[core] provide array_extract_element and use it

From: Stefan Bühler <stbuehler@web.de>

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@3102 152afb58-edef-0310-8abb-c4023f1b3aa9

NEWS

@@ -30,6 +30,7 @@ NEWS
   * [core] improve array API to prevent memory leaks
   * [core] refactor array search; raise array size limit to SSIZE_MAX
   * [core] fix memory leak in configparser_merge_data
+  * [core] provide array_extract_element and use it
 
 - 1.4.39 - 2016-01-02
   * [core] fix memset_s call (fixes #2698)

src/array.c

@@ -134,6 +134,45 @@ data_unset *array_get_element(array *a, const char *key) {
 	return NULL;
 }
 
+data_unset *array_extract_element(array *a, const char *key) {
+	size_t ndx, pos;
+	force_assert(NULL != key);
+
+	if (ARRAY_NOT_FOUND != (ndx = array_get_index(a, key, strlen(key), &pos))) {
+		/* found */
+		const size_t last_ndx = a->used - 1;
+		data_unset *entry = a->data[ndx];
+
+		/* now we need to swap it with the last element (if it isn't already the last element) */
+		if (ndx != last_ndx) {
+			/* to swap we also need to modify the index in a->sorted - find pos of last_elem there */
+			size_t last_elem_pos;
+			/* last element must be present at the expected position */
+			force_assert(last_ndx == array_get_index(a, CONST_BUF_LEN(a->data[last_ndx]->key), &last_elem_pos));
+
+			/* move entry from last_ndx to ndx */
+			a->data[ndx] = a->data[last_ndx];
+			a->data[last_ndx] = NULL;
+
+			/* fix index entry for moved entry */
+			a->sorted[last_elem_pos] = ndx;
+		} else {
+			a->data[ndx] = NULL;
+		}
+
+		/* remove entry in a->sorted: move everything after pos one step to the left */
+		if (pos != last_ndx) {
+			memmove(a->sorted + pos, a->sorted + pos + 1, (last_ndx - pos) * sizeof(*a->sorted));
+		}
+		a->sorted[last_ndx] = ARRAY_NOT_FOUND;
+		--a->used;
+
+		return entry;
+	}
+
+	return NULL;
+}
+
 data_unset *array_get_unused_element(array *a, data_type_t t) {
 	data_unset *ds = NULL;
 	unsigned int i;

src/array.h

@@ -166,6 +166,7 @@ data_unset *array_pop(array *a); /* only works on "simple" lists with autogenera
 int array_print(array *a, int depth);
 data_unset *array_get_unused_element(array *a, data_type_t t);
 data_unset *array_get_element(array *a, const char *key);
+data_unset *array_extract_element(array *a, const char *key); /* removes found entry from array */
 void array_set_key_value(array *hdrs, const char *key, size_t key_len, const char *value, size_t val_len);
 void array_replace(array *a, data_unset *entry);
 int array_strcasecmp(const char *a, size_t a_len, const char *b, size_t b_len);

src/configparser.y

@@ -177,27 +177,7 @@ varline ::= key(A) APPEND expression(B). {
           ctx->current->context_ndx,
           ctx->current->key->ptr, A->ptr);
       ctx->ok = 0;
-    } else if (NULL != (du = array_get_element(vars, A->ptr))) {
-      /* exists in current block */
-      if (du->type != B->type) {
-        /* might create new data when merging different types; need to replace old array entry */
-        /* also merging will kill the old data */
-        du = du->copy(du);
-        du = configparser_merge_data(du, B);
-        if (NULL != du) {
-          buffer_copy_buffer(du->key, A);
-          array_replace(vars, du);
-        }
-      } else {
-        data_unset *old_du = du;
-        du = configparser_merge_data(old_du, B);
-        force_assert((NULL == du) || (du == old_du)); /* must not create new data when types match */
-      }
-      if (NULL == du) {
-        ctx->ok = 0;
-      }
-      B->free(B);
-    } else if (NULL != (du = configparser_get_variable(ctx, A))) {
+    } else if (NULL != (du = array_extract_element(vars, A->ptr)) || NULL != (du = configparser_get_variable(ctx, A))) {
       du = configparser_merge_data(du, B);
       if (NULL == du) {
         ctx->ok = 0;