aux/util: Add string hashset

src/xrt/auxiliary/CMakeLists.txt

@@ -18,6 +18,8 @@ set(SOURCE_FILES
 	util/u_device.c
 	util/u_device.h
 	util/u_documentation.h
+	util/u_hashset.cpp
+	util/u_hashset.h
 	util/u_time.cpp
 	util/u_time.h
 	)

src/xrt/auxiliary/util/u_hashset.cpp

+// Copyright 2019, Collabora, Ltd.
+// SPDX-License-Identifier: BSL-1.0
+/*!
+ * @file
+ * @brief  Hashset struct header.
+ * @author Jakob Bornecrantz <jakob@collabora.com>
+ * @ingroup aux_util
+ */
+
+#include "util/u_hashset.h"
+
+#include <cstring>
+#include <unordered_map>
+#include <vector>
+
+
+/*
+ *
+ * Private structs and defines.
+ *
+ */
+
+struct u_hashset
+{
+	std::unordered_map<std::string, struct u_hashset_item *> map = {};
+};
+
+
+/*
+ *
+ * "Exported" functions.
+ *
+ */
+
+extern "C" int
+u_hashset_create(struct u_hashset **out_hashset)
+{
+	auto hs = new u_hashset;
+	*out_hashset = hs;
+	return 0;
+}
+
+extern "C" int
+u_hashset_destroy(struct u_hashset **hs)
+{
+	delete *hs;
+	*hs = NULL;
+	return 0;
+}
+
+extern "C" int
+u_hashset_find_str(struct u_hashset *hs,
+                   const char *str,
+                   size_t length,
+                   struct u_hashset_item **out_item)
+{
+	std::string key = std::string(str, length);
+	auto search = hs->map.find(key);
+
+	if (search != hs->map.end()) {
+		*out_item = search->second;
+		return 0;
+	} else {
+		return -1;
+	}
+}
+
+extern "C" int
+u_hashset_find_c_str(struct u_hashset *hs,
+                     const char *c_str,
+                     struct u_hashset_item **out_item)
+{
+	size_t length = strlen(c_str);
+	return u_hashset_find_str(hs, c_str, length, out_item);
+}
+
+extern "C" int
+u_hashset_insert_item(struct u_hashset *hs, struct u_hashset_item *item)
+{
+	std::string key = std::string(item->c_str, item->length);
+	hs->map[key] = item;
+	return 0;
+}
+
+extern "C" int
+u_hashset_erase_item(struct u_hashset *hs, struct u_hashset_item *item)
+{
+	std::string key = std::string(item->c_str, item->length);
+	hs->map.erase(key);
+	return 0;
+}
+
+extern "C" int
+u_hashset_erase_str(struct u_hashset *hs, const char *str, size_t length)
+{
+	std::string key = std::string(str, length);
+	hs->map.erase(key);
+	return 0;
+}
+
+extern "C" int
+u_hashset_erase_c_str(struct u_hashset *hs, const char *c_str)
+{
+	size_t length = strlen(c_str);
+	return u_hashset_erase_str(hs, c_str, length);
+}
+
+extern "C" void
+u_hashset_clear_and_call_for_each(struct u_hashset *hs,
+                                  u_hashset_callback cb,
+                                  void *priv)
+{
+	std::vector<struct u_hashset_item *> tmp;
+	tmp.reserve(hs->map.size());
+
+	for (auto &n : hs->map) {
+		tmp.push_back(n.second);
+	}
+
+	hs->map.clear();
+
+	for (auto n : tmp) {
+		cb(n, priv);
+	}
+}

src/xrt/auxiliary/util/u_hashset.h

+// Copyright 2019, Collabora, Ltd.
+// SPDX-License-Identifier: BSL-1.0
+/*!
+ * @file
+ * @brief  Hashset struct header.
+ * @author Jakob Bornecrantz <jakob@collabora.com>
+ * @ingroup aux_util
+ */
+
+#pragma once
+
+#include "xrt/xrt_compiler.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/*!
+ * @struct u_hashset
+ * @ingroup aux_util
+ *
+ * Kind of bespoke hashset implementation, where the user is responsible for
+ * allocating and freeing the items themselves.
+ *
+ * This allows embedding the @ref u_hashset_item at the end of structs.
+ */
+struct u_hashset;
+
+/*!
+ * A embeddable hashset item, note that the string directly follows the
+ * @ref u_hashset_item.
+ *
+ * @ingroup aux_util
+ */
+struct u_hashset_item
+{
+	size_t hash;
+	size_t length;
+	const char c_str[];
+};
+
+typedef void (*u_hashset_callback)(struct u_hashset_item *item, void *priv);
+
+int
+u_hashset_create(struct u_hashset **out_hashset);
+
+int
+u_hashset_destroy(struct u_hashset **hs);
+
+int
+u_hashset_find_str(struct u_hashset *hs,
+                   const char *str,
+                   size_t length,
+                   struct u_hashset_item **out_item);
+
+int
+u_hashset_find_c_str(struct u_hashset *hs,
+                     const char *c_str,
+                     struct u_hashset_item **out_item);
+
+int
+u_hashset_insert_item(struct u_hashset *hs, struct u_hashset_item *item);
+
+int
+u_hashset_erase_item(struct u_hashset *hs, struct u_hashset_item *item);
+
+int
+u_hashset_erase_str(struct u_hashset *hs, const char *str, size_t length);
+
+int
+u_hashset_erase_c_str(struct u_hashset *hs, const char *c_str);
+
+/*!
+ * First clear the hashset and then call the given callback with each item that
+ * was in the hashset.
+ *
+ * @ingroup aux_util
+ */
+void
+u_hashset_clear_and_call_for_each(struct u_hashset *hs,
+                                  u_hashset_callback cb,
+                                  void *priv);
+
+
+#ifdef __cplusplus
+}
+#endif