init

1 files changed, 57 insertions, 0 deletions

diff --git a/utils/utils.go b/utils/utils.go
new file mode 100644
index 0000000..62924c2
--- /dev/null
+++ b/utils/utils.go
@@ -0,0 +1,57 @@
+package utils
+
+import (
+        "encoding/binary"
+        "log"
+        "math"
+        "os"
+        "unsafe"
+
+        "github.com/potterxu/bitreader"
+)
+
+func ReadByteFromFile(file *os.File, size int32) []byte {
+        tmp := make([]byte, size)
+        file.Read(tmp)
+        return tmp
+}
+
+func CheckError(e error) {
+        if e != nil {
+                log.Panic(e)
+        }
+}
+
+func CheckFirstBit(byteArr []byte) bool {
+        reader := bitreader.BitReader(byteArr)
+        state, err := reader.ReadBit()
+        if err != nil {
+                state = false
+        }
+        return state
+}
+
+func IntFromBytes(byteArr []byte) uint32 {
+        int := binary.LittleEndian.Uint32(byteArr)
+        return int
+}
+
+func FloatFromBytes(byteArr []byte) float32 {
+        bits := binary.LittleEndian.Uint32(byteArr)
+        float := math.Float32frombits(bits)
+        return float
+}
+
+func FloatArrFromBytes(byteArr []byte) []float32 {
+        if len(byteArr) == 0 {
+                return nil
+        }
+
+        l := len(byteArr) / 4
+        ptr := unsafe.Pointer(&byteArr[0])
+        // It is important to keep in mind that the Go garbage collector
+        // will not interact with this data, and that if src if freed,
+        // the behavior of any Go code using the slice is nondeterministic.
+        // Reference: https://github.com/golang/go/wiki/cgo#turning-c-arrays-into-go-slices
+        return (*[1 << 26]float32)((*[1 << 26]float32)(ptr))[:l:l]
+}