Page Speed Optimization Libraries  1.6.29.3
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) const;
00183 
00186   bool GetApplicableMedia(const HtmlElement* element,
00187                           StringVector* media) const;
00188 
00189   bool in_style_element_; 
00190 
00191   HtmlElement* style_element_; 
00192 
00194   GoogleString meta_tag_charset_;
00195 
00197   CacheExtender* cache_extender_;
00198   ImageRewriteFilter* image_rewrite_filter_;
00199   ImageCombineFilter* image_combiner_;
00200 
00204   Variable* num_blocks_rewritten_;
00206   Variable* num_parse_failures_;
00209   Variable* num_fallback_rewrites_;
00211   Variable* num_fallback_failures_;
00214   Variable* num_rewrites_dropped_;
00220   Variable* total_bytes_saved_;
00224   Variable* total_original_bytes_;
00227   Variable* num_uses_;
00229   Variable* num_flatten_imports_charset_mismatch_;
00231   Variable* num_flatten_imports_invalid_url_;
00233   Variable* num_flatten_imports_limit_exceeded_;
00235   Variable* num_flatten_imports_minify_failed_;
00237   Variable* num_flatten_imports_recursion_;
00239   Variable* num_flatten_imports_complex_queries_;
00240 
00241   CssUrlEncoder encoder_;
00242 
00244   static const RewriteOptions::Filter* merged_filters_;
00245   static int merged_filters_size_;
00246 
00248   static StringPieceVector* related_options_;
00249 
00250   DISALLOW_COPY_AND_ASSIGN(CssFilter);
00251 };
00252 
00254 class CssFilter::Context : public SingleRewriteContext {
00255  public:
00256   Context(CssFilter* filter, RewriteDriver* driver,
00257           RewriteContext* parent,
00258           CacheExtender* cache_extender,
00259           ImageRewriteFilter* image_rewriter,
00260           ImageCombineFilter* image_combiner,
00261           ResourceContext* context);
00262   virtual ~Context();
00263 
00265   void SetupInlineRewrite(HtmlElement* style_element, HtmlCharactersNode* text);
00266   void SetupAttributeRewrite(HtmlElement* element,
00267                              HtmlElement::Attribute* src,
00268                              InlineCssKind inline_css_kind);
00269   void SetupExternalRewrite(const GoogleUrl& base_gurl,
00270                             const GoogleUrl& trim_gurl);
00271 
00274   void RewriteCssFromNested(RewriteContext* parent, CssHierarchy* hierarchy);
00275 
00278   virtual bool AbsolutifyIfNeeded(const StringPiece& input_contents,
00279                                   Writer* writer, MessageHandler* handler);
00280 
00281   CssResourceSlotFactory* slot_factory() { return &slot_factory_; }
00282 
00283   CssHierarchy* mutable_hierarchy() { return &hierarchy_; }
00284 
00285  protected:
00286   virtual void Render();
00287   virtual void Harvest();
00288   virtual bool Partition(OutputPartitions* partitions,
00289                          OutputResourceVector* outputs);
00290   virtual void RewriteSingle(const ResourcePtr& input,
00291                              const OutputResourcePtr& output);
00292   virtual const char* id() const { return filter_->id(); }
00293   virtual OutputResourceKind kind() const { return kRewrittenResource; }
00294   virtual GoogleString CacheKeySuffix() const;
00295   virtual const UrlSegmentEncoder* encoder() const;
00296 
00298   virtual GoogleString UserAgentCacheKey(
00299       const ResourceContext* resource_context) const;
00300 
00301  private:
00302   bool RewriteCssText(const GoogleUrl& css_base_gurl,
00303                       const GoogleUrl& css_trim_gurl,
00304                       const StringPiece& in_text,
00305                       int64 in_text_size,
00306                       bool text_is_declarations,
00307                       MessageHandler* handler);
00308 
00310   void RewriteCssFromRoot(const StringPiece& in_text, int64 in_text_size,
00311                           bool has_unparseables, Css::Stylesheet* stylesheet);
00312 
00318   bool FallbackRewriteUrls(const StringPiece& in_text);
00319 
00322   bool SerializeCss(int64 in_text_size,
00323                     const Css::Stylesheet* stylesheet,
00324                     const GoogleUrl& css_base_gurl,
00325                     const GoogleUrl& css_trim_gurl,
00326                     bool previously_optimized,
00327                     bool stylesheet_is_declarations,
00328                     bool add_utf8_bom,
00329                     GoogleString* out_text,
00330                     MessageHandler* handler);
00331 
00335   bool IsInlineAttribute() const {
00336     return (rewrite_inline_attribute_ != NULL);
00337   }
00338 
00342   int64 ImageInlineMaxBytes() const;
00343 
00344   CssFilter* filter_;
00345   RewriteDriver* driver_;
00346   scoped_ptr<CssImageRewriter> css_image_rewriter_;
00347   CssResourceSlotFactory slot_factory_;
00348   CssHierarchy hierarchy_;
00349   bool css_rewritten_;
00350   bool has_utf8_bom_;
00351 
00353   bool fallback_mode_;
00356   scoped_ptr<AssociationTransformer> fallback_transformer_;
00359   scoped_ptr<RewriteDomainTransformer> absolutifier_;
00360 
00364   HtmlElement* rewrite_inline_element_;
00365 
00367   HtmlCharactersNode* rewrite_inline_char_node_;
00368 
00372   HtmlElement::Attribute* rewrite_inline_attribute_;
00373 
00377   InlineCssKind rewrite_inline_css_kind_;
00378 
00380   int64 in_text_size_;
00381   GoogleUrl css_base_gurl_;
00382   GoogleUrl css_trim_gurl_;
00383   ResourcePtr input_resource_;
00384   OutputResourcePtr output_resource_;
00385 
00386   DISALLOW_COPY_AND_ASSIGN(Context);
00387 };
00388 
00389 }  
00390 
00391 #endif  ///< NET_INSTAWEB_REWRITER_PUBLIC_CSS_FILTER_H_
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