package pq import ( "bytes" "database/sql" "database/sql/driver" "encoding/hex" "fmt" "reflect" "strconv" "strings" ) var typeByteSlice = reflect.TypeOf([]byte{}) var typeDriverValuer = reflect.TypeOf((*driver.Valuer)(nil)).Elem() var typeSqlScanner = reflect.TypeOf((*sql.Scanner)(nil)).Elem() // Array returns the optimal driver.Valuer and sql.Scanner for an array or // slice of any dimension. // // For example: // db.Query(`SELECT * FROM t WHERE id = ANY($1)`, pq.Array([]int{235, 401})) // // var x []sql.NullInt64 // db.QueryRow('SELECT ARRAY[235, 401]').Scan(pq.Array(&x)) // // Scanning multi-dimensional arrays is not supported. Arrays where the lower // bound is not one (such as `[0:0]={1}') are not supported. func Array(a interface{}) interface { driver.Valuer sql.Scanner } { switch a := a.(type) { case []bool: return (*BoolArray)(&a) case []float64: return (*Float64Array)(&a) case []int64: return (*Int64Array)(&a) case []string: return (*StringArray)(&a) case *[]bool: return (*BoolArray)(a) case *[]float64: return (*Float64Array)(a) case *[]int64: return (*Int64Array)(a) case *[]string: return (*StringArray)(a) } return GenericArray{a} } // ArrayDelimiter may be optionally implemented by driver.Valuer or sql.Scanner // to override the array delimiter used by GenericArray. type ArrayDelimiter interface { // ArrayDelimiter returns the delimiter character(s) for this element's type. ArrayDelimiter() string } // BoolArray represents a one-dimensional array of the PostgreSQL boolean type. type BoolArray []bool // Scan implements the sql.Scanner interface. func (a *BoolArray) Scan(src interface{}) error { switch src := src.(type) { case []byte: return a.scanBytes(src) case string: return a.scanBytes([]byte(src)) } return fmt.Errorf("pq: cannot convert %T to BoolArray", src) } func (a *BoolArray) scanBytes(src []byte) error { elems, err := scanLinearArray(src, []byte{','}, "BoolArray") if err != nil { return err } if len(elems) == 0 { *a = (*a)[:0] } else { b := make(BoolArray, len(elems)) for i, v := range elems { if len(v) != 1 { return fmt.Errorf("pq: could not parse boolean array index %d: invalid boolean %q", i, v) } switch v[0] { case 't': b[i] = true case 'f': b[i] = false default: return fmt.Errorf("pq: could not parse boolean array index %d: invalid boolean %q", i, v) } } *a = b } return nil } // Value implements the driver.Valuer interface. func (a BoolArray) Value() (driver.Value, error) { if a == nil { return nil, nil } if n := len(a); n > 0 { // There will be exactly two curly brackets, N bytes of values, // and N-1 bytes of delimiters. b := make([]byte, 1+2*n) for i := 0; i < n; i++ { b[2*i] = ',' if a[i] { b[1+2*i] = 't' } else { b[1+2*i] = 'f' } } b[0] = '{' b[2*n] = '}' return string(b), nil } return "{}", nil } // ByteaArray represents a one-dimensional array of the PostgreSQL bytea type. type ByteaArray [][]byte // Scan implements the sql.Scanner interface. func (a *ByteaArray) Scan(src interface{}) error { switch src := src.(type) { case []byte: return a.scanBytes(src) case string: return a.scanBytes([]byte(src)) } return fmt.Errorf("pq: cannot convert %T to ByteaArray", src) } func (a *ByteaArray) scanBytes(src []byte) error { elems, err := scanLinearArray(src, []byte{','}, "ByteaArray") if err != nil { return err } if len(elems) == 0 { *a = (*a)[:0] } else { b := make(ByteaArray, len(elems)) for i, v := range elems { b[i], err = parseBytea(v) if err != nil { return fmt.Errorf("could not parse bytea array index %d: %s", i, err.Error()) } } *a = b } return nil } // Value implements the driver.Valuer interface. It uses the "hex" format which // is only supported on PostgreSQL 9.0 or newer. func (a ByteaArray) Value() (driver.Value, error) { if a == nil { return nil, nil } if n := len(a); n > 0 { // There will be at least two curly brackets, 2*N bytes of quotes, // 3*N bytes of hex formatting, and N-1 bytes of delimiters. size := 1 + 6*n for _, x := range a { size += hex.EncodedLen(len(x)) } b := make([]byte, size) for i, s := 0, b; i < n; i++ { o := copy(s, `,"\\x`) o += hex.Encode(s[o:], a[i]) s[o] = '"' s = s[o+1:] } b[0] = '{' b[size-1] = '}' return string(b), nil } return "{}", nil } // Float64Array represents a one-dimensional array of the PostgreSQL double // precision type. type Float64Array []float64 // Scan implements the sql.Scanner interface. func (a *Float64Array) Scan(src interface{}) error { switch src := src.(type) { case []byte: return a.scanBytes(src) case string: return a.scanBytes([]byte(src)) } return fmt.Errorf("pq: cannot convert %T to Float64Array", src) } func (a *Float64Array) scanBytes(src []byte) error { elems, err := scanLinearArray(src, []byte{','}, "Float64Array") if err != nil { return err } if len(elems) == 0 { *a = (*a)[:0] } else { b := make(Float64Array, len(elems)) for i, v := range elems { if b[i], err = strconv.ParseFloat(string(v), 64); err != nil { return fmt.Errorf("pq: parsing array element index %d: %v", i, err) } } *a = b } return nil } // Value implements the driver.Valuer interface. func (a Float64Array) Value() (driver.Value, error) { if a == nil { return nil, nil } if n := len(a); n > 0 { // There will be at least two curly brackets, N bytes of values, // and N-1 bytes of delimiters. b := make([]byte, 1, 1+2*n) b[0] = '{' b = strconv.AppendFloat(b, a[0], 'f', -1, 64) for i := 1; i < n; i++ { b = append(b, ',') b = strconv.AppendFloat(b, a[i], 'f', -1, 64) } return string(append(b, '}')), nil } return "{}", nil } // GenericArray implements the driver.Valuer and sql.Scanner interfaces for // an array or slice of any dimension. type GenericArray struct{ A interface{} } func (GenericArray) evaluateDestination(rt reflect.Type) (reflect.Type, func([]byte, reflect.Value) error, string) { var assign func([]byte, reflect.Value) error var del = "," // TODO calculate the assign function for other types // TODO repeat this section on the element type of arrays or slices (multidimensional) { if reflect.PtrTo(rt).Implements(typeSqlScanner) { // dest is always addressable because it is an element of a slice. assign = func(src []byte, dest reflect.Value) (err error) { ss := dest.Addr().Interface().(sql.Scanner) if src == nil { err = ss.Scan(nil) } else { err = ss.Scan(src) } return } goto FoundType } assign = func([]byte, reflect.Value) error { return fmt.Errorf("pq: scanning to %s is not implemented; only sql.Scanner", rt) } } FoundType: if ad, ok := reflect.Zero(rt).Interface().(ArrayDelimiter); ok { del = ad.ArrayDelimiter() } return rt, assign, del } // Scan implements the sql.Scanner interface. func (a GenericArray) Scan(src interface{}) error { dpv := reflect.ValueOf(a.A) switch { case dpv.Kind() != reflect.Ptr: return fmt.Errorf("pq: destination %T is not a pointer to array or slice", a.A) case dpv.IsNil(): return fmt.Errorf("pq: destination %T is nil", a.A) } dv := dpv.Elem() switch dv.Kind() { case reflect.Slice: case reflect.Array: default: return fmt.Errorf("pq: destination %T is not a pointer to array or slice", a.A) } switch src := src.(type) { case []byte: return a.scanBytes(src, dv) case string: return a.scanBytes([]byte(src), dv) } return fmt.Errorf("pq: cannot convert %T to %s", src, dv.Type()) } func (a GenericArray) scanBytes(src []byte, dv reflect.Value) error { dtype, assign, del := a.evaluateDestination(dv.Type().Elem()) dims, elems, err := parseArray(src, []byte(del)) if err != nil { return err } // TODO allow multidimensional if len(dims) > 1 { return fmt.Errorf("pq: scanning from multidimensional ARRAY%s is not implemented", strings.Replace(fmt.Sprint(dims), " ", "][", -1)) } // Treat a zero-dimensional array like an array with a single dimension of zero. if len(dims) == 0 { dims = append(dims, 0) } for i, rt := 0, dv.Type(); i < len(dims); i, rt = i+1, rt.Elem() { switch rt.Kind() { case reflect.Slice: case reflect.Array: if rt.Len() != dims[i] { return fmt.Errorf("pq: cannot convert ARRAY%s to %s", strings.Replace(fmt.Sprint(dims), " ", "][", -1), dv.Type()) } default: // TODO handle multidimensional } } values := reflect.MakeSlice(reflect.SliceOf(dtype), len(elems), len(elems)) for i, e := range elems { if err := assign(e, values.Index(i)); err != nil { return fmt.Errorf("pq: parsing array element index %d: %v", i, err) } } // TODO handle multidimensional switch dv.Kind() { case reflect.Slice: dv.Set(values.Slice(0, dims[0])) case reflect.Array: for i := 0; i < dims[0]; i++ { dv.Index(i).Set(values.Index(i)) } } return nil } // Value implements the driver.Valuer interface. func (a GenericArray) Value() (driver.Value, error) { if a.A == nil { return nil, nil } rv := reflect.ValueOf(a.A) if k := rv.Kind(); k != reflect.Array && k != reflect.Slice { return nil, fmt.Errorf("pq: Unable to convert %T to array", a.A) } if n := rv.Len(); n > 0 { // There will be at least two curly brackets, N bytes of values, // and N-1 bytes of delimiters. b := make([]byte, 0, 1+2*n) b, _, err := appendArray(b, rv, n) return string(b), err } return "{}", nil } // Int64Array represents a one-dimensional array of the PostgreSQL integer types. type Int64Array []int64 // Scan implements the sql.Scanner interface. func (a *Int64Array) Scan(src interface{}) error { switch src := src.(type) { case []byte: return a.scanBytes(src) case string: return a.scanBytes([]byte(src)) } return fmt.Errorf("pq: cannot convert %T to Int64Array", src) } func (a *Int64Array) scanBytes(src []byte) error { elems, err := scanLinearArray(src, []byte{','}, "Int64Array") if err != nil { return err } if len(elems) == 0 { *a = (*a)[:0] } else { b := make(Int64Array, len(elems)) for i, v := range elems { if b[i], err = strconv.ParseInt(string(v), 10, 64); err != nil { return fmt.Errorf("pq: parsing array element index %d: %v", i, err) } } *a = b } return nil } // Value implements the driver.Valuer interface. func (a Int64Array) Value() (driver.Value, error) { if a == nil { return nil, nil } if n := len(a); n > 0 { // There will be at least two curly brackets, N bytes of values, // and N-1 bytes of delimiters. b := make([]byte, 1, 1+2*n) b[0] = '{' b = strconv.AppendInt(b, a[0], 10) for i := 1; i < n; i++ { b = append(b, ',') b = strconv.AppendInt(b, a[i], 10) } return string(append(b, '}')), nil } return "{}", nil } // StringArray represents a one-dimensional array of the PostgreSQL character types. type StringArray []string // Scan implements the sql.Scanner interface. func (a *StringArray) Scan(src interface{}) error { switch src := src.(type) { case []byte: return a.scanBytes(src) case string: return a.scanBytes([]byte(src)) } return fmt.Errorf("pq: cannot convert %T to StringArray", src) } func (a *StringArray) scanBytes(src []byte) error { elems, err := scanLinearArray(src, []byte{','}, "StringArray") if err != nil { return err } if len(elems) == 0 { *a = (*a)[:0] } else { b := make(StringArray, len(elems)) for i, v := range elems { if b[i] = string(v); v == nil { return fmt.Errorf("pq: parsing array element index %d: cannot convert nil to string", i) } } *a = b } return nil } // Value implements the driver.Valuer interface. func (a StringArray) Value() (driver.Value, error) { if a == nil { return nil, nil } if n := len(a); n > 0 { // There will be at least two curly brackets, 2*N bytes of quotes, // and N-1 bytes of delimiters. b := make([]byte, 1, 1+3*n) b[0] = '{' b = appendArrayQuotedBytes(b, []byte(a[0])) for i := 1; i < n; i++ { b = append(b, ',') b = appendArrayQuotedBytes(b, []byte(a[i])) } return string(append(b, '}')), nil } return "{}", nil } // appendArray appends rv to the buffer, returning the extended buffer and // the delimiter used between elements. // // It panics when n <= 0 or rv's Kind is not reflect.Array nor reflect.Slice. func appendArray(b []byte, rv reflect.Value, n int) ([]byte, string, error) { var del string var err error b = append(b, '{') if b, del, err = appendArrayElement(b, rv.Index(0)); err != nil { return b, del, err } for i := 1; i < n; i++ { b = append(b, del...) if b, del, err = appendArrayElement(b, rv.Index(i)); err != nil { return b, del, err } } return append(b, '}'), del, nil } // appendArrayElement appends rv to the buffer, returning the extended buffer // and the delimiter to use before the next element. // // When rv's Kind is neither reflect.Array nor reflect.Slice, it is converted // using driver.DefaultParameterConverter and the resulting []byte or string // is double-quoted. // // See http://www.postgresql.org/docs/current/static/arrays.html#ARRAYS-IO func appendArrayElement(b []byte, rv reflect.Value) ([]byte, string, error) { if k := rv.Kind(); k == reflect.Array || k == reflect.Slice { if t := rv.Type(); t != typeByteSlice && !t.Implements(typeDriverValuer) { if n := rv.Len(); n > 0 { return appendArray(b, rv, n) } return b, "", nil } } var del string = "," var err error var iv interface{} = rv.Interface() if ad, ok := iv.(ArrayDelimiter); ok { del = ad.ArrayDelimiter() } if iv, err = driver.DefaultParameterConverter.ConvertValue(iv); err != nil { return b, del, err } switch v := iv.(type) { case nil: return append(b, "NULL"...), del, nil case []byte: return appendArrayQuotedBytes(b, v), del, nil case string: return appendArrayQuotedBytes(b, []byte(v)), del, nil } b, err = appendValue(b, iv) return b, del, err } func appendArrayQuotedBytes(b, v []byte) []byte { b = append(b, '"') for { i := bytes.IndexAny(v, `"\`) if i < 0 { b = append(b, v...) break } if i > 0 { b = append(b, v[:i]...) } b = append(b, '\\', v[i]) v = v[i+1:] } return append(b, '"') } func appendValue(b []byte, v driver.Value) ([]byte, error) { return append(b, encode(nil, v, 0)...), nil } // parseArray extracts the dimensions and elements of an array represented in // text format. Only representations emitted by the backend are supported. // Notably, whitespace around brackets and delimiters is significant, and NULL // is case-sensitive. // // See http://www.postgresql.org/docs/current/static/arrays.html#ARRAYS-IO func parseArray(src, del []byte) (dims []int, elems [][]byte, err error) { var depth, i int if len(src) < 1 || src[0] != '{' { return nil, nil, fmt.Errorf("pq: unable to parse array; expected %q at offset %d", '{', 0) } Open: for i < len(src) { switch src[i] { case '{': depth++ i++ case '}': elems = make([][]byte, 0) goto Close default: break Open } } dims = make([]int, i) Element: for i < len(src) { switch src[i] { case '{': depth++ dims[depth-1] = 0 i++ case '"': var elem = []byte{} var escape bool for i++; i < len(src); i++ { if escape { elem = append(elem, src[i]) escape = false } else { switch src[i] { default: elem = append(elem, src[i]) case '\\': escape = true case '"': elems = append(elems, elem) i++ break Element } } } default: for start := i; i < len(src); i++ { if bytes.HasPrefix(src[i:], del) || src[i] == '}' { elem := src[start:i] if len(elem) == 0 { return nil, nil, fmt.Errorf("pq: unable to parse array; unexpected %q at offset %d", src[i], i) } if bytes.Equal(elem, []byte("NULL")) { elem = nil } elems = append(elems, elem) break Element } } } } for i < len(src) { if bytes.HasPrefix(src[i:], del) { dims[depth-1]++ i += len(del) goto Element } else if src[i] == '}' { dims[depth-1]++ depth-- i++ } else { return nil, nil, fmt.Errorf("pq: unable to parse array; unexpected %q at offset %d", src[i], i) } } Close: for i < len(src) { if src[i] == '}' && depth > 0 { depth-- i++ } else { return nil, nil, fmt.Errorf("pq: unable to parse array; unexpected %q at offset %d", src[i], i) } } if depth > 0 { err = fmt.Errorf("pq: unable to parse array; expected %q at offset %d", '}', i) } if err == nil { for _, d := range dims { if (len(elems) % d) != 0 { err = fmt.Errorf("pq: multidimensional arrays must have elements with matching dimensions") } } } return } func scanLinearArray(src, del []byte, typ string) (elems [][]byte, err error) { dims, elems, err := parseArray(src, del) if err != nil { return nil, err } if len(dims) > 1 { return nil, fmt.Errorf("pq: cannot convert ARRAY%s to %s", strings.Replace(fmt.Sprint(dims), " ", "][", -1), typ) } return elems, err }