From 916aa42260290e9e864304bc7d9395b6aa693c27 Mon Sep 17 00:00:00 2001
From: Anton Kling <anton@kling.gg>
Date: Tue, 10 Dec 2024 12:24:07 +0100
Subject: kernel: Add string view and string builder
This makes write/read calls that use strings to communicate much
simpler and less error prone.
---
kernel/audio.c | 37 +++++++++++--------------------------
1 file changed, 11 insertions(+), 26 deletions(-)
(limited to 'kernel/audio.c')
diff --git a/kernel/audio.c b/kernel/audio.c
index d8fcd3c..fe78938 100644
--- a/kernel/audio.c
+++ b/kernel/audio.c
@@ -5,6 +5,7 @@
#include <drivers/ac97.h>
#include <errno.h>
#include <fs/devfs.h>
+#include <lib/sv.h>
#include <math.h>
int audio_write(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
@@ -25,24 +26,18 @@ int audio_can_write(vfs_inode_t *inode) {
int volume_write(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
(void)offset;
(void)fd;
- int volume = 0;
-
- size_t i = 0;
- for (; i < len; i++) {
- u8 c = buffer[i];
- if (!isdigit(c)) {
- break;
- }
- volume *= 10;
- volume += c - '0';
- if (volume > 100) {
- volume = 100;
- break;
- }
- }
+ struct sv string_view = sv_init(buffer, len);
+ struct sv rest;
+ u64 volume = sv_parse_unsigned_number(string_view, &rest);
+ int i = sv_length(string_view) - sv_length(rest);
if (0 == i) {
return 0;
}
+
+ if (volume > 100) {
+ volume = 0;
+ }
+
ac97_set_volume(volume);
return i;
}
@@ -52,18 +47,8 @@ int volume_read(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
return 0;
}
(void)fd;
- if (len < 3) {
- return 0;
- }
int volume = ac97_get_volume();
- assert(volume <= 100);
- if (volume == 100) {
- memcpy(buffer, "100", 3);
- return 3;
- }
- buffer[1] = (volume % 10) + '0';
- buffer[0] = ((volume - (volume % 10)) / 10) + '0';
- return 2;
+ return min(len, (u64)kbnprintf(buffer, len, "%d", volume));
}
static int add_files(void) {
--
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