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
16namespace logging {
17
18const int VlogInfo::kDefaultVlogLevel = 0;
19
20struct 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
32VlogInfo::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
43VlogInfo::VmodulePattern::VmodulePattern()
44    : vlog_level(VlogInfo::kDefaultVlogLevel),
45      match_target(MATCH_MODULE) {}
46
47VlogInfo::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
81VlogInfo::~VlogInfo() {}
82
83namespace {
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.
88base::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
105int 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
119void VlogInfo::SetMaxVlogLevel(int level) {
120  // Log severity is the negative verbosity.
121  *min_log_level_ = -level;
122}
123
124int VlogInfo::GetMaxVlogLevel() const {
125  return -*min_log_level_;
126}
127
128bool 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
182