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