From 5e95d35f6c0b49f202c0ab3c5241186da253948c Mon Sep 17 00:00:00 2001
From: Andrew Leech <andrew.leech@planetinnovation.com.au>
Date: Thu, 15 Aug 2024 11:54:35 +1000
Subject: [PATCH] py/ringbuf: Add micropython.ringbuffer() interface for
 general use.

Signed-off-by: Andrew Leech <andrew.leech@planetinnovation.com.au>
---
 py/ringbuf.c | 62 ++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 43 insertions(+), 19 deletions(-)

diff --git a/py/ringbuf.c b/py/ringbuf.c
index ad82528ea18ae..91220a0bbbd63 100644
--- a/py/ringbuf.c
+++ b/py/ringbuf.c
@@ -75,14 +75,8 @@ int ringbuf_put16(ringbuf_t *r, uint16_t v) {
     return 0;
 }
 
-// Returns:
-//    0: Success
-//   -1: Not enough data available to complete read (try again later)
-//   -2: Requested read is larger than buffer - will never succeed
-int ringbuf_get_bytes(ringbuf_t *r, uint8_t *data, size_t data_len) {
-    if (ringbuf_avail(r) < data_len) {
-        return (r->size <= data_len) ? -2 : -1;
-    }
+static inline __attribute__((always_inline)) void _ringbuf_memcpy_get(ringbuf_t *r, uint8_t *data, size_t data_len) {
+    // Ensure bounds / space checking is done before running this
     uint32_t iget = r->iget;
     uint32_t iget_a = (iget + data_len) % r->size;
     uint8_t *datap = data;
@@ -94,17 +88,10 @@ int ringbuf_get_bytes(ringbuf_t *r, uint8_t *data, size_t data_len) {
     }
     memcpy(datap, r->buf + iget, iget_a - iget);
     r->iget = iget_a;
-    return 0;
 }
 
-// Returns:
-//    0: Success
-//   -1: Not enough free space available to complete write (try again later)
-//   -2: Requested write is larger than buffer - will never succeed
-int ringbuf_put_bytes(ringbuf_t *r, const uint8_t *data, size_t data_len) {
-    if (ringbuf_free(r) < data_len) {
-        return (r->size <= data_len) ? -2 : -1;
-    }
+static inline __attribute__((always_inline)) void _ringbuf_memcpy_put(ringbuf_t *r, const uint8_t *data, size_t data_len) {
+    // Ensure bounds / space checking is done before running this
     uint32_t iput = r->iput;
     uint32_t iput_a = (iput + data_len) % r->size;
     const uint8_t *datap = data;
@@ -116,6 +103,29 @@ int ringbuf_put_bytes(ringbuf_t *r, const uint8_t *data, size_t data_len) {
     }
     memcpy(r->buf + iput, datap, iput_a - iput);
     r->iput = iput_a;
+}
+
+// Returns:
+//    0: Success
+//   -1: Not enough data available to complete read (try again later)
+//   -2: Requested read is larger than buffer - will never succeed
+int ringbuf_get_bytes(ringbuf_t *r, uint8_t *data, size_t data_len) {
+    if (ringbuf_avail(r) < data_len) {
+        return (r->size <= data_len) ? -2 : -1;
+    }
+    _ringbuf_memcpy_get(r, data, data_len);
+    return 0;
+}
+
+// Returns:
+//    0: Success
+//   -1: Not enough free space available to complete write (try again later)
+//   -2: Requested write is larger than buffer - will never succeed
+int ringbuf_put_bytes(ringbuf_t *r, const uint8_t *data, size_t data_len) {
+    if (ringbuf_free(r) < data_len) {
+        return (r->size <= data_len) ? -2 : -1;
+    }
+    _ringbuf_memcpy_put(r, data, data_len);
     return 0;
 }
 
@@ -124,6 +134,10 @@ int ringbuf_put_bytes(ringbuf_t *r, const uint8_t *data, size_t data_len) {
 #include "py/stream.h"
 #include "py/mphal.h"
 
+#ifndef MICROPY_PY_MICROPYTHON_RINGBUFFER_USE_MEMCPY
+#define MICROPY_PY_MICROPYTHON_RINGBUFFER_USE_MEMCPY (1)
+#endif
+
 typedef struct _micropython_ringbuffer_obj_t {
     mp_obj_base_t base;
     ringbuf_t ringbuffer;
@@ -154,10 +168,15 @@ static mp_obj_t micropython_ringbuffer_make_new(const mp_obj_type_t *type, size_
 static mp_uint_t micropython_ringbuffer_read(mp_obj_t self_in, void *buf_in, mp_uint_t size, int *errcode) {
     micropython_ringbuffer_obj_t *self = MP_OBJ_TO_PTR(self_in);
     size = MIN(size, ringbuf_avail(&self->ringbuffer));
+    #if MICROPY_PY_MICROPYTHON_RINGBUFFER_USE_MEMCPY
+    _ringbuf_memcpy_get(&(self->ringbuffer), buf_in, size);
+    #else
     uint8_t *dest = buf_in;
-    for (mp_uint_t i = 0; i < size; i++) {
+    const uint8_t *dest_end = dest + size;
+    while (dest < dest_end) {
         *dest++ = ringbuf_get(&(self->ringbuffer));
     }
+    #endif
     *errcode = 0;
     return size;
 }
@@ -165,10 +184,15 @@ static mp_uint_t micropython_ringbuffer_read(mp_obj_t self_in, void *buf_in, mp_
 static mp_uint_t micropython_ringbuffer_write(mp_obj_t self_in, const void *buf_in, mp_uint_t size, int *errcode) {
     micropython_ringbuffer_obj_t *self = MP_OBJ_TO_PTR(self_in);
     size = MIN(size, ringbuf_free(&self->ringbuffer));
+    #if MICROPY_PY_MICROPYTHON_RINGBUFFER_USE_MEMCPY
+    _ringbuf_memcpy_put(&(self->ringbuffer), buf_in, size);
+    #else
     const uint8_t *src = buf_in;
-    for (mp_uint_t i = 0; i < size; i++) {
+    const uint8_t *src_end = src + size;
+    while (src < src_end) {
         ringbuf_put(&(self->ringbuffer), *src++);
     }
+    #endif
     *errcode = 0;
     return size;
 }