Merge bitcoin#11191: RPC: Improve help text and behavior of RPC-logging.

c60c49b Improve help text and behavior of RPC-logging (Akio Nakamura)

Pull request description:

  1. It is allowed `libevent` logging to be updated during runtime,
    but still described that restriction in the help text.
    So we delete these text.
  2. Add a descrption about the evaluation order of `<include>` and
    `<exclude>` to clarify how debug loggig categories to be set.
  3. Add a description about the available logging category `"all"`
    which is not explained.
  4. Add `"optional"` to the help text of `<include>` and `<exclude>`.
  5. Add missing new lines before `"Argument:"`.
  6. `"0"`,`"1"` are allowed in both array of `<include>` and `<exclude>`.
    `"0"` is **ignored** and `"1"` is treated **same as** `"all"`.
    It is confusing, so forbid them.
  7. It always returns all logging categories with status.
    Fix the help text to match this behavior.

Tree-SHA512: c2142da1a9bf714af8ebc38ac0d82394e2073fc0bd56f136372e3db7b2af3b6746f8d6b0241fe66c1698c208c124deb076be83f07dec0d0a180ad150593af415

Author: laanwj

src/init.cpp

@@ -919,7 +919,8 @@ bool AppInitParameterInteraction()
         // Special-case: if -debug=0/-nodebug is set, turn off debugging messages
         const std::vector<std::string> categories = gArgs.GetArgs("-debug");
 
-        if (find(categories.begin(), categories.end(), std::string("0")) == categories.end()) {
+        if (std::none_of(categories.begin(), categories.end(),
+            [](std::string cat){return cat == "0" || cat == "none";})) {
             for (const auto& cat : categories) {
                 uint32_t flag = 0;
                 if (!GetLogCategory(&flag, &cat)) {

src/rpc/misc.cpp

@@ -533,6 +533,9 @@ uint32_t getCategoryMask(UniValue cats) {
         if (!GetLogCategory(&flag, &cat)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "unknown logging category " + cat);
         }
+        if (flag == BCLog::NONE) {
+            return 0;
+        }
         mask |= flag;
     }
     return mask;
@@ -542,16 +545,32 @@ UniValue logging(const JSONRPCRequest& request)
 {
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
-            "logging [include,...] <exclude>\n"
+            "logging ( <include> <exclude> )\n"
             "Gets and sets the logging configuration.\n"
-            "When called without an argument, returns the list of categories that are currently being debug logged.\n"
-            "When called with arguments, adds or removes categories from debug logging.\n"
+            "When called without an argument, returns the list of categories with status that are currently being debug logged or not.\n"
+            "When called with arguments, adds or removes categories from debug logging and return the lists above.\n"
+            "The arguments are evaluated in order \"include\", \"exclude\".\n"
+            "If an item is both included and excluded, it will thus end up being excluded.\n"
             "The valid logging categories are: " + ListLogCategories() + "\n"
-            "libevent logging is configured on startup and cannot be modified by this RPC during runtime."
-            "Arguments:\n"
-            "1. \"include\" (array of strings) add debug logging for these categories.\n"
-            "2. \"exclude\" (array of strings) remove debug logging for these categories.\n"
-            "\nResult: <categories>  (string): a list of the logging categories that are active.\n"
+            "In addition, the following are available as category names with special meanings:\n"
+            "  - \"all\",  \"1\" : represent all logging categories.\n"
+            "  - \"none\", \"0\" : even if other logging categories are specified, ignore all of them.\n"
+            "\nArguments:\n"
+            "1. \"include\"        (array of strings, optional) A json array of categories to add debug logging\n"
+            "     [\n"
+            "       \"category\"   (string) the valid logging category\n"
+            "       ,...\n"
+            "     ]\n"
+            "2. \"exclude\"        (array of strings, optional) A json array of categories to remove debug logging\n"
+            "     [\n"
+            "       \"category\"   (string) the valid logging category\n"
+            "       ,...\n"
+            "     ]\n"
+            "\nResult:\n"
+            "{                   (json object where keys are the logging categories, and values indicates its status\n"
+            "  \"category\": 0|1,  (numeric) if being debug logged or not. 0:inactive, 1:active\n"
+            "  ...\n"
+            "}\n"
             "\nExamples:\n"
             + HelpExampleCli("logging", "\"[\\\"all\\\"]\" \"[\\\"http\\\"]\"")
             + HelpExampleRpc("logging", "[\"all\"], \"[libevent]\"")

src/util.cpp

@@ -220,6 +220,7 @@ struct CLogCategoryDesc
 const CLogCategoryDesc LogCategories[] =
 {
     {BCLog::NONE, "0"},
+    {BCLog::NONE, "none"},
     {BCLog::NET, "net"},
     {BCLog::TOR, "tor"},
     {BCLog::MEMPOOL, "mempool"},