Started rewriting logging

src/kernel/logging/klog.c

@@ -1,41 +1,123 @@
 #include "klog.h"
 
+#include <stdbool.h>
+#include <stdio.h>
 #include <stdarg.h>
 #include <stdbigos/types.h>
 
 // NOTE: In the future this lib should manage logging (formating and outputing to the screen or uart) on its own.
 //  Right now I will leave it as is, will change once the basic kernel at least runs.
 #include "debug/debug_stdio.h"
 
-static u32 g_indent_level = 0;
+// static u32 g_indent_level = 0;
 static const char* g_prefixes[] = {"[ERROR]", "[WARNING]", "[ ]", "[~]"};
+static const char* overwrite_warning = "[WARNING]Some of the logs were lost due to too small size of buffer";
 
-void klog_indent_increase() {
-	++g_indent_level;
+#ifdef __DEBUG__
+#define RING_BUF_SIZE 1<<20
+#else
+#define RING_BUF_SIZE 1<<16
+#endif // !__DEBUG__
+
+#define TEMP_BUF_SIZE 1<<12
+
+typedef struct {
+	char ring[RING_BUF_SIZE];
+	i32 read;
+	i32 write;
+	bool full;
+} ring_buffer;
+
+static ring_buffer buffer;
+
+size_t available_space(const ring_buffer* buf) {
+    if (buf->full) return 0;
+    if (buf->write >= buf->read)
+        return RING_BUF_SIZE - (buf->write - buf->read);
+    else
+        return buf->read - buf->write;
+}
+
+void put_char(ring_buffer* buf, char c){
+	buf->ring[buf->write++] = c;
+	buf->write %= RING_BUF_SIZE;
+	if(buf->full){
+		buf->read = (buf->read + 1) % RING_BUF_SIZE;
+	}
+	buf->full = buf->read == buf->write;
+}
+
+void put_string(ring_buffer* buf, const char* str){
+	size_t it = 0;
+	while(str[it]){
+		put_char(buf, str[it++]);
+	}
 }
 
-void klog_indent_decrease() {
-	if (g_indent_level != 0)
-		--g_indent_level;
+void put_msg(ring_buffer* buf, const char* msg, int msg_len){
+	if ((size_t)msg_len > available_space(buf))
+        put_string(buf, overwrite_warning);
+    put_string(buf, msg);
 }
 
+char get_char(ring_buffer* buf){
+	if(buf->read == buf->write && !buf->full)
+		return 0;
+	char ret = buf->ring[buf->read++];
+	buf->read %= RING_BUF_SIZE;
+	buf->full = false;
+	return ret;
+}
+
+// void klog_indent_increase() {
+// 	++g_indent_level;
+// }
+
+// void klog_indent_decrease() {
+// 	if (g_indent_level != 0)
+// 		--g_indent_level;
+// }
+
 static void klogv(klog_severity_level_t loglvl, const char* fmt, va_list va) {
-	(void)fmt;
-	(void)va;
+	static char temp_buffer[TEMP_BUF_SIZE];
 
 	if (loglvl > KLSL_TRACE) {
 		KLOGLN_ERROR("Invalid loglvl passed to klog");
 		loglvl = KLSL_ERROR;
 	}
 
-	DEBUG_PUTGAP(g_indent_level);
-	DEBUG_PRINTF("%s ", g_prefixes[loglvl]);
-	DEBUG_VPRINTF(fmt, va);
+	const char* prefix = g_prefixes[loglvl];
+    size_t prefix_len = 0;
+    while (prefix[prefix_len]) ++prefix_len;
+
+	for (size_t i=0;i<prefix_len;i++)
+        temp_buffer[i] = prefix[i];
+
+	va_list copy;
+	va_copy(copy, va);
+	int written = vsnprintf(temp_buffer + prefix_len, sizeof(temp_buffer) - prefix_len, fmt, copy);
+	va_end(copy);
+
+	// TODO: proper error handling
+	if (written < 0) {
+		// Format error
+		written = 0;
+	} else if ((size_t)written >= sizeof(temp_buffer)) {
+		// Truncated
+		written = sizeof(temp_buffer) - 1;
+	}
+
+	put_msg(&buffer, &temp_buffer, written);
+
+	// DEBUG_PUTGAP(g_indent_level);
+	// DEBUG_PRINTF("%s ", g_prefixes[loglvl]);
+	// DEBUG_VPRINTF(fmt, va);
 }
 
 static void kloglnv(klog_severity_level_t loglvl, const char* fmt, va_list va) {
 	klogv(loglvl, fmt, va);
-	DEBUG_PUTC('\n');
+	put_msg(&buffer, "\n", 1);
+	// DEBUG_PUTC('\n');
 }
 
 void klog(klog_severity_level_t loglvl, const char* fmt, ...) {

src/kernel/logging/klog.h

@@ -10,8 +10,8 @@ typedef enum {
 	KLSL_TRACE = 3,
 } klog_severity_level_t;
 
-void klog_indent_increase();
-void klog_indent_decrease();
+// void klog_indent_increase();
+// void klog_indent_decrease();
 
 [[gnu::format(printf, 2, 3)]]
 void klog(klog_severity_level_t loglvl, const char* fmt, ...);