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PrototypeDocumentParser.cpp (7584B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
      6 
      7 #include "PrototypeDocumentParser.h"
      8 
      9 #include "nsXULPrototypeCache.h"
     10 #include "nsXULContentSink.h"
     11 #include "nsXULPrototypeDocument.h"
     12 #include "mozilla/Encoding.h"
     13 #include "nsCharsetSource.h"
     14 #include "nsParser.h"
     15 #include "mozilla/dom/Document.h"
     16 #include "mozilla/dom/PrototypeDocumentContentSink.h"
     17 
     18 using namespace mozilla::dom;
     19 
     20 namespace mozilla {
     21 namespace parser {
     22 
     23 PrototypeDocumentParser::PrototypeDocumentParser(nsIURI* aDocumentURI,
     24                                                 dom::Document* aDocument)
     25    : mDocumentURI(aDocumentURI),
     26      mDocument(aDocument),
     27      mPrototypeAlreadyLoaded(false),
     28      mIsComplete(false) {}
     29 
     30 PrototypeDocumentParser::~PrototypeDocumentParser() {}
     31 
     32 NS_INTERFACE_TABLE_HEAD(PrototypeDocumentParser)
     33  NS_INTERFACE_TABLE(PrototypeDocumentParser, nsIParser, nsIStreamListener,
     34                     nsIRequestObserver)
     35  NS_INTERFACE_TABLE_TO_MAP_SEGUE_CYCLE_COLLECTION(PrototypeDocumentParser)
     36 NS_INTERFACE_MAP_END
     37 
     38 NS_IMPL_CYCLE_COLLECTING_ADDREF(PrototypeDocumentParser)
     39 NS_IMPL_CYCLE_COLLECTING_RELEASE(PrototypeDocumentParser)
     40 
     41 NS_IMPL_CYCLE_COLLECTION(PrototypeDocumentParser, mDocumentURI, mOriginalSink,
     42                         mDocument, mStreamListener, mCurrentPrototype)
     43 
     44 NS_IMETHODIMP_(void)
     45 PrototypeDocumentParser::SetContentSink(nsIContentSink* aSink) {
     46  MOZ_ASSERT(aSink, "sink cannot be null!");
     47  mOriginalSink = static_cast<PrototypeDocumentContentSink*>(aSink);
     48  MOZ_ASSERT(mOriginalSink);
     49 
     50  aSink->SetParser(this);
     51 }
     52 
     53 NS_IMETHODIMP_(nsIContentSink*)
     54 PrototypeDocumentParser::GetContentSink() { return mOriginalSink; }
     55 
     56 nsIStreamListener* PrototypeDocumentParser::GetStreamListener() { return this; }
     57 
     58 NS_IMETHODIMP_(bool)
     59 PrototypeDocumentParser::IsComplete() { return mIsComplete; }
     60 
     61 NS_IMETHODIMP
     62 PrototypeDocumentParser::Parse(nsIURI* aURL) {
     63  // Look in the chrome cache: we've got this puppy loaded
     64  // already.
     65  nsXULPrototypeDocument* proto =
     66      mDocumentURI->SchemeIs("chrome")
     67          ? nsXULPrototypeCache::GetInstance()->GetPrototype(mDocumentURI)
     68          : nullptr;
     69 
     70  // We don't abort on failure here because there are too many valid
     71  // cases that can return failure, and the null-ness of |proto| is enough
     72  // to trigger the fail-safe parse-from-disk solution. Example failure cases
     73  // (for reference) include:
     74  //
     75  // NS_ERROR_NOT_AVAILABLE: the URI cannot be found in the startup cache,
     76  //                         parse from disk
     77  // other: the startup cache file could not be found, probably
     78  //        due to being accessed before a profile has been selected (e.g.
     79  //        loading chrome for the profile manager itself). This must be
     80  //        parsed from disk.
     81  nsresult rv;
     82  if (proto) {
     83    mCurrentPrototype = proto;
     84 
     85    // Set up the right principal on the document.
     86    mDocument->SetPrincipals(proto->DocumentPrincipal(),
     87                             proto->DocumentPrincipal());
     88  } else {
     89    // It's just a vanilla document load. Create a parser to deal
     90    // with the stream n' stuff.
     91 
     92    nsCOMPtr<nsIParser> parser;
     93    // Get the document's principal
     94    nsCOMPtr<nsIPrincipal> principal = mDocument->NodePrincipal();
     95    rv =
     96        PrepareToLoadPrototype(mDocumentURI, principal, getter_AddRefs(parser));
     97    if (NS_FAILED(rv)) return rv;
     98 
     99    nsCOMPtr<nsIStreamListener> listener = do_QueryInterface(parser, &rv);
    100    NS_ASSERTION(NS_SUCCEEDED(rv), "parser doesn't support nsIStreamListener");
    101    if (NS_FAILED(rv)) return rv;
    102 
    103    mStreamListener = listener;
    104 
    105    parser->Parse(mDocumentURI);
    106  }
    107 
    108  // If we're racing with another document to load proto, wait till the
    109  // load has finished loading before trying build the document.
    110  // Either the nsXULContentSink finishing to load the XML or
    111  // the nsXULPrototypeDocument completing deserialization will trigger the
    112  // OnPrototypeLoadDone callback.
    113  // If the prototype is already loaded, OnPrototypeLoadDone will be called
    114  // in OnStopRequest.
    115  RefPtr<PrototypeDocumentParser> self = this;
    116  rv = mCurrentPrototype->AwaitLoadDone(
    117      [self]() { self->OnPrototypeLoadDone(); }, &mPrototypeAlreadyLoaded);
    118  if (NS_FAILED(rv)) return rv;
    119 
    120  return NS_OK;
    121 }
    122 
    123 NS_IMETHODIMP
    124 PrototypeDocumentParser::OnStartRequest(nsIRequest* request) {
    125  if (mStreamListener) {
    126    return mStreamListener->OnStartRequest(request);
    127  }
    128  // There's already a prototype cached, so return cached here so the original
    129  // request will be aborted. Either OnStopRequest or the prototype load
    130  // finishing will notify the content sink that we're done loading the
    131  // prototype.
    132  return NS_ERROR_PARSED_DATA_CACHED;
    133 }
    134 
    135 NS_IMETHODIMP
    136 PrototypeDocumentParser::OnStopRequest(nsIRequest* request, nsresult aStatus) {
    137  if (mStreamListener) {
    138    return mStreamListener->OnStopRequest(request, aStatus);
    139  }
    140  if (mPrototypeAlreadyLoaded) {
    141    return this->OnPrototypeLoadDone();
    142  }
    143  // The prototype will handle calling OnPrototypeLoadDone when it is ready.
    144  return NS_OK;
    145 }
    146 
    147 NS_IMETHODIMP
    148 PrototypeDocumentParser::OnDataAvailable(nsIRequest* request,
    149                                         nsIInputStream* aInStr,
    150                                         uint64_t aSourceOffset,
    151                                         uint32_t aCount) {
    152  if (mStreamListener) {
    153    return mStreamListener->OnDataAvailable(request, aInStr, aSourceOffset,
    154                                            aCount);
    155  }
    156  MOZ_ASSERT_UNREACHABLE("Cached prototype doesn't receive data");
    157  return NS_ERROR_UNEXPECTED;
    158 }
    159 
    160 nsresult PrototypeDocumentParser::OnPrototypeLoadDone() {
    161  MOZ_ASSERT(!mIsComplete, "Should not be called more than once.");
    162  mIsComplete = true;
    163 
    164  RefPtr<PrototypeDocumentContentSink> sink = mOriginalSink;
    165  RefPtr<nsXULPrototypeDocument> prototype = mCurrentPrototype;
    166  return sink->OnPrototypeLoadDone(prototype);
    167 }
    168 
    169 nsresult PrototypeDocumentParser::PrepareToLoadPrototype(
    170    nsIURI* aURI, nsIPrincipal* aDocumentPrincipal, nsIParser** aResult) {
    171  nsresult rv;
    172 
    173  // Create a new prototype document.
    174  rv = NS_NewXULPrototypeDocument(getter_AddRefs(mCurrentPrototype));
    175  if (NS_FAILED(rv)) return rv;
    176 
    177  rv = mCurrentPrototype->InitPrincipal(aURI, aDocumentPrincipal);
    178  if (NS_FAILED(rv)) {
    179    mCurrentPrototype = nullptr;
    180    return rv;
    181  }
    182 
    183  // Store the new prototype right away so if there are multiple requests
    184  // for the same document they all get the same prototype.
    185  if (mDocumentURI->SchemeIs("chrome") &&
    186      nsXULPrototypeCache::GetInstance()->IsEnabled()) {
    187    nsXULPrototypeCache::GetInstance()->PutPrototype(mCurrentPrototype);
    188  }
    189 
    190  mDocument->SetPrincipals(aDocumentPrincipal, aDocumentPrincipal);
    191 
    192  // Create a XUL content sink, a parser, and kick off a load for
    193  // the document.
    194  RefPtr<XULContentSinkImpl> sink = new XULContentSinkImpl();
    195 
    196  rv = sink->Init(mDocument, mCurrentPrototype);
    197  NS_ASSERTION(NS_SUCCEEDED(rv), "Unable to initialize datasource sink");
    198  if (NS_FAILED(rv)) return rv;
    199 
    200  nsCOMPtr<nsIParser> parser = new nsParser();
    201 
    202  parser->SetCommand(eViewNormal);
    203 
    204  parser->SetDocumentCharset(UTF_8_ENCODING, kCharsetFromDocTypeDefault);
    205  parser->SetContentSink(sink);  // grabs a reference to the parser
    206 
    207  parser.forget(aResult);
    208  return NS_OK;
    209 }
    210 
    211 }  // namespace parser
    212 }  // namespace mozilla