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