vlog.cc revision 201ade2fbba22bfb27ae029f4d23fca6ded109a0 
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/string_number_conversions.h"
10#include "base/string_split.h"
11
12namespace logging {
13
14const int VlogInfo::kDefaultVlogLevel = 0;
15
16VlogInfo::VmodulePattern::VmodulePattern(const std::string& pattern)
17    : pattern(pattern),
18      vlog_level(VlogInfo::kDefaultVlogLevel),
19      match_target(MATCH_MODULE) {
20  // If the pattern contains a {forward,back} slash, we assume that
21  // it's meant to be tested against the entire __FILE__ string.
22  std::string::size_type first_slash = pattern.find_first_of("\\/");
23  if (first_slash != std::string::npos)
24    match_target = MATCH_FILE;
25}
26
27VlogInfo::VmodulePattern::VmodulePattern()
28    : vlog_level(VlogInfo::kDefaultVlogLevel),
29      match_target(MATCH_MODULE) {}
30
31VlogInfo::VlogInfo(const std::string& v_switch,
32                   const std::string& vmodule_switch,
33                   int* min_log_level)
34    : min_log_level_(min_log_level) {
35  DCHECK(min_log_level != NULL);
36
37  typedef std::pair<std::string, std::string> KVPair;
38  int vlog_level = 0;
39  if (!v_switch.empty()) {
40    if (base::StringToInt(v_switch, &vlog_level)) {
41      SetMaxVlogLevel(vlog_level);
42    } else {
43      LOG(WARNING) << "Could not parse v switch \"" << v_switch << "\"";
44    }
45  }
46
47  std::vector<KVPair> kv_pairs;
48  if (!base::SplitStringIntoKeyValuePairs(
49          vmodule_switch, '=', ',', &kv_pairs)) {
50    LOG(WARNING) << "Could not fully parse vmodule switch \""
51                 << vmodule_switch << "\"";
52  }
53  for (std::vector<KVPair>::const_iterator it = kv_pairs.begin();
54       it != kv_pairs.end(); ++it) {
55    VmodulePattern pattern(it->first);
56    if (!base::StringToInt(it->second, &pattern.vlog_level)) {
57      LOG(WARNING) << "Parsed vlog level for \""
58                   << it->first << "=" << it->second
59                   << "\" as " << pattern.vlog_level;
60    }
61    vmodule_levels_.push_back(pattern);
62  }
63}
64
65VlogInfo::~VlogInfo() {}
66
67void VlogInfo::SetMaxVlogLevel(int level) {
68  // Log severity is the negative verbosity.
69  *min_log_level_ = -level;
70}
71
72int VlogInfo::GetMaxVlogLevel() const {
73  return -*min_log_level_;
74}
75
76namespace {
77
78// Given a path, returns the basename with the extension chopped off
79// (and any -inl suffix).  We avoid using FilePath to minimize the
80// number of dependencies the logging system has.
81base::StringPiece GetModule(const base::StringPiece& file) {
82  base::StringPiece module(file);
83  base::StringPiece::size_type last_slash_pos =
84      module.find_last_of("\\/");
85  if (last_slash_pos != base::StringPiece::npos)
86    module.remove_prefix(last_slash_pos + 1);
87  base::StringPiece::size_type extension_start = module.rfind('.');
88  module = module.substr(0, extension_start);
89  static const char kInlSuffix[] = "-inl";
90  static const int kInlSuffixLen = arraysize(kInlSuffix) - 1;
91  if (module.ends_with(kInlSuffix))
92    module.remove_suffix(kInlSuffixLen);
93  return module;
94}
95
96}  // namespace
97
98int VlogInfo::GetVlogLevel(const base::StringPiece& file) const {
99  if (!vmodule_levels_.empty()) {
100    base::StringPiece module(GetModule(file));
101    for (std::vector<VmodulePattern>::const_iterator it =
102             vmodule_levels_.begin(); it != vmodule_levels_.end(); ++it) {
103      base::StringPiece target(
104          (it->match_target == VmodulePattern::MATCH_FILE) ? file : module);
105      if (MatchVlogPattern(target, it->pattern))
106        return it->vlog_level;
107    }
108  }
109  return GetMaxVlogLevel();
110}
111
112bool MatchVlogPattern(const base::StringPiece& string,
113                      const base::StringPiece& vlog_pattern) {
114  base::StringPiece p(vlog_pattern);
115  base::StringPiece s(string);
116  // Consume characters until the next star.
117  while (!p.empty() && !s.empty() && (p[0] != '*')) {
118    switch (p[0]) {
119      // A slash (forward or back) must match a slash (forward or back).
120      case '/':
121      case '\\':
122        if ((s[0] != '/') && (s[0] != '\\'))
123          return false;
124        break;
125
126      // A '?' matches anything.
127      case '?':
128        break;
129
130      // Anything else must match literally.
131      default:
132        if (p[0] != s[0])
133          return false;
134        break;
135    }
136    p.remove_prefix(1), s.remove_prefix(1);
137  }
138
139  // An empty pattern here matches only an empty string.
140  if (p.empty())
141    return s.empty();
142
143  // Coalesce runs of consecutive stars.  There should be at least
144  // one.
145  while (!p.empty() && (p[0] == '*'))
146    p.remove_prefix(1);
147
148  // Since we moved past the stars, an empty pattern here matches
149  // anything.
150  if (p.empty())
151    return true;
152
153  // Since we moved past the stars and p is non-empty, if some
154  // non-empty substring of s matches p, then we ourselves match.
155  while (!s.empty()) {
156    if (MatchVlogPattern(s, p))
157      return true;
158    s.remove_prefix(1);
159  }
160
161  // Otherwise, we couldn't find a match.
162  return false;
163}
164
165}  // namespace
166