hex/json: use util_json

Factorize the code to util_json.c

Author: vjardin

src/TODO

@@ -1,5 +1,4 @@
 * use getopt_long() for each subcommand
-* move hex/sprintf to util json
 * add a usage_long() for some complex commands
 * improve main() using a table of token -> function
 * factorize the ldexp() from double to uint16_t, XXX libm is not needed when:

src/mfr_fwdata.c

@@ -18,13 +18,7 @@ cmd_fwdata(int fd, int pretty) {
 
   json_t *o = json_object();
   json_object_set_new(o, "len", json_integer(n));
-
-  char *hex = malloc(n * 2 + 1);
-  for (int i = 0; i < n; i++)
-    sprintf(hex + 2 * i, "%02X", b[i]);
-  hex[n * 2] = '\0';
-  json_object_set_new(o, "hex", json_string(hex));
-  free(hex);
+  json_add_hex_ascii(o, "hex", b, (size_t)n);
 
   /* Extract printable runs >= 3 */
   json_t *runs = json_array();

src/mfr_ramp_data.c

@@ -30,15 +30,8 @@ cmd_ramp_data(int fd, int argc, char *const *argv, int pretty) {
     return 1;
   }
 
-  char *hex = (char *) malloc((size_t) n * 2 + 1);
-  for (int i = 0; i < n; i++)
-    sprintf(hex + 2 * i, "%02X", buf[i]);
-  hex[n * 2] = '\0';
-
   json_t *o = json_object();
-  json_object_set_new(o, "len", json_integer(n));
-  json_object_set_new(o, "hex", json_string(hex));
-  free(hex);
+  json_add_len_and_hex(o, "hex", buf, (size_t)n);
 
   json_print_or_pretty(o, pretty);
 

src/mfr_snapshot.c

@@ -78,14 +78,7 @@ cmd_snapshot(int fd, int argc, char * const *argv, int pretty) {
 
   json_t *o = json_object();
   json_object_set_new(o, "len", json_integer(n));
-
-  char *hex = malloc(n * 2 + 1);
-  for (int i = 0; i < n; i++)
-    sprintf(hex + 2 * i, "%02X", blk[i]);
-  hex[n * 2] = '\0';
-
-  json_object_set_new(o, "hex", json_string(hex));
-  free(hex);
+  json_add_hex_ascii(o, "hex", blk, (size_t)n);
 
   if (decode && n >= 32) {
     json_object_set_new(o, "decoded", decode_snapshot_block(fd, blk, n));

src/mfr_status_data.c

@@ -30,15 +30,8 @@ cmd_status_data(int fd, int argc, char *const *argv, int pretty) {
     return 1;
   }
 
-  char *hex = (char *) malloc((size_t) n * 2 + 1);
-  for (int i = 0; i < n; i++)
-    sprintf(hex + 2 * i, "%02X", buf[i]);
-  hex[n * 2] = '\0';
-
   json_t *o = json_object();
-  json_object_set_new(o, "len", json_integer(n));
-  json_object_set_new(o, "hex", json_string(hex));
-  free(hex);
+  json_add_len_and_hex(o, "hex", buf, (size_t)n);
 
   json_print_or_pretty(o, pretty);
 

src/mfr_user_data.c

@@ -27,13 +27,7 @@ cmd_user_data(int fd, int argc, char *const *argv, int pretty) {
     json_t *o = json_object();
     json_object_set_new(o, "len", json_integer(n));
     json_object_set_new(o, "ascii", json_stringn((char *) buf, n));
-
-    char *hex = malloc(n * 2 + 1);
-    for (int i = 0; i < n; i++)
-      sprintf(hex + 2 * i, "%02X", buf[i]);
-    hex[n * 2] = '\0';
-    json_object_set_new(o, "hex", json_string(hex));
-    free(hex);
+    json_add_hex_ascii(o, "hex", buf, (size_t)n);
 
     json_print_or_pretty(o, pretty);
 

src/util_json.c

@@ -5,6 +5,7 @@
 
 #include <jansson.h>
 
+/* TODO: replace with json_add_len_and_hex() */
 static void
 add_hex_ascii(json_t *dst, const uint8_t *buf, int n) {
   json_object_set_new(dst, "len", json_integer(n));
@@ -45,3 +46,45 @@ json_print_or_pretty(json_t *o, int pretty) {
 
   json_decref(o);
 }
+
+int
+json_add_hex_ascii(json_t *dst, const char *key, const void *bufv, size_t n) {
+  if (!dst || !key || (!bufv && n))
+    return -1;
+  if (n > (SIZE_MAX / 2))
+    return -1;
+
+  const uint8_t *buf = (const uint8_t *) bufv;
+  size_t outlen = n * 2;
+
+  char *hex = (char *) malloc(outlen + 1);
+  if (!hex)
+    return -1;
+
+  static const char *HD = "0123456789ABCDEF";
+  /* avoid using sprintf() */
+  for (size_t i = 0; i < n; ++i) {
+    hex[(i << 1)] = HD[(buf[i] >> 4) & 0xF];
+    hex[(i << 1) + 1] = HD[buf[i] & 0xF];
+  }
+  hex[outlen] = '\0';
+
+  json_t *s = json_stringn(hex, outlen);
+  free(hex);
+
+  if (!s)
+    return -1;
+
+  return json_object_set_new(dst, key, s);
+}
+
+int
+json_add_len_and_hex(json_t *dst, const char *key, const void *buf, size_t n) {
+  if (!dst)
+    return -1;
+
+  if (json_object_set_new(dst, "len", json_integer((json_int_t) n)) != 0)
+    return -1;
+
+  return json_add_hex_ascii(dst, key, buf, n);
+}

src/util_json.h

@@ -6,5 +6,7 @@
 #include <stdint.h>
 
 void json_print_or_pretty(json_t * o, int pretty);
+int json_add_hex_ascii(json_t *dst, const char *key, const void *buf, size_t n);
+int json_add_len_and_hex(json_t *dst, const char *key, const void *buf, size_t n);
 
 void rd_block_string(int fd, uint8_t cmd, const char *key, json_t *root);