Adds handling of JSON pointers (RFC 6901)

Change-Id: Ib2e1c75f81c32d0b6bc50af2ba48bb95a413842a
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

diff --git a/src/wgtpkg-mustach.c b/src/wgtpkg-mustach.c
index 4b05bc2..6c3311d 100644 (file)
--- a/src/wgtpkg-mustach.c
+++ b/src/wgtpkg-mustach.c
@@ -45,47 +45,67 @@ struct expl {
  * If the sign = is not here, returns NULL.
  * Replace any \= of the key by its unescaped version =.
  */
-static char *keyval(char *head)
+static char *keyval(char *read, int isptr)
 {
-       char *w, c;
+       char *write, c;
 
-       c = *(w = head);
+       c = *(write = read);
        while (c && c != '=') {
-               if (c == '\\') {
-                       switch (head[1]) {
-                       case '\\': *w++ = c;
-                       case '=': c = *++head;
-                       default: break;
+               if (isptr) {
+                       if (c == '~' && read[1] == '=') {
+                               c = *++read;
+                       }
+               } else {
+                       if (c == '\\') {
+                               switch (read[1]) {
+                               case '\\': *write++ = c;
+                               case '=': c = *++read;
+                               default: break;
+                               }
                        }
                }
-               *w++ = c;
-               c = *++head;
+               *write++ = c;
+               c = *++read;
        }
-       *w = 0;
-       return c == '=' ? ++head : NULL;
+       *write = 0;
+       return c == '=' ? ++read : NULL;
 }
 
 /*
  * Returns the unescaped version of the first component
  * and update 'name' to point the next components if any.
  */
-static char *first(char **name)
+static char *first(char **name, int isptr)
 {
-       char *r, *i, *w, c;
+       char *r, *read, *write, c;
 
-       c = *(i = *name);
+       c = *(read = *name);
        if (!c)
                r = NULL;
        else {
-               r = w = i;
-               while (c && c != '.') {
-                       if (c == '\\' && (i[1] == '.' || i[1] == '\\'))
-                               c = *++i;
-                       *w++ = c;
-                       c = *++i;
+               r = write = read;
+               if (isptr) {
+                       while (c && c != '/') {
+                               if (c == '~') {
+                                       switch(read[1]) {
+                                       case '1': c = '/';
+                                       case '0': read++;
+                                       default: break;
+                                       }
+                               }
+                               *write++ = c;
+                               c = *++read;
+                       }
+               } else {
+                       while (c && c != '.') {
+                               if (c == '\\' && (read[1] == '.' || read[1] == '\\'))
+                                       c = *++read;
+                               *write++ = c;
+                               c = *++read;
+                       }
                }
-               *w = 0;
-               *name = i + !!c;
+               *write = 0;
+               *name = read + !!c;
        }
        return r;
 }
@@ -119,19 +139,23 @@ static char *globalize(char *key)
  */
 static struct json_object *find(struct expl *e, const char *name)
 {
-       int i;
+       int i, isptr;
        struct json_object *o, *r;
        char *n, *c, *v;
 
        /* get a local key */
        n = strdupa(name);
 
+       /* is it a JSON pointer? */
+       isptr = n[0] == '/';
+       n += isptr;
+
        /* extract its value */
-       v = keyval(n);
+       v = keyval(n, isptr);
 
        /* search the first component for each valid globalisation */
        i = e->depth;
-       c = first(&n);
+       c = first(&n, isptr);
        while (c) {
                if (i < 0) {
                        /* next globalisation */
@@ -141,7 +165,7 @@ static struct json_object *find(struct expl *e, const char *name)
                else if (json_object_object_get_ex(e->stack[i].obj, c, &o)) {
 
                        /* found the root, search the subcomponents */
-                       c = first(&n);
+                       c = first(&n, isptr);
                        while(c) {
                                while (!json_object_object_get_ex(o, c, &r)) {
                                        c = globalize(c);
@@ -149,7 +173,7 @@ static struct json_object *find(struct expl *e, const char *name)
                                                return NULL;
                                }
                                o = r;
-                               c = first(&n);
+                               c = first(&n, isptr);
                        }
 
                        /* check the value if requested */