Refactor RST_STREAM status code handling.

net/spdy/spdy_protocol.h

Index: net/spdy/spdy_protocol.h
diff --git a/net/spdy/spdy_protocol.h b/net/spdy/spdy_protocol.h
index 9696bf120890a04a4d62da8e126615b3797361ca..b02339a155688a2fcd3303a6b2366ed00d74a71f 100644
--- a/net/spdy/spdy_protocol.h
+++ b/net/spdy/spdy_protocol.h
@@ -360,6 +360,7 @@ enum SpdyRstStreamStatus {
   RST_STREAM_INVALID = 0,
   RST_STREAM_PROTOCOL_ERROR = 1,
   RST_STREAM_INVALID_STREAM = 2,
+  RST_STREAM_STREAM_CLOSED = 2,  // Equivalent to INVALID_STREAM
   RST_STREAM_REFUSED_STREAM = 3,
   RST_STREAM_UNSUPPORTED_VERSION = 4,
   RST_STREAM_CANCEL = 5,
@@ -369,7 +370,11 @@ enum SpdyRstStreamStatus {
   RST_STREAM_STREAM_ALREADY_CLOSED = 9,
   RST_STREAM_INVALID_CREDENTIALS = 10,
   RST_STREAM_FRAME_TOO_LARGE = 11,
-  RST_STREAM_NUM_STATUS_CODES = 12
+  RST_STREAM_FRAME_SIZE_ERROR = 11,  // Equivalent to FRAME_TOO_LARGE

[jar (doing other things), 2014/04/22 00:02:59]

nit: If you're not going to distigiush them... why not just use FRAME_SIZE_ERROR
everywhere, and get rid of TOO_LARGE?

[Johnny, 2014/04/22 00:31:27]

Yea, this is not optimal, but: FRAME_TOO_LARGE is a specific error name in the
SPDY/3.1 specification. FRAME_SIZE_ERROR is a specific error name in the HTTP/2
specification.

We're supporting both specifications with this codebase; their meanings are so
semantically close that Hasan elected to map them to the same internal error in
this CL.

[jar (doing other things), 2014/04/25 16:03:45]

OK... good enough.  Might be worth a comment... but your choice.

+  RST_STREAM_SETTINGS_TIMEOUT = 12,
+  RST_STREAM_CONNECT_ERROR = 13,
+  RST_STREAM_ENHANCE_YOUR_CALM = 14,
+  RST_STREAM_NUM_STATUS_CODES = 15
 };
 
 // Status codes for GOAWAY frames.
@@ -426,6 +431,26 @@ class NET_EXPORT_PRIVATE SpdyConstants {
   // given protocol version.
   // Returns -1 on failure (I.E. Invalid setting id for the given version).
   static int SerializeSettingId(SpdyMajorVersion version, SpdySettingsIds id);
+
+  // Returns true if a given on-the-wire enumeration of a RST_STREAM status code
+  // is valid for a given protocol version, false otherwise.
+  static bool IsValidRstStreamStatus(SpdyMajorVersion version,
+                                     int rst_stream_status_field);
+
+  // Parses a RST_STREAM status code from an on-the-wire enumeration of a given
+  // protocol version.
+  // Behavior is undefined for invalid RST_STREAM status code fields; consumers
+  // should first use IsValidRstStreamStatus() to verify validity of RST_STREAM
+  // status code fields..
+  static SpdyRstStreamStatus ParseRstStreamStatus(SpdyMajorVersion version,
+                                                  int rst_stream_status_field);
+
+  // Serializes a given RST_STREAM status code to the on-the-wire enumeration
+  // value for the given protocol version.
+  // Returns -1 on failure (I.E. Invalid RST_STREAM status code for the given
+  // version).
+  static int SerializeRstStreamStatus(SpdyMajorVersion version,
+                                      SpdyRstStreamStatus rst_stream_status);
 };
 
 class SpdyFrame;
@@ -636,8 +661,6 @@ class NET_EXPORT_PRIVATE SpdyRstStreamIR : public SpdyFrameWithStreamIdIR {
     return status_;
   }
   void set_status(SpdyRstStreamStatus status) {
-    DCHECK_NE(status, RST_STREAM_INVALID);
-    DCHECK_LT(status, RST_STREAM_NUM_STATUS_CODES);
     status_ = status;
   }