Perf: Remove more breakpoint checking in the interpreter. Move filtering earlier in the logging chain

src/common/logging/log.h

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <array>
 #include <fmt/format.h>
 #include "common/common_types.h"
 
@@ -113,6 +114,47 @@ enum class Class : ClassType {
     Count              ///< Total number of logging classes
 };
 
+/**
+ * Implements a log message filter which allows different log classes to have different minimum
+ * severity levels. The filter can be changed at runtime and can be parsed from a string to allow
+ * editing via the interface or loading from a configuration file.
+ */
+class Filter {
+public:
+    /// Initializes the filter with all classes having `default_level` as the minimum level.
+    explicit Filter(Level default_level = Level::Info);
+
+    /// Resets the filter so that all classes have `level` as the minimum displayed level.
+    void ResetAll(Level level);
+    /// Sets the minimum level of `log_class` (and not of its subclasses) to `level`.
+    void SetClassLevel(Class log_class, Level level);
+
+    /**
+     * Parses a filter string and applies it to this filter.
+     *
+     * A filter string consists of a space-separated list of filter rules, each of the format
+     * `<class>:<level>`. `<class>` is a log class name, with subclasses separated using periods.
+     * `*` is allowed as a class name and will reset all filters to the specified level. `<level>`
+     * a severity level name which will be set as the minimum logging level of the matched classes.
+     * Rules are applied left to right, with each rule overriding previous ones in the sequence.
+     *
+     * A few examples of filter rules:
+     *  - `*:Info` -- Resets the level of all classes to Info.
+     *  - `Service:Info` -- Sets the level of Service to Info.
+     *  - `Service.FS:Trace` -- Sets the level of the Service.FS class to Trace.
+     */
+    void ParseFilterString(std::string_view filter_view);
+
+    /// Matches class/level combination against the filter, returning true if it passed.
+    bool CheckMessage(Class log_class, Level level) const;
+
+private:
+    std::array<Level, static_cast<std::size_t>(Class::Count)> class_levels;
+};
+extern Filter filter;
+
+void SetGlobalFilter(const Filter& f);
+
 /// Logs a message to the global logger, using fmt
 void FmtLogMessageImpl(Class log_class, Level log_level, const char* filename,
                        unsigned int line_num, const char* function, const char* format,
@@ -121,6 +163,9 @@ void FmtLogMessageImpl(Class log_class, Level log_level, const char* filename,
 template <typename... Args>
 void FmtLogMessage(Class log_class, Level log_level, const char* filename, unsigned int line_num,
                    const char* function, const char* format, const Args&... args) {
+    if (!filter.CheckMessage(log_class, log_level))
+        return;
+
     FmtLogMessageImpl(log_class, log_level, filename, line_num, function, format,
                       fmt::make_format_args(args...));
 }