Refactor ipmi::sensor::GetSensorResponse away from std::array

This change refactors GetSensorResponse from std::array to struct.
This change depends on change #23544.

GetSensorResponse is an internal, intermediate structure, an unpacked
form of a Get Sensor Reading response, providing direct access to its
fields. Its life time is:
GetReadingResponse -> GetSensorResponse -> ipmi::RspType.

It is written to in 5 functions in the ipmi::sensor::get namespace, by
four setter functions (setOffset, setReading, setAssertionBytes,
enableScanning).
It is currently read from by 1 function (ipmiSensorGetSensorReading)
for transforming to an ipmi::RspType.

Originally, the setter functions assumed bitwise equivalence between
GetSensorResponse and GetReadingResponse, and the setter functions
used reinterpret_cast to assign to a GetSensorResponse as if it were
a GetReadingResponse.

With this change, the reinterpret_cast's are removed, and the set
functions now accept GetSensorResponse instead of GetReadingResponse,
so the code gets a bit easier to read.

Tested: Tested using a server with a BMC; sensor readings obtained
through `ipmitool` appear to be correct (the reading might change
within a small range):
 # ipmitool raw 0x04 0x2d 0x16
   9B 40 00 00

Signed-off-by: Sui Chen <suichen@google.com>
Change-Id: I5d454d6249f5431fb98169e6ef7c585c34024004

1 files changed, 11 insertions, 9 deletions

diff --git a/sensorhandler.hpp b/sensorhandler.hpp
index f5a8b41..8780235 100644
--- a/sensorhandler.hpp
+++ b/sensorhandler.hpp
@@ -644,15 +644,15 @@ namespace sensor
  * @param[in] offset - offset number.
  * @param[in/out] resp - get sensor reading response.
  */
-inline void setOffset(uint8_t offset, ipmi::sensor::GetReadingResponse* resp)
+inline void setOffset(uint8_t offset, ipmi::sensor::GetSensorResponse* resp)
 {
     if (offset > 7)
     {
-        resp->assertOffset8_14 |= 1 << (offset - 8);
+        resp->discreteReadingSensorStates |= 1 << (offset - 8);
     }
     else
     {
-        resp->assertOffset0_7 |= 1 << offset;
+        resp->thresholdLevelsStates |= 1 << offset;
     }
 }
 
@@ -662,7 +662,7 @@ inline void setOffset(uint8_t offset, ipmi::sensor::GetReadingResponse* resp)
  * @param[in] offset - offset number.
  * @param[in/out] resp - get sensor reading response.
  */
-inline void setReading(uint8_t value, ipmi::sensor::GetReadingResponse* resp)
+inline void setReading(uint8_t value, ipmi::sensor::GetSensorResponse* resp)
 {
     resp->reading = value;
 }
@@ -675,10 +675,10 @@ inline void setReading(uint8_t value, ipmi::sensor::GetReadingResponse* resp)
  * @param[in/out] resp - get sensor reading response.
  */
 inline void setAssertionBytes(uint16_t value,
-                              ipmi::sensor::GetReadingResponse* resp)
+                              ipmi::sensor::GetSensorResponse* resp)
 {
-    resp->assertOffset0_7 = static_cast<uint8_t>(value & 0x00FF);
-    resp->assertOffset8_14 = static_cast<uint8_t>(value >> 8);
+    resp->thresholdLevelsStates = static_cast<uint8_t>(value & 0x00FF);
+    resp->discreteReadingSensorStates = static_cast<uint8_t>(value >> 8);
 }
 
 /**
@@ -686,9 +686,11 @@ inline void setAssertionBytes(uint16_t value,
  *
  * @param[in/out] resp - get sensor reading response.
  */
-inline void enableScanning(ipmi::sensor::GetReadingResponse* resp)
+inline void enableScanning(ipmi::sensor::GetSensorResponse* resp)
 {
-    resp->operation = 1 << 6;
+    resp->readingOrStateUnavailable = false;
+    resp->scanningEnabled = true;
+    resp->allEventMessagesEnabled = false;
 }
 
 } // namespace sensor