util/HexFormat: use std::span instead of ConstBuffer

src/input/plugins/QobuzClient.cxx

@@ -211,8 +211,8 @@ QobuzClient::MakeSignedUrl(const char *object, const char *method,
 
 	concatenated_query += app_secret;
 
-	const auto md5_hex = MD5Hex({concatenated_query.data(), concatenated_query.size()});
-	q(uri, "request_sig", md5_hex.c_str());
+	const auto md5_hex = MD5Hex(std::as_bytes(std::span{concatenated_query}));
+	q(uri, "request_sig", std::string_view{md5_hex.data(), md5_hex.size()});
 
 	return uri;
 }

src/lib/crypto/MD5.cxx

@@ -50,21 +50,22 @@ GlobalInitMD5() noexcept
 #endif
 }
 
-std::array<uint8_t, 16>
-MD5(ConstBuffer<void> input) noexcept
+std::array<std::byte, 16>
+MD5(std::span<const std::byte> input) noexcept
 {
 #ifdef HAVE_LIBAVUTIL
-	std::array<uint8_t, 16> result;
-	av_md5_sum(&result.front(), (const uint8_t *)input.data, input.size);
+	std::array<std::byte, 16> result;
+	av_md5_sum((uint8_t *)result.data(),
+		   (const uint8_t *)input.data(), input.size());
 	return result;
 #else
 	return Gcrypt::MD5(input);
 #endif
 }
 
-StringBuffer<33>
-MD5Hex(ConstBuffer<void> input) noexcept
+std::array<char, 32>
+MD5Hex(std::span<const std::byte> input) noexcept
 {
 	const auto raw = MD5(input);
-	return HexFormatBuffer<raw.size()>(&raw.front());
+	return HexFormat<raw.size()>(raw);
 }

src/lib/crypto/MD5.hxx

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2019 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2018-2022 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -27,25 +27,18 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef MD5_HXX
-#define MD5_HXX
-
-#include "util/StringBuffer.hxx"
+#pragma once
 
 #include <array>
-#include <cstdint>
-
-template<typename T> struct ConstBuffer;
+#include <span>
 
 void
 GlobalInitMD5() noexcept;
 
 [[gnu::pure]]
-std::array<uint8_t, 16>
-MD5(ConstBuffer<void> input) noexcept;
+std::array<std::byte, 16>
+MD5(std::span<const std::byte> input) noexcept;
 
 [[gnu::pure]]
-StringBuffer<33>
-MD5Hex(ConstBuffer<void> input) noexcept;
-
-#endif
+std::array<char, 32>
+MD5Hex(std::span<const std::byte> input) noexcept;

src/lib/gcrypt/Hash.hxx

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2018 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2018-2022 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -27,28 +27,24 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef GCRYPT_HASH_HXX
-#define GCRYPT_HASH_HXX
-
-#include "util/ConstBuffer.hxx"
+#pragma once
 
 #include <gcrypt.h>
 
 #include <array>
+#include <span>
 
 namespace Gcrypt {
 
 template<int algo, size_t size>
 [[gnu::pure]]
 auto
-Hash(ConstBuffer<void> input) noexcept
+Hash(std::span<const std::byte> input) noexcept
 {
-	std::array<uint8_t, size> result;
+	std::array<std::byte, size> result;
 	gcry_md_hash_buffer(algo, &result.front(),
-			    input.data, input.size);
+			    input.data(), input.size());
 	return result;
 }
 
 } /* namespace Gcrypt */
-
-#endif

src/lib/gcrypt/MD5.cxx

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2019 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2018-2022 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -32,8 +32,8 @@
 
 namespace Gcrypt {
 
-std::array<uint8_t, 16>
-MD5(ConstBuffer<void> input) noexcept
+std::array<std::byte, 16>
+MD5(std::span<const std::byte> input) noexcept
 {
 	return Gcrypt::Hash<GCRY_MD_MD5, 16>(input);
 }

src/lib/gcrypt/MD5.hxx

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2019 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2018-2022 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -27,22 +27,15 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef GCRYPT_MD5_HXX
-#define GCRYPT_MD5_HXX
-
-#include "util/StringBuffer.hxx"
+#pragma once
 
 #include <array>
-#include <cstdint>
-
-template<typename T> struct ConstBuffer;
+#include <span>
 
 namespace Gcrypt {
 
 [[gnu::pure]]
-std::array<uint8_t, 16>
-MD5(ConstBuffer<void> input) noexcept;
+std::array<std::byte, 16>
+MD5(std::span<const std::byte> input) noexcept;
 
 } // namespace Gcrypt
-
-#endif

src/util/HexFormat.hxx

@@ -32,10 +32,7 @@
 
 #pragma once
 
-#include "ConstBuffer.hxx"
-#include "StringBuffer.hxx"
-
-#include <cstddef>
+#include <array>
 #include <cstdint>
 
 constexpr char hex_digits[] = "0123456789abcdef";
@@ -84,6 +81,14 @@ HexFormatUint64Fixed(char dest[16], uint64_t number) noexcept
 	return dest;
 }
 
+#if __cplusplus >= 202002 || (defined(__GNUC__) && __GNUC__ >= 10)
+#include <version>
+#endif
+
+#ifdef __cpp_lib_span
+#include <array>
+#include <span>
+
 /**
  * Format the given input buffer of bytes to hex.  The caller ensures
  * that the output buffer is at least twice as large as the input.
@@ -92,24 +97,25 @@ HexFormatUint64Fixed(char dest[16], uint64_t number) noexcept
  * @return a pointer to one after the last written character
  */
 constexpr char *
-HexFormat(char *output, ConstBuffer<uint8_t> input) noexcept
+HexFormat(char *output, std::span<const std::byte> input) noexcept
 {
 	for (const auto &i : input)
-		output = HexFormatUint8Fixed(output, i);
+		output = HexFormatUint8Fixed(output, (uint8_t)i);
 
 	return output;
 }
 
 /**
- * Like HexFormat(), but return a #StringBuffer with exactly the
- * required size.
+ * Return a std::array<char> (not null-terminated) containing a hex
+ * dump of the given fixed-size input.
  */
-template<size_t size>
-[[gnu::pure]]
+template<std::size_t size>
 constexpr auto
-HexFormatBuffer(const uint8_t *src) noexcept
+HexFormat(std::span<const std::byte, size> input) noexcept
 {
-	StringBuffer<size * 2 + 1> dest;
-	*HexFormat(dest.data(), {src, size}) = 0;
-	return dest;
+	std::array<char, size * 2> output;
+	HexFormat(output.data(), input);
+	return output;
 }
+
+#endif