Page Speed Optimization Libraries  1.7.30.1
net/instaweb/rewriter/public/css_filter.h
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00001 /*
00002  * Copyright 2010 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_CSS_FILTER_H_
00020 #define NET_INSTAWEB_REWRITER_PUBLIC_CSS_FILTER_H_
00021 
00022 #include "net/instaweb/htmlparse/public/html_element.h"
00023 #include "net/instaweb/rewriter/public/css_hierarchy.h"
00024 #include "net/instaweb/rewriter/public/css_resource_slot.h"
00025 #include "net/instaweb/rewriter/public/css_url_encoder.h"
00026 #include "net/instaweb/rewriter/public/output_resource_kind.h"
00027 #include "net/instaweb/rewriter/public/resource.h"
00028 #include "net/instaweb/rewriter/public/server_context.h"
00029 #include "net/instaweb/rewriter/public/resource_slot.h"
00030 #include "net/instaweb/rewriter/public/rewrite_filter.h"
00031 #include "net/instaweb/rewriter/public/rewrite_options.h"
00032 #include "net/instaweb/rewriter/public/single_rewrite_context.h"
00033 #include "net/instaweb/util/public/basictypes.h"
00034 #include "net/instaweb/util/public/google_url.h"
00035 #include "net/instaweb/util/public/scoped_ptr.h"
00036 #include "net/instaweb/util/public/string.h"
00037 #include "net/instaweb/util/public/string_util.h"
00038 
00039 namespace Css {
00040 
00041 class Stylesheet;
00042 
00043 }  
00044 
00045 namespace net_instaweb {
00046 
00047 class AssociationTransformer;
00048 class CssImageRewriter;
00049 class CacheExtender;
00050 class HtmlCharactersNode;
00051 class ImageCombineFilter;
00052 class ImageRewriteFilter;
00053 class MessageHandler;
00054 class OutputPartitions;
00055 class ResourceContext;
00056 class RewriteContext;
00057 class RewriteDriver;
00058 class RewriteDomainTransformer;
00059 class Statistics;
00060 class UrlSegmentEncoder;
00061 class Variable;
00062 class Writer;
00063 
00074 class CssFilter : public RewriteFilter {
00075  public:
00076   class Context;
00077 
00078   CssFilter(RewriteDriver* driver,
00081             CacheExtender* cache_extender,
00082             ImageRewriteFilter* image_rewriter,
00083             ImageCombineFilter* image_combiner);
00084   virtual ~CssFilter();
00085 
00088   static void InitStats(Statistics* statistics);
00089 
00091   static void Initialize();
00092   static void Terminate();
00093 
00095   static void AddRelatedOptions(StringPieceVector* target);
00096 
00100   static void InitializeAtExitManager();
00101 
00102   virtual void StartDocumentImpl();
00103   virtual void StartElementImpl(HtmlElement* element);
00104   virtual void Characters(HtmlCharactersNode* characters);
00105   virtual void EndElementImpl(HtmlElement* element);
00106 
00107   virtual const char* Name() const { return "CssFilter"; }
00108   virtual const char* id() const { return RewriteOptions::kCssFilterId; }
00109   virtual void EncodeUserAgentIntoResourceContext(
00110       ResourceContext* context) const;
00111 
00112   static const char kBlocksRewritten[];
00113   static const char kParseFailures[];
00114   static const char kFallbackRewrites[];
00115   static const char kFallbackFailures[];
00116   static const char kRewritesDropped[];
00117   static const char kTotalBytesSaved[];
00118   static const char kTotalOriginalBytes[];
00119   static const char kUses[];
00120   static const char kCharsetMismatch[];
00121   static const char kInvalidUrl[];
00122   static const char kLimitExceeded[];
00123   static const char kMinifyFailed[];
00124   static const char kRecursion[];
00125   static const char kComplexQueries[];
00126 
00127   RewriteContext* MakeNestedFlatteningContextInNewSlot(
00128       const ResourcePtr& resource, const GoogleString& location,
00129       CssFilter::Context* rewriter, RewriteContext* parent,
00130       CssHierarchy* hierarchy);
00131 
00132   virtual const RewriteOptions::Filter* RelatedFilters(int* num_filters) const {
00133     *num_filters = merged_filters_size_;
00134     return merged_filters_;
00135   }
00136   virtual const StringPieceVector* RelatedOptions() const {
00137     return related_options_;
00138   }
00139 
00140  protected:
00141   virtual RewriteContext* MakeRewriteContext();
00142   virtual const UrlSegmentEncoder* encoder() const;
00143   virtual RewriteContext* MakeNestedRewriteContext(
00144       RewriteContext* parent, const ResourceSlotPtr& slot);
00145 
00146  private:
00147   friend class Context;
00148   friend class CssFlattenImportsContext; 
00149   friend class CssHierarchy; 
00150 
00151   enum InlineCssKind {
00152     kInsideStyleTag,
00153     kAttributeWithoutUrls,
00154     kAttributeWithUrls
00155   };
00156 
00157   Context* MakeContext(RewriteDriver* driver,
00158                        RewriteContext* parent);
00159 
00161   void StartInlineRewrite(HtmlCharactersNode* text);
00162 
00165   void StartAttributeRewrite(HtmlElement* element,
00166                              HtmlElement::Attribute* style,
00167                              InlineCssKind inline_css_kind);
00168 
00171   void StartExternalRewrite(HtmlElement* link, HtmlElement::Attribute* src);
00172 
00173   ResourceSlot* MakeSlotForInlineCss(const StringPiece& content);
00174   CssFilter::Context* StartRewriting(const ResourceSlotPtr& slot);
00175 
00181   bool GetApplicableCharset(const HtmlElement* element,
00182                             GoogleString* charset,
00183                             GoogleString* failure_reason) const;
00184 
00187   bool GetApplicableMedia(const HtmlElement* element,
00188                           StringVector* media) const;
00189 
00190   bool in_style_element_; 
00191 
00192   HtmlElement* style_element_; 
00193 
00195   GoogleString meta_tag_charset_;
00196 
00198   CacheExtender* cache_extender_;
00199   ImageRewriteFilter* image_rewrite_filter_;
00200   ImageCombineFilter* image_combiner_;
00201 
00205   Variable* num_blocks_rewritten_;
00207   Variable* num_parse_failures_;
00210   Variable* num_fallback_rewrites_;
00212   Variable* num_fallback_failures_;
00215   Variable* num_rewrites_dropped_;
00221   Variable* total_bytes_saved_;
00225   Variable* total_original_bytes_;
00228   Variable* num_uses_;
00230   Variable* num_flatten_imports_charset_mismatch_;
00232   Variable* num_flatten_imports_invalid_url_;
00234   Variable* num_flatten_imports_limit_exceeded_;
00236   Variable* num_flatten_imports_minify_failed_;
00238   Variable* num_flatten_imports_recursion_;
00240   Variable* num_flatten_imports_complex_queries_;
00241 
00242   CssUrlEncoder encoder_;
00243 
00245   static const RewriteOptions::Filter* merged_filters_;
00246   static int merged_filters_size_;
00247 
00249   static StringPieceVector* related_options_;
00250 
00251   DISALLOW_COPY_AND_ASSIGN(CssFilter);
00252 };
00253 
00255 class CssFilter::Context : public SingleRewriteContext {
00256  public:
00257   Context(CssFilter* filter, RewriteDriver* driver,
00258           RewriteContext* parent,
00259           CacheExtender* cache_extender,
00260           ImageRewriteFilter* image_rewriter,
00261           ImageCombineFilter* image_combiner,
00262           ResourceContext* context);
00263   virtual ~Context();
00264 
00266   void SetupInlineRewrite(HtmlElement* style_element, HtmlCharactersNode* text);
00267   void SetupAttributeRewrite(HtmlElement* element,
00268                              HtmlElement::Attribute* src,
00269                              InlineCssKind inline_css_kind);
00270   void SetupExternalRewrite(HtmlElement* element,
00271                             const GoogleUrl& base_gurl,
00272                             const GoogleUrl& trim_gurl);
00273 
00276   void RewriteCssFromNested(RewriteContext* parent, CssHierarchy* hierarchy);
00277 
00280   virtual bool AbsolutifyIfNeeded(const StringPiece& input_contents,
00281                                   Writer* writer, MessageHandler* handler);
00282 
00283   CssResourceSlotFactory* slot_factory() { return &slot_factory_; }
00284 
00285   CssHierarchy* mutable_hierarchy() { return &hierarchy_; }
00286 
00287  protected:
00288   virtual void Render();
00289   virtual void Harvest();
00290   virtual bool Partition(OutputPartitions* partitions,
00291                          OutputResourceVector* outputs);
00292   virtual void RewriteSingle(const ResourcePtr& input,
00293                              const OutputResourcePtr& output);
00294   virtual const char* id() const { return filter_->id(); }
00295   virtual OutputResourceKind kind() const { return kRewrittenResource; }
00296   virtual GoogleString CacheKeySuffix() const;
00297   virtual const UrlSegmentEncoder* encoder() const;
00298 
00300   virtual GoogleString UserAgentCacheKey(
00301       const ResourceContext* resource_context) const;
00302 
00303  private:
00304   bool RewriteCssText(const GoogleUrl& css_base_gurl,
00305                       const GoogleUrl& css_trim_gurl,
00306                       const StringPiece& in_text,
00307                       int64 in_text_size,
00308                       bool text_is_declarations,
00309                       MessageHandler* handler);
00310 
00312   void RewriteCssFromRoot(const StringPiece& in_text, int64 in_text_size,
00313                           bool has_unparseables, Css::Stylesheet* stylesheet);
00314 
00320   bool FallbackRewriteUrls(const StringPiece& in_text);
00321 
00324   bool SerializeCss(int64 in_text_size,
00325                     const Css::Stylesheet* stylesheet,
00326                     const GoogleUrl& css_base_gurl,
00327                     const GoogleUrl& css_trim_gurl,
00328                     bool previously_optimized,
00329                     bool stylesheet_is_declarations,
00330                     bool add_utf8_bom,
00331                     GoogleString* out_text,
00332                     MessageHandler* handler);
00333 
00337   bool IsInlineAttribute() const {
00338     return (rewrite_inline_attribute_ != NULL);
00339   }
00340 
00344   int64 ImageInlineMaxBytes() const;
00345 
00346   CssFilter* filter_;
00347   RewriteDriver* driver_;
00348   scoped_ptr<CssImageRewriter> css_image_rewriter_;
00349   CssResourceSlotFactory slot_factory_;
00350   CssHierarchy hierarchy_;
00351   bool css_rewritten_;
00352   bool has_utf8_bom_;
00353 
00355   bool fallback_mode_;
00358   scoped_ptr<AssociationTransformer> fallback_transformer_;
00361   scoped_ptr<RewriteDomainTransformer> absolutifier_;
00362 
00365   HtmlElement* rewrite_element_;
00366 
00370   HtmlElement* rewrite_inline_element_;
00371 
00373   HtmlCharactersNode* rewrite_inline_char_node_;
00374 
00378   HtmlElement::Attribute* rewrite_inline_attribute_;
00379 
00383   InlineCssKind rewrite_inline_css_kind_;
00384 
00386   int64 in_text_size_;
00387   GoogleUrl css_base_gurl_;
00388   GoogleUrl css_trim_gurl_;
00389   ResourcePtr input_resource_;
00390   OutputResourcePtr output_resource_;
00391 
00392   DISALLOW_COPY_AND_ASSIGN(Context);
00393 };
00394 
00395 }  
00396 
00397 #endif  ///< NET_INSTAWEB_REWRITER_PUBLIC_CSS_FILTER_H_
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