| /* |
| * Copyright 2013 Google Inc. |
| * |
| * Licensed 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. |
| */ |
| |
| // Author: jmarantz@google.com (Joshua Marantz) |
| |
| #include "pagespeed/kernel/cache/compressed_cache.h" |
| |
| #include "base/logging.h" |
| #include "pagespeed/kernel/base/shared_string.h" |
| #include "pagespeed/kernel/base/statistics.h" |
| #include "pagespeed/kernel/base/string_util.h" |
| #include "pagespeed/kernel/base/string_writer.h" |
| #include "pagespeed/kernel/cache/cache_interface.h" |
| #include "pagespeed/kernel/util/gzip_inflater.h" |
| |
| namespace net_instaweb { |
| |
| namespace { |
| |
| // A few bytes to put at the end of the physical payload we can track |
| // corruption. Note that CompressedCacheTest.CrapAtEnd fails without this. |
| const char kTrailer[] = "[[]]"; |
| |
| // TODO(jmarantz): Evaluate the impact of histogramming the size reduction of |
| // each entry. The compressed_cache_speed_test.cc side-steps this because |
| // SimpleStats doesn't implement histograms. See split_statistics_test.cc:93 |
| // for mechanism to speed-test histograms. |
| #define INCLUDE_HISTOGRAMS 0 |
| |
| #if INCLUDE_HISTOGRAMS |
| const char kCompressedCacheSavings[] = "compressed_cache_savings"; |
| #endif |
| const char kCompressedCacheOriginalSize[] = "compressed_cache_original_size"; |
| const char kCompressedCacheCompressedSize[] = |
| "compressed_cache_compressed_size"; |
| const char kCompressedCacheCorruptPayloads[] = |
| "compressed_cache_corrupt_payloads"; |
| |
| class CompressedCallback : public CacheInterface::Callback { |
| public: |
| CompressedCallback(CacheInterface::Callback* callback, |
| Variable* corrupt_payloads) |
| : callback_(callback), |
| corrupt_payloads_(corrupt_payloads), |
| validate_candidate_called_(false) { |
| } |
| |
| virtual ~CompressedCallback() {} |
| |
| virtual bool ValidateCandidate(const GoogleString& key, |
| CacheInterface::KeyState state) { |
| validate_candidate_called_ = true; |
| bool ret = false; |
| if (state == CacheInterface::kAvailable) { |
| GoogleString uncompressed; |
| StringWriter writer(&uncompressed); |
| StringPiece compressed = value()->Value(); |
| if (compressed.ends_with( |
| StringPiece(kTrailer, STATIC_STRLEN(kTrailer))) && |
| GzipInflater::Inflate( |
| compressed.substr(0, compressed.size() - STATIC_STRLEN(kTrailer)), |
| GzipInflater::kDeflate, &writer)) { |
| callback_->value()->SwapWithString(&uncompressed); |
| ret = true; |
| } else { |
| state = CacheInterface::kNotFound; |
| corrupt_payloads_->Add(1); |
| } |
| } |
| ret &= callback_->DelegatedValidateCandidate(key, state); |
| return ret; |
| } |
| |
| virtual void Done(CacheInterface::KeyState state) { |
| DCHECK(validate_candidate_called_); |
| callback_->DelegatedDone(state); |
| delete this; |
| } |
| |
| Callback* callback_; |
| Variable* corrupt_payloads_; |
| bool validate_candidate_called_; |
| }; |
| |
| } // namespace |
| |
| CompressedCache::CompressedCache(CacheInterface* cache, Statistics* stats) |
| : cache_(cache) { |
| #if INCLUDE_HISTOGRAMS |
| compressed_cache_savings_ = stats->GetHistogram(kCompressedCacheSavings); |
| #endif |
| corrupt_payloads_ = stats->GetVariable(kCompressedCacheCorruptPayloads); |
| original_size_ = stats->GetVariable(kCompressedCacheOriginalSize); |
| compressed_size_ = stats->GetVariable(kCompressedCacheCompressedSize); |
| } |
| |
| CompressedCache::~CompressedCache() { |
| } |
| |
| GoogleString CompressedCache::FormatName(StringPiece name) { |
| return StrCat("Compressed(", name, ")"); |
| } |
| |
| void CompressedCache::InitStats(Statistics* statistics) { |
| #if INCLUDE_HISTOGRAMS |
| statistics->AddHistogram(kCompressedCacheSavings); |
| #endif |
| statistics->AddVariable(kCompressedCacheCorruptPayloads); |
| statistics->AddVariable(kCompressedCacheOriginalSize); |
| statistics->AddVariable(kCompressedCacheCompressedSize); |
| } |
| |
| void CompressedCache::Get(const GoogleString& key, Callback* callback) { |
| CompressedCallback* cb = new CompressedCallback(callback, corrupt_payloads_); |
| cache_->Get(key, cb); |
| } |
| |
| void CompressedCache::Put(const GoogleString& key, SharedString* value) { |
| int64 old_size = value->size(); |
| GoogleString buf; |
| buf.reserve(old_size + STATIC_STRLEN(kTrailer)); |
| StringWriter writer(&buf); |
| original_size_->Add(old_size); |
| if (GzipInflater::Deflate(value->Value(), GzipInflater::kDeflate, &writer)) { |
| buf.append(kTrailer, STATIC_STRLEN(kTrailer)); |
| #if INCLUDE_HISTOGRAMS |
| compressed_cache_savings_->Add( |
| old_size - static_cast<int64>(buf.size())); |
| #endif |
| compressed_size_->Add(buf.size()); |
| cache_->PutSwappingString(key, &buf); |
| } |
| } |
| |
| void CompressedCache::Delete(const GoogleString& key) { |
| cache_->Delete(key); |
| } |
| |
| bool CompressedCache::IsHealthy() const { |
| return cache_->IsHealthy(); |
| } |
| |
| void CompressedCache::ShutDown() { |
| return cache_->ShutDown(); |
| } |
| |
| int64 CompressedCache::CorruptPayloads() const { |
| return corrupt_payloads_->Get(); |
| } |
| |
| int64 CompressedCache::OriginalSize() const { |
| return original_size_->Get(); |
| } |
| |
| int64 CompressedCache::CompressedSize() const { |
| return compressed_size_->Get(); |
| } |
| |
| } // namespace net_instaweb |