[yql/udfs/string] Add base32

Добавил в String UDF поддержку base32

1 files changed, 120 insertions, 0 deletions

diff --git a/library/cpp/string_utils/base32/base32.h b/library/cpp/string_utils/base32/base32.h
new file mode 100644
index 0000000000..2596bf78a2
--- /dev/null
+++ b/library/cpp/string_utils/base32/base32.h
@@ -0,0 +1,120 @@
+#pragma once
+
+#include <util/generic/string.h>
+
+#include <string>
+#include <string_view>
+
+// Base32 encoding based on RFC 4648 alphabet (incompatible with Crockford and Geohash alphabet)
+// https://en.wikipedia.org/wiki/Base32#RFC_4648_Base32_alphabet
+
+///
+/// @return Size of the buffer required to decode Base32 encoded data of size `len`.
+///
+constexpr size_t Base32DecodeBufSize(size_t len) noexcept {
+    return (len * 5 + 7) / 8;
+}
+
+///
+/// @brief Decodes only valid Base32 string, behaviour for invalid data is unspecified.
+///
+/// @param src a base32 encoded string.
+/// @param dst an pointer to allocated memory for writing result.
+///
+/// @return Count of written bytes.
+///
+size_t Base32Decode(std::string_view src, char* dst);
+
+///
+/// @param src a base32 encoded string.
+/// @param dst a decoded string.
+///
+inline void Base32Decode(std::string_view src, std::string& dst)
+{
+    ::ResizeUninitialized(dst, Base32DecodeBufSize(src.size()));
+    dst.resize(Base32Decode(src, dst.data()));
+}
+
+///
+/// @param s a base32 encoded string.
+///
+/// @returns a decoded string.
+///
+inline std::string Base32Decode(std::string_view s)
+{
+    std::string ret;
+    Base32Decode(s, ret);
+    return ret;
+}
+
+///
+/// @brief Decodes Base32 string with strict verification of invalid symbols,
+///        also tries to decode Base32 string with padding inside.
+///
+/// @throws Throws exceptions on inputs which contain invalid symbols or incorrect padding.
+///
+/// @param src a base32 encoded string.
+/// @param dst an pointer to allocated memory for writing result.
+///
+/// @return Count of written bytes.
+///
+size_t Base32StrictDecode(std::string_view src, char* dst);
+
+///
+/// @param src a base32 encoded string.
+/// @param dst a decoded string.
+///
+inline void Base32StrictDecode(std::string_view src, std::string& dst)
+{
+    ::ResizeUninitialized(dst, Base32DecodeBufSize(src.size()));
+    dst.resize(Base32StrictDecode(src, dst.data()));
+}
+
+///
+/// @param s a base32 encoded string.
+///
+/// @returns a decoded string.
+///
+inline std::string Base32StrictDecode(std::string_view s)
+{
+    std::string ret;
+    Base32StrictDecode(s, ret);
+    return ret;
+}
+
+///
+/// @return Size of the buffer required to encode Base32 decoded data of size `len`.
+///
+constexpr size_t Base32EncodeBufSize(size_t len) noexcept {
+    return ((len * 8 + 4) / 5 + 7) / 8 * 8;
+}
+
+///
+/// @param src a base32 decoded string.
+/// @param dst an pointer to allocated memory for writing result.
+///
+/// @return Count of written bytes.
+///
+size_t Base32Encode(std::string_view src, char* dst);
+
+///
+/// @param src a base32 decoded string.
+/// @param dst a encoded string.
+///
+inline void Base32Encode(std::string_view src, std::string& dst)
+{
+    ::ResizeUninitialized(dst, Base32EncodeBufSize(src.size()));
+    dst.resize(Base32Encode(src, dst.data()));
+}
+
+///
+/// @param s a base32 decoded string.
+///
+/// @returns a encoded string.
+///
+inline std::string Base32Encode(std::string_view s)
+{
+    std::string ret;
+    Base32Encode(s, ret);
+    return ret;
+}