Page Speed Optimization Libraries
1.7.30.3
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00001 /* 00002 * Copyright 2011 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_REWRITE_CONTEXT_H_ 00020 #define NET_INSTAWEB_REWRITER_PUBLIC_REWRITE_CONTEXT_H_ 00021 00022 #include <set> 00023 #include <vector> 00024 00025 #include "net/instaweb/http/public/http_cache.h" 00026 #include "net/instaweb/rewriter/cached_result.pb.h" 00027 #include "net/instaweb/rewriter/public/output_resource_kind.h" 00028 #include "net/instaweb/rewriter/public/resource.h" 00029 #include "net/instaweb/rewriter/public/server_context.h" 00030 #include "net/instaweb/rewriter/public/resource_slot.h" 00031 #include "net/instaweb/rewriter/public/rewrite_context.h" 00032 #include "net/instaweb/rewriter/public/rewrite_result.h" 00033 #include "net/instaweb/util/public/basictypes.h" 00034 #include "net/instaweb/util/public/scoped_ptr.h" 00035 #include "net/instaweb/util/public/string.h" 00036 #include "net/instaweb/util/public/string_util.h" 00037 #include "net/instaweb/util/public/url_segment_encoder.h" 00038 00039 namespace net_instaweb { 00040 00041 class AsyncFetch; 00042 class GoogleUrl; 00043 class MessageHandler; 00044 class NamedLock; 00045 class RequestTrace; 00046 class ResponseHeaders; 00047 class RewriteDriver; 00048 class RewriteOptions; 00049 class Statistics; 00050 class Variable; 00051 class Writer; 00052 class FreshenMetadataUpdateManager; 00053 00146 class RewriteContext { 00147 public: 00148 typedef std::vector<InputInfo*> InputInfoStarVector; 00149 static const char kNumDeadlineAlarmInvocations[]; 00150 static const char kNumDistributedRewriteSuccesses[]; 00151 static const char kNumDistributedRewriteFailures[]; 00152 static const char kNumDistributedMetadataFailures[]; 00154 static const char kDistributedExt[]; 00156 static const char kDistributedHash[]; 00159 struct CacheLookupResult { 00160 CacheLookupResult() 00161 : cache_ok(false), 00162 can_revalidate(false), 00163 useable_cache_content(false), 00164 is_stale_rewrite(false), 00165 partitions(new OutputPartitions) {} 00166 00167 bool cache_ok; 00168 bool can_revalidate; 00169 bool useable_cache_content; 00170 bool is_stale_rewrite; 00171 InputInfoStarVector revalidate; 00172 scoped_ptr<OutputPartitions> partitions; 00173 }; 00174 00176 class CacheLookupResultCallback { 00177 public: 00178 CacheLookupResultCallback() {} 00179 virtual ~CacheLookupResultCallback(); 00180 virtual void Done(const GoogleString& cache_key, 00181 CacheLookupResult* result) = 0; 00182 private: 00183 DISALLOW_COPY_AND_ASSIGN(CacheLookupResultCallback); 00184 }; 00185 00188 RewriteContext(RewriteDriver* driver, 00189 RewriteContext* parent, 00190 ResourceContext* resource_context); 00191 virtual ~RewriteContext(); 00192 00197 int num_slots() const { return slots_.size(); } 00198 ResourceSlotPtr slot(int index) const { return slots_[index]; } 00199 00202 int num_outputs() const { return outputs_.size(); } 00203 OutputResourcePtr output(int i) const { return outputs_[i]; } 00204 00207 int num_output_partitions() const; 00208 const CachedResult* output_partition(int i) const; 00209 CachedResult* output_partition(int i); 00210 00213 bool chained() const { return chained_; } 00214 00218 void AddSlot(const ResourceSlotPtr& slot); 00219 00222 void RemoveLastSlot(); 00223 00229 void AddNestedContext(RewriteContext* context); 00230 00241 void Initiate(); 00242 00248 bool Fetch(const OutputResourcePtr& output_resource, 00249 AsyncFetch* fetch, 00250 MessageHandler* message_handler); 00251 00265 static bool LookupMetadataForOutputResource( 00266 const GoogleString& url, 00267 RewriteDriver* driver, 00268 GoogleString* error_out, 00269 CacheLookupResultCallback* callback); 00270 00273 bool slow() const { return slow_; } 00274 00276 bool is_metadata_cache_miss() const { return is_metadata_cache_miss_; } 00277 00279 bool has_parent() const { return parent_ != NULL; } 00280 00283 bool IsNestedIn(StringPiece id) const; 00284 00286 RewriteContext* parent() { return parent_; } 00287 const RewriteContext* parent() const { return parent_; } 00288 00290 void set_force_rewrite(bool x) { force_rewrite_ = x; } 00291 00292 bool rewrite_uncacheable() const { return rewrite_uncacheable_; } 00293 void set_rewrite_uncacheable(bool rewrite_uncacheable) { 00294 rewrite_uncacheable_ = rewrite_uncacheable; 00295 } 00296 00297 const ResourceContext* resource_context() const { 00298 return resource_context_.get(); 00299 } 00300 00302 GoogleString ToString(StringPiece prefix) const; 00303 00305 static void InitStats(Statistics* stats); 00306 00307 protected: 00308 typedef std::vector<GoogleUrl*> GoogleUrlStarVector; 00309 00314 00318 ServerContext* FindServerContext() const; 00319 const RewriteOptions* Options() const; 00320 RewriteDriver* Driver() const; 00321 00323 int num_nested() const { return nested_.size(); } 00324 RewriteContext* nested(int i) const { return nested_[i]; } 00325 00326 OutputPartitions* partitions() { return partitions_.get(); } 00327 00330 void AddRecheckDependency(); 00331 00335 virtual bool OptimizationOnly() const { return true; } 00336 00354 virtual bool Partition(OutputPartitions* partitions, 00355 OutputResourceVector* outputs); 00356 00362 virtual void PartitionAsync(OutputPartitions* partitions, 00363 OutputResourceVector* outputs); 00364 00368 void PartitionDone(bool result); 00369 00372 void CrossThreadPartitionDone(bool result); 00373 00392 virtual void Rewrite(int partition_index, 00393 CachedResult* partition, 00394 const OutputResourcePtr& output) = 0; 00395 00400 void RewriteDone(RewriteResult result, int partition_index); 00401 00408 virtual bool AbsolutifyIfNeeded(const StringPiece& input_contents, 00409 Writer* writer, MessageHandler* handler); 00410 00414 void StartNestedTasks(); 00415 00420 virtual void Harvest(); 00421 00433 virtual void Render(); 00434 00445 virtual void WillNotRender(); 00446 00450 virtual void Cancel(); 00451 00454 00461 virtual const UrlSegmentEncoder* encoder() const; 00462 00465 virtual GoogleString CacheKeySuffix() const; 00466 00473 virtual GoogleString UserAgentCacheKey( 00474 const ResourceContext* context) const { 00475 return ""; 00476 } 00477 00482 virtual void EncodeUserAgentIntoResourceContext(ResourceContext* context) {} 00483 00485 virtual const char* id() const = 0; 00486 00495 virtual OutputResourceKind kind() const = 0; 00496 00500 00503 void AttachDependentRequestTrace(const StringPiece& label); 00504 00508 RequestTrace* dependent_request_trace() { return dependent_request_trace_; } 00509 00512 void TracePrintf(const char* fmt, ...); 00513 00521 00531 virtual void StartFetchReconstruction(); 00532 00538 bool ShouldDistributeRewrite() const; 00539 00542 bool IsDistributedRewriteForHtml() const; 00543 00547 void DistributeRewrite(); 00548 00554 void DetachFetch(); 00555 00560 virtual bool DecodeFetchUrls(const OutputResourcePtr& output_resource, 00561 MessageHandler* message_handler, 00562 GoogleUrlStarVector* url_vector); 00563 00568 virtual void FixFetchFallbackHeaders(ResponseHeaders* headers); 00569 00572 virtual void FetchCallbackDone(bool success); 00573 00578 virtual void FetchTryFallback(const GoogleString& url, 00579 const StringPiece& hash); 00580 00582 void Freshen(); 00583 00584 bool notify_driver_on_fetch_done() const { 00585 return notify_driver_on_fetch_done_; 00586 } 00587 void set_notify_driver_on_fetch_done(bool value) { 00588 notify_driver_on_fetch_done_ = value; 00589 } 00590 00595 bool block_distribute_rewrite() const { return block_distribute_rewrite_; } 00596 void set_block_distribute_rewrite(const bool x) { 00597 block_distribute_rewrite_ = x; 00598 } 00599 00601 AsyncFetch* async_fetch(); 00602 00604 bool FetchContextDetached(); 00605 00607 MessageHandler* fetch_message_handler(); 00608 00610 bool stale_rewrite() const { return stale_rewrite_; } 00611 00615 virtual int64 GetRewriteDeadlineAlarmMs() const; 00616 00618 virtual bool CreationLockBeforeStartFetch() { return true; } 00619 00620 private: 00621 class DistributedRewriteCallback; 00622 class DistributedRewriteFetch; 00623 class OutputCacheCallback; 00624 class LookupMetadataForOutputResourceCallback; 00625 class HTTPCacheCallback; 00626 class ResourceCallbackUtils; 00627 class ResourceFetchCallback; 00628 class ResourceReconstructCallback; 00629 class ResourceRevalidateCallback; 00630 class InvokeRewriteFunction; 00631 class RewriteFreshenCallback; 00632 friend class RewriteDriver; 00633 00634 typedef std::set<RewriteContext*> ContextSet; 00635 00639 enum FallbackCondition { 00640 kFallbackDiscretional, 00641 00642 kFallbackEmergency 00643 00644 }; 00645 00647 void Start(); 00648 void SetPartitionKey(); 00649 void StartFetch(); 00650 void StartFetchImpl(); 00651 void CancelFetch(); 00652 void OutputCacheDone(CacheLookupResult* cache_result); 00653 void OutputCacheHit(bool write_partitions); 00654 void OutputCacheRevalidate(const InputInfoStarVector& to_revalidate); 00655 void OutputCacheMiss(); 00656 void ResourceFetchDone(bool success, ResourcePtr resource, int slot_index); 00657 void ResourceRevalidateDone(InputInfo* input_info, bool success); 00658 void LogMetadataCacheInfo(bool cache_ok, bool can_revalidate); 00659 00664 void RepeatedSuccess(const RewriteContext* primary); 00665 void RepeatedFailure(); 00666 00675 void Finalize(); 00676 00678 NamedLock* Lock(); 00679 00689 void FetchInputs(); 00690 00695 void DistributeRewriteDone(bool success); 00696 00700 bool ParseAndRemoveMetadataFromResponseHeaders( 00701 ResponseHeaders* response_headers, CacheLookupResult* cache_result); 00702 00705 bool CreateOutputResourceFromContent(const CachedResult& cached_result, 00706 const ResponseHeaders& response_headers, 00707 StringPiece content, 00708 OutputResourcePtr* output_resource); 00709 00719 GoogleString DistributedFetchUrl(StringPiece url); 00720 00723 bool IsFetchRewrite() const { return fetch_.get() != NULL; } 00724 00729 void NestedRewriteDone(const RewriteContext* context); 00730 00734 void Activate(); 00735 00759 void Propagate(bool render_slots); 00760 00767 void StartRewriteForHtml(); 00768 void StartRewriteForFetch(); 00769 00776 bool ReadyToRewrite() const; 00777 00782 void DetachSlots(); 00783 00786 void RunSuccessors(); 00787 00790 void WritePartition(); 00791 00801 void FinalizeRewriteForHtml(); 00802 00808 void RetireRewriteForHtml(bool permit_render); 00809 00812 void MarkSlow(); 00813 00816 void MarkTooBusy(); 00817 00821 void CollectDependentTopLevel(ContextSet* contexts); 00822 00825 void RewriteDoneImpl(RewriteResult result, int partition_index); 00826 00829 void StartNestedTasksImpl(); 00830 00834 void RenderPartitionOnDetach(int partition_index); 00835 00838 bool PrepareFetch( 00839 const OutputResourcePtr& output_resource, 00840 AsyncFetch* fetch, 00841 MessageHandler* message_handler); 00842 00845 bool CreateOutputResourceForCachedOutput(const CachedResult* cached_result, 00846 OutputResourcePtr* output_resource); 00847 00849 void FetchCacheDone(CacheLookupResult* cache_result); 00850 00853 void FetchFallbackCacheDone(HTTPCache::FindResult result, 00854 HTTPCache::Callback* data); 00855 00860 bool CanFetchFallbackToOriginal(FallbackCondition circumstance) const; 00861 00864 bool HasDuplicateOtherDependency(const InputInfo& input); 00865 00869 void CheckAndAddOtherDependency(const InputInfo& input); 00870 00873 void CheckAndFreshenResource(const InputInfo& input_info, 00874 ResourcePtr resource, int partition_index, 00875 int input_index, 00876 FreshenMetadataUpdateManager* freshen_manager); 00877 ResourcePtr CreateUrlResource(const StringPiece& input_url); 00878 00880 ResourceSlotVector slots_; 00881 00885 std::vector<bool> render_slots_; 00886 00897 00898 bool started_; 00899 scoped_ptr<OutputPartitions> partitions_; 00900 OutputResourceVector outputs_; 00901 int outstanding_fetches_; 00902 int outstanding_rewrites_; 00903 scoped_ptr<ResourceContext> resource_context_; 00904 GoogleString partition_key_; 00905 00906 UrlSegmentEncoder default_encoder_; 00907 00910 scoped_ptr<NamedLock> lock_; 00911 00915 class FetchContext; 00916 scoped_ptr<FetchContext> fetch_; 00917 00920 std::vector<RewriteContext*> successors_; 00921 00925 std::vector<RewriteContext*> repeated_; 00926 00930 int num_pending_nested_; 00931 std::vector<RewriteContext*> nested_; 00932 00934 RewriteContext* parent_; 00935 00945 RewriteDriver* driver_; 00946 00948 int num_predecessors_; 00949 00952 bool chained_; 00953 00971 00973 bool rewrite_done_; 00974 00979 bool ok_to_write_output_partitions_; 00980 00983 bool was_too_busy_; 00984 00988 bool slow_; 00989 00991 bool revalidate_ok_; 00992 00995 bool notify_driver_on_fetch_done_; 00996 00999 bool force_rewrite_; 01000 01003 bool stale_rewrite_; 01004 01007 bool is_metadata_cache_miss_; 01008 01011 bool rewrite_uncacheable_; 01012 01015 RequestTrace* dependent_request_trace_; 01016 01019 bool block_distribute_rewrite_; 01020 01022 scoped_ptr<DistributedRewriteFetch> distributed_fetch_; 01023 01025 StringIntMap other_dependency_map_; 01026 01027 Variable* const num_distributed_rewrite_failures_; 01028 Variable* const num_distributed_rewrite_successes_; 01029 Variable* const num_distributed_metadata_failures_; 01030 DISALLOW_COPY_AND_ASSIGN(RewriteContext); 01031 }; 01032 01033 } 01034 01035 #endif ///< NET_INSTAWEB_REWRITER_PUBLIC_REWRITE_CONTEXT_H_