base/vlog.cc

   1 // Copyright (c) 2010 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 #include "base/vlog.h"
   6
   7 #include <cstddef>
   8 #include <ostream>
   9 #include <utility>
  10
  11 #include "base/basictypes.h"
  12 #include "base/logging.h"
  13 #include "base/strings/string_number_conversions.h"
  14 #include "base/strings/string_split.h"
  15
  16 namespace logging {
  17
  18 const int VlogInfo::kDefaultVlogLevel = 0;
  19
  20 struct VlogInfo::VmodulePattern {
  21   enum MatchTarget { MATCH_MODULE, MATCH_FILE };
  22
  23   explicit VmodulePattern(const std::string& pattern);
  24
  25   VmodulePattern();
  26
  27   std::string pattern;
  28   int vlog_level;
  29   MatchTarget match_target;
  30 };
  31
  32 VlogInfo::VmodulePattern::VmodulePattern(const std::string& pattern)
  33     : pattern(pattern),
  34       vlog_level(VlogInfo::kDefaultVlogLevel),
  35       match_target(MATCH_MODULE) {
  36   // If the pattern contains a {forward,back} slash, we assume that
  37   // it's meant to be tested against the entire __FILE__ string.
  38   std::string::size_type first_slash = pattern.find_first_of("\\/");
  39   if (first_slash != std::string::npos)
  40     match_target = MATCH_FILE;
  41 }
  42
  43 VlogInfo::VmodulePattern::VmodulePattern()
  44     : vlog_level(VlogInfo::kDefaultVlogLevel),
  45       match_target(MATCH_MODULE) {}
  46
  47 VlogInfo::VlogInfo(const std::string& v_switch,
  48                    const std::string& vmodule_switch,
  49                    int* min_log_level)
  50     : min_log_level_(min_log_level) {
  51   DCHECK(min_log_level != NULL);
  52
  53   typedef std::pair<std::string, std::string> KVPair;
  54   int vlog_level = 0;
  55   if (!v_switch.empty()) {
  56     if (base::StringToInt(v_switch, &vlog_level)) {
  57       SetMaxVlogLevel(vlog_level);
  58     } else {
  59       DLOG(WARNING) << "Could not parse v switch \"" << v_switch << "\"";
  60     }
  61   }
  62
  63   std::vector<KVPair> kv_pairs;
  64   if (!base::SplitStringIntoKeyValuePairs(
  65           vmodule_switch, '=', ',', &kv_pairs)) {
  66     DLOG(WARNING) << "Could not fully parse vmodule switch \""
  67                   << vmodule_switch << "\"";
  68   }
  69   for (std::vector<KVPair>::const_iterator it = kv_pairs.begin();
  70        it != kv_pairs.end(); ++it) {
  71     VmodulePattern pattern(it->first);
  72     if (!base::StringToInt(it->second, &pattern.vlog_level)) {
  73       DLOG(WARNING) << "Parsed vlog level for \""
  74                     << it->first << "=" << it->second
  75                     << "\" as " << pattern.vlog_level;
  76     }
  77     vmodule_levels_.push_back(pattern);
  78   }
  79 }
  80
  81 VlogInfo::~VlogInfo() {}
  82
  83 namespace {
  84
  85 // Given a path, returns the basename with the extension chopped off
  86 // (and any -inl suffix).  We avoid using FilePath to minimize the
  87 // number of dependencies the logging system has.
  88 base::StringPiece GetModule(const base::StringPiece& file) {
  89   base::StringPiece module(file);
  90   base::StringPiece::size_type last_slash_pos =
  91       module.find_last_of("\\/");
  92   if (last_slash_pos != base::StringPiece::npos)
  93     module.remove_prefix(last_slash_pos + 1);
  94   base::StringPiece::size_type extension_start = module.rfind('.');
  95   module = module.substr(0, extension_start);
  96   static const char kInlSuffix[] = "-inl";
  97   static const int kInlSuffixLen = arraysize(kInlSuffix) - 1;
  98   if (module.ends_with(kInlSuffix))
  99     module.remove_suffix(kInlSuffixLen);
 100   return module;
 101 }
 102
 103 }  // namespace
 104
 105 int VlogInfo::GetVlogLevel(const base::StringPiece& file) const {
 106   if (!vmodule_levels_.empty()) {
 107     base::StringPiece module(GetModule(file));
 108     for (std::vector<VmodulePattern>::const_iterator it =
 109              vmodule_levels_.begin(); it != vmodule_levels_.end(); ++it) {
 110       base::StringPiece target(
 111           (it->match_target == VmodulePattern::MATCH_FILE) ? file : module);
 112       if (MatchVlogPattern(target, it->pattern))
 113         return it->vlog_level;
 114     }
 115   }
 116   return GetMaxVlogLevel();
 117 }
 118
 119 void VlogInfo::SetMaxVlogLevel(int level) {
 120   // Log severity is the negative verbosity.
 121   *min_log_level_ = -level;
 122 }
 123
 124 int VlogInfo::GetMaxVlogLevel() const {
 125   return -*min_log_level_;
 126 }
 127
 128 bool MatchVlogPattern(const base::StringPiece& string,
 129                       const base::StringPiece& vlog_pattern) {
 130   base::StringPiece p(vlog_pattern);
 131   base::StringPiece s(string);
 132   // Consume characters until the next star.
 133   while (!p.empty() && !s.empty() && (p[0] != '*')) {
 134     switch (p[0]) {
 135       // A slash (forward or back) must match a slash (forward or back).
 136       case '/':
 137       case '\\':
 138         if ((s[0] != '/') && (s[0] != '\\'))
 139           return false;
 140         break;
 141
 142       // A '?' matches anything.
 143       case '?':
 144         break;
 145
 146       // Anything else must match literally.
 147       default:
 148         if (p[0] != s[0])
 149           return false;
 150         break;
 151     }
 152     p.remove_prefix(1), s.remove_prefix(1);
 153   }
 154
 155   // An empty pattern here matches only an empty string.
 156   if (p.empty())
 157     return s.empty();
 158
 159   // Coalesce runs of consecutive stars.  There should be at least
 160   // one.
 161   while (!p.empty() && (p[0] == '*'))
 162     p.remove_prefix(1);
 163
 164   // Since we moved past the stars, an empty pattern here matches
 165   // anything.
 166   if (p.empty())
 167     return true;
 168
 169   // Since we moved past the stars and p is non-empty, if some
 170   // non-empty substring of s matches p, then we ourselves match.
 171   while (!s.empty()) {
 172     if (MatchVlogPattern(s, p))
 173       return true;
 174     s.remove_prefix(1);
 175   }
 176
 177   // Otherwise, we couldn't find a match.
 178   return false;
 179 }
 180
 181 }  // namespace