base/vlog.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_VLOG_H_
   6 #define BASE_VLOG_H_
   7 #pragma once
   8
   9 #include <cstddef>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/base_export.h"
  14 #include "base/basictypes.h"
  15 #include "base/string_piece.h"
  16
  17 namespace logging {
  18
  19 // A helper class containing all the settings for vlogging.
  20 class BASE_EXPORT VlogInfo {
  21  public:
  22   static const int kDefaultVlogLevel;
  23
  24   // |v_switch| gives the default maximal active V-logging level; 0 is
  25   // the default.  Normally positive values are used for V-logging
  26   // levels.
  27   //
  28   // |vmodule_switch| gives the per-module maximal V-logging levels to
  29   // override the value given by |v_switch|.
  30   // E.g. "my_module=2,foo*=3" would change the logging level for all
  31   // code in source files "my_module.*" and "foo*.*" ("-inl" suffixes
  32   // are also disregarded for this matching).
  33   //
  34   // |log_severity| points to an int that stores the log level. If a valid
  35   // |v_switch| is provided, it will set the log level, and the default
  36   // vlog severity will be read from there..
  37   //
  38   // Any pattern containing a forward or backward slash will be tested
  39   // against the whole pathname and not just the module.  E.g.,
  40   // "*/foo/bar/*=2" would change the logging level for all code in
  41   // source files under a "foo/bar" directory.
  42   VlogInfo(const std::string& v_switch,
  43            const std::string& vmodule_switch,
  44            int* min_log_level);
  45   ~VlogInfo();
  46
  47   // Returns the vlog level for a given file (usually taken from
  48   // __FILE__).
  49   int GetVlogLevel(const base::StringPiece& file) const;
  50
  51  private:
  52   void SetMaxVlogLevel(int level);
  53   int GetMaxVlogLevel() const;
  54
  55   // VmodulePattern holds all the information for each pattern parsed
  56   // from |vmodule_switch|.
  57   struct VmodulePattern;
  58   std::vector<VmodulePattern> vmodule_levels_;
  59   int* min_log_level_;
  60
  61   DISALLOW_COPY_AND_ASSIGN(VlogInfo);
  62 };
  63
  64 // Returns true if the string passed in matches the vlog pattern.  The
  65 // vlog pattern string can contain wildcards like * and ?.  ? matches
  66 // exactly one character while * matches 0 or more characters.  Also,
  67 // as a special case, a / or \ character matches either / or \.
  68 //
  69 // Examples:
  70 //   "kh?n" matches "khan" but not "khn" or "khaan"
  71 //   "kh*n" matches "khn", "khan", or even "khaaaaan"
  72 //   "/foo\bar" matches "/foo/bar", "\foo\bar", or "/foo\bar"
  73 //     (disregarding C escaping rules)
  74 BASE_EXPORT bool MatchVlogPattern(const base::StringPiece& string,
  75                                   const base::StringPiece& vlog_pattern);
  76
  77 }  // namespace logging
  78
  79 #endif  // BASE_VLOG_H_