Merge bitcoin/bitcoin#23438: refactor: Use spans of std::byte in serialize

fa5d2e678c809c26bd40d7e7c171529d3ffb5903 Remove unused char serialize (MarcoFalke)
fa24493d6394b3a477535f480664c9596f18e3c5 Use spans of std::byte in serialize (MarcoFalke)
fa65bbf217b725ada35107b4ad646d250228355c span: Add BytePtr helper (MarcoFalke)

Pull request description:

  This changes the serialize code (`.read()` and `.write()` functions) to take a `Span` instead of a pointer and size. This is a breaking change for the serialize interface, so at no additional cost we can also switch to `std::byte` (instead of using `char`).

  The benefits of using `Span`:
  * Less verbose and less fragile code when passing an already existing `Span`(-like) object to or from serialization

  The benefits of using `std::byte`:
  * `std::byte` can't accidentally be mistaken for an integer

  The goal here is to only change serialize to use spans of `std::byte`. If needed, `AsBytes`,  `MakeUCharSpan`, ... can be used (temporarily) to pass spans of the right type.

  Other changes that are included here:

  * [#22167](https://github.com/bitcoin/bitcoin/pull/22167) (refactor: Remove char serialize by MarcoFalke)
  * [#21906](https://github.com/bitcoin/bitcoin/pull/21906) (Preserve const in cast on CTransactionSignatureSerializer by promag)

ACKs for top commit:
  laanwj:
    Concept and code review ACK fa5d2e678c809c26bd40d7e7c171529d3ffb5903
  sipa:
    re-utACK fa5d2e678c809c26bd40d7e7c171529d3ffb5903

Tree-SHA512: 08ee9eced5fb777cedae593b11e33660bed9a3e1711a7451a87b835089a96c99ce0632918bb4666a4e859c4d020f88fb50f2dd734216b0c3d1a9a704967ece6f

3 files changed, 18 insertions, 18 deletions

diff --git a/src/wallet/bdb.cpp b/src/wallet/bdb.cpp
index e0be914a2b..cea120a81e 100644
--- a/src/wallet/bdb.cpp
+++ b/src/wallet/bdb.cpp
@@ -681,10 +681,10 @@ bool BerkeleyBatch::ReadAtCursor(CDataStream& ssKey, CDataStream& ssValue, bool&
     // Convert to streams
     ssKey.SetType(SER_DISK);
     ssKey.clear();
-    ssKey.write((char*)datKey.get_data(), datKey.get_size());
+    ssKey.write({BytePtr(datKey.get_data()), datKey.get_size()});
     ssValue.SetType(SER_DISK);
     ssValue.clear();
-    ssValue.write((char*)datValue.get_data(), datValue.get_size());
+    ssValue.write({BytePtr(datValue.get_data()), datValue.get_size()});
     return true;
 }
 
@@ -756,7 +756,7 @@ bool BerkeleyBatch::ReadKey(CDataStream&& key, CDataStream& value)
     SafeDbt datValue;
     int ret = pdb->get(activeTxn, datKey, datValue, 0);
     if (ret == 0 && datValue.get_data() != nullptr) {
-        value.write((char*)datValue.get_data(), datValue.get_size());
+        value.write({BytePtr(datValue.get_data()), datValue.get_size()});
         return true;
     }
     return false;
diff --git a/src/wallet/dump.cpp b/src/wallet/dump.cpp
index 7dfb1d8839..3e34a2f776 100644
--- a/src/wallet/dump.cpp
+++ b/src/wallet/dump.cpp
@@ -47,12 +47,12 @@ bool DumpWallet(CWallet& wallet, bilingual_str& error)
     // Write out a magic string with version
     std::string line = strprintf("%s,%u\n", DUMP_MAGIC, DUMP_VERSION);
     dump_file.write(line.data(), line.size());
-    hasher.write(line.data(), line.size());
+    hasher.write(MakeByteSpan(line));
 
     // Write out the file format
     line = strprintf("%s,%s\n", "format", db.Format());
     dump_file.write(line.data(), line.size());
-    hasher.write(line.data(), line.size());
+    hasher.write(MakeByteSpan(line));
 
     if (ret) {
 
@@ -73,7 +73,7 @@ bool DumpWallet(CWallet& wallet, bilingual_str& error)
             std::string value_str = HexStr(ss_value);
             line = strprintf("%s,%s\n", key_str, value_str);
             dump_file.write(line.data(), line.size());
-            hasher.write(line.data(), line.size());
+            hasher.write(MakeByteSpan(line));
         }
     }
 
@@ -150,7 +150,7 @@ bool CreateFromDump(const std::string& name, const fs::path& wallet_path, biling
         return false;
     }
     std::string magic_hasher_line = strprintf("%s,%s\n", magic_key, version_value);
-    hasher.write(magic_hasher_line.data(), magic_hasher_line.size());
+    hasher.write(MakeByteSpan(magic_hasher_line));
 
     // Get the stored file format
     std::string format_key;
@@ -181,7 +181,7 @@ bool CreateFromDump(const std::string& name, const fs::path& wallet_path, biling
         warnings.push_back(strprintf(_("Warning: Dumpfile wallet format \"%s\" does not match command line specified format \"%s\"."), format_value, file_format));
     }
     std::string format_hasher_line = strprintf("%s,%s\n", format_key, format_value);
-    hasher.write(format_hasher_line.data(), format_hasher_line.size());
+    hasher.write(MakeByteSpan(format_hasher_line));
 
     DatabaseOptions options;
     DatabaseStatus status;
@@ -225,7 +225,7 @@ bool CreateFromDump(const std::string& name, const fs::path& wallet_path, biling
             }
 
             std::string line = strprintf("%s,%s\n", key, value);
-            hasher.write(line.data(), line.size());
+            hasher.write(MakeByteSpan(line));
 
             if (key.empty() || value.empty()) {
                 continue;
diff --git a/src/wallet/sqlite.cpp b/src/wallet/sqlite.cpp
index 07e387f177..2b2181e70b 100644
--- a/src/wallet/sqlite.cpp
+++ b/src/wallet/sqlite.cpp
@@ -395,9 +395,9 @@ bool SQLiteBatch::ReadKey(CDataStream&& key, CDataStream& value)
         return false;
     }
     // Leftmost column in result is index 0
-    const char* data = reinterpret_cast<const char*>(sqlite3_column_blob(m_read_stmt, 0));
-    int data_size = sqlite3_column_bytes(m_read_stmt, 0);
-    value.write(data, data_size);
+    const std::byte* data{BytePtr(sqlite3_column_blob(m_read_stmt, 0))};
+    size_t data_size(sqlite3_column_bytes(m_read_stmt, 0));
+    value.write({data, data_size});
 
     sqlite3_clear_bindings(m_read_stmt);
     sqlite3_reset(m_read_stmt);
@@ -512,12 +512,12 @@ bool SQLiteBatch::ReadAtCursor(CDataStream& key, CDataStream& value, bool& compl
     }
 
     // Leftmost column in result is index 0
-    const char* key_data = reinterpret_cast<const char*>(sqlite3_column_blob(m_cursor_stmt, 0));
-    int key_data_size = sqlite3_column_bytes(m_cursor_stmt, 0);
-    key.write(key_data, key_data_size);
-    const char* value_data = reinterpret_cast<const char*>(sqlite3_column_blob(m_cursor_stmt, 1));
-    int value_data_size = sqlite3_column_bytes(m_cursor_stmt, 1);
-    value.write(value_data, value_data_size);
+    const std::byte* key_data{BytePtr(sqlite3_column_blob(m_cursor_stmt, 0))};
+    size_t key_data_size(sqlite3_column_bytes(m_cursor_stmt, 0));
+    key.write({key_data, key_data_size});
+    const std::byte* value_data{BytePtr(sqlite3_column_blob(m_cursor_stmt, 1))};
+    size_t value_data_size(sqlite3_column_bytes(m_cursor_stmt, 1));
+    value.write({value_data, value_data_size});
     return true;
 }