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+/**
+ * @file dict.h
+ * @author Radek Krejci <rkrejci@cesnet.cz>
+ * @brief libyang dictionary
+ *
+ * Copyright (c) 2015-2018 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://opensource.org/licenses/BSD-3-Clause
+ */
+
+#ifndef LY_DICT_H_
+#define LY_DICT_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "log.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* dummy context structure */
+struct ly_ctx;
+
+/**
+ * @page howtoContextDict Context Dictionary
+ *
+ * Context includes dictionary to store strings more effectively. The most of strings repeats quite often in schema
+ * as well as data trees. Therefore, instead of allocating those strings each time they appear, libyang stores them
+ * as records in the dictionary. The basic API to the context dictionary is public, so even a caller application can
+ * use the dictionary.
+ *
+ * To insert a string into the dictionary, caller can use ::lydict_insert() (adding a constant string) or
+ * ::lydict_insert_zc() (for dynamically allocated strings that won't be used by the caller after its insertion into
+ * the dictionary). Both functions provide the pointer to the inserted string in the dictionary record.
+ *
+ * To remove (reference of the) string from the context dictionary, ::lydict_remove() is supposed to be used.
+ *
+ * \note Incorrect usage of the dictionary can break libyang functionality.
+ *
+ * \note API for this group of functions is described in the [Dictionary module](@ref dict).
+ *
+ * Functions List
+ * --------------
+ * - ::lydict_insert()
+ * - ::lydict_insert_zc()
+ * - ::lydict_remove()
+ */
+
+/**
+ * @defgroup dict Dictionary
+ * @{
+ *
+ * Publicly visible functions and values of the libyang dictionary. They provide
+ * access to the strings stored in the libyang context. More detailed information can be found at
+ * @ref howtoContextDict page.
+ */
+
+/**
+ * @brief Insert string into dictionary. If the string is already present,
+ * only a reference counter is incremented and no memory allocation is
+ * performed.
+ *
+ * @param[in] ctx libyang context handler
+ * @param[in] value String to be stored in the dictionary. If NULL, function does nothing.
+ * @param[in] len Number of bytes to store. The value is not required to be
+ * NULL terminated string, the len parameter says number of bytes stored in
+ * dictionary. The specified number of bytes is duplicated and terminating NULL
+ * byte is added automatically. If \p len is 0, it is count automatically using strlen().
+ * @param[out] str_p Optional parameter to get pointer to the string corresponding to the @p value and stored in dictionary.
+ * @return LY_SUCCESS in case of successful insertion into dictionary, note that the function does not return LY_EEXIST.
+ * @return LY_EINVAL in case of invalid input parameters.
+ * @return LY_EMEM in case of memory allocation failure.
+ */
+LIBYANG_API_DECL LY_ERR lydict_insert(const struct ly_ctx *ctx, const char *value, size_t len, const char **str_p);
+
+/**
+ * @brief Insert string into dictionary - zerocopy version. If the string is
+ * already present, only a reference counter is incremented and no memory
+ * allocation is performed. This insert function variant avoids duplication of
+ * specified value - it is inserted into the dictionary directly.
+ *
+ * @param[in] ctx libyang context handler
+ * @param[in] value NULL-terminated string to be stored in the dictionary. If
+ * the string is not present in dictionary, the pointer is directly used by the
+ * dictionary. Otherwise, the reference counter is incremented and the value is
+ * freed. So, after calling the function, caller is supposed to not use the
+ * value address anymore. If NULL, function does nothing.
+ * @param[out] str_p Optional parameter to get pointer to the string corresponding to the @p value and stored in dictionary.
+ * @return LY_SUCCESS in case of successful insertion into dictionary, note that the function does not return LY_EEXIST.
+ * @return LY_EINVAL in case of invalid input parameters.
+ * @return LY_EMEM in case of memory allocation failure.
+ */
+LIBYANG_API_DECL LY_ERR lydict_insert_zc(const struct ly_ctx *ctx, char *value, const char **str_p);
+
+/**
+ * @brief Remove specified string from the dictionary. It decrement reference
+ * counter for the string and if it is zero, the string itself is freed.
+ *
+ * @param[in] ctx libyang context handler
+ * @param[in] value String to be freed. Note, that not only the string itself
+ * must match the stored value, but also the address is being compared and the
+ * counter is decremented only if it matches. If NULL, function does nothing.
+ * @return LY_SUCCESS if the value was found and removed (or refcount decreased).
+ * @return LY_ENOTFOUND if the value was not found.
+ * @return LY_ERR on other errors.
+ */
+LIBYANG_API_DECL LY_ERR lydict_remove(const struct ly_ctx *ctx, const char *value);
+
+/** @} dict */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LY_DICT_H_ */