Page Speed Optimization Libraries
1.7.30.1
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00001 /* 00002 * Copyright 2013 Google Inc. 00003 * 00004 * Licensed under the Apache License, Version 2.0 (the "License"); 00005 * you may not use this file except in compliance with the License. 00006 * You may obtain a copy of the License at 00007 * 00008 * http:///www.apache.org/licenses/LICENSE-2.0 00009 * 00010 * Unless required by applicable law or agreed to in writing, software 00011 * distributed under the License is distributed on an "AS IS" BASIS, 00012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00013 * See the License for the specific language governing permissions and 00014 * limitations under the License. 00015 */ 00016 00018 00019 #ifndef NET_INSTAWEB_REWRITER_PUBLIC_DEDUP_INLINED_IMAGES_FILTER_H_ 00020 #define NET_INSTAWEB_REWRITER_PUBLIC_DEDUP_INLINED_IMAGES_FILTER_H_ 00021 00022 #include "net/instaweb/util/public/basictypes.h" 00023 #include "net/instaweb/rewriter/public/common_filter.h" 00024 #include "net/instaweb/util/public/string_util.h" 00025 00026 namespace net_instaweb { 00027 00028 class HtmlElement; 00029 class RewriteDriver; 00030 class Statistics; 00031 class Variable; 00032 00033 /* 00034 * The Dedup Inlined Images filter replaces the second & subsequent occurences 00035 * a repeated inlined image (data:image/... URL) with JavaScript that loads 00036 * the image from the first occurence. This requires the first occurence to be 00037 * tagged with a unique id; if it already has an id then that's used instead. 00038 */ 00039 class DedupInlinedImagesFilter : public CommonFilter { 00040 public: 00041 static const unsigned int kMinimumImageCutoff; 00042 00043 static const char kDiiInitializer[]; 00044 00046 static const char kCandidatesFound[]; 00047 static const char kCandidatesReplaced[]; 00048 00049 explicit DedupInlinedImagesFilter(RewriteDriver* driver); 00050 virtual ~DedupInlinedImagesFilter(); 00051 00053 static void InitStats(Statistics* statistics); 00054 00055 virtual void StartDocumentImpl(); 00056 virtual void EndDocument(); 00057 virtual void StartElementImpl(HtmlElement* element); 00058 virtual void EndElementImpl(HtmlElement* element); 00059 virtual void DetermineEnabled(); 00060 00061 virtual const char* Name() const { return "DedupInlinedImages"; } 00062 00063 private: 00064 bool IsDedupCandidate(HtmlElement* element, StringPiece* src_iff_true); 00065 void InsertOurScriptElement(HtmlElement* before); 00066 00067 bool script_inserted_; 00068 StringStringMap hash_to_id_map_; 00069 int snippet_id_; 00070 00072 Variable* num_dedup_inlined_images_candidates_found_; 00074 Variable* num_dedup_inlined_images_candidates_replaced_; 00075 00076 DISALLOW_COPY_AND_ASSIGN(DedupInlinedImagesFilter); 00077 }; 00078 00079 } 00080 00081 #endif ///< NET_INSTAWEB_REWRITER_PUBLIC_DEDUP_INLINED_IMAGES_FILTER_H_