func New() encoding.Integer {
f := &FastPFOR{
pageSize: DefaultPageSize,
byteContainer: bytebuffer.NewByteBuffer(3*DefaultPageSize/DefaultBlockSize + DefaultPageSize),
dataPointers: make([]int32, 33),
freqs: make([]int32, 33),
}
for i := 1; i < 33; i++ {
f.dataToBePacked[i] = make([]int32, DefaultPageSize/32*4)
}
return f
}
func (this *VariableByte) Compress(in []int32, inpos *cursor.Cursor, inlength int, out []int32, outpos *cursor.Cursor) error {
if inlength == 0 {
return errors.New("variablebyte/Compress: inlength = 0. No work done.")
}
//fmt.Printf("variablebyte/Compress: after inlength = %d\n", inlength)
buf := bytebuffer.NewByteBuffer(inlength * 8)
initoffset := int32(0)
tmpinpos := inpos.Get()
for _, v := range in[tmpinpos : tmpinpos+inlength] {
val := uint32(v - initoffset)
initoffset = v
for val >= 0x80 {
buf.Put(byte(val) | 0x80)
val >>= 7
}
buf.Put(byte(val))
}
for buf.Position()%4 != 0 {
//fmt.Printf("variablebyte/Compress: putting 128\n")
buf.Put(128)
}
length := buf.Position()
buf.Flip()
ibuf := buf.AsInt32Buffer()
//fmt.Printf("variablebyte/Compress: l = %d, outpos = %d, ibuf = %v, buf = %v\n", length/4, outpos.Get(), ibuf, buf)
err := ibuf.GetInt32s(out, outpos.Get(), length/4)
if err != nil {
//fmt.Printf("variablebyte/Compress: error with GetUint32s - %v\n", err)
return err
}
outpos.Add(length / 4)
inpos.Add(inlength)
//fmt.Printf("variablebyte/Compress: out = %v\n", out)
return nil
}