Change HTTPMessage default urgency and incremental values

Summary:
urgency = 3 and incremental = true will be our default. Leaving them
to 0 and false will change the default transport behavior

Reviewed By: mjoras

Differential Revision: D24573524

fbshipit-source-id: e2837ec44cff41f544e5e6a5e41c9558e0cf54a2

Author: Yang Chi

proxygen/lib/http/HTTPMessage.cpp

@@ -67,8 +67,8 @@ HTTPMessage::HTTPMessage()
       sslVersion_(0),
       sslCipher_(nullptr),
       protoStr_(nullptr),
-      pri_(0),
-      incremental_(false),
+      pri_(kDefaultHttpPriorityUrgency),
+      incremental_(kDefaultHttpPriorityIncremental),
       version_(1, 0),
       parsedCookies_(false),
       parsedQueryParams_(false),

proxygen/lib/http/HTTPMessage.h

@@ -26,6 +26,13 @@
 
 namespace proxygen {
 
+// Default urgency = 3 is from the draft. It leaves space for both higher and
+// lower urgency level which is good. We default to Incremental = True as
+// opposed to False. This is because our transport layer has been behaving
+// like that before the HTTP priority support is introduced.
+constexpr uint8_t kDefaultHttpPriorityUrgency = 3;
+constexpr bool kDefaultHttpPriorityIncremental = true;
+
 /**
  * An HTTP request or response minus the body.
  *

proxygen/lib/http/codec/test/HQCodecTest.cpp

@@ -921,8 +921,8 @@ TEST_F(HQCodecTest, PriorityHeaderBadUrgency) {
 
   parse();
   const auto& msg = callbacks_.msg;
-  EXPECT_EQ(msg->getPriority(), 0);
-  EXPECT_FALSE(msg->getIncremental());
+  EXPECT_EQ(msg->getPriority(), kDefaultHttpPriorityUrgency);
+  EXPECT_TRUE(msg->getIncremental());
 }
 
 TEST_F(HQCodecTest, PriorityHeaderBadUrgencyWithIncremental) {
@@ -933,8 +933,8 @@ TEST_F(HQCodecTest, PriorityHeaderBadUrgencyWithIncremental) {
 
   parse();
   const auto& msg = callbacks_.msg;
-  EXPECT_EQ(msg->getPriority(), 0);
-  EXPECT_FALSE(msg->getIncremental());
+  EXPECT_EQ(msg->getPriority(), kDefaultHttpPriorityUrgency);
+  EXPECT_TRUE(msg->getIncremental());
 }
 
 TEST_F(HQCodecTest, PriorityHeaderBadIncremental) {
@@ -945,8 +945,8 @@ TEST_F(HQCodecTest, PriorityHeaderBadIncremental) {
 
   parse();
   const auto& msg = callbacks_.msg;
-  EXPECT_EQ(msg->getPriority(), 0);
-  EXPECT_FALSE(msg->getIncremental());
+  EXPECT_EQ(msg->getPriority(), kDefaultHttpPriorityUrgency);
+  EXPECT_TRUE(msg->getIncremental());
 }
 
 struct FrameAllowedParams {

proxygen/lib/http/codec/test/HTTP2CodecTest.cpp

@@ -2456,8 +2456,8 @@ TEST_F(HTTP2CodecTest, PriorityHeaderBadUrgency) {
 
   parse();
   const auto& msg = callbacks_.msg;
-  EXPECT_EQ(msg->getPriority(), 0);
-  EXPECT_FALSE(msg->getIncremental());
+  EXPECT_EQ(msg->getPriority(), kDefaultHttpPriorityUrgency);
+  EXPECT_TRUE(msg->getIncremental());
 }
 
 TEST_F(HTTP2CodecTest, PriorityHeaderBadUrgencyWithIncremental) {
@@ -2467,8 +2467,8 @@ TEST_F(HTTP2CodecTest, PriorityHeaderBadUrgencyWithIncremental) {
 
   parse();
   const auto& msg = callbacks_.msg;
-  EXPECT_EQ(msg->getPriority(), 0);
-  EXPECT_FALSE(msg->getIncremental());
+  EXPECT_EQ(msg->getPriority(), kDefaultHttpPriorityUrgency);
+  EXPECT_TRUE(msg->getIncremental());
 }
 
 TEST_F(HTTP2CodecTest, PriorityHeaderBadIncremental) {
@@ -2478,6 +2478,6 @@ TEST_F(HTTP2CodecTest, PriorityHeaderBadIncremental) {
 
   parse();
   const auto& msg = callbacks_.msg;
-  EXPECT_EQ(msg->getPriority(), 0);
-  EXPECT_FALSE(msg->getIncremental());
+  EXPECT_EQ(msg->getPriority(), kDefaultHttpPriorityUrgency);
+  EXPECT_TRUE(msg->getIncremental());
 }