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package types
import (
"bytes"
"compress/gzip"
"database/sql/driver"
"encoding/json"
"errors"
"io/ioutil"
)
// GzippedText is a []byte which transparently gzips data being submitted to
// a database and ungzips data being Scanned from a database.
type GzippedText []byte
// Value implements the driver.Valuer interface, gzipping the raw value of
// this GzippedText.
func (g GzippedText) Value() (driver.Value, error) {
b := make([]byte, 0, len(g))
buf := bytes.NewBuffer(b)
w := gzip.NewWriter(buf)
w.Write(g)
w.Close()
return buf.Bytes(), nil
}
// Scan implements the sql.Scanner interface, ungzipping the value coming off
// the wire and storing the raw result in the GzippedText.
func (g *GzippedText) Scan(src interface{}) error {
var source []byte
switch src := src.(type) {
case string:
source = []byte(src)
case []byte:
source = src
default:
return errors.New("Incompatible type for GzippedText")
}
reader, err := gzip.NewReader(bytes.NewReader(source))
if err != nil {
return err
}
defer reader.Close()
b, err := ioutil.ReadAll(reader)
if err != nil {
return err
}
*g = GzippedText(b)
return nil
}
// JSONText is a json.RawMessage, which is a []byte underneath.
// Value() validates the json format in the source, and returns an error if
// the json is not valid. Scan does no validation. JSONText additionally
// implements `Unmarshal`, which unmarshals the json within to an interface{}
type JSONText json.RawMessage
var emptyJSON = JSONText("{}")
// MarshalJSON returns the *j as the JSON encoding of j.
func (j JSONText) MarshalJSON() ([]byte, error) {
if len(j) == 0 {
return emptyJSON, nil
}
return j, nil
}
// UnmarshalJSON sets *j to a copy of data
func (j *JSONText) UnmarshalJSON(data []byte) error {
if j == nil {
return errors.New("JSONText: UnmarshalJSON on nil pointer")
}
*j = append((*j)[0:0], data...)
return nil
}
// Value returns j as a value. This does a validating unmarshal into another
// RawMessage. If j is invalid json, it returns an error.
func (j JSONText) Value() (driver.Value, error) {
var m json.RawMessage
var err = j.Unmarshal(&m)
if err != nil {
return []byte{}, err
}
return []byte(j), nil
}
// Scan stores the src in *j. No validation is done.
func (j *JSONText) Scan(src interface{}) error {
var source []byte
switch t := src.(type) {
case string:
source = []byte(t)
case []byte:
if len(t) == 0 {
source = emptyJSON
} else {
source = t
}
case nil:
*j = emptyJSON
default:
return errors.New("Incompatible type for JSONText")
}
*j = JSONText(append((*j)[0:0], source...))
return nil
}
// Unmarshal unmarshal's the json in j to v, as in json.Unmarshal.
func (j *JSONText) Unmarshal(v interface{}) error {
if len(*j) == 0 {
*j = emptyJSON
}
return json.Unmarshal([]byte(*j), v)
}
// String supports pretty printing for JSONText types.
func (j JSONText) String() string {
return string(j)
}
// NullJSONText represents a JSONText that may be null.
// NullJSONText implements the scanner interface so
// it can be used as a scan destination, similar to NullString.
type NullJSONText struct {
JSONText
Valid bool // Valid is true if JSONText is not NULL
}
// Scan implements the Scanner interface.
func (n *NullJSONText) Scan(value interface{}) error {
if value == nil {
n.JSONText, n.Valid = emptyJSON, false
return nil
}
n.Valid = true
return n.JSONText.Scan(value)
}
// Value implements the driver Valuer interface.
func (n NullJSONText) Value() (driver.Value, error) {
if !n.Valid {
return nil, nil
}
return n.JSONText.Value()
}
// BitBool is an implementation of a bool for the MySQL type BIT(1).
// This type allows you to avoid wasting an entire byte for MySQL's boolean type TINYINT.
type BitBool bool
// Value implements the driver.Valuer interface,
// and turns the BitBool into a bitfield (BIT(1)) for MySQL storage.
func (b BitBool) Value() (driver.Value, error) {
if b {
return []byte{1}, nil
}
return []byte{0}, nil
}
// Scan implements the sql.Scanner interface,
// and turns the bitfield incoming from MySQL into a BitBool
func (b *BitBool) Scan(src interface{}) error {
v, ok := src.([]byte)
if !ok {
return errors.New("bad []byte type assertion")
}
*b = v[0] == 1
return nil
}