Sdch view for net-internals

net/filter/sdch_filter.cc

Index: net/filter/sdch_filter.cc
diff --git a/net/filter/sdch_filter.cc b/net/filter/sdch_filter.cc
index df72367c1dd7729a8ba353ac37b70af4e56089b7..c3b70fcc24d0724e1569ddf0515bee3cd58b3269 100644
--- a/net/filter/sdch_filter.cc
+++ b/net/filter/sdch_filter.cc
@@ -12,6 +12,7 @@
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "net/base/sdch_manager.h"
+#include "net/base/sdch_net_log_params.h"
 #include "net/url_request/url_request_context.h"
 
 #include "sdch/open-vcdiff/src/google/vcdecoder.h"
@@ -84,12 +85,12 @@ SdchFilter::~SdchFilter() {
   if (vcdiff_streaming_decoder_.get()) {
     if (!vcdiff_streaming_decoder_->FinishDecoding()) {
       decoding_status_ = DECODING_ERROR;
-      SdchManager::SdchErrorRecovery(SdchManager::INCOMPLETE_SDCH_CONTENT);
+      LogSdchProblem(SDCH_INCOMPLETE_SDCH_CONTENT);
       // Make it possible for the user to hit reload, and get non-sdch content.
       // Note this will "wear off" quickly enough, and is just meant to assure
       // in some rare case that the user is not stuck.
       url_request_context_->sdch_manager()->BlacklistDomain(
-          url_, SdchManager::INCOMPLETE_SDCH_CONTENT);
+          url_, SDCH_INCOMPLETE_SDCH_CONTENT);
       UMA_HISTOGRAM_COUNTS("Sdch3.PartialBytesIn",
            static_cast<int>(filter_context_.GetByteReadCount()));
       UMA_HISTOGRAM_COUNTS("Sdch3.PartialVcdiffIn", source_bytes_);
@@ -99,7 +100,7 @@ SdchFilter::~SdchFilter() {
 
   if (!dest_buffer_excess_.empty()) {
     // Filter chaining error, or premature teardown.
-    SdchManager::SdchErrorRecovery(SdchManager::UNFLUSHED_CONTENT);
+    LogSdchProblem(SDCH_UNFLUSHED_CONTENT);
     UMA_HISTOGRAM_COUNTS("Sdch3.UnflushedBytesIn",
          static_cast<int>(filter_context_.GetByteReadCount()));
     UMA_HISTOGRAM_COUNTS("Sdch3.UnflushedBufferSize",
@@ -111,7 +112,7 @@ SdchFilter::~SdchFilter() {
   if (filter_context_.IsCachedContent()) {
     // Not a real error, but it is useful to have this tally.
     // TODO(jar): Remove this stat after SDCH stability is validated.
-    SdchManager::SdchErrorRecovery(SdchManager::CACHE_DECODED);
+    LogSdchProblem(SDCH_CACHE_DECODED);
     return;  // We don't need timing stats, and we aready got ratios.
   }
 
@@ -135,15 +136,15 @@ SdchFilter::~SdchFilter() {
       return;
     }
     case DECODING_UNINITIALIZED: {
-      SdchManager::SdchErrorRecovery(SdchManager::UNINITIALIZED);
+      LogSdchProblem(SDCH_UNINITIALIZED);
       return;
     }
     case WAITING_FOR_DICTIONARY_SELECTION: {
-      SdchManager::SdchErrorRecovery(SdchManager::PRIOR_TO_DICTIONARY);
+      LogSdchProblem(SDCH_PRIOR_TO_DICTIONARY);
       return;
     }
     case DECODING_ERROR: {
-      SdchManager::SdchErrorRecovery(SdchManager::DECODE_ERROR);
+      LogSdchProblem(SDCH_DECODE_ERROR);
       return;
     }
     case META_REFRESH_RECOVERY: {
@@ -210,7 +211,7 @@ Filter::FilterStatus SdchFilter::ReadFilteredData(char* dest_buffer,
         // We could be more generous, but for now, only a "NOT FOUND" code will
         // cause a pass through.  All other bad codes will fall into a
         // meta-refresh.
-        SdchManager::SdchErrorRecovery(SdchManager::PASS_THROUGH_404_CODE);
+        LogSdchProblem(SDCH_PASS_THROUGH_404_CODE);
         cause = RESPONSE_404;
         decoding_status_ = PASS_THROUGH;
       } else if (filter_context_.GetResponseCode() != 200) {
@@ -220,7 +221,7 @@ Filter::FilterStatus SdchFilter::ReadFilteredData(char* dest_buffer,
                  && !dictionary_hash_is_plausible_) {
         // We must have hit the back button, and gotten content that was fetched
         // before we *really* advertised SDCH and a dictionary.
-        SdchManager::SdchErrorRecovery(SdchManager::PASS_THROUGH_OLD_CACHED);
+        LogSdchProblem(SDCH_PASS_THROUGH_OLD_CACHED);
         decoding_status_ = PASS_THROUGH;
         cause = RESPONSE_OLD_UNENCODED;
       } else if (possible_pass_through_) {
@@ -256,11 +257,11 @@ Filter::FilterStatus SdchFilter::ReadFilteredData(char* dest_buffer,
         // though it is not!
         // Meta-refresh won't help, as we didn't advertise an SDCH dictionary!!
         // Worse yet, meta-refresh could lead to an infinite refresh loop.
-        SdchManager::SdchErrorRecovery(SdchManager::PASSING_THROUGH_NON_SDCH);
+        LogSdchProblem(SDCH_PASSING_THROUGH_NON_SDCH);
         decoding_status_ = PASS_THROUGH;
         // ... but further back-off on advertising SDCH support.
         url_request_context_->sdch_manager()->BlacklistDomain(
-            url_, SdchManager::PASSING_THROUGH_NON_SDCH);
+            url_, SDCH_PASSING_THROUGH_NON_SDCH);
         cause = RESPONSE_ENCODING_LIE;
       }
       DCHECK_NE(RESPONSE_NONE, cause);
@@ -282,13 +283,12 @@ Filter::FilterStatus SdchFilter::ReadFilteredData(char* dest_buffer,
         if (std::string::npos == mime_type_.find("text/html")) {
           // Since we can't do a meta-refresh (along with an exponential
           // backoff), we'll just make sure this NEVER happens again.
-          SdchManager::ProblemCodes problem =
-              (filter_context_.IsCachedContent() ?
-               SdchManager::CACHED_META_REFRESH_UNSUPPORTED :
-               SdchManager::META_REFRESH_UNSUPPORTED);
+          SdchProblemCode problem = (filter_context_.IsCachedContent()
+                                         ? SDCH_CACHED_META_REFRESH_UNSUPPORTED
+                                         : SDCH_META_REFRESH_UNSUPPORTED);
           url_request_context_->sdch_manager()->BlacklistDomainForever(
               url_, problem);
-          SdchManager::SdchErrorRecovery(problem);
+          LogSdchProblem(problem);
           return FILTER_ERROR;
         }
         // HTML content means we can issue a meta-refresh, and get the content
@@ -296,14 +296,13 @@ Filter::FilterStatus SdchFilter::ReadFilteredData(char* dest_buffer,
         if (filter_context_.IsCachedContent()) {
           // Cached content is probably a startup tab, so we'll just get fresh
           // content and try again, without disabling sdch.
-          SdchManager::SdchErrorRecovery(
-              SdchManager::META_REFRESH_CACHED_RECOVERY);
+          LogSdchProblem(SDCH_META_REFRESH_CACHED_RECOVERY);
         } else {
           // Since it wasn't in the cache, we definately need at least some
           // period of blacklisting to get the correct content.
           url_request_context_->sdch_manager()->BlacklistDomain(
-              url_, SdchManager::META_REFRESH_RECOVERY);
-          SdchManager::SdchErrorRecovery(SdchManager::META_REFRESH_RECOVERY);
+              url_, SDCH_META_REFRESH_RECOVERY);
+          LogSdchProblem(SDCH_META_REFRESH_RECOVERY);
         }
         decoding_status_ = META_REFRESH_RECOVERY;
         // Issue a meta redirect with SDCH disabled.
@@ -357,7 +356,7 @@ Filter::FilterStatus SdchFilter::ReadFilteredData(char* dest_buffer,
   if (!ret) {
     vcdiff_streaming_decoder_.reset(NULL);  // Don't call it again.
     decoding_status_ = DECODING_ERROR;
-    SdchManager::SdchErrorRecovery(SdchManager::DECODE_BODY_ERROR);
+    LogSdchProblem(SDCH_DECODE_BODY_ERROR);
     return FILTER_ERROR;
   }
 
@@ -394,32 +393,39 @@ Filter::FilterStatus SdchFilter::InitializeDictionary() {
   DCHECK(!dictionary_.get());
   dictionary_hash_is_plausible_ = true;  // Assume plausible, but check.
 
+  SdchProblemCode rv = SDCH_OK;
   if ('\0' == dictionary_hash_[kServerIdLength - 1]) {
     SdchManager* manager(url_request_context_->sdch_manager());
-    manager->GetVcdiffDictionary(
+    rv = manager->GetVcdiffDictionary(
         std::string(dictionary_hash_, 0, kServerIdLength - 1),
-        url_, &dictionary_);
+        url_,
+        &dictionary_);
+    if (rv != SDCH_OK) {

[Randy Smith (Not in Mondays), 2014/10/31 19:05:35]

I think you can skip this check; if rv == SDCH_DICTIONARY_HASH_NOT_FOUND, it's
not going to be SDCH_OK.

[baranovich, 2014/10/31 19:55:33]

True, but it may also be SDCH_DISABLED, SDCH_*_BLACKLIST_* or SDCH_SECURE_*

[Randy Smith (Not in Mondays), 2014/11/03 21:01:27]

Sorry, I may be being dense, but how does the effect of the code change if you
remove the "if (rv != SDCH_OK)"?  If it's one of the others you mentioned, the
code inside the SDCH_DICTIONARY_HASH_NOT_FOUND will still not be executed.  

[baranovich, 2014/11/03 22:34:23]

Got it finally, sorry for being so slow:) Done.

+      if (rv == SDCH_DICTIONARY_HASH_NOT_FOUND) {
+        DCHECK(dictionary_hash_.size() == kServerIdLength);
+        // Since dictionary was not found, check to see if hash was even
+        // plausible.
+        for (size_t i = 0; i < kServerIdLength - 1; ++i) {
+          char base64_char = dictionary_hash_[i];
+          if (!isalnum(base64_char) && '-' != base64_char &&
+              '_' != base64_char) {
+            rv = SDCH_DICTIONARY_HASH_MALFORMED;
+            dictionary_hash_is_plausible_ = false;
+            break;
+          }
+        }
+      }
+    }
   } else {
     dictionary_hash_is_plausible_ = false;
+    rv = SDCH_DICTIONARY_HASH_MALFORMED;
   }
-
-  if (!dictionary_.get()) {
-    DCHECK(dictionary_hash_.size() == kServerIdLength);
-    // Since dictionary was not found, check to see if hash was even plausible.
-    for (size_t i = 0; i < kServerIdLength - 1; ++i) {
-      char base64_char = dictionary_hash_[i];
-      if (!isalnum(base64_char) && '-' != base64_char && '_' != base64_char) {
-        dictionary_hash_is_plausible_ = false;
-        break;
-      }
-    }
-    if (dictionary_hash_is_plausible_)
-      SdchManager::SdchErrorRecovery(SdchManager::DICTIONARY_HASH_NOT_FOUND);
-    else
-      SdchManager::SdchErrorRecovery(SdchManager::DICTIONARY_HASH_MALFORMED);
+  if (rv != SDCH_OK) {
+    LogSdchProblem(rv);
     decoding_status_ = DECODING_ERROR;
     return FILTER_ERROR;
   }
+  DCHECK(dictionary_.get());
   vcdiff_streaming_decoder_.reset(new open_vcdiff::VCDiffStreamingDecoder);
   vcdiff_streaming_decoder_->SetAllowVcdTarget(false);
   vcdiff_streaming_decoder_->StartDecoding(dictionary_->text().data(),
@@ -446,4 +452,11 @@ int SdchFilter::OutputBufferExcess(char* const dest_buffer,
   return amount;
 }
 
+void SdchFilter::LogSdchProblem(SdchProblemCode problem) {
+  SdchManager::SdchErrorRecovery(problem);
+  filter_context_.GetNetLog().AddEvent(
+      NetLog::TYPE_SDCH_DECODING_ERROR,
+      base::Bind(&NetLogSdchResourceProblemCallback, problem));
+}
+
 }  // namespace net