simplify shit

include/utils.h

@@ -29,11 +29,9 @@ char *pretty_num(double num, char *buf, size_t bufsz);
 
 char *pretty_bytes(uint64_t bytes, int8_t start_suffix, char *buf, size_t bufsz);
 
-bool file_exists(const char *path);
-
 int get_hwmon_dir(char *path, size_t bufsz);
 
-size_t read_file(const char *path, char *buffer, size_t n);
+size_t read_file(const char *dir, const char *file, char *buffer, size_t n);
 
 void fast_read_num_u64(const char *dir, const char *file, char *buf, uint64_t *result, uint32_t divider);
 

src/utils.c

@@ -10,13 +10,6 @@
 #include "log.h"
 #include "utils.h"
 
-#define MKPATH(path, dir, file)               \
-	do {                                  \
-		char *nt = stpcpy(path, dir); \
-		*nt++ = '/';                  \
-		stpcpy(nt, file);             \
-	} while (0)
-
 inline void timespec_add_ms(struct timespec *ts, const uint16_t ms) {
 	ts->tv_nsec += ms * 1000000L;
 	if (ts->tv_nsec >= 1000000000L) {
@@ -50,10 +43,6 @@ inline char *pretty_bytes(const uint64_t bytes, int8_t start_suffix, char *buf,
 	return buf;
 }
 
-inline bool file_exists(const char *path) {
-	return access(path, F_OK) == 0;
-}
-
 /* path has to have at least 8 free chars at the end for glob */
 int get_hwmon_dir(char *path, const size_t bufsz) {
 	glob_t g;
@@ -67,51 +56,49 @@ int get_hwmon_dir(char *path, const size_t bufsz) {
 	return -1;
 }
 
+
+/* instead of building the path here we could build it once in *_detect funcs for each sensor, but thats a lot of paths damn
+ * actual slowdown is in the syscalls anyway, open(), read(), close () */
+
 /* read n bytes from path into buffer */
-inline size_t read_file(const char *path, char *buffer, const size_t n) {
+inline size_t read_file(const char *dir, const char *file, char *buffer, const size_t n) {
+	char path[192];		      // bug alert
+	char *nt = stpcpy(path, dir); // nt is a pointer to the null terminator of the copied string
+	stpcpy(nt, file);	      // write at the null terminator address, aka append to the end
 	const int fd = open(path, O_RDONLY | O_CLOEXEC);
 	if (fd < 0) {
-		applog(LOG_ERR, "Error reading %s", path);
+		if (buffer != NULL)
+			applog(LOG_ERR, "Error reading %s", path);
 		return 0;
 	}
 	const ssize_t len = read(fd, buffer, n);
-	if (len >= 0)
+	if (len >= 0 && buffer)
 		buffer[len] = '\0';
 	close(fd);
 	return len;
 }
 
 inline void fast_read_num_u64(const char *dir, const char *file, char *buf, uint64_t *result, const uint32_t divider) {
-	char path[256];
-	MKPATH(path, dir, file);
-	read_file(path, buf, 32);
+	read_file(dir, file, buf, 32);
 	*result = strtoull(buf, NULL, 10) / divider;
 }
 
 inline void fast_read_num_u16(const char *dir, const char *file, char *buf, uint16_t *result, const uint32_t divider) {
-	char path[256];
-	MKPATH(path, dir, file);
-	read_file(path, buf, 32);
+	read_file(dir, file, buf, 32);
 	*result = strtol(buf, NULL, 10) / divider;
 }
 
 inline void fast_read_num_u8(const char *dir, const char *file, char *buf, uint8_t *result, const uint32_t divider) {
-	char path[256];
-	MKPATH(path, dir, file);
-	read_file(path, buf, 32);
+	read_file(dir, file, buf, 32);
 	*result = strtol(buf, NULL, 10) / divider;
 }
 
 inline void fast_read_num_i16(const char *dir, const char *file, char *buf, int16_t *result, const uint32_t divider) {
-	char path[256];
-	MKPATH(path, dir, file);
-	read_file(path, buf, 32);
-	*result = strtol(buf, NULL, 10) / divider;
+	read_file(dir, file, buf, 32);
+	*result = (int16_t)(strtol(buf, NULL, 10) / divider);
 }
 
 inline void fast_read_num_f(const char *dir, const char *file, char *buf, float *result, const uint32_t divider) {
-	char path[256];
-	MKPATH(path, dir, file);
-	read_file(path, buf, 32);
+	read_file(dir, file, buf, 32);
 	*result = (float)strtoull(buf, NULL, 10) / (float)divider;
 }