From c5bba84940399899a402c04acc479424aa2f1740 Mon Sep 17 00:00:00 2001
From: icex2 <djh.icex2@gmail.com>
Date: Sun, 11 Jun 2023 17:03:34 +0200
Subject: [PATCH] refactor(p3io/cmd): Add and improve p3io command helper
 functions

With the overhaul of commands, some helpers needed tweaks while
new ones were added to abstract p3io command details with a
common interface, e.g. dealing with the command length field.
---
 src/main/p3io/cmd.c | 48 +++++++++++++++++++++++++++++++++------------
 src/main/p3io/cmd.h | 11 ++++++++---
 2 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/src/main/p3io/cmd.c b/src/main/p3io/cmd.c
index 6a0a7ff..bfb4e82 100644
--- a/src/main/p3io/cmd.c
+++ b/src/main/p3io/cmd.c
@@ -4,25 +4,49 @@
 
 #include "util/log.h"
 
-uint8_t p3io_req_cmd(const union p3io_req_any *src)
+uint8_t p3io_get_full_req_size(const union p3io_req_any *req)
 {
-    log_assert(src != NULL);
+    /* Length byte in this packet format counts everything from the length
+       byte onwards. The length byte itself occurs at the start of the frame. */
 
-    /* In requests, the command byte is the first byte after the header. */
-
-    return src->raw[sizeof(struct p3io_hdr)];
+    return req->hdr.nbytes + 1;
 }
 
-void p3io_resp_init(
-    struct p3io_hdr *dest, size_t nbytes, const struct p3io_hdr *req)
+uint8_t p3io_get_full_resp_size(const union p3io_resp_any *resp)
 {
-    log_assert(dest != NULL);
-    log_assert(req != NULL);
-    log_assert(nbytes < 0x100);
+    /* Length byte in this packet format counts everything from the length
+       byte onwards. The length byte itself occurs at the start of the frame. */
+
+    return resp->hdr.nbytes + 1;
+}
+
+void p3io_req_hdr_init(
+    struct p3io_hdr *req_hdr, uint8_t seq_no, uint8_t cmd, size_t size)
+{
+    log_assert(req_hdr != NULL);
+    log_assert(size < P3IO_MAX_MESSAGE_SIZE);
+
+    memset(req_hdr, 0, sizeof(struct p3io_hdr));
 
     /* Length byte in this packet format counts everything from the length
        byte onwards. The length byte itself occurs at the start of the frame. */
 
-    dest->nbytes = nbytes - 1;
-    dest->seq_no = req->seq_no;
+    req_hdr->nbytes = size - 1;
+    req_hdr->seq_no = seq_no;
+    req_hdr->cmd = cmd;
+}
+
+void p3io_resp_hdr_init(
+    struct p3io_hdr *resp_hdr, size_t nbytes, const struct p3io_hdr *req_hdr)
+{
+    log_assert(resp_hdr != NULL);
+    log_assert(req_hdr != NULL);
+    log_assert(nbytes < P3IO_MAX_MESSAGE_SIZE);
+
+    /* Length byte in this packet format counts everything from the length
+       byte onwards. The length byte itself occurs at the start of the frame. */
+
+    resp_hdr->nbytes = nbytes - 1;
+    resp_hdr->seq_no = req_hdr->seq_no;
+    resp_hdr->cmd = req_hdr->cmd;
 }
diff --git a/src/main/p3io/cmd.h b/src/main/p3io/cmd.h
index d70b192..5359ec4 100644
--- a/src/main/p3io/cmd.h
+++ b/src/main/p3io/cmd.h
@@ -293,9 +293,14 @@ union p3io_resp_any {
 
 #pragma pack(pop)
 
-uint8_t p3io_req_cmd(const union p3io_req_any *src);
+uint8_t p3io_get_full_req_size(const union p3io_req_any *req);
 
-void p3io_resp_init(
-    struct p3io_hdr *dest, size_t nbytes, const struct p3io_hdr *req);
+uint8_t p3io_get_full_resp_size(const union p3io_resp_any *resp);
+
+void p3io_req_hdr_init(
+    struct p3io_hdr *hdr, uint8_t seq_no, uint8_t cmd, size_t size);
+
+void p3io_resp_hdr_init(
+    struct p3io_hdr *resp_hdr, size_t nbytes, const struct p3io_hdr *req_hdr);
 
 #endif