add a blobmsg-to-json function

diff --git a/blobmsg.c b/blobmsg.c
index bddf2c8..b16510b 100644 (file)
--- a/blobmsg.c
+++ b/blobmsg.c
@@ -15,6 +15,161 @@
 
 #include "blobmsg.h"
 
+struct strbuf {
+       int len;
+       int pos;
+       char *buf;
+};
+
+static bool blobmsg_puts(struct strbuf *s, char *c, int len)
+{
+       if (len <= 0)
+               return true;
+
+       if (s->pos + len >= s->len) {
+               s->len += 16;
+               s->buf = realloc(s->buf, s->len);
+               if (!s->buf)
+                       return false;
+       }
+       memcpy(s->buf + s->pos, c, len);
+       s->pos += len;
+       return true;
+}
+
+static void blobmsg_format_string(struct strbuf *s, char *str)
+{
+       char *p, *last = str, *end = str + strlen(str);
+       char buf[8] = "\\u00";
+
+       blobmsg_puts(s, "\"", 1);
+       for (p = str; *p; p++) {
+               char escape = '\0';
+               int len;
+
+               switch(*p) {
+               case '\b':
+                       escape = 'b';
+                       break;
+               case '\n':
+                       escape = 'n';
+                       break;
+               case '\t':
+                       escape = 't';
+                       break;
+               case '\r':
+                       escape = 'r';
+                       break;
+               case '"':
+               case '\\':
+               case '/':
+                       escape = *p;
+                       break;
+               default:
+                       if (*p < ' ')
+                               escape = 'u';
+                       break;
+               }
+
+               if (!escape)
+                       continue;
+
+               if (p > last)
+                       blobmsg_puts(s, last, p - last);
+               last = p + 1;
+               buf[1] = escape;
+
+               if (escape == 'u') {
+                       sprintf(buf + 4, "%02x", (unsigned char) *p);
+                       len = 4;
+               } else {
+                       len = 2;
+               }
+               blobmsg_puts(s, buf, len);
+       }
+
+       blobmsg_puts(s, last, end - last);
+       blobmsg_puts(s, "\"", 1);
+}
+
+static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array);
+
+static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, bool array)
+{
+       char buf[32];
+       void *data;
+       int len;
+
+       if (array) {
+               data = blob_data(attr);
+               len  = blob_len(attr);
+       } else {
+               blobmsg_format_string(s, blobmsg_name(attr));
+               blobmsg_puts(s, ":", 1);
+               data = blobmsg_data(attr);
+               len = blobmsg_data_len(attr);
+       }
+
+       switch(blob_id(attr)) {
+       case BLOBMSG_TYPE_INT8:
+               sprintf(buf, "%d", *(uint8_t *)data);
+               break;
+       case BLOBMSG_TYPE_INT16:
+               sprintf(buf, "%d", *(uint16_t *)data);
+               break;
+       case BLOBMSG_TYPE_INT32:
+               sprintf(buf, "%d", *(uint32_t *)data);
+               break;
+       case BLOBMSG_TYPE_INT64:
+               sprintf(buf, "%lld", *(uint64_t *)data);
+               break;
+       case BLOBMSG_TYPE_STRING:
+               blobmsg_puts(s, data, strlen(data));
+               return;
+       case BLOBMSG_TYPE_ARRAY:
+               blobmsg_format_json_list(s, data, len, true);
+               return;
+       case BLOBMSG_TYPE_TABLE:
+               blobmsg_format_json_list(s, data, len, false);
+               return;
+       }
+       blobmsg_puts(s, buf, strlen(buf));
+}
+
+static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array)
+{
+       struct blob_attr *pos;
+       bool first = true;
+       int rem = len;
+
+       blobmsg_puts(s, (array ? "[ " : "{ "), 2);
+       __blob_for_each_attr(pos, attr, rem) {
+               if (!first)
+                       blobmsg_puts(s, ", ", 2);
+
+               blobmsg_format_element(s, pos, array);
+               first = false;
+       }
+       blobmsg_puts(s, (array ? " ]" : " }"), 2);
+}
+
+char *blobmsg_format_json(struct blob_attr *attr)
+{
+       struct strbuf s;
+
+       s.len = blob_len(attr);
+       s.buf = malloc(s.len);
+       s.pos = 0;
+
+       blobmsg_format_element(&s, attr, false);
+
+       if (!s.len)
+               return NULL;
+
+       s.buf = realloc(s.buf, s.pos + 1);
+       return s.buf;
+}
+
 bool blobmsg_check_attr(const struct blob_attr *attr, bool name)
 {
        const struct blobmsg_hdr *hdr;

diff --git a/blobmsg.h b/blobmsg.h
index 8594add..c64cedb 100644 (file)
--- a/blobmsg.h
+++ b/blobmsg.h
@@ -139,4 +139,6 @@ static inline int blobmsg_buf_init(struct blob_buf *buf)
        return blob_buf_init(buf, BLOBMSG_TYPE_TABLE);
 }
 
+char *blobmsg_format_json(struct blob_attr *attr);
+
 #endif