// ReadPropertyMap reads a PropertyMap from the buffer. `context` and
// friends behave the same way that they do for ReadKey.
func ReadPropertyMap(buf Buffer, context KeyContext, appid, namespace string) (pm ds.PropertyMap, err error) {
defer recoverTo(&err)
numRows := uint64(0)
numRows, _, e := cmpbin.ReadUint(buf)
panicIf(e)
if numRows > ReadPropertyMapReasonableLimit {
err = fmt.Errorf("helper: tried to decode map with huge number of rows %d", numRows)
return
}
pm = make(ds.PropertyMap, numRows)
name, prop := "", ds.Property{}
for i := uint64(0); i < numRows; i++ {
name, _, e = cmpbin.ReadString(buf)
panicIf(e)
numProps, _, e := cmpbin.ReadUint(buf)
panicIf(e)
if numProps > ReadPropertyMapReasonableLimit {
err = fmt.Errorf("helper: tried to decode map with huge number of properties %d", numProps)
return
}
props := make([]ds.Property, 0, numProps)
for j := uint64(0); j < numProps; j++ {
prop, err = ReadProperty(buf, context, appid, namespace)
panicIf(err)
props = append(props, prop)
}
pm[name] = props
}
return
}
// decode returns the encoded IndexColumns, the raw row (cursor) data, or an
// error.
func (q queryCursor) decode() ([]ds.IndexColumn, []byte, error) {
buf := bytes.NewBuffer([]byte(q))
count, _, err := cmpbin.ReadUint(buf)
if err != nil {
return nil, nil, fmt.Errorf("invalid cursor: bad prefix number")
}
if count == 0 || count > MaxIndexColumns {
return nil, nil, fmt.Errorf("invalid cursor: bad column count %d", count)
}
if count == 0 {
return nil, nil, fmt.Errorf("invalid cursor: zero prefix number")
}
cols := make([]ds.IndexColumn, count)
for i := range cols {
if cols[i], err = serialize.ReadIndexColumn(buf); err != nil {
return nil, nil, fmt.Errorf("invalid cursor: unable to decode IndexColumn %d: %s", i, err)
}
}
if cols[len(cols)-1].Property != "__key__" {
return nil, nil, fmt.Errorf("invalid cursor: last column was not __key__: %v", cols[len(cols)-1])
}
return cols, buf.Bytes(), nil
}
// ReadTime reads a time.Time from the buffer.
func ReadTime(buf Buffer) (time.Time, error) {
v, _, err := cmpbin.ReadUint(buf)
if err != nil {
return time.Time{}, err
}
return time.Unix(int64(v/1e6), int64((v%1e6)*1e3)).UTC(), nil
}