Utils review - numerical read functions

All numerical read functions decomposed
into two phases - "read" phase and "convert" phase.
The "read" phase is same for all types, the only
difference is the type specific conversion function.

Change-Id: I6358d593e3804c2a00a0252f0c3bd0e18c67b9b9
Signed-off-by: Viorel Suman <viorel.suman@intel.com>

diff --git a/utils.c b/utils.c
index 7016cda..6ee1f47 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -76,72 +76,90 @@ int sysfs_write(const char path[PATH_MAX], const void *buf, const int buf_len)
 }
 
 
-int sysfs_write_int(const char path[PATH_MAX], int value)
+static void str2int(const char* buf, void *v)
 {
-       int ret;
-       int fd;
-       int len;
-       char buf[20];
+       *(int*)v = atoi(buf);
+}
 
-       len = sprintf(buf, "%d", value);
 
-       if (!path[0] || len <= 0) {
-               ALOGE("Unexpected condition in sysfs_write_int\n");
-               return -1;
-       }
+static void str2float(const char* buf, void *v)
+{
+       *(float*)v = strtof(buf, NULL);
+}
 
-       fd = open(path, O_WRONLY);
 
-       if (fd == -1) {
-               ALOGV("Cannot open %s (%s)\n", path, strerror(errno));
-               return -1;
-       }
+static void str2uint64(const char* buf, void *v)
+{
+       *(uint64_t*)v = atoll(buf);
+}
 
-       ret = write(fd, buf, len);
 
-       if (ret != len) {
-               ALOGW("Cannot write %s (%d bytes) to %s (%s)\n", buf, len, path,
+int sysfs_read_num(const char path[PATH_MAX], void *v,
+               void (*str2num)(const char* buf, void *v))
+{
+       char buf[20];
+       int len = sysfs_read_str(path, buf, sizeof(buf));
+
+       if (len <= 0) {
+               ALOGW("Cannot read number from %s (%s)\n", path,
                      strerror(errno));
+               return -1;
        }
 
-       close(fd);
-
-       return ret;
+       str2num(buf, v);
+       return 0;
 }
 
 
 int sysfs_read_int(const char path[PATH_MAX], int *value)
 {
+       return sysfs_read_num(path, value, str2int);
+}
+
+
+int sysfs_read_float(const char path[PATH_MAX], float *value)
+{
+       return sysfs_read_num(path, value, str2float);
+}
+
+
+int sysfs_read_uint64(const char path[PATH_MAX], uint64_t *value)
+{
+       return sysfs_read_num(path, value, str2uint64);
+}
+
+
+int sysfs_write_int(const char path[PATH_MAX], int value)
+{
+       int ret;
        int fd;
        int len;
-       char buf[20] = {0};
+       char buf[20];
+
+       len = sprintf(buf, "%d", value);
 
-       if (!path[0] || !value) {
+       if (!path[0] || len <= 0) {
+               ALOGE("Unexpected condition in sysfs_write_int\n");
                return -1;
        }
 
-       fd = open(path, O_RDONLY);
+       fd = open(path, O_WRONLY);
 
        if (fd == -1) {
                ALOGV("Cannot open %s (%s)\n", path, strerror(errno));
                return -1;
        }
 
-       len = read(fd, buf, sizeof(buf));
-
-       close(fd);
+       ret = write(fd, buf, len);
 
-       if (len <= 0) {
-               ALOGW("Cannot read integer from %s (%s)\n", path,
+       if (ret != len) {
+               ALOGW("Cannot write %s (%d bytes) to %s (%s)\n", buf, len, path,
                      strerror(errno));
-               return -1;
        }
 
-       *value = atoi(buf);
-
-       ALOGV("Read %d from %s\n", *value, path);
+       close(fd);
 
-       return 0;
+       return ret;
 }
 
 
@@ -211,76 +229,6 @@ int sysfs_write_float(const char path[PATH_MAX], float value)
 }
 
 
-int sysfs_read_float(const char path[PATH_MAX], float *value)
-{
-       int fd;
-       int len;
-       char buf[20] = {0};
-
-       if (!path[0] || !value) {
-               return -1;
-       }
-
-       fd = open(path, O_RDONLY);
-
-       if (fd == -1) {
-               ALOGV("Cannot open %s (%s)\n", path, strerror(errno));
-               return -1;
-       }
-
-       len = read(fd, buf, sizeof(buf));
-
-       close(fd);
-
-       if (len <= 0) {
-               ALOGW("Cannot read float from %s (%s)\n", path,
-                     strerror(errno));
-               return -1;
-       }
-
-       *value = (float) strtod(buf, NULL);
-
-       ALOGV("Read %g from %s\n", *value, path);
-
-       return 0;
-}
-
-int sysfs_read_uint64(const char path[PATH_MAX], uint64_t *value)
-{
-       int fd;
-       int len;
-       char buf[20] = {0};
-
-       if (!path[0] || !value) {
-               return -1;
-       }
-
-       fd = open(path, O_RDONLY);
-
-       if (fd == -1) {
-               ALOGV("Cannot open %s (%s)\n", path, strerror(errno));
-               return -1;
-       }
-
-       len = read(fd, buf, sizeof(buf));
-
-       close(fd);
-
-       if (len <= 0) {
-               ALOGW("Cannot read uint64 from %s (%s)\n", path,
-                     strerror(errno));
-               return -1;
-       }
-
-       *value =  atoll(buf);
-
-       ALOGV("Read %llu from %s\n", *value, path);
-
-       return 0;
-}
-
-
-
 int64_t get_timestamp_realtime (void)
 {
        struct timespec ts = {0};