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