From 70bce9b264ec42b3a57f064349d11dd03972a4e6 Mon Sep 17 00:00:00 2001
From: MacRsh <macrsh@163.com>
Date: Wed, 14 May 2025 23:56:35 +0800
Subject: [PATCH] feat(kfifo): Add kfifo overwrite write function.

---
 include/kernel/mr_kfifo.h | 11 +++++++++++
 kernel/kfifo.c            | 27 ++++++++++++++++++++++++---
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/include/kernel/mr_kfifo.h b/include/kernel/mr_kfifo.h
index 95630fb..cfb6246 100644
--- a/include/kernel/mr_kfifo.h
+++ b/include/kernel/mr_kfifo.h
@@ -93,6 +93,17 @@ mr_uint32_t mr_kfifo_pop(mr_kfifo_t *kfifo, void *data);
  */
 mr_uint32_t mr_kfifo_in(mr_kfifo_t *kfifo, const void *buf, mr_uint32_t num);
 
+/**
+ * @brief This function puts data to a kfifo with overwrite.
+ *
+ * @param kfifo The kfifo.
+ * @param buf The buffer.
+ * @param num The buffer number.
+ * @return The actual pushed element number.
+ */
+mr_uint32_t mr_kfifo_in_overwrite(mr_kfifo_t *kfifo, const void *buf,
+                                  mr_uint32_t num);
+
 /**
  * @brief This function peeks data from a kfifo.
  *
diff --git a/kernel/kfifo.c b/kernel/kfifo.c
index 9d31716..cb79c6c 100644
--- a/kernel/kfifo.c
+++ b/kernel/kfifo.c
@@ -115,7 +115,7 @@ mr_uint32_t mr_kfifo_pop(mr_kfifo_t *kfifo, void *data) {
 mr_uint32_t mr_kfifo_in(mr_kfifo_t *kfifo, const void *buf, mr_uint32_t num) {
     mr_uint32_t avail, num2, in, size, n;
 
-    /* Limit length */
+    /* Limit number */
     avail = mr_kfifo_avail(kfifo);
     if (num > avail) {
         num = avail;
@@ -142,10 +142,31 @@ mr_uint32_t mr_kfifo_in(mr_kfifo_t *kfifo, const void *buf, mr_uint32_t num) {
     return num2;
 }
 
+mr_uint32_t mr_kfifo_in_overwrite(mr_kfifo_t *kfifo, const void *buf,
+                                  mr_uint32_t num) {
+    mr_uint32_t capacity, avail;
+
+    /* Limit number */
+    capacity = kfifo->mask + 1;
+    if (num > capacity) {
+        buf = ((mr_uint8_t *)buf) + ((num - capacity) * kfifo->elem_size);
+        num = capacity;
+    }
+
+    /* Limit size */
+    avail = mr_kfifo_avail(kfifo);
+    if (num > avail) {
+        mr_kfifo_skip(kfifo, num - avail);
+    }
+
+    /* Push buffer */
+    return mr_kfifo_in(kfifo, buf, num);
+}
+
 mr_uint32_t mr_kfifo_peek(mr_kfifo_t *kfifo, void *buf, mr_uint32_t num) {
     mr_uint32_t avail, num2, out, size, n;
 
-    /* Limit size */
+    /* Limit number */
     avail = mr_kfifo_len(kfifo);
     if (num > avail) {
         num = avail;
@@ -164,7 +185,7 @@ mr_uint32_t mr_kfifo_peek(mr_kfifo_t *kfifo, void *buf, mr_uint32_t num) {
         num *= kfifo->elem_size;
     }
 
-    /* Pop buffer */
+    /* Peek buffer */
     n = MR_MIN(num, size - out);
     mr_memcpy(buf, (mr_uint8_t *)kfifo->buf + out, n);
     mr_memcpy((mr_uint8_t *)buf + n, kfifo->buf, num - n);