Batch column scans. (#52)

driver/driver.go

@@ -50,6 +50,7 @@ import (
 	"net/url"
 	"strings"
 	"time"
+	"unsafe"
 
 	"github.com/ncruces/go-sqlite3"
 	"github.com/ncruces/go-sqlite3/internal/util"
@@ -532,46 +533,34 @@ func (r *rows) Next(dest []driver.Value) error {
 		return io.EOF
 	}
 
+	data := unsafe.Slice((*any)(unsafe.SliceData(dest)), len(dest))
+	err := r.Stmt.Columns(data)
 	for i := range dest {
-		t := r.Stmt.ColumnType(i)
-		if tm, ok := r.decodeTime(i, t); ok {
-			dest[i] = tm
-			continue
+		if t, ok := r.decodeTime(i, dest[i]); ok {
+			dest[i] = t
+		} else if s, ok := dest[i].(string); ok {
+			dest[i] = stringOrTime(s)
 		}
-		switch t {
-		case sqlite3.INTEGER:
-			dest[i] = r.Stmt.ColumnInt64(i)
-		case sqlite3.FLOAT:
-			dest[i] = r.Stmt.ColumnFloat(i)
-		case sqlite3.BLOB:
-			dest[i] = r.Stmt.ColumnRawBlob(i)
-		case sqlite3.TEXT:
-			dest[i] = stringOrTime(r.Stmt.ColumnText(i))
-		case sqlite3.NULL:
-			dest[i] = nil
-		default:
-			panic(util.AssertErr())
 	}
+	return err
 }
 
-	return r.Stmt.Err()
-}
-
-func (r *rows) decodeTime(i int, typ sqlite3.Datatype) (_ time.Time, _ bool) {
+func (r *rows) decodeTime(i int, v any) (_ time.Time, _ bool) {
 	if r.tmRead == sqlite3.TimeFormatDefault {
 		return
 	}
-	switch typ {
-	case sqlite3.INTEGER, sqlite3.FLOAT, sqlite3.TEXT:
-		// maybe
-	default:
-		return
-	}
 	switch r.declType(i) {
 	case "DATE", "TIME", "DATETIME", "TIMESTAMP":
 		// maybe
 	default:
 		return
 	}
-	return r.Stmt.ColumnTime(i, r.tmRead), r.Stmt.Err() == nil
+	switch v.(type) {
+	case int64, float64, string:
+		// maybe
+	default:
+		return
+	}
+	t, err := r.tmRead.Decode(v)
+	return t, err == nil
 }

embed/build.sh

@@ -7,7 +7,8 @@ ROOT=../
 BINARYEN="$ROOT/tools/binaryen-version_116/bin"
 WASI_SDK="$ROOT/tools/wasi-sdk-21.0/bin"
 
-"$WASI_SDK/clang" --target=wasm32-wasi -flto -g0 -O2 \
+"$WASI_SDK/clang" --target=wasm32-wasi -std=c17 -flto -g0 -O2 \
+  -Wall -Wextra -Wno-unused-parameter \
 	-o sqlite3.wasm "$ROOT/sqlite3/main.c" \
 	-I"$ROOT/sqlite3" \
 	-mexec-model=reactor \

embed/exports.txt

@@ -39,6 +39,7 @@ sqlite3_column_name
 sqlite3_column_text
 sqlite3_column_type
 sqlite3_column_value
+sqlite3_columns_go
 sqlite3_config_log_go
 sqlite3_create_aggregate_function_go
 sqlite3_create_collation_go

sqlite3/column.c

@@ -0,0 +1,51 @@
+#include <stddef.h>
+
+#include "sqlite3.h"
+
+union sqlite3_data {
+  sqlite3_int64 i;
+  double d;
+  struct {
+    const void *ptr;
+    int len;
+  };
+};
+
+int sqlite3_columns_go(sqlite3_stmt *stmt, int nCol, char *aType,
+                       union sqlite3_data *aData) {
+  if (nCol != sqlite3_column_count(stmt)) {
+    return SQLITE_MISUSE;
+  }
+  int rc = SQLITE_OK;
+  for (int i = 0; i < nCol; ++i) {
+    const void *ptr = NULL;
+    switch (aType[i] = sqlite3_column_type(stmt, i)) {
+      default:  // SQLITE_NULL
+        aData[i] = (union sqlite3_data){};
+      case SQLITE_INTEGER:
+        aData[i].i = sqlite3_column_int64(stmt, i);
+        continue;
+      case SQLITE_FLOAT:
+        aData[i].d = sqlite3_column_double(stmt, i);
+        continue;
+      case SQLITE_TEXT:
+        ptr = sqlite3_column_text(stmt, i);
+        break;
+      case SQLITE_BLOB:
+        ptr = sqlite3_column_blob(stmt, i);
+        break;
+    }
+    if (ptr == NULL && rc == SQLITE_OK) {
+      rc = sqlite3_errcode(sqlite3_db_handle(stmt));
+    }
+    aData[i].ptr = ptr;
+    aData[i].len = sqlite3_column_bytes(stmt, i);
+  }
+  return rc;
+}
+
+static_assert(offsetof(union sqlite3_data, i) == 0, "Unexpected offset");
+static_assert(offsetof(union sqlite3_data, d) == 0, "Unexpected offset");
+static_assert(offsetof(union sqlite3_data, ptr) == 0, "Unexpected offset");
+static_assert(offsetof(union sqlite3_data, len) == 4, "Unexpected offset");
+static_assert(sizeof(union sqlite3_data) == 8, "Unexpected size");

sqlite3/main.c

@@ -10,6 +10,7 @@
 #include "ext/uint.c"
 #include "ext/uuid.c"
 // Bindings
+#include "column.c"
 #include "func.c"
 #include "log.c"
 #include "pointer.c"

sqlite3/vtab.c

@@ -136,8 +136,6 @@ static int go_cur_close_wrapper(sqlite3_vtab_cursor *pCursor) {
 static int go_vtab_find_function_wrapper(
     sqlite3_vtab *pVTab, int nArg, const char *zName,
     void (**pxFunc)(sqlite3_context *, int, sqlite3_value **), void **ppArg) {
-  struct go_vtab *vtab = container_of(pVTab, struct go_vtab, base);
-
   go_handle handle;
   int rc = go_vtab_find_function(pVTab, nArg, zName, &handle);
   if (rc) {

stmt.go

@@ -549,3 +549,40 @@ func (s *Stmt) ColumnValue(col int) Value {
 		handle: uint32(r),
 	}
 }
+
+func (s *Stmt) Columns(dest []any) error {
+	defer s.c.arena.mark()()
+	count := uint64(len(dest))
+	typePtr := s.c.arena.new(count)
+	dataPtr := s.c.arena.new(8 * count)
+
+	r := s.c.call("sqlite3_columns_go",
+		uint64(s.handle), count, uint64(typePtr), uint64(dataPtr))
+	if err := s.c.error(r); err != nil {
+		return err
+	}
+
+	types := util.View(s.c.mod, typePtr, count)
+	for i := range dest {
+		switch types[i] {
+		case byte(INTEGER):
+			dest[i] = int64(util.ReadUint64(s.c.mod, dataPtr+8*uint32(i)))
+			continue
+		case byte(FLOAT):
+			dest[i] = util.ReadFloat64(s.c.mod, dataPtr+8*uint32(i))
+			continue
+		case byte(NULL):
+			dest[i] = nil
+			continue
+		}
+		ptr := util.ReadUint32(s.c.mod, dataPtr+8*uint32(i)+0)
+		len := util.ReadUint32(s.c.mod, dataPtr+8*uint32(i)+4)
+		buf := util.View(s.c.mod, ptr, uint64(len))
+		if types[i] == byte(TEXT) {
+			dest[i] = string(buf)
+		} else {
+			dest[i] = buf
+		}
+	}
+	return nil
+}

vfs/tests/mptest/testdata/build.sh

@@ -7,7 +7,7 @@ ROOT=../../../../
 BINARYEN="$ROOT/tools/binaryen-version_116/bin"
 WASI_SDK="$ROOT/tools/wasi-sdk-21.0/bin"
 
-"$WASI_SDK/clang" --target=wasm32-wasi -flto -g0 -O2 \
+"$WASI_SDK/clang" --target=wasm32-wasi -std=c17 -flto -g0 -O2 \
   -o mptest.wasm main.c \
 	-I"$ROOT/sqlite3" \
 	-msimd128 -mmutable-globals \

vfs/tests/speedtest1/testdata/build.sh

@@ -7,7 +7,7 @@ ROOT=../../../../
 BINARYEN="$ROOT/tools/binaryen-version_116/bin"
 WASI_SDK="$ROOT/tools/wasi-sdk-21.0/bin"
 
-"$WASI_SDK/clang" --target=wasm32-wasi -flto -g0 -O2 \
+"$WASI_SDK/clang" --target=wasm32-wasi -std=c17 -flto -g0 -O2 \
 	-o speedtest1.wasm main.c \
 	-I"$ROOT/sqlite3" \
 	-msimd128 -mmutable-globals \