SPDY: Headers & Push-Promise now use Continuations

net/spdy/spdy_frame_builder.cc

Index: net/spdy/spdy_frame_builder.cc
diff --git a/net/spdy/spdy_frame_builder.cc b/net/spdy/spdy_frame_builder.cc
index 7ea7716b41bfff075e51f796415e8130d2f209f0..fc37c0b4a290d534859b425a822ee3392d7418d3 100644
--- a/net/spdy/spdy_frame_builder.cc
+++ b/net/spdy/spdy_frame_builder.cc
@@ -32,10 +32,12 @@ FlagsAndLength CreateFlagsAndLength(uint8 flags, size_t length) {
 
 }  // namespace
 
-SpdyFrameBuilder::SpdyFrameBuilder(size_t size)
+  SpdyFrameBuilder::SpdyFrameBuilder(size_t size, SpdyMajorVersion version)
     : buffer_(new char[size]),
       capacity_(size),
-      length_(0) {
+      length_(0),
+      offset_(0),
+      version_(version) {
 }
 
 SpdyFrameBuilder::~SpdyFrameBuilder() {
@@ -45,7 +47,7 @@ char* SpdyFrameBuilder::GetWritableBuffer(size_t length) {
   if (!CanWrite(length)) {
     return NULL;
   }
-  return buffer_.get() + length_;
+  return buffer_.get() + offset_ + length_;
 }
 
 bool SpdyFrameBuilder::Seek(size_t length) {
@@ -78,7 +80,7 @@ bool SpdyFrameBuilder::WriteDataFrameHeader(const SpdyFramer& framer,
                                             SpdyStreamId stream_id,
                                             uint8 flags) {
   if (framer.protocol_version() >= 4) {
-    return WriteFramePrefix(framer, DATA, flags, stream_id);
+    return BeginNewFrame(framer, DATA, flags, stream_id);
   }
   DCHECK_EQ(0u, stream_id & ~kStreamIdMask);
   bool success = true;
@@ -94,28 +96,37 @@ bool SpdyFrameBuilder::WriteDataFrameHeader(const SpdyFramer& framer,
   return success;
 }
 
-bool SpdyFrameBuilder::WriteFramePrefix(const SpdyFramer& framer,
-                                        SpdyFrameType type,
-                                        uint8 flags,
-                                        SpdyStreamId stream_id) {
-  DCHECK_NE(-1,
-            SpdyConstants::SerializeFrameType(framer.protocol_version(), type));
+bool SpdyFrameBuilder::BeginNewFrame(const SpdyFramer& framer,
+                                     SpdyFrameType type,
+                                     uint8 flags,
+                                     SpdyStreamId stream_id) {
+  DCHECK(SpdyConstants::IsValidFrameType(version_,
+      SpdyConstants::SerializeFrameType(version_, type)));
   DCHECK_EQ(0u, stream_id & ~kStreamIdMask);
-  DCHECK_LE(4, framer.protocol_version());
+  DCHECK_LE(4, version_);
+
   bool success = true;
-  // Upstream DCHECK's that capacity_ is under the maximum frame size at this
-  // point. Chromium does not, because of the large additional zlib inflation
-  // factor we use. (Frame size is is still checked by OverwriteLength() below).
-  if (type != DATA) {
-    success &= WriteUInt16(capacity_ - framer.GetControlFrameHeaderSize());
-  } else {
-    success &= WriteUInt16(capacity_ - framer.GetDataFrameMinimumSize());
+  if (length_ > 0) {
+    // Update length field for previous frame.
+    OverwriteLength(framer, length_ - framer.GetPrefixLength(type));
+    DLOG_IF(DFATAL, SpdyConstants::GetFrameMaximumSize(version_) < length_)
+        << "Frame length  " << length_
+        << " is longer than the maximum allowed length.";
   }
+
+  offset_ += length_;
+  length_ = 0;
+
+  // Assume all remaining capacity will be used for this frame. If not,
+  // the length will get overwritten when we begin the next frame.
+  // Don't check for length limits here because this may be larger than the
+  // actual frame length.
+  success &= WriteUInt16(capacity_ - offset_ - framer.GetPrefixLength(type));
   success &= WriteUInt8(
-      SpdyConstants::SerializeFrameType(framer.protocol_version(), type));
+      SpdyConstants::SerializeFrameType(version_, type));
   success &= WriteUInt8(flags);
   success &= WriteUInt32(stream_id);
-  DCHECK_EQ(framer.GetDataFrameMinimumSize(), length());
+  DCHECK_EQ(framer.GetDataFrameMinimumSize(), length_);
   return success;
 }
 
@@ -157,16 +168,17 @@ bool SpdyFrameBuilder::RewriteLength(const SpdyFramer& framer) {
 
 bool SpdyFrameBuilder::OverwriteLength(const SpdyFramer& framer,
                                        size_t length) {
-  if (framer.protocol_version() < 4) {
-    DCHECK_GE(framer.GetFrameMaximumSize() - framer.GetFrameMinimumSize(),
+  if (version_ < 4) {
+    DCHECK_GE(SpdyConstants::GetFrameMaximumSize(version_) -
+              framer.GetFrameMinimumSize(),
               length);
   } else {
-    DCHECK_GE(framer.GetFrameMaximumSize(), length);
+    DCHECK_GE(SpdyConstants::GetFrameMaximumSize(version_), length);
   }
   bool success = false;
   const size_t old_length = length_;
 
-  if (framer.protocol_version() < 4) {
+  if (version_ < 4) {
     FlagsAndLength flags_length = CreateFlagsAndLength(
         0,  // We're not writing over the flags value anyway.
         length);
@@ -202,7 +214,7 @@ bool SpdyFrameBuilder::CanWrite(size_t length) const {
     return false;
   }
 
-  if (length_ + length > capacity_) {
+  if (offset_ + length_ + length > capacity_) {
     DCHECK(false);
     return false;
   }