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      1 // Copyright (c) 2012 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/version.h"
      6 
      7 #include <stddef.h>
      8 
      9 #include <algorithm>
     10 
     11 #include "base/logging.h"
     12 #include "base/strings/string_number_conversions.h"
     13 #include "base/strings/string_split.h"
     14 #include "base/strings/string_util.h"
     15 
     16 namespace base {
     17 
     18 namespace {
     19 
     20 // Parses the |numbers| vector representing the different numbers
     21 // inside the version string and constructs a vector of valid integers. It stops
     22 // when it reaches an invalid item (including the wildcard character). |parsed|
     23 // is the resulting integer vector. Function returns true if all numbers were
     24 // parsed successfully, false otherwise.
     25 bool ParseVersionNumbers(const std::string& version_str,
     26                          std::vector<uint16>* parsed) {
     27   std::vector<std::string> numbers;
     28   SplitString(version_str, '.', &numbers);
     29   if (numbers.empty())
     30     return false;
     31 
     32   for (std::vector<std::string>::const_iterator it = numbers.begin();
     33        it != numbers.end(); ++it) {
     34     int num;
     35     if (!StringToInt(*it, &num))
     36       return false;
     37 
     38     if (num < 0)
     39       return false;
     40 
     41     const uint16 max = 0xFFFF;
     42     if (num > max)
     43       return false;
     44 
     45     // This throws out things like +3, or 032.
     46     if (IntToString(num) != *it)
     47       return false;
     48 
     49     parsed->push_back(static_cast<uint16>(num));
     50   }
     51   return true;
     52 }
     53 
     54 // Compares version components in |components1| with components in
     55 // |components2|. Returns -1, 0 or 1 if |components1| is less than, equal to,
     56 // or greater than |components2|, respectively.
     57 int CompareVersionComponents(const std::vector<uint16>& components1,
     58                              const std::vector<uint16>& components2) {
     59   const size_t count = std::min(components1.size(), components2.size());
     60   for (size_t i = 0; i < count; ++i) {
     61     if (components1[i] > components2[i])
     62       return 1;
     63     if (components1[i] < components2[i])
     64       return -1;
     65   }
     66   if (components1.size() > components2.size()) {
     67     for (size_t i = count; i < components1.size(); ++i) {
     68       if (components1[i] > 0)
     69         return 1;
     70     }
     71   } else if (components1.size() < components2.size()) {
     72     for (size_t i = count; i < components2.size(); ++i) {
     73       if (components2[i] > 0)
     74         return -1;
     75     }
     76   }
     77   return 0;
     78 }
     79 
     80 }  // namespace
     81 
     82 Version::Version() {
     83 }
     84 
     85 Version::~Version() {
     86 }
     87 
     88 Version::Version(const std::string& version_str) {
     89   std::vector<uint16> parsed;
     90   if (!ParseVersionNumbers(version_str, &parsed))
     91     return;
     92 
     93   components_.swap(parsed);
     94 }
     95 
     96 bool Version::IsValid() const {
     97   return (!components_.empty());
     98 }
     99 
    100 // static
    101 bool Version::IsValidWildcardString(const std::string& wildcard_string) {
    102   std::string version_string = wildcard_string;
    103   if (EndsWith(wildcard_string.c_str(), ".*", false))
    104     version_string = wildcard_string.substr(0, wildcard_string.size() - 2);
    105 
    106   Version version(version_string);
    107   return version.IsValid();
    108 }
    109 
    110 bool Version::IsOlderThan(const std::string& version_str) const {
    111   Version proposed_ver(version_str);
    112   if (!proposed_ver.IsValid())
    113     return false;
    114   return (CompareTo(proposed_ver) < 0);
    115 }
    116 
    117 int Version::CompareToWildcardString(const std::string& wildcard_string) const {
    118   DCHECK(IsValid());
    119   DCHECK(Version::IsValidWildcardString(wildcard_string));
    120 
    121   // Default behavior if the string doesn't end with a wildcard.
    122   if (!EndsWith(wildcard_string.c_str(), ".*", false)) {
    123     Version version(wildcard_string);
    124     DCHECK(version.IsValid());
    125     return CompareTo(version);
    126   }
    127 
    128   std::vector<uint16> parsed;
    129   const bool success = ParseVersionNumbers(
    130       wildcard_string.substr(0, wildcard_string.length() - 2), &parsed);
    131   DCHECK(success);
    132   const int comparison = CompareVersionComponents(components_, parsed);
    133   // If the version is smaller than the wildcard version's |parsed| vector,
    134   // then the wildcard has no effect (e.g. comparing 1.2.3 and 1.3.*) and the
    135   // version is still smaller. Same logic for equality (e.g. comparing 1.2.2 to
    136   // 1.2.2.* is 0 regardless of the wildcard). Under this logic,
    137   // 1.2.0.0.0.0 compared to 1.2.* is 0.
    138   if (comparison == -1 || comparison == 0)
    139     return comparison;
    140 
    141   // Catch the case where the digits of |parsed| are found in |components_|,
    142   // which means that the two are equal since |parsed| has a trailing "*".
    143   // (e.g. 1.2.3 vs. 1.2.* will return 0). All other cases return 1 since
    144   // components is greater (e.g. 3.2.3 vs 1.*).
    145   DCHECK_GT(parsed.size(), 0UL);
    146   const size_t min_num_comp = std::min(components_.size(), parsed.size());
    147   for (size_t i = 0; i < min_num_comp; ++i) {
    148     if (components_[i] != parsed[i])
    149       return 1;
    150   }
    151   return 0;
    152 }
    153 
    154 bool Version::Equals(const Version& that) const {
    155   DCHECK(IsValid());
    156   DCHECK(that.IsValid());
    157   return (CompareTo(that) == 0);
    158 }
    159 
    160 int Version::CompareTo(const Version& other) const {
    161   DCHECK(IsValid());
    162   DCHECK(other.IsValid());
    163   return CompareVersionComponents(components_, other.components_);
    164 }
    165 
    166 const std::string Version::GetString() const {
    167   DCHECK(IsValid());
    168   std::string version_str;
    169   size_t count = components_.size();
    170   for (size_t i = 0; i < count - 1; ++i) {
    171     version_str.append(IntToString(components_[i]));
    172     version_str.append(".");
    173   }
    174   version_str.append(IntToString(components_[count - 1]));
    175   return version_str;
    176 }
    177 
    178 }  // namespace base
    179