pw_uart: Move non-blocking methods from Uart to UartBase

* ConservativeReadAvailable()
* ClearPendingReceiveBytes()

Bug: 369679732
Change-Id: Idecd3f2089631e0062c3a186e519c10abbad3392
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/238533
Presubmit-Verified: CQ Bot Account <[email protected]>
Lint: Lint 🤖 <[email protected]>
Commit-Queue: Jonathon Reinhart <[email protected]>
Reviewed-by: Taylor Cramer <[email protected]>
Docs-Not-Needed: Jonathon Reinhart <[email protected]>

pw_uart/public/pw_uart/uart.h

@@ -230,15 +230,6 @@ class Uart : public UartBase {
     return DoTryWriteFor(tx_buffer, timeout);
   }
 
-  /// Returns the number of bytes currently available for reading.
-  ///
-  /// This function checks the receive buffer to determine how many bytes of
-  /// data are ready to be read.
-  ///
-  /// @returns The number of bytes available for reading. When no data is
-  /// available or in case of an error this function returns 0.
-  size_t ConservativeReadAvailable() { return DoConservativeReadAvailable(); }
-
   /// Blocks until all queued data in the UART  has been transmitted and the
   /// FIFO is empty.
   ///
@@ -257,23 +248,6 @@ class Uart : public UartBase {
   /// @endrst
   Status FlushOutput() { return DoFlushOutput(); }
 
-  /// Empties the UART's receive buffer and discards any unread data.
-  ///
-  /// This function removes all data from the receive buffer, resetting the
-  /// buffer to an empty state. This is useful for situations where you want to
-  /// disregard any previously received data and resynchronize.
-  ///
-  /// @returns @rst
-  ///
-  /// .. pw-status-codes::
-  ///
-  ///    OK: The operation was successful.
-  ///
-  /// May return other implementation-specific status codes.
-  ///
-  /// @endrst
-  Status ClearPendingReceiveBytes() { return DoClearPendingReceiveBytes(); }
-
  private:
   /// Reads data from the UART into a provided buffer with an optional timeout
   /// provided.
@@ -377,9 +351,7 @@ class Uart : public UartBase {
   virtual StatusWithSize DoTryWriteFor(
       ConstByteSpan tx_buffer,
       std::optional<chrono::SystemClock::duration> timeout) = 0;
-  virtual size_t DoConservativeReadAvailable() = 0;
   virtual Status DoFlushOutput() = 0;
-  virtual Status DoClearPendingReceiveBytes() = 0;
 };
 
 }  // namespace pw::uart

pw_uart/public/pw_uart/uart_base.h

@@ -109,12 +109,40 @@ class UartBase {
   /// @endrst
   Status SetFlowControl(bool enable) { return DoSetFlowControl(enable); }
 
+  /// Returns the number of bytes currently available for reading.
+  ///
+  /// This function checks the receive buffer to determine how many bytes of
+  /// data are ready to be read.
+  ///
+  /// @returns The number of bytes available for reading. When no data is
+  /// available or in case of an error this function returns 0.
+  size_t ConservativeReadAvailable() { return DoConservativeReadAvailable(); }
+
+  /// Empties the UART's receive buffer and discards any unread data.
+  ///
+  /// This function removes all data from the receive buffer, resetting the
+  /// buffer to an empty state. This is useful for situations where you want to
+  /// disregard any previously received data and resynchronize.
+  ///
+  /// @returns @rst
+  ///
+  /// .. pw-status-codes::
+  ///
+  ///    OK: The operation was successful.
+  ///
+  /// May return other implementation-specific status codes.
+  ///
+  /// @endrst
+  Status ClearPendingReceiveBytes() { return DoClearPendingReceiveBytes(); }
+
  private:
   virtual Status DoEnable(bool enable) = 0;
   virtual Status DoSetBaudRate(uint32_t baud_rate) = 0;
   virtual Status DoSetFlowControl(bool /*enable*/) {
     return pw::Status::Unimplemented();
   }
+  virtual size_t DoConservativeReadAvailable() = 0;
+  virtual Status DoClearPendingReceiveBytes() = 0;
 };
 
 }  // namespace pw::uart

pw_uart/uart_non_blocking_test.cc

@@ -44,6 +44,8 @@ class UartNonBlockingStub : public UartNonBlocking {
     return OkStatus();
   }
   bool DoCancelWrite() override { return true; }
+  size_t DoConservativeReadAvailable() override { return 0; }
+  Status DoClearPendingReceiveBytes() override { return OkStatus(); }
 };
 
 class UartNonBlockingTest : public ::testing::Test {
@@ -57,4 +59,4 @@ class UartNonBlockingTest : public ::testing::Test {
 TEST_F(UartNonBlockingTest, CompilationSucceeds) { EXPECT_TRUE(true); }
 
 }  // namespace
-}  // namespace pw::uart
+}  // namespace pw::uart