1 files changed, 106 insertions, 0 deletions
diff --git a/src/uri_utils.h b/src/uri_utils.h
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--- /dev/null
+++ b/src/uri_utils.h
@@ -0,0 +1,106 @@
+/*
+  Copyright 2011-2020 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef SERD_URI_UTILS_H
+#define SERD_URI_UTILS_H
+
+#include "string_utils.h"
+
+#include <string.h>
+
+static inline bool
+chunk_equals(const SerdChunk* a, const SerdChunk* b)
+{
+	return a->len == b->len
+		&& !strncmp((const char*)a->buf, (const char*)b->buf, a->len);
+}
+
+static inline size_t
+uri_path_len(const SerdURI* uri)
+{
+	return uri->path_base.len + uri->path.len;
+}
+
+static inline uint8_t
+uri_path_at(const SerdURI* uri, size_t i)
+{
+	if (i < uri->path_base.len) {
+		return uri->path_base.buf[i];
+	} else {
+		return uri->path.buf[i - uri->path_base.len];
+	}
+}
+
+/**
+   Return the index of the first differing character after the last root slash,
+   or zero if `uri` is not under `root`.
+*/
+static inline size_t
+uri_rooted_index(const SerdURI* uri, const SerdURI* root)
+{
+	if (!root || !root->scheme.len ||
+	    !chunk_equals(&root->scheme, &uri->scheme) ||
+	    !chunk_equals(&root->authority, &uri->authority)) {
+		return 0;
+	}
+
+	bool         differ          = false;
+	const size_t path_len        = uri_path_len(uri);
+	const size_t root_len        = uri_path_len(root);
+	size_t       last_root_slash = 0;
+	for (size_t i = 0; i < path_len && i < root_len; ++i) {
+		const uint8_t u = uri_path_at(uri, i);
+		const uint8_t r = uri_path_at(root, i);
+
+		differ = differ || u != r;
+		if (r == '/') {
+			last_root_slash = i;
+			if (differ) {
+				return 0;
+			}
+		}
+	}
+
+	return last_root_slash + 1;
+}
+
+/** Return true iff `uri` shares path components with `root` */
+static inline bool
+uri_is_related(const SerdURI* uri, const SerdURI* root)
+{
+	return uri_rooted_index(uri, root) > 0;
+}
+
+/** Return true iff `uri` is within the base of `root` */
+static inline bool
+uri_is_under(const SerdURI* uri, const SerdURI* root)
+{
+	const size_t index = uri_rooted_index(uri, root);
+	return index > 0 && uri->path.len > index;
+}
+
+static inline bool
+is_uri_scheme_char(const int c)
+{
+	switch (c) {
+	case ':': case '+': case '-': case '.':
+		return true;
+	default:
+		return is_alpha(c) || is_digit(c);
+	}
+}
+
+#endif  // SERD_URI_UTILS_H