directory structure change to work with glide

glide has its own requirements. My previous workaround caused me some
code checkin errors. Need to fix this.

weed/compress/compression_test.go

@@ -0,0 +1,45 @@
+package compress
+
+import (
+	"math/rand"
+	"testing"
+)
+
+func TestSortedData(t *testing.T) {
+	data := make([]int32, 102400)
+	for i := 1; i < len(data); i++ {
+		data[i] = data[i-1] + rand.Int31n(15)
+	}
+	testCompressAndUncompress(t, data, "Sorted data")
+}
+
+func TestUnsortedData(t *testing.T) {
+	data := make([]int32, 102400)
+	for i := 0; i < len(data); i++ {
+		data[i] = rand.Int31n(255)
+	}
+	testCompressAndUncompress(t, data, "Unsorted data")
+}
+
+func testCompressAndUncompress(t *testing.T, data []int32, desc string) {
+
+	compressed_data, err := Compress32(data)
+	if err != nil {
+		t.Fatal("Compress error", err.Error())
+	}
+	uncompressed_data, err := Uncompress32(compressed_data, make([]int32, len(data)*2))
+	if err != nil {
+		t.Fatal("Compress error", err.Error())
+	}
+	if len(uncompressed_data) != len(data) {
+		t.Fatal("Len differs", len(data), len(uncompressed_data))
+	}
+	for i := 0; i < len(data); i++ {
+		if data[i] != uncompressed_data[i] {
+			t.Fatal("Data differs:", i, data[i], uncompressed_data[i])
+		}
+	}
+
+	println(desc, " Data length:", len(data), " => Compressed length:", len(compressed_data))
+
+}

weed/compress/delta_binary_pack32.go

@@ -0,0 +1,32 @@
+package compress
+
+import (
+	"github.com/reducedb/encoding/cursor"
+	"github.com/reducedb/encoding/delta/bp32"
+)
+
+// Compress compresses in[]int32 to out[]int32
+func Compress32(in []int32) (out []int32, err error) {
+	out = make([]int32, len(in)*2)
+	inpos := cursor.New()
+	outpos := cursor.New()
+
+	if err = bp32.New().Compress(in, inpos, len(in), out, outpos); err != nil {
+		return nil, err
+	}
+
+	return out[:outpos.Get()], nil
+}
+
+// Uncompress uncompresses in[]int32 to out[]int32
+func Uncompress32(in []int32, buffer []int32) (out []int32, err error) {
+	out = buffer
+	inpos := cursor.New()
+	outpos := cursor.New()
+
+	if err = bp32.New().Uncompress(in, inpos, len(in), out, outpos); err != nil {
+		return nil, err
+	}
+
+	return out[:outpos.Get()], nil
+}