Makefile, server entry point prototype, compareFiles function + other minor changes

internal/core/utils.go

@@ -1,8 +1,36 @@
 package core
 
+import (
+	"crypto/sha256"
+	"io"
+	"os"
+)
 
-//! Not implemented
-func CompareFiles(file1 File, file2 File) bool {
-	return false
+// Panic if e contains an error
+func Check(e error) {
+	if e != nil {
+		panic("Check: A fatal error occured during execution -> " + e.Error())
+	}
 }
 
+// Returns true if files correspond
+func CompareFiles(file1 File, file2 File) bool {
+	return file1.Metadata.Hash == file2.Metadata.Hash
+}
+
+// Gets the sha256 hash of a file's content
+func GetHash(file File) ([]byte, error) {
+	// init
+	hasher := sha256.New()
+	file_path := "" //TODO: missing
+	// Open file
+	f, err := os.Open(file_path)
+	if err != nil { // Path error
+		return nil, err
+	}
+	// Compute hash
+	io.Copy(hasher, f)
+	sum := hasher.Sum(nil)
+
+	return sum, nil
+}