table: string, key: string): seq[Row] =
+  let fullKey = table & "." & key
+  let (found, val) = ctx.db.get(fullKey)
+  if found:
+    var row: Row
+    row["$key"] = key
+    let valStr = cast[string](val)
+    row["$value"] = valStr
+    for k, v in parseRowData(valStr):
+      row[k] = v
+    let eqPos = key.find('=')
+    if eqPos >= 0:
+      row[key[0..<eqPos]] = key[eqPos+1..^1]
+    return @[row]
+  return @[]
diff --git a/src/barabadb/query/executor.nim b/src/barabadb/query/executor.nim
index 51a45a8..ea4e391 100644
--- a/src/barabadb/query/executor.nim
+++ b/src/barabadb/query/executor.nim
@@ -49,6 +49,7 @@ import exec/migrations  # internal — not re-exported
 import exec/eval
 import exec/lower
 import exec/rls  # internal — not re-exported
+import exec/scan  # internal — not re-exported
 export types
 export values
 export schema
@@ -64,70 +65,12 @@ proc executePlan*(ctx: ExecutionContext, plan: IRPlan): seq[Row]
 # Forward declarations
 # ----------------------------------------------------------------------
 
-proc execScan(ctx: ExecutionContext, table: string): seq[Row]
 proc executeQuery*(ctx: ExecutionContext, astNode: Node, params: seq[WireValue] = @[]): ExecResult
 
 # ----------------------------------------------------------------------
-# Table scan and storage
+# Table storage
 # ----------------------------------------------------------------------
 
-proc execScan(ctx: ExecutionContext, table: string): seq[Row] =
-  result = @[]
-  # Check CTE tables first
-  if table in ctx.cteTables:
-    return ctx.cteTables[table]
-  let prefix = table & "."
-  for (key, value) in ctx.db.scanAll():
-    if not key.startsWith(prefix): continue
-    let rest = key[prefix.len..^1]
-    var row: Row
-    row["$key"] = rest
-    let valStr = cast[string](value)
-    row["$value"] = valStr
-    # Also parse individual columns
-    for k, v in parseRowData(valStr):
-      row[k] = v
-    # Extract PK value from key
-    let eqPos = rest.find('=')
-    if eqPos >= 0:
-      row[rest[0..<eqPos]] = rest[eqPos+1..^1]
-    # RLS filter
-    if passesPolicy(ctx, table, "SELECT", row):
-      # Inject qualified columns from outerRow for correlated subqueries
-      if ctx.outerRow.len > 0:
-        var outerTables: seq[string] = @[]
-        # Try to infer outer table from qualified refs already in outerRow keys
-        for k in ctx.outerRow.keys:
-          if k.contains('.') and not k.startsWith('$'):
-            let tbl = k.split('.')[0]
-            if tbl notin outerTables: outerTables.add(tbl)
-        # If no qualified keys found, scan subquery plan for correlated refs
-        if outerTables.len == 0 and ctx.subqueryPlan != nil:
-          collectCorrelatedTablesFromPlan(ctx.subqueryPlan, outerTables)
-        # Inject qualified columns
-        for k, v in ctx.outerRow:
-          if k.startsWith('$'): continue
-          if k.contains('.'): continue  # already qualified
-          for tbl in outerTables:
-            row[tbl & "." & k] = v
-      result.add(row)
-
-proc execPointRead(ctx: ExecutionContext, table: string, key: string): seq[Row] =
-  let fullKey = table & "." & key
-  let (found, val) = ctx.db.get(fullKey)
-  if found:
-    var row: Row
-    row["$key"] = key
-    let valStr = cast[string](val)
-    row["$value"] = valStr
-    for k, v in parseRowData(valStr):
-      row[k] = v
-    let eqPos = key.find('=')
-    if eqPos >= 0:
-      row[key[0..<eqPos]] = key[eqPos+1..^1]
-    return @[row]
-  return @[]
-
 proc execInsert*(ctx: ExecutionContext, table: string, fields: seq[string], values: seq[seq[string]],
                   kvPairs: var seq[(string, seq[byte])]): int =
   if not hasPrivilege(ctx, table, "INSERT"):
@@ -3334,9 +3277,9 @@ proc executeMigrationSql(ctx: ExecutionContext, sql: string): ExecResult =
 
 # ----------------------------------------------------------------------
 # Hook wiring — eval.nim back-edges (subqueries, hybrid search, NL->SQL
-# validation). Resolved at module scope; stays valid when executePlan /
-# execScan move to their own modules in later tasks.
+# validation). Resolved at module scope; stays valid when executePlan
+# moves to its own module in a later task.
 # ----------------------------------------------------------------------
 eval.executePlanHook = executePlan
-eval.execScanHook = execScan
+eval.execScanHook = scan.execScan
 eval.executeQueryHook = executeQuery