net/instaweb/rewriter/file_load_mapping.cc

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

//
// Implementations of FileLoadMappingLiteral and FileLoadMappingRegexp, two
// subclasses of the abstract class FileLoadMapping.
//
// Tests are in file_load_policy_test.

#include "net/instaweb/rewriter/public/file_load_mapping.h"
#include "pagespeed/kernel/base/string.h"
#include "pagespeed/kernel/base/string_util.h"
#include "pagespeed/kernel/util/re2.h"

namespace net_instaweb {

FileLoadMapping::~FileLoadMapping() {}

bool FileLoadMappingRegexp::Substitute(StringPiece url,
                                       GoogleString* filename) const {
  GoogleString potential_filename;
  url.CopyToString(&potential_filename);
  const bool ok =
      RE2::Replace(&potential_filename, url_regexp_, filename_prefix_);
  if (ok) {
    filename->swap(potential_filename);  // Using swap() to avoid copying.
  }
  return ok;
}

bool FileLoadMappingLiteral::Substitute(StringPiece url,
                                        GoogleString* filename) const {
  if (url.starts_with(url_prefix_)) {
    // Replace url_prefix_ with filename_prefix_.
    const StringPiece suffix = url.substr(url_prefix_.size());
    *filename = StrCat(filename_prefix_, suffix);
    return true;
  }
  return false;
}

}  // namespace net_instaweb