AP_HAL: eliminate AP_HAL::Print and AP_HAL::Stream

Just *way* too many layers involved here

libraries/AP_HAL/AP_HAL.h

@@ -23,8 +23,6 @@
 #include "CAN.h"
 #endif
 
-#include "utility/Print.h"
-#include "utility/Stream.h"
 #include "utility/BetterStream.h"
 
 /* HAL Class definition */

libraries/AP_HAL/UARTDriver.h

@@ -2,8 +2,6 @@
 
 #include <stdint.h>
 
-#include <AP_Common/AP_Common.h>
-
 #include "AP_HAL_Namespace.h"
 #include "utility/BetterStream.h"
 
@@ -53,13 +51,6 @@ class AP_HAL::UARTDriver : public AP_HAL::BetterStream {
      */
     virtual bool set_unbuffered_writes(bool on){ return false; };
 
-    /* Implementations of BetterStream virtual methods. These are
-     * provided by AP_HAL to ensure consistency between ports to
-     * different boards
-     */
-    void printf(const char *s, ...) FMT_PRINTF(2, 3);
-    void vprintf(const char *s, va_list ap);
-
     /*
       wait for at least n bytes of incoming data, with timeout in
       milliseconds. Return true if n bytes are available, false if

libraries/AP_HAL/Util.cpp

@@ -11,10 +11,11 @@
 #endif
 
 /* Helper class implements AP_HAL::Print so we can use utility/vprintf */
-class BufferPrinter : public AP_HAL::Print {
+class BufferPrinter : public AP_HAL::BetterStream {
 public:
     BufferPrinter(char* str, size_t size)  : _offs(0), _str(str), _size(size)  {}
-    size_t write(uint8_t c) {
+
+    size_t write(uint8_t c) override {
         if (_offs < _size) {
             _str[_offs] = c;
             _offs++;
@@ -23,17 +24,21 @@ class BufferPrinter : public AP_HAL::Print {
             return 0;
         }
     }
-    size_t write(const uint8_t *buffer, size_t size) {
+    size_t write(const uint8_t *buffer, size_t size) override {
         size_t n = 0;
         while (size--) {
             n += write(*buffer++);
         }
         return n;
     }
 
-    size_t _offs; 
+    size_t _offs;
     char* const  _str;
     const size_t _size;
+
+    uint32_t available() override { return 0; }
+    int16_t read() override { return -1; }
+    uint32_t txspace() override { return 0; }
 };
 
 int AP_HAL::Util::snprintf(char* str, size_t size, const char *format, ...)

libraries/AP_HAL/Util.h

@@ -81,7 +81,7 @@ class AP_HAL::Util {
     /*
       return a stream for access to a system shell, if available
      */
-    virtual AP_HAL::Stream *get_shell_stream() { return nullptr; }
+    virtual AP_HAL::BetterStream *get_shell_stream() { return nullptr; }
 
     /* Support for an imu heating system */
     virtual void set_imu_temp(float current) {}

libraries/AP_HAL/utility/BetterStream.cpp

@@ -0,0 +1,31 @@
+#include "BetterStream.h"
+
+#include "print_vprintf.h"
+
+void AP_HAL::BetterStream::printf(const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    vprintf(fmt, ap);
+    va_end(ap);
+}
+
+void AP_HAL::BetterStream::vprintf(const char *fmt, va_list ap)
+{
+    print_vprintf(this, fmt, ap);
+}
+
+size_t AP_HAL::BetterStream::write(const uint8_t *buffer, size_t size)
+{
+    for (size_t i=0; i<size;i++) {
+        if (write(buffer[i] == 0)) {
+            return i;
+        }
+    };
+    return size;
+}
+
+size_t AP_HAL::BetterStream::write(const char *str)
+{
+    return write((const uint8_t *)str, strlen(str));
+}

libraries/AP_HAL/utility/BetterStream.h

@@ -24,12 +24,26 @@
 #include <AP_Common/AP_Common.h>
 #include <AP_HAL/AP_HAL_Namespace.h>
 
-#include "Stream.h"
-
-class AP_HAL::BetterStream : public AP_HAL::Stream {
+class AP_HAL::BetterStream {
 public:
-    BetterStream(void) {}
 
-    virtual void printf(const char *, ...) FMT_PRINTF(2, 3) = 0;
-    virtual void vprintf(const char *, va_list) = 0;
+    virtual void printf(const char *, ...) FMT_PRINTF(2, 3);
+    virtual void vprintf(const char *, va_list);
+
+    void print(const char *str) { write(str); }
+    void println(const char *str) { printf("%s\r\n", str); }
+
+    virtual size_t write(uint8_t) = 0;
+    virtual size_t write(const uint8_t *buffer, size_t size);
+    size_t write(const char *str);
+
+    virtual uint32_t available() = 0;
+
+    /* return value for read():
+     * -1 if nothing available, uint8_t value otherwise. */
+    virtual int16_t read() = 0;
+
+    /* NB txspace was traditionally a member of BetterStream in the
+     * FastSerial library. As far as concerns go, it belongs with available() */
+    virtual uint32_t txspace() = 0;
 };