Code comments and consistency improvements. (#12)

src/util.cpp

@@ -0,0 +1,84 @@
+#include <string>
+#include <sodium.h>
+
+using namespace std;
+
+namespace util
+{
+
+void replace_string_contents(string &str, const char *bytes, size_t bytes_len)
+{
+    if (str.length() > 0)
+        str.clear();
+    str.append(bytes, bytes_len);
+}
+
+int base64_encode(const unsigned char *bin, size_t bin_len, string &encoded_string)
+{
+    // Get length of encoded result from sodium.
+    const size_t base64_len = sodium_base64_encoded_len(bin_len, sodium_base64_VARIANT_ORIGINAL);
+    char base64chars[base64_len];
+
+    // Get encoded string.
+    const char *encoded_str_char = sodium_bin2base64(
+        base64chars, base64_len,
+        bin, bin_len,
+        sodium_base64_VARIANT_ORIGINAL);
+
+    if (encoded_str_char == NULL)
+        return -1;
+
+    // Assign the encoded char* onto the provided string reference.
+    replace_string_contents(encoded_string, base64chars, base64_len);
+    return 0;
+}
+
+int base64_decode(const string &base64_str, unsigned char *decoded, size_t decoded_len)
+{
+    const char *b64_end;
+    size_t bin_len;
+    if (sodium_base642bin(
+            decoded, decoded_len,
+            base64_str.data(), base64_str.size() + 1,
+            "", &bin_len, &b64_end,
+            sodium_base64_VARIANT_ORIGINAL))
+    {
+        return -1;
+    }
+
+    return 0;
+}
+
+//   v1 <  v2  -> -1
+//   v1 == v2  ->  0
+//   v1 >  v2  -> +1
+int version_compare(const string &v1, const string &v2)
+{
+    size_t i = 0, j = 0;
+    while (i < v1.length() || j < v2.length())
+    {
+        int acc1 = 0, acc2 = 0;
+
+        while (i < v1.length() && v1[i] != '.')
+        {
+            acc1 = acc1 * 10 + (v1[i] - '0');
+            i++;
+        }
+        while (j < v2.length() && v2[j] != '.')
+        {
+            acc2 = acc2 * 10 + (v2[j] - '0');
+            j++;
+        }
+
+        if (acc1 < acc2)
+            return -1;
+        if (acc1 > acc2)
+            return +1;
+
+        ++i;
+        ++j;
+    }
+    return 0;
+}
+
+} // namespace util