ppapi/native_client/src/trusted/plugin/nacl_http_response_headers.cc

   1 // Copyright 2013 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 "ppapi/native_client/src/trusted/plugin/nacl_http_response_headers.h"
   6
   7 #include <algorithm>
   8 #include <sstream>
   9
  10 namespace {
  11
  12 // TODO(jvoung): Use Tokenize from base/strings/string_util.h when this moves
  13 // to Chromium.
  14 void SplitString(const std::string& str,
  15                  char delim,
  16                  std::vector<std::string>* elems) {
  17   std::stringstream ss(str);
  18   std::string item;
  19   while (std::getline(ss, item, delim)) {
  20     elems->push_back(item);
  21   }
  22 }
  23
  24 bool SplitOnce(const std::string& str,
  25                char delim,
  26                std::vector<std::string>* elems) {
  27   size_t pos = str.find(delim);
  28   if (pos != std::string::npos) {
  29     elems->push_back(str.substr(0, pos));
  30     elems->push_back(str.substr(pos + 1));
  31     return true;
  32   }
  33   return false;
  34 }
  35
  36 }  // namespace
  37
  38 namespace plugin {
  39
  40 NaClHttpResponseHeaders::NaClHttpResponseHeaders() {}
  41
  42 NaClHttpResponseHeaders::~NaClHttpResponseHeaders() {}
  43
  44 void NaClHttpResponseHeaders::Parse(const std::string& headers_str) {
  45   // PPAPI response headers are \n delimited. Separate out the lines.
  46   std::vector<std::string> lines;
  47   SplitString(headers_str, '\n', &lines);
  48
  49   for (size_t i = 0; i < lines.size(); ++i) {
  50     std::vector<std::string> tokens;
  51     // Split along the key-value pair separator char.
  52     if (!SplitOnce(lines[i], ':', &tokens)) {
  53       // Ignore funny header lines that don't have the key-value separator.
  54       continue;
  55     }
  56     std::string key = tokens[0];
  57     // Also ignore keys that start with white-space (they are invalid).
  58     // See: HttpResponseHeadersTest.NormalizeHeadersLeadingWhitespace.
  59     if (key[0] == ' ' || key[0] == '\t')
  60       continue;
  61     // TODO(jvoung): replace some of this with TrimWhitespaceASCII when
  62     // we move code to chromium.
  63     // Strip trailing whitespace from the key to normalize.
  64     size_t pos = key.find_last_not_of(" \t");
  65     if (pos != std::string::npos)
  66       key.erase(pos + 1);
  67     // Strip leading whitespace from the value to normalize.
  68     std::string value = tokens[1];
  69     value.erase(0, value.find_first_not_of(" \t"));
  70     header_entries_.push_back(Entry(key, value));
  71   }
  72 }
  73
  74 std::string NaClHttpResponseHeaders::GetHeader(const std::string& name) {
  75   for (size_t i = 0; i < header_entries_.size(); ++i) {
  76     const Entry& entry = header_entries_[i];
  77     std::string key = entry.first;
  78     // TODO(jvoung): replace with LowerCaseEqualsASCII later.
  79     std::transform(key.begin(), key.end(), key.begin(), ::tolower);
  80     if (key.compare(name) == 0)
  81       return entry.second;
  82   }
  83   return std::string();
  84 }
  85
  86 std::string NaClHttpResponseHeaders::GetCacheValidators() {
  87   std::string result = GetHeader("etag");
  88   if (!result.empty())
  89     result = "etag:" + result;
  90   std::string lm = GetHeader("last-modified");
  91   if (!lm.empty()) {
  92     if (!result.empty())
  93       result += "&";
  94     result += "last-modified:" + lm;
  95   }
  96   return result;
  97 }
  98
  99 bool NaClHttpResponseHeaders::CacheControlNoStore() {
 100   for (size_t i = 0; i < header_entries_.size(); ++i) {
 101     const Entry& entry = header_entries_[i];
 102     std::string key = entry.first;
 103     // TODO(jvoung): replace with LowerCaseEqualsASCII later.
 104     std::transform(key.begin(), key.end(), key.begin(), ::tolower);
 105     if (key.compare("cache-control") == 0) {
 106       std::string cc = entry.second;
 107       std::transform(cc.begin(), cc.end(), cc.begin(), ::tolower);
 108       if (entry.second.find("no-store") != std::string::npos)
 109         return true;
 110     }
 111   }
 112   return false;
 113 }
 114
 115 }  // namespace plugin