Extend trace module to allow for filtering

Attempt to reduce the debug.log noise by filtering the err module
warnf/logf calls and others.

Signed-off-by: Tobias Ulmer <tu@emlix.com>

diff --git a/generic/e2lib.lua b/generic/e2lib.lua
index 66c7d6c991f5a815a2556d102c91e57dff058dd7..62bdaf1cbab897af65cf43f954ed4777220e9843 100644 (file)
--- a/generic/e2lib.lua
+++ b/generic/e2lib.lua
@@ -321,6 +321,7 @@ function e2lib.init()
     e2lib.log(4, "e2lib.init()")
 
     trace.enable()
+    trace.default_filter()
 
     local rc, re = e2lib.signal_reset()
     if not rc then

diff --git a/generic/trace.lua b/generic/trace.lua
index 516e53d2f52a326ba4fbbfc7f978dada301a2968..511c33750a6c5bf8a599f2abc76e859735a592a6 100644 (file)
--- a/generic/trace.lua
+++ b/generic/trace.lua
@@ -22,11 +22,14 @@ local trace = {}
 local e2lib = require("e2lib")
 local strict = require("strict")
 
+local module_blacklist = {}
+local function_blacklist = {}
+
 --- Function call tracer. Logs all function calls at debug level while active.
 -- @param event string: type of event
 -- @param line line number of event (unused)
 local function tracer(event, line)
-    local ftbl, module, out, name, value, isbinary, svalue
+    local ftbl, module, out, name, value, isbinary, svalue, fnbl
 
     ftbl = debug.getinfo(2)
     if ftbl == nil or ftbl.name == nil then
@@ -36,13 +39,20 @@ local function tracer(event, line)
     -- approximate module name, not always accurate but good enough
     if ftbl.source == nil or ftbl.source == "=[C]" then
         module = "C."
-        -- DEBUG: comment this to see all C calls.
-        return
     else
         module = string.match(ftbl.source, "([^/]+%.)lua$")
         if module == nil then
             module = "<unknown module>."
-            -- DEBUG: comment this to see all unknown calls.
+        end
+    end
+
+    if module_blacklist[module] then
+        return
+    end
+
+    fnbl = function_blacklist[ftbl.name]
+    if fnbl then
+        if fnbl[module] then
             return
         end
     end
@@ -103,6 +113,41 @@ function trace.disable()
     debug.sethook()
 end
 
+--- Exclude entire module from being logged by the tracer.
+-- @param module_name Module name.
+function trace.filter_module(module_name)
+    module_name = module_name.."."
+    module_blacklist[module_name] = true
+end
+
+--- Exclude function in a module from being logged by the tracer.
+-- @param module_name Module name.
+-- @param function_name Function name.
+function trace.filter_function(module_name, function_name)
+    local fnbl
+
+    module_name = module_name.."."
+    if not function_blacklist[function_name] then
+        function_blacklist[function_name] = {}
+    end
+
+    function_blacklist[function_name][module_name] = true
+end
+
+--- Default filter setup.
+function trace.default_filter()
+    trace.filter_module("C")
+    trace.filter_module("<unknown module>")
+    trace.filter_module("err")
+    trace.filter_function("e2lib", "log")
+    trace.filter_function("e2lib", "logf")
+    trace.filter_function("e2lib", "getlog")
+    trace.filter_function("e2lib", "warnf")
+    trace.filter_function("e2lib", "(for generator)")
+    trace.filter_function("eio", "new")
+    trace.filter_function("eio", "is_eio_object")
+end
+
 return strict.lock(trace)
 
 -- vim:sw=4:sts=4:et: