diff options
Diffstat (limited to 'vendor/github.com/jackc/pgx/hstore.go')
| -rw-r--r-- | vendor/github.com/jackc/pgx/hstore.go | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/vendor/github.com/jackc/pgx/hstore.go b/vendor/github.com/jackc/pgx/hstore.go new file mode 100644 index 0000000..0ab9f77 --- /dev/null +++ b/vendor/github.com/jackc/pgx/hstore.go @@ -0,0 +1,222 @@ +package pgx + +import ( + "bytes" + "errors" + "fmt" + "unicode" + "unicode/utf8" +) + +const ( + hsPre = iota + hsKey + hsSep + hsVal + hsNul + hsNext +) + +type hstoreParser struct { + str string + pos int +} + +func newHSP(in string) *hstoreParser { + return &hstoreParser{ + pos: 0, + str: in, + } +} + +func (p *hstoreParser) Consume() (r rune, end bool) { + if p.pos >= len(p.str) { + end = true + return + } + r, w := utf8.DecodeRuneInString(p.str[p.pos:]) + p.pos += w + return +} + +func (p *hstoreParser) Peek() (r rune, end bool) { + if p.pos >= len(p.str) { + end = true + return + } + r, _ = utf8.DecodeRuneInString(p.str[p.pos:]) + return +} + +func parseHstoreToMap(s string) (m map[string]string, err error) { + keys, values, err := ParseHstore(s) + if err != nil { + return + } + m = make(map[string]string, len(keys)) + for i, key := range keys { + if !values[i].Valid { + err = fmt.Errorf("key '%s' has NULL value", key) + m = nil + return + } + m[key] = values[i].String + } + return +} + +func parseHstoreToNullHstore(s string) (store map[string]NullString, err error) { + keys, values, err := ParseHstore(s) + if err != nil { + return + } + + store = make(map[string]NullString, len(keys)) + + for i, key := range keys { + store[key] = values[i] + } + return +} + +// ParseHstore parses the string representation of an hstore column (the same +// you would get from an ordinary SELECT) into two slices of keys and values. it +// is used internally in the default parsing of hstores, but is exported for use +// in handling custom data structures backed by an hstore column without the +// overhead of creating a map[string]string +func ParseHstore(s string) (k []string, v []NullString, err error) { + if s == "" { + return + } + + buf := bytes.Buffer{} + keys := []string{} + values := []NullString{} + p := newHSP(s) + + r, end := p.Consume() + state := hsPre + + for !end { + switch state { + case hsPre: + if r == '"' { + state = hsKey + } else { + err = errors.New("String does not begin with \"") + } + case hsKey: + switch r { + case '"': //End of the key + if buf.Len() == 0 { + err = errors.New("Empty Key is invalid") + } else { + keys = append(keys, buf.String()) + buf = bytes.Buffer{} + state = hsSep + } + case '\\': //Potential escaped character + n, end := p.Consume() + switch { + case end: + err = errors.New("Found EOS in key, expecting character or \"") + case n == '"', n == '\\': + buf.WriteRune(n) + default: + buf.WriteRune(r) + buf.WriteRune(n) + } + default: //Any other character + buf.WriteRune(r) + } + case hsSep: + if r == '=' { + r, end = p.Consume() + switch { + case end: + err = errors.New("Found EOS after '=', expecting '>'") + case r == '>': + r, end = p.Consume() + switch { + case end: + err = errors.New("Found EOS after '=>', expecting '\"' or 'NULL'") + case r == '"': + state = hsVal + case r == 'N': + state = hsNul + default: + err = fmt.Errorf("Invalid character '%c' after '=>', expecting '\"' or 'NULL'", r) + } + default: + err = fmt.Errorf("Invalid character after '=', expecting '>'") + } + } else { + err = fmt.Errorf("Invalid character '%c' after value, expecting '='", r) + } + case hsVal: + switch r { + case '"': //End of the value + values = append(values, NullString{String: buf.String(), Valid: true}) + buf = bytes.Buffer{} + state = hsNext + case '\\': //Potential escaped character + n, end := p.Consume() + switch { + case end: + err = errors.New("Found EOS in key, expecting character or \"") + case n == '"', n == '\\': + buf.WriteRune(n) + default: + buf.WriteRune(r) + buf.WriteRune(n) + } + default: //Any other character + buf.WriteRune(r) + } + case hsNul: + nulBuf := make([]rune, 3) + nulBuf[0] = r + for i := 1; i < 3; i++ { + r, end = p.Consume() + if end { + err = errors.New("Found EOS in NULL value") + return + } + nulBuf[i] = r + } + if nulBuf[0] == 'U' && nulBuf[1] == 'L' && nulBuf[2] == 'L' { + values = append(values, NullString{String: "", Valid: false}) + state = hsNext + } else { + err = fmt.Errorf("Invalid NULL value: 'N%s'", string(nulBuf)) + } + case hsNext: + if r == ',' { + r, end = p.Consume() + switch { + case end: + err = errors.New("Found EOS after ',', expcting space") + case (unicode.IsSpace(r)): + r, end = p.Consume() + state = hsKey + default: + err = fmt.Errorf("Invalid character '%c' after ', ', expecting \"", r) + } + } else { + err = fmt.Errorf("Invalid character '%c' after value, expecting ','", r) + } + } + + if err != nil { + return + } + r, end = p.Consume() + } + if state != hsNext { + err = errors.New("Improperly formatted hstore") + return + } + k = keys + v = values + return +} |