Bug 1429973 part 1 - plumb through trailers in h2 to support server-timing. r=bagder

MozReview-Commit-ID: JV1Ikb9cYCV

--HG--
extra : rebase_source : fa67fef606fc02355579dae42f8e66c4754d60a0

netwerk/protocol/http/Http2Session.cpp

@@ -1433,13 +1433,16 @@ Http2Session::ResponseHeadersComplete()
   LOG3(("Http2Session::ResponseHeadersComplete %p for 0x%X fin=%d",
         this, mInputFrameDataStream->StreamID(), mInputFrameFinal));
 
-  // only interpret headers once, afterwards ignore as trailers
+  // Anything prior to AllHeadersReceived() => true is actual headers. After
+  // that, we need to handle them as trailers instead (which are special-cased
+  // so we don't have to use the nasty chunked parser for all h2, just in case).
   if (mInputFrameDataStream->AllHeadersReceived()) {
-    LOG3(("Http2Session::ResponseHeadersComplete extra headers"));
+    LOG3(("Http2Session::ResponseHeadersComplete processing trailers"));
     MOZ_ASSERT(mInputFrameFlags & kFlag_END_STREAM);
-    nsresult rv = UncompressAndDiscard(false);
+    nsresult rv = mInputFrameDataStream->ConvertResponseTrailers(&mDecompressor,
+        mDecompressBuffer);
     if (NS_FAILED(rv)) {
-      LOG3(("Http2Session::ResponseHeadersComplete extra uncompress failed\n"));
+      LOG3(("Http2Session::ResponseHeadersComplete trailer conversion failed\n"));
       return rv;
     }
     mFlatHTTPResponseHeadersOut = 0;

netwerk/protocol/http/Http2Stream.cpp

@@ -1023,6 +1023,8 @@ Http2Stream::ConvertResponseHeaders(Http2Decompressor *decompressor,
                                     int32_t &httpResponseCode)
 {
   aHeadersOut.Truncate();
+  // Add in some space to hopefully not have to reallocate while decompressing
+  // the headers. 512 bytes seems like a good enough number.
   aHeadersOut.SetCapacity(aHeadersIn.Length() + 512);
 
   nsresult rv =
@@ -1106,6 +1108,8 @@ Http2Stream::ConvertPushHeaders(Http2Decompressor *decompressor,
                                 nsACString &aHeadersOut)
 {
   aHeadersOut.Truncate();
+  // Add in some space to hopefully not have to reallocate while decompressing
+  // the headers. 512 bytes seems like a good enough number.
   aHeadersOut.SetCapacity(aHeadersIn.Length() + 512);
   nsresult rv =
     decompressor->DecodeHeaderBlock(reinterpret_cast<const uint8_t *>(aHeadersIn.BeginReading()),
@@ -1142,6 +1146,35 @@ Http2Stream::ConvertPushHeaders(Http2Decompressor *decompressor,
   return NS_OK;
 }
 
+nsresult
+Http2Stream::ConvertResponseTrailers(Http2Decompressor *decompressor,
+                                     nsACString &aTrailersIn)
+{
+  LOG3(("Http2Stream::ConvertResponseTrailers %p", this));
+  nsAutoCString flatTrailers;
+  // Add in some space to hopefully not have to reallocate while decompressing
+  // the headers. 512 bytes seems like a good enough number.
+  flatTrailers.SetCapacity(aTrailersIn.Length() + 512);
+
+  nsresult rv =
+    decompressor->DecodeHeaderBlock(reinterpret_cast<const uint8_t *>(aTrailersIn.BeginReading()),
+                                    aTrailersIn.Length(),
+                                    flatTrailers, false);
+  if (NS_FAILED(rv)) {
+    LOG3(("Http2Stream::ConvertResponseTrailers %p decode Error", this));
+    return rv;
+  }
+
+  nsHttpTransaction *trans = mTransaction->QueryHttpTransaction();
+  if (trans) {
+    trans->SetHttpTrailers(flatTrailers);
+  } else {
+    LOG3(("Http2Stream::ConvertResponseTrailers %p no trans", this));
+  }
+
+  return NS_OK;
+}
+
 void
 Http2Stream::Close(nsresult reason)
 {

netwerk/protocol/http/Http2Stream.h

@@ -125,6 +125,8 @@ public:
                                                nsACString &, int32_t &);
   MOZ_MUST_USE nsresult ConvertPushHeaders(Http2Decompressor *, nsACString &,
                                            nsACString &);
+  MOZ_MUST_USE nsresult ConvertResponseTrailers(Http2Decompressor *,
+                                                nsACString &);
 
   bool AllowFlowControlledWrite();
   void UpdateServerReceiveWindow(int32_t delta);

netwerk/protocol/http/nsHttpTransaction.cpp

@@ -1782,9 +1782,9 @@ nsHttpTransaction::HandleContent(char *buf,
     if ((mContentRead == mContentLength) ||
         (mChunkedDecoder && mChunkedDecoder->ReachedEOF())) {
         MutexAutoLock lock(*nsHttp::GetLock());
-        mForTakeResponseTrailers = mChunkedDecoder
-            ? mChunkedDecoder->TakeTrailers()
-            : nullptr;
+        if (mChunkedDecoder) {
+            mForTakeResponseTrailers = mChunkedDecoder->TakeTrailers();
+        }
 
         // the transaction is done with a complete response.
         mTransactionDone = true;
@@ -2438,5 +2438,42 @@ nsHttpTransaction::Refused0RTT()
     }
 }
 
+void
+nsHttpTransaction::SetHttpTrailers(nsCString &aTrailers)
+{
+    LOG(("nsHttpTransaction::SetHttpTrailers %p", this));
+    LOG(("[\n    %s\n]", aTrailers.BeginReading()));
+    if (!mForTakeResponseTrailers) {
+        mForTakeResponseTrailers = new nsHttpHeaderArray();
+    }
+
+    int32_t cur = 0;
+    int32_t len = aTrailers.Length();
+    while (cur < len) {
+        int32_t newline = aTrailers.FindCharInSet("\n", cur);
+        if (newline == -1) {
+            newline = len;
+        }
+
+        int32_t end = aTrailers[newline - 1] == '\r' ? newline - 1 : newline;
+        nsDependentCSubstring line(aTrailers, cur, end);
+        nsHttpAtom hdr = {nullptr};
+        nsAutoCString hdrNameOriginal;
+        nsAutoCString val;
+        if (NS_SUCCEEDED(mForTakeResponseTrailers->ParseHeaderLine(line, &hdr, &hdrNameOriginal, &val))) {
+            if (hdr == nsHttp::Server_Timing) {
+                Unused << mForTakeResponseTrailers->SetHeaderFromNet(hdr, hdrNameOriginal, val, true);
+            }
+        }
+
+        cur = newline + 1;
+    }
+
+    if (mForTakeResponseTrailers->Count() == 0) {
+        // Didn't find a Server-Timing header, so get rid of this.
+        mForTakeResponseTrailers = nullptr;
+    }
+}
+
 } // namespace net
 } // namespace mozilla

netwerk/protocol/http/nsHttpTransaction.h

@@ -191,6 +191,8 @@ public:
     }
 
     void SetFastOpenStatus(uint8_t aStatus) override;
+
+    void SetHttpTrailers(nsCString &aTrailers);
 private:
     friend class DeleteHttpTransaction;
     virtual ~nsHttpTransaction();