| /* |
| * Copyright 2010 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| // Author: jmarantz@google.com (Joshua Marantz) |
| |
| #include "pagespeed/kernel/util/url_multipart_encoder.h" |
| |
| #include "pagespeed/kernel/base/message_handler.h" |
| #include "pagespeed/kernel/base/string.h" |
| #include "pagespeed/kernel/base/string_util.h" |
| #include "pagespeed/kernel/util/url_escaper.h" |
| |
| namespace { |
| |
| // Ultimately these will be encoded by the URL Escaper so we want to |
| // stay within legal URL space so we don't blow up. We'll have to |
| // see how we like this aesthetically. We want to stay within legal |
| // filename space as well so the filenames don't look too ugly. |
| |
| const char kEscape = '='; // Nice if this is filename-legal |
| const char kEscapedEscape[] = "=="; |
| const char kSeparator = '+'; |
| const char kEscapedSeparator[] = "=+"; |
| |
| } // namespace |
| |
| namespace net_instaweb { |
| class ResourceContext; |
| |
| UrlMultipartEncoder::~UrlMultipartEncoder() { |
| } |
| |
| void UrlMultipartEncoder::Encode(const StringVector& urls, |
| const ResourceContext* data, |
| GoogleString* encoding) const { |
| GoogleString buf; |
| |
| // Encoding is a two-part process. First we take the array of |
| // URLs and concatenate them together with + signs, escaping |
| // any + signs that appear in the URLs themselves. Since the |
| // escape for this encoder is '=' we must escape that too. |
| for (int i = 0, n = urls.size(); i < n; ++i) { |
| if (i != 0) { |
| buf += kSeparator; |
| } |
| const GoogleString& url = urls[i]; |
| for (int c = 0, nc = url.size(); c < nc; ++c) { |
| char ch = url[c]; |
| if (ch == kEscape) { |
| buf += kEscapedEscape; |
| } else if (ch == kSeparator) { |
| buf += kEscapedSeparator; |
| } else { |
| buf += ch; |
| } |
| } |
| } |
| |
| // Next we escape the whole blob with restrictions appropriate for URLs. |
| UrlEscaper::EncodeToUrlSegment(buf, encoding); |
| } |
| |
| bool UrlMultipartEncoder::Decode(const StringPiece& encoding, |
| StringVector* urls, |
| ResourceContext* data, |
| MessageHandler* handler) const { |
| GoogleString buf; |
| |
| // Reverse the two-step encoding process described above. |
| if (!UrlEscaper::DecodeFromUrlSegment(encoding, &buf)) { |
| handler->Message(kWarning, "Invalid escaped URL segment: %s", |
| encoding.as_string().c_str()); |
| return false; |
| } |
| |
| urls->clear(); |
| GoogleString url; |
| bool append_last = false; |
| for (int c = 0, nc = buf.size(); c < nc; ++c) { |
| char ch = buf[c]; |
| if (ch == kSeparator) { |
| urls->push_back(url); |
| url.clear(); |
| append_last = true; |
| // ensure that a "a+b+" results in 3 urls with the last one empty. |
| } else { |
| if (ch == kEscape) { |
| ++c; |
| if (c == nc) { |
| handler->Message(kWarning, |
| "Invalid encoding: escape at end of string %s", |
| buf.c_str()); |
| return false; |
| } |
| ch = buf[c]; |
| if ((ch != kEscape) && (ch != kSeparator)) { |
| handler->Message(kWarning, |
| "Invalid character `%c', after escape `%c' in %s", |
| ch, kEscape, buf.c_str()); |
| return false; |
| } |
| } |
| url += ch; |
| } |
| } |
| if (append_last || !url.empty()) { |
| urls->push_back(url); |
| } |
| return true; |
| } |
| |
| } // namespace net_instaweb |