JSON experiment.

context.go

@@ -1,7 +1,6 @@
 package sqlite3
 
 import (
-	"encoding/json"
 	"errors"
 	"math"
 	"time"
@@ -173,21 +172,6 @@ func (ctx Context) ResultPointer(ptr any) {
 		stk_t(ctx.handle), stk_t(valPtr))
 }
 
-// ResultJSON sets the result of the function to the JSON encoding of value.
-//
-// https://sqlite.org/c3ref/result_blob.html
-func (ctx Context) ResultJSON(value any) {
-	err := json.NewEncoder(callbackWriter(func(p []byte) (int, error) {
-		ctx.ResultRawText(p[:len(p)-1]) // remove the newline
-		return 0, nil
-	})).Encode(value)
-
-	if err != nil {
-		ctx.ResultError(err)
-		return // notest
-	}
-}
-
 // ResultValue sets the result of the function to a copy of [Value].
 //
 // https://sqlite.org/c3ref/result_blob.html

internal/util/json.go

@@ -1,3 +1,5 @@
+//go:build !goexperiment.jsonv2
+
 package util
 
 import (

internal/util/json_v2.go

@@ -0,0 +1,52 @@
+//go:build goexperiment.jsonv2
+
+package util
+
+import (
+	"encoding/json/v2"
+	"math"
+	"strconv"
+	"time"
+	"unsafe"
+)
+
+type JSON struct{ Value any }
+
+func (j JSON) Scan(value any) error {
+	var buf []byte
+
+	switch v := value.(type) {
+	case []byte:
+		buf = v
+	case string:
+		buf = unsafe.Slice(unsafe.StringData(v), len(v))
+	case int64:
+		buf = strconv.AppendInt(nil, v, 10)
+	case float64:
+		buf = AppendNumber(nil, v)
+	case time.Time:
+		buf = append(buf, '"')
+		buf = v.AppendFormat(buf, time.RFC3339Nano)
+		buf = append(buf, '"')
+	case nil:
+		buf = []byte("null")
+	default:
+		panic(AssertErr())
+	}
+
+	return json.Unmarshal(buf, j.Value)
+}
+
+func AppendNumber(dst []byte, f float64) []byte {
+	switch {
+	case math.IsNaN(f):
+		dst = append(dst, "null"...)
+	case math.IsInf(f, 1):
+		dst = append(dst, "9.0e999"...)
+	case math.IsInf(f, -1):
+		dst = append(dst, "-9.0e999"...)
+	default:
+		return strconv.AppendFloat(dst, f, 'g', -1, 64)
+	}
+	return dst
+}

json.go

@@ -1,6 +1,13 @@
+//go:build !goexperiment.jsonv2
+
 package sqlite3
 
-import "github.com/ncruces/go-sqlite3/internal/util"
+import (
+	"encoding/json"
+	"strconv"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
+)
 
 // JSON returns a value that can be used as an argument to
 // [database/sql.DB.Exec], [database/sql.Row.Scan] and similar methods to
@@ -10,3 +17,77 @@ import "github.com/ncruces/go-sqlite3/internal/util"
 func JSON(value any) any {
 	return util.JSON{Value: value}
 }
+
+// ResultJSON sets the result of the function to the JSON encoding of value.
+//
+// https://sqlite.org/c3ref/result_blob.html
+func (ctx Context) ResultJSON(value any) {
+	err := json.NewEncoder(callbackWriter(func(p []byte) (int, error) {
+		ctx.ResultRawText(p[:len(p)-1]) // remove the newline
+		return 0, nil
+	})).Encode(value)
+
+	if err != nil {
+		ctx.ResultError(err)
+		return // notest
+	}
+}
+
+// BindJSON binds the JSON encoding of value to the prepared statement.
+// The leftmost SQL parameter has an index of 1.
+//
+// https://sqlite.org/c3ref/bind_blob.html
+func (s *Stmt) BindJSON(param int, value any) error {
+	return json.NewEncoder(callbackWriter(func(p []byte) (int, error) {
+		return 0, s.BindRawText(param, p[:len(p)-1]) // remove the newline
+	})).Encode(value)
+}
+
+// ColumnJSON parses the JSON-encoded value of the result column
+// and stores it in the value pointed to by ptr.
+// The leftmost column of the result set has the index 0.
+//
+// https://sqlite.org/c3ref/column_blob.html
+func (s *Stmt) ColumnJSON(col int, ptr any) error {
+	var data []byte
+	switch s.ColumnType(col) {
+	case NULL:
+		data = []byte("null")
+	case TEXT:
+		data = s.ColumnRawText(col)
+	case BLOB:
+		data = s.ColumnRawBlob(col)
+	case INTEGER:
+		data = strconv.AppendInt(nil, s.ColumnInt64(col), 10)
+	case FLOAT:
+		data = util.AppendNumber(nil, s.ColumnFloat(col))
+	default:
+		panic(util.AssertErr())
+	}
+	return json.Unmarshal(data, ptr)
+}
+
+// JSON parses a JSON-encoded value
+// and stores the result in the value pointed to by ptr.
+func (v Value) JSON(ptr any) error {
+	var data []byte
+	switch v.Type() {
+	case NULL:
+		data = []byte("null")
+	case TEXT:
+		data = v.RawText()
+	case BLOB:
+		data = v.RawBlob()
+	case INTEGER:
+		data = strconv.AppendInt(nil, v.Int64(), 10)
+	case FLOAT:
+		data = util.AppendNumber(nil, v.Float())
+	default:
+		panic(util.AssertErr())
+	}
+	return json.Unmarshal(data, ptr)
+}
+
+type callbackWriter func(p []byte) (int, error)
+
+func (fn callbackWriter) Write(p []byte) (int, error) { return fn(p) }

json_v2.go

@@ -0,0 +1,113 @@
+//go:build goexperiment.jsonv2
+
+package sqlite3
+
+import (
+	"encoding/json/v2"
+	"strconv"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
+)
+
+// JSON returns a value that can be used as an argument to
+// [database/sql.DB.Exec], [database/sql.Row.Scan] and similar methods to
+// store value as JSON, or decode JSON into value.
+// JSON should NOT be used with [Stmt.BindJSON], [Stmt.ColumnJSON],
+// [Value.JSON], or [Context.ResultJSON].
+func JSON(value any) any {
+	return util.JSON{Value: value}
+}
+
+// ResultJSON sets the result of the function to the JSON encoding of value.
+//
+// https://sqlite.org/c3ref/result_blob.html
+func (ctx Context) ResultJSON(value any) {
+	w := bytesWriter{sqlite: ctx.c.sqlite}
+	if err := json.MarshalWrite(&w, value); err != nil {
+		ctx.c.free(w.ptr)
+		ctx.ResultError(err)
+		return // notest
+	}
+	ctx.c.call("sqlite3_result_text_go",
+		stk_t(ctx.handle), stk_t(w.ptr), stk_t(len(w.buf)))
+}
+
+// BindJSON binds the JSON encoding of value to the prepared statement.
+// The leftmost SQL parameter has an index of 1.
+//
+// https://sqlite.org/c3ref/bind_blob.html
+func (s *Stmt) BindJSON(param int, value any) error {
+	w := bytesWriter{sqlite: s.c.sqlite}
+	if err := json.MarshalWrite(&w, value); err != nil {
+		s.c.free(w.ptr)
+		return err
+	}
+	rc := res_t(s.c.call("sqlite3_bind_text_go",
+		stk_t(s.handle), stk_t(param),
+		stk_t(w.ptr), stk_t(len(w.buf))))
+	return s.c.error(rc)
+}
+
+// ColumnJSON parses the JSON-encoded value of the result column
+// and stores it in the value pointed to by ptr.
+// The leftmost column of the result set has the index 0.
+//
+// https://sqlite.org/c3ref/column_blob.html
+func (s *Stmt) ColumnJSON(col int, ptr any) error {
+	var data []byte
+	switch s.ColumnType(col) {
+	case NULL:
+		data = []byte("null")
+	case TEXT:
+		data = s.ColumnRawText(col)
+	case BLOB:
+		data = s.ColumnRawBlob(col)
+	case INTEGER:
+		data = strconv.AppendInt(nil, s.ColumnInt64(col), 10)
+	case FLOAT:
+		data = util.AppendNumber(nil, s.ColumnFloat(col))
+	default:
+		panic(util.AssertErr())
+	}
+	return json.Unmarshal(data, ptr)
+}
+
+// JSON parses a JSON-encoded value
+// and stores the result in the value pointed to by ptr.
+func (v Value) JSON(ptr any) error {
+	var data []byte
+	switch v.Type() {
+	case NULL:
+		data = []byte("null")
+	case TEXT:
+		data = v.RawText()
+	case BLOB:
+		data = v.RawBlob()
+	case INTEGER:
+		data = strconv.AppendInt(nil, v.Int64(), 10)
+	case FLOAT:
+		data = util.AppendNumber(nil, v.Float())
+	default:
+		panic(util.AssertErr())
+	}
+	return json.Unmarshal(data, ptr)
+}
+
+type bytesWriter struct {
+	*sqlite
+	buf []byte
+	ptr ptr_t
+}
+
+func (b *bytesWriter) Write(p []byte) (n int, err error) {
+	if len(p) > cap(b.buf)-len(b.buf) {
+		want := int64(len(b.buf)) + int64(len(p))
+		grow := int64(cap(b.buf))
+		grow += grow >> 1
+		want = max(want, grow)
+		b.ptr = b.realloc(b.ptr, want)
+		b.buf = util.View(b.mod, b.ptr, want)[:len(b.buf)]
+	}
+	b.buf = append(b.buf, p...)
+	return len(p), nil
+}

stmt.go

@@ -1,9 +1,7 @@
 package sqlite3
 
 import (
-	"encoding/json"
 	"math"
-	"strconv"
 	"time"
 
 	"github.com/ncruces/go-sqlite3/internal/util"
@@ -362,16 +360,6 @@ func (s *Stmt) BindPointer(param int, ptr any) error {
 	return s.c.error(rc)
 }
 
-// BindJSON binds the JSON encoding of value to the prepared statement.
-// The leftmost SQL parameter has an index of 1.
-//
-// https://sqlite.org/c3ref/bind_blob.html
-func (s *Stmt) BindJSON(param int, value any) error {
-	return json.NewEncoder(callbackWriter(func(p []byte) (int, error) {
-		return 0, s.BindRawText(param, p[:len(p)-1]) // remove the newline
-	})).Encode(value)
-}
-
 // BindValue binds a copy of value to the prepared statement.
 // The leftmost SQL parameter has an index of 1.
 //
@@ -598,30 +586,6 @@ func (s *Stmt) columnRawBytes(col int, ptr ptr_t, nul int32) []byte {
 	return util.View(s.c.mod, ptr, int64(n+nul))[:n]
 }
 
-// ColumnJSON parses the JSON-encoded value of the result column
-// and stores it in the value pointed to by ptr.
-// The leftmost column of the result set has the index 0.
-//
-// https://sqlite.org/c3ref/column_blob.html
-func (s *Stmt) ColumnJSON(col int, ptr any) error {
-	var data []byte
-	switch s.ColumnType(col) {
-	case NULL:
-		data = []byte("null")
-	case TEXT:
-		data = s.ColumnRawText(col)
-	case BLOB:
-		data = s.ColumnRawBlob(col)
-	case INTEGER:
-		data = strconv.AppendInt(nil, s.ColumnInt64(col), 10)
-	case FLOAT:
-		data = util.AppendNumber(nil, s.ColumnFloat(col))
-	default:
-		panic(util.AssertErr())
-	}
-	return json.Unmarshal(data, ptr)
-}
-
 // ColumnValue returns the unprotected value of the result column.
 // The leftmost column of the result set has the index 0.
 //
@@ -748,7 +712,3 @@ func (s *Stmt) columns(count int64) ([]byte, ptr_t, error) {
 
 	return util.View(s.c.mod, typePtr, count), dataPtr, nil
 }
-
-type callbackWriter func(p []byte) (int, error)
-
-func (fn callbackWriter) Write(p []byte) (int, error) { return fn(p) }

tests/stmt_test.go

@@ -496,7 +496,7 @@ func TestStmt(t *testing.T) {
 		if got := stmt.ColumnBlob(0, nil); string(got) != "true" {
 			t.Errorf("got %q, want true", got)
 		}
-		var got any = 1
+		var got any
 		if err := stmt.ColumnJSON(0, &got); err != nil {
 			t.Error(err)
 		} else if got != true {

value.go

@@ -1,9 +1,7 @@
 package sqlite3
 
 import (
-	"encoding/json"
 	"math"
-	"strconv"
 	"time"
 
 	"github.com/ncruces/go-sqlite3/internal/util"
@@ -162,27 +160,6 @@ func (v Value) Pointer() any {
 	return util.GetHandle(v.c.ctx, ptr)
 }
 
-// JSON parses a JSON-encoded value
-// and stores the result in the value pointed to by ptr.
-func (v Value) JSON(ptr any) error {
-	var data []byte
-	switch v.Type() {
-	case NULL:
-		data = []byte("null")
-	case TEXT:
-		data = v.RawText()
-	case BLOB:
-		data = v.RawBlob()
-	case INTEGER:
-		data = strconv.AppendInt(nil, v.Int64(), 10)
-	case FLOAT:
-		data = util.AppendNumber(nil, v.Float())
-	default:
-		panic(util.AssertErr())
-	}
-	return json.Unmarshal(data, ptr)
-}
-
 // NoChange returns true if and only if the value is unchanged
 // in a virtual table update operatiom.
 //