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Issue 2368433002:
Add net::SdchSourceStream and net::SdchPolicyDelegate (Closed)
| Index: net/filter/sdch_policy_delegate.cc |
| diff --git a/net/filter/sdch_policy_delegate.cc b/net/filter/sdch_policy_delegate.cc |
| new file mode 100644 |
| index 0000000000000000000000000000000000000000..b1b64f8c655d5aede260f907de5d4b6050301f99 |
| --- /dev/null |
| +++ b/net/filter/sdch_policy_delegate.cc |
| @@ -0,0 +1,176 @@ |
| +// Copyright 2016 The Chromium Authors. All rights reserved. |
| +// Use of this source code is governed by a BSD-style license that can be |
| +// found in the LICENSE file. |
| + |
| +#include "net/filter/sdch_policy_delegate.h" |
| + |
| +#include "base/metrics/histogram_macros.h" |
| +#include "base/values.h" |
| +#include "net/base/sdch_net_log_params.h" |
| +#include "net/filter/sdch_source_stream.h" |
| +#include "net/log/net_log.h" |
| +#include "net/log/net_log_event_type.h" |
| + |
| +namespace net { |
| + |
| +namespace { |
| + |
| +const char kRefreshHtml[] = |
| + "<head><META HTTP-EQUIV=\"Refresh\" CONTENT=\"0\"></head>"; |
| + |
| +} // namespace |
| + |
| +SdchPolicyDelegate::SdchPolicyDelegate(std::unique_ptr<Context> context) |
| + : dictionary_requested_(false), context_(std::move(context)) {} |
| + |
| +SdchPolicyDelegate::~SdchPolicyDelegate() {} |
| + |
| +// Dictionary errors are often the first indication that the SDCH stream has |
| +// become corrupt. There are many possible causes: non-200 response codes, a |
| +// cached non-SDCH-ified reply, the server opting not to use SDCH, a cached |
| +// SDCH-ified reply for which the SdchManager did not have the dictionary, a |
| +// corrupted response, or a response that claims to be SDCH but isn't actually. |
| +// These are handled here by issuing a meta-refresh or swapping to passthrough |
| +// mode if appropriate, or failing the request if the error is unrecoverable. |
| +bool SdchPolicyDelegate::OnDictionaryError(SdchSourceStream* source) { |
| + // HTTP 404 might be an unencoded error page, so if decoding failed, pass it |
| + // through. |
| + // TODO(xunjieli): Figure out whether this special case can be removed. |
| + // crbug.com/516773. |
| + if (context_->GetResponseCode() == 404) { |
| + source->StopDecoding(); |
| + LogSdchProblem(SDCH_PASS_THROUGH_404_CODE); |
| + return true; |
| + } |
| + |
| + // HTTP !200 gets a meta-refresh for HTML and a hard failure otherwise. |
| + if (context_->GetResponseCode() != 200) |
| + return IssueMetaRefreshIfPossible(source); |
| + |
| + // If this is a cached result and the source hasn't requested a dictionary, it |
| + // probably never had a dictionary to begin and is an unencoded response from |
| + // earlier. If the source has requested a dictionary, but there was still a |
| + // dictionary error, then the SdchManager does not have it so this method |
| + // needs to issue a meta-refresh to get it. |
|
Randy Smith (Not in Mondays)
2016/09/27 20:09:12
nit: The second sentence of this comment appears t
xunjieli
2016/09/30 15:32:17
Done.
|
| + if (context_->IsCachedContent() && !dictionary_requested_) { |
| + source->StopDecoding(); |
| + LogSdchProblem(SDCH_PASS_THROUGH_OLD_CACHED); |
| + return true; |
| + } |
| + |
| + // Ow. The original request didn't advertise any dictionaries, but the |
| + // response claimed to be SDCH, but did not have a plausible dictionary hash. |
| + // There is no way to repair this situation: the original request already |
| + // didn't advertise any dictionaries, and retrying it would likely have the |
| + // same result. Blacklist the domain and try passing through. |
| + if (!context_->SdchDictionariesAdvertised() && !dictionary_requested_) { |
| + GURL url; |
| + if (!context_->GetURL(&url)) |
| + return false; |
| + source->StopDecoding(); |
| + context_->GetSdchManager()->BlacklistDomain(url, |
| + SDCH_PASSING_THROUGH_NON_SDCH); |
| + return true; |
| + } |
| + |
| + return IssueMetaRefreshIfPossible(source); |
| +} |
| + |
| +bool SdchPolicyDelegate::OnDecodingError(SdchSourceStream* source) { |
| + // A decoding error, as opposed to a dictionary error, indicates a |
| + // decompression failure partway through the payload of the SDCH stream, |
| + // which means that the filter already witnessed a valid dictionary ID and |
| + // successfully retrieved a dictionary for it. Decoding errors are not |
| + // recoverable and it is not appropriate to stop decoding, so there are |
| + // relatively few error cases here. |
| + // |
| + // In particular, a decoding error for an HTML payload is recoverable by |
| + // issuing a meta-refresh, but to avoid having that happen too often, this |
| + // class also temporarily blacklists the domain. A decoding error for a |
| + // non-HTML payload is unrecoverable, so such an error gets a permanent |
| + // blacklist entry. If the content was cached, no blacklisting is needed. |
| + return IssueMetaRefreshIfPossible(source); |
| +} |
| + |
| +bool SdchPolicyDelegate::OnGetDictionary(const std::string& server_id, |
| + const std::string** text) { |
| + dictionary_requested_ = true; |
| + SdchManager::DictionarySet* set = context_->SdchDictionariesAdvertised(); |
| + if (set) { |
| + *text = set->GetDictionaryText(server_id); |
| + if (*text) |
| + return true; |
| + } |
| + GURL url; |
| + if (!context_->GetURL(&url)) |
| + return false; |
| + // This is a hack. Naively, the dictionaries available for |
| + // decoding should be only the ones advertised. However, there are |
| + // cases, specifically resources encoded with old dictionaries living |
| + // in the cache, that mean the full set of dictionaries should be made |
| + // available for decoding. It's not known how often this happens; |
| + // if it happens rarely enough, this code can be removed. |
| + // |
| + // TODO(rdsmith): Long-term, a better solution is necessary, since |
| + // an entry in the cache being encoded with the dictionary doesn't |
| + // guarantee that the dictionary is present. That solution probably |
| + // involves storing unencoded resources in the cache, but might |
| + // involve evicting encoded resources on dictionary removal. |
| + // See http://crbug.com/383405. |
| + SdchProblemCode rv = SDCH_OK; |
| + unexpected_dictionary_set_ = |
| + context_->GetSdchManager()->GetDictionarySetByHash(url, server_id, &rv); |
| + if (unexpected_dictionary_set_) { |
| + *text = unexpected_dictionary_set_->GetDictionaryText(server_id); |
| + LogSdchProblem(context_->IsCachedContent() |
| + ? SDCH_UNADVERTISED_DICTIONARY_USED_CACHED |
| + : SDCH_UNADVERTISED_DICTIONARY_USED); |
| + if (*text) |
| + return true; |
| + } else { |
| + LogSdchProblem(SDCH_DICTIONARY_HASH_NOT_FOUND); |
| + } |
| + return false; |
| +} |
| + |
| +bool SdchPolicyDelegate::IssueMetaRefreshIfPossible(SdchSourceStream* source) { |
|
Randy Smith (Not in Mondays)
2016/09/27 20:09:12
TODO with a bug for nuking the ugly meta-refresh h
xunjieli
2016/09/30 15:32:17
Done.
|
| + std::string mime_type; |
| + GURL url; |
| + if (!context_->GetMimeType(&mime_type) || !context_->GetURL(&url)) |
| + return false; |
| + SdchManager* manager = context_->GetSdchManager(); |
| + |
| + // Errors for non-HTML payloads are unrecoverable and get the domain |
| + // blacklisted indefinitely. |
| + if (mime_type.npos == mime_type.find("text/html")) { |
| + SdchProblemCode problem = |
| + (context_->IsCachedContent() ? SDCH_CACHED_META_REFRESH_UNSUPPORTED |
| + : SDCH_META_REFRESH_UNSUPPORTED); |
| + manager->BlacklistDomainForever(url, problem); |
| + LogSdchProblem(problem); |
| + return false; |
| + } |
| + |
| + if (context_->IsCachedContent()) { |
| + // Cached content is a probably startup tab, so just get the fresh content |
| + // and try again, without disabling SDCH. |
| + LogSdchProblem(SDCH_META_REFRESH_CACHED_RECOVERY); |
| + } else { |
| + // Since it wasn't in the cache, blacklist for some period to get the |
| + // correct content. |
| + manager->BlacklistDomain(url, SDCH_META_REFRESH_RECOVERY); |
| + LogSdchProblem(SDCH_META_REFRESH_RECOVERY); |
| + } |
| + |
| + source->ReplaceOutput(kRefreshHtml, strlen(kRefreshHtml)); |
| + return true; |
| +} |
| + |
| +void SdchPolicyDelegate::LogSdchProblem(SdchProblemCode problem) { |
| + SdchManager::SdchErrorRecovery(problem); |
| + context_->GetNetLog().AddEvent( |
| + NetLogEventType::SDCH_DECODING_ERROR, |
| + base::Bind(&NetLogSdchResourceProblemCallback, problem)); |
| +} |
| + |
| +} // namespace net |
