aboutsummaryrefslogtreecommitdiff
path: root/src/common/varint.h
diff options
context:
space:
mode:
authorAntonio Juarez <antonio.maria.juarez@live.com>2014-03-03 22:07:58 +0000
committerAntonio Juarez <antonio.maria.juarez@live.com>2014-03-03 22:07:58 +0000
commit296ae46ed8f8f6e5f986f978febad302e3df231a (patch)
tree1629164454a239308f33c9e12afb22e7f3cd8eeb /src/common/varint.h
parentchanged name (diff)
downloadmonero-296ae46ed8f8f6e5f986f978febad302e3df231a.tar.xz
moved all stuff to github
Diffstat (limited to '')
-rw-r--r--src/common/varint.h62
1 files changed, 62 insertions, 0 deletions
diff --git a/src/common/varint.h b/src/common/varint.h
new file mode 100644
index 000000000..e62470fdf
--- /dev/null
+++ b/src/common/varint.h
@@ -0,0 +1,62 @@
+// Copyright (c) 2012-2013 The Cryptonote developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#pragma once
+
+#include <limits>
+#include <type_traits>
+#include <utility>
+#include <sstream>
+#include <string>
+
+namespace tools {
+
+ template<typename OutputIt, typename T>
+ typename std::enable_if<std::is_integral<T>::value && std::is_unsigned<T>::value, void>::type
+ write_varint(OutputIt &&dest, T i) {
+ while (i >= 0x80) {
+ *dest++ = (static_cast<char>(i) & 0x7f) | 0x80;
+ i >>= 7;
+ }
+ *dest++ = static_cast<char>(i);
+ }
+
+ template<typename t_type>
+ std::string get_varint_data(const t_type& v)
+ {
+ std::stringstream ss;
+ write_varint(std::ostreambuf_iterator<char>(ss), v);
+ return ss.str();
+ }
+
+ template<int bits, typename InputIt, typename T>
+ typename std::enable_if<std::is_integral<T>::value && std::is_unsigned<T>::value && 0 <= bits && bits <= std::numeric_limits<T>::digits, int>::type
+ read_varint(InputIt &&first, InputIt &&last, T &i) {
+ int read = 0;
+ i = 0;
+ for (int shift = 0;; shift += 7) {
+ if (first == last) {
+ return read; // End of input.
+ }
+ unsigned char byte = *first++;
+ ++read;
+ if (shift + 7 >= bits && byte >= 1 << (bits - shift)) {
+ return -1; // Overflow.
+ }
+ if (byte == 0 && shift != 0) {
+ return -2; // Non-canonical representation.
+ }
+ i |= static_cast<T>(byte & 0x7f) << shift;
+ if ((byte & 0x80) == 0) {
+ break;
+ }
+ }
+ return read;
+ }
+
+ template<typename InputIt, typename T>
+ int read_varint(InputIt &&first, InputIt &&last, T &i) {
+ return read_varint<std::numeric_limits<T>::digits, InputIt, T>(std::move(first), std::move(last), i);
+ }
+}