Bug 1296280 (part 2) - Add pref for our SETTINGS_MAX_TABLE_SIZE. r=mcmanus

MozReview-Commit-ID: 44CYEvJOno0

--HG--
extra : rebase_source : 5317d25981bf83ab8cc9b921055cc9028a1d4470

netwerk/protocol/http/Http2Compression.cpp

@@ -281,6 +281,7 @@ Http2BaseCompressor::Http2BaseCompressor()
   : mOutput(nullptr)
   , mMaxBuffer(kDefaultMaxBuffer)
   , mMaxBufferSetting(kDefaultMaxBuffer)
+  , mSetInitialMaxBufferSizeAllowed(true)
   , mPeakSize(0)
   , mPeakCount(0)
 {
@@ -383,10 +384,24 @@ Http2BaseCompressor::SetMaxBufferSizeInternal(uint32_t maxBufferSize)
   mMaxBuffer = maxBufferSize;
 }
 
+nsresult
+Http2BaseCompressor::SetInitialMaxBufferSize(uint32_t maxBufferSize)
+{
+  MOZ_ASSERT(mSetInitialMaxBufferSizeAllowed);
+
+  if (mSetInitialMaxBufferSizeAllowed) {
+    mMaxBufferSetting = maxBufferSize;
+    return NS_OK;
+  }
+
+  return NS_ERROR_FAILURE;
+}
+
 nsresult
 Http2Decompressor::DecodeHeaderBlock(const uint8_t *data, uint32_t datalen,
                                      nsACString &output, bool isPush)
 {
+  mSetInitialMaxBufferSizeAllowed = false;
   mOffset = 0;
   mData = data;
   mDataLen = datalen;
@@ -1035,6 +1050,7 @@ Http2Compressor::EncodeHeaderBlock(const nsCString &nvInput,
                                    const nsACString &host, const nsACString &scheme,
                                    bool connectForm, nsACString &output)
 {
+  mSetInitialMaxBufferSizeAllowed = false;
   mOutput = &output;
   output.SetCapacity(1024);
   output.Truncate();

netwerk/protocol/http/Http2Compression.h

@@ -66,6 +66,7 @@ public:
   Http2BaseCompressor();
   virtual ~Http2BaseCompressor();
   size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+  nsresult SetInitialMaxBufferSize(uint32_t maxBufferSize);
 
 protected:
   const static uint32_t kDefaultMaxBuffer = 4096;
@@ -80,6 +81,7 @@ protected:
 
   uint32_t mMaxBuffer;
   uint32_t mMaxBufferSetting;
+  bool mSetInitialMaxBufferSizeAllowed;
 
   uint32_t mPeakSize;
   uint32_t mPeakCount;

netwerk/protocol/http/Http2Session.cpp

@@ -832,10 +832,10 @@ Http2Session::SendHello()
   MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
   LOG3(("Http2Session::SendHello %p\n", this));
 
-  // sized for magic + 4 settings and a session window update and 5 priority frames
+  // sized for magic + 5 settings and a session window update and 5 priority frames
   // 24 magic, 33 for settings (9 header + 4 settings @6), 13 for window update,
   // 5 priority frames at 14 (9 + 5) each
-  static const uint32_t maxSettings = 4;
+  static const uint32_t maxSettings = 5;
   static const uint32_t prioritySize = 5 * (kFrameHeaderBytes + 5);
   static const uint32_t maxDataLen = 24 + kFrameHeaderBytes + maxSettings * 6 + 13 + prioritySize;
   char *packet = EnsureOutputBuffer(maxDataLen);
@@ -854,6 +854,14 @@ Http2Session::SendHello()
   // 2nd entry is bytes 15 to 20
   // 3rd entry is bytes 21 to 26
   // 4th entry is bytes 27 to 32
+  // 5th entry is bytes 33 to 38
+
+  // Let the other endpoint know about our default HPACK decompress table size
+  uint32_t maxHpackBufferSize = gHttpHandler->DefaultHpackBuffer();
+  mDecompressor.SetInitialMaxBufferSize(maxHpackBufferSize);
+  NetworkEndian::writeUint16(packet + kFrameHeaderBytes + (6 * numberOfEntries), SETTINGS_TYPE_HEADER_TABLE_SIZE);
+  NetworkEndian::writeUint32(packet + kFrameHeaderBytes + (6 * numberOfEntries) + 2, maxHpackBufferSize);
+  numberOfEntries++;
 
   if (!gHttpHandler->AllowPush()) {
     // If we don't support push then set MAX_CONCURRENT to 0 and also

netwerk/protocol/http/nsHttpHandler.cpp

@@ -239,6 +239,7 @@ nsHttpHandler::nsHttpHandler()
     , mTCPKeepaliveLongLivedIdleTimeS(600)
     , mEnforceH1Framing(FRAMECHECK_BARELY)
     , mKeepEmptyResponseHeadersAsEmtpyString(false)
+    , mDefaultHpackBuffer(4096)
 {
     LOG(("Creating nsHttpHandler [this=%p].\n", this));
 
@@ -1693,6 +1694,13 @@ nsHttpHandler::PrefsChanged(nsIPrefBranch *prefs, const char *pref)
         }
     }
 
+    if (PREF_CHANGED(HTTP_PREF("spdy.hpack-default-buffer"))) {
+        rv = prefs->GetIntPref(HTTP_PREF("spdy.default-hpack-buffer"), &val);
+        if (NS_SUCCEEDED(rv)) {
+            mDefaultHpackBuffer = val;
+        }
+    }
+
     // Enable HTTP response timeout if TCP Keepalives are disabled.
     mResponseTimeoutEnabled = !mTCPKeepaliveShortLivedEnabled &&
                               !mTCPKeepaliveLongLivedEnabled;

netwerk/protocol/http/nsHttpHandler.h

@@ -368,6 +368,11 @@ public:
         return mKeepEmptyResponseHeadersAsEmtpyString;
     }
 
+    uint32_t DefaultHpackBuffer() const
+    {
+        return mDefaultHpackBuffer;
+    }
+
 private:
     virtual ~nsHttpHandler();
 
@@ -587,6 +592,9 @@ private:
     // (Bug 6699259)
     bool mKeepEmptyResponseHeadersAsEmtpyString;
 
+    // The default size (in bytes) of the HPACK decompressor table.
+    uint32_t mDefaultHpackBuffer;
+
 private:
     // For Rate Pacing Certain Network Events. Only assign this pointer on
     // socket thread.