Merge bitcoin/bitcoin#22530: log: sort logging categories alphabetically

d596dba9877e7ead3fb5426cbe7e608fbcbfe3eb test: assert logging categories are sorted in rpc and help (Jon Atack)
17bbff3b88132c0c95b29b59100456b85e26df75 log, refactor: use guard clause in LogCategoriesList() (Jon Atack)
7c57297319bc386afaf06528778384fe58576ef9 log: sort LogCategoriesList and LogCategoriesString alphabetically (Jon Atack)
f720cfa824f1be863349e7016080f8fb1c3c76c2 test: verify number of categories returned by logging RPC (Jon Atack)

Pull request description:

  Sorting the logging categories seems more user-friendly with the number of categories we now have, allowing CLI users to more quickly find a particular category.

  before
  ```
  $ bitcoin-cli help logging
  ...
  The valid logging categories are: net, tor, mempool, http, bench, zmq, walletdb, rpc, estimatefee, addrman, selectcoins, reindex, cmpctblock, rand, prune, proxy, mempoolrej, libevent, coindb, qt, leveldb, validation, i2p, ipc

  $ bitcoind -h | grep -A8 "debug=<category>"
    -debug=<category>
         ...
         output all debugging information. <category> can be: net, tor,
         mempool, http, bench, zmq, walletdb, rpc, estimatefee, addrman,
         selectcoins, reindex, cmpctblock, rand, prune, proxy, mempoolrej,
         libevent, coindb, qt, leveldb, validation, i2p, ipc.

  $ bitcoin-cli logging [] '["addrman"]'
  {
    "net": false,
    "tor": true,
    "mempool": false,
    "http": false,
    "bench": false,
    "zmq": false,
    "walletdb": false,
    "rpc": false,
    "estimatefee": false,
    "addrman": false,
    "selectcoins": false,
    "reindex": false,
    "cmpctblock": false,
    "rand": false,
    "prune": false,
    "proxy": true,
    "mempoolrej": false,
    "libevent": false,
    "coindb": false,
    "qt": false,
    "leveldb": false,
    "validation": false,
    "i2p": true,
    "ipc": false
  }
  ```

  after

  ```
  $ bitcoin-cli help logging
  ...
  The valid logging categories are: addrman, bench, cmpctblock, coindb, estimatefee, http, i2p, ipc, leveldb, libevent, mempool, mempoolrej, net, proxy, prune, qt, rand, reindex, rpc, selectcoins, tor, validation, walletdb, zmq

  $ bitcoind -h | grep -A8 "debug=<category>"
    -debug=<category>
         ...
         output all debugging information. <category> can be: addrman,
         bench, cmpctblock, coindb, estimatefee, http, i2p, ipc, leveldb,
         libevent, mempool, mempoolrej, net, proxy, prune, qt, rand,
         reindex, rpc, selectcoins, tor, validation, walletdb, zmq.

  $ bitcoin-cli logging [] '["addrman"]'
  {
    "addrman": false,
    "bench": false,
    "cmpctblock": false,
    "coindb": false,
    "estimatefee": false,
    "http": false,
    "i2p": false,
    "ipc": false,
    "leveldb": false,
    "libevent": false,
    "mempool": false,
    "mempoolrej": false,
    "net": false,
    "proxy": false,
    "prune": false,
    "qt": false,
    "rand": false,
    "reindex": false,
    "rpc": false,
    "selectcoins": false,
    "tor": false,
    "validation": false,
    "walletdb": false,
    "zmq": false
  }
  ```

ACKs for top commit:
  theStack:
    re-ACK d596dba9877e7ead3fb5426cbe7e608fbcbfe3eb

Tree-SHA512: d546257f562b0a288d1b19a028f1a510aaf21bd21da058e7c84653d305ea8662ecb4647ebefd2b97411f845fe5b0b841d40d3fe6814eefcb8ce82df341dfce22

2 files changed, 17 insertions, 13 deletions

diff --git a/src/logging.cpp b/src/logging.cpp
index e5187fd596..b456108b61 100644
--- a/src/logging.cpp
+++ b/src/logging.cpp
@@ -8,6 +8,8 @@
 #include <util/string.h>
 #include <util/time.h>
 
+#include <algorithm>
+#include <array>
 #include <mutex>
 
 const char * const DEFAULT_DEBUGLOGFILE = "debug.log";
@@ -124,8 +126,7 @@ bool BCLog::Logger::DefaultShrinkDebugFile() const
     return m_categories == BCLog::NONE;
 }
 
-struct CLogCategoryDesc
-{
+struct CLogCategoryDesc {
     BCLog::LogFlags flag;
     std::string category;
 };
@@ -179,15 +180,18 @@ bool GetLogCategory(BCLog::LogFlags& flag, const std::string& str)
 
 std::vector<LogCategory> BCLog::Logger::LogCategoriesList() const
 {
+    // Sort log categories by alphabetical order.
+    std::array<CLogCategoryDesc, std::size(LogCategories)> categories;
+    std::copy(std::begin(LogCategories), std::end(LogCategories), categories.begin());
+    std::sort(categories.begin(), categories.end(), [](auto a, auto b) { return a.category < b.category; });
+
     std::vector<LogCategory> ret;
-    for (const CLogCategoryDesc& category_desc : LogCategories) {
-        // Omit the special cases.
-        if (category_desc.flag != BCLog::NONE && category_desc.flag != BCLog::ALL) {
-            LogCategory catActive;
-            catActive.category = category_desc.category;
-            catActive.active = WillLogCategory(category_desc.flag);
-            ret.push_back(catActive);
-        }
+    for (const CLogCategoryDesc& category_desc : categories) {
+        if (category_desc.flag == BCLog::NONE || category_desc.flag == BCLog::ALL) continue;
+        LogCategory catActive;
+        catActive.category = category_desc.category;
+        catActive.active = WillLogCategory(category_desc.flag);
+        ret.push_back(catActive);
     }
     return ret;
 }
@@ -237,7 +241,7 @@ namespace BCLog {
         }
         return ret;
     }
-}
+} // namespace BCLog
 
 void BCLog::Logger::LogPrintStr(const std::string& str, const std::string& logging_function, const std::string& source_file, const int source_line)
 {
diff --git a/src/logging.h b/src/logging.h
index d04bc99268..38d73863e7 100644
--- a/src/logging.h
+++ b/src/logging.h
@@ -138,9 +138,9 @@ namespace BCLog {
         bool DisableCategory(const std::string& str);
 
         bool WillLogCategory(LogFlags category) const;
-        /** Returns a vector of the log categories */
+        /** Returns a vector of the log categories in alphabetical order. */
         std::vector<LogCategory> LogCategoriesList() const;
-        /** Returns a string with the log categories */
+        /** Returns a string with the log categories in alphabetical order. */
         std::string LogCategoriesString() const
         {
             return Join(LogCategoriesList(), ", ", [&](const LogCategory& i) { return i.category; });