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+/**
+ * @file json.h
+ * @author Radek Krejci <rkrejci@cesnet.cz>
+ * @brief Generic JSON format parser routines.
+ *
+ * Copyright (c) 2020 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_JSON_H_
+#define LY_JSON_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "log.h"
+#include "set.h"
+
+struct ly_ctx;
+struct ly_in;
+
+/* Macro to test if character is whitespace */
+#define is_jsonws(c) (c == 0x20 || c == 0x9 || c == 0xa || c == 0xd)
+
+/* Macro to test if character is valid string character */
+#define is_jsonstrchar(c) (c == 0x20 || c == 0x21 || (c >= 0x23 && c <= 0x5b) || (c >= 0x5d && c <= 0x10ffff))
+
+/* Macro to push JSON parser status */
+#define LYJSON_STATUS_PUSH_RET(CTX, STATUS) \
+ LY_CHECK_RET(ly_set_add(&CTX->status, (void *)(uintptr_t)(STATUS), 1, NULL))
+
+/* Macro to pop JSON parser status */
+#define LYJSON_STATUS_POP_RET(CTX) \
+ assert(CTX->status.count); CTX->status.count--;
+
+/**
+ * @brief Status of the parser providing information what is expected next (which function is supposed to be called).
+ */
+enum LYJSON_PARSER_STATUS {
+ LYJSON_ERROR, /* JSON parser error - value is used as an error return code */
+ LYJSON_ROOT, /* JSON document root, used internally */
+ LYJSON_OBJECT, /* JSON object */
+ LYJSON_OBJECT_CLOSED, /* JSON object closed */
+ LYJSON_OBJECT_EMPTY, /* empty JSON object { } */
+ LYJSON_ARRAY, /* JSON array */
+ LYJSON_ARRAY_CLOSED, /* JSON array closed */
+ LYJSON_ARRAY_EMPTY, /* empty JSON array */
+ LYJSON_NUMBER, /* JSON number value */
+ LYJSON_STRING, /* JSON string value */
+ LYJSON_FALSE, /* JSON false value */
+ LYJSON_TRUE, /* JSON true value */
+ LYJSON_NULL, /* JSON null value */
+ LYJSON_END /* end of input data */
+};
+
+struct lyjson_ctx {
+ const struct ly_ctx *ctx;
+ struct ly_in *in; /* input structure */
+
+ struct ly_set status; /* stack of ::LYJSON_PARSER_STATUS values corresponding to the JSON items being processed */
+
+ const char *value; /* ::LYJSON_STRING, ::LYJSON_NUMBER, ::LYJSON_OBJECT */
+ size_t value_len; /* ::LYJSON_STRING, ::LYJSON_NUMBER, ::LYJSON_OBJECT */
+ ly_bool dynamic; /* ::LYJSON_STRING, ::LYJSON_NUMBER, ::LYJSON_OBJECT */
+ uint32_t depth; /* current number of nested blocks, see ::LY_MAX_BLOCK_DEPTH */
+
+ struct {
+ enum LYJSON_PARSER_STATUS status;
+ uint32_t status_count;
+ const char *value;
+ size_t value_len;
+ ly_bool dynamic;
+ uint32_t depth;
+ const char *input;
+ } backup;
+};
+
+/**
+ * @brief Create a new JSON parser context and start parsing.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] in JSON string data to parse.
+ * @param[in] subtree Whether this is a special case of parsing a subtree (starting with object name).
+ * @param[out] jsonctx New JSON context with status referring the parsed value.
+ * @return LY_ERR value.
+ */
+LY_ERR lyjson_ctx_new(const struct ly_ctx *ctx, struct ly_in *in, ly_bool subtree, struct lyjson_ctx **jsonctx);
+
+/**
+ * @brief Get status of the parser as the last/previous parsed token
+ *
+ * @param[in] jsonctx JSON context to check.
+ * @param[in] index Index of the token, starting by 0 for the last token
+ * @return ::LYJSON_ERROR in case of invalid index, other ::LYJSON_PARSER_STATUS corresponding to the token.
+ */
+enum LYJSON_PARSER_STATUS lyjson_ctx_status(struct lyjson_ctx *jsonctx, uint32_t index);
+
+/**
+ * @brief Get string representation of the JSON context status (token).
+ *
+ * @param[in] status Context status (aka JSON token)
+ * @return String representation of the @p status.
+ */
+const char *lyjson_token2str(enum LYJSON_PARSER_STATUS status);
+
+/**
+ * @brief Move to the next JSON artifact and update parser status.
+ *
+ * @param[in] jsonctx XML context to move.
+ * @param[out] status Optional parameter to provide new parser status
+ * @return LY_ERR value.
+ */
+LY_ERR lyjson_ctx_next(struct lyjson_ctx *jsonctx, enum LYJSON_PARSER_STATUS *status);
+
+/**
+ * @brief Backup the JSON parser context's state To restore the backup, use ::lyjson_ctx_restore().
+ * @param[in] jsonctx JSON parser context to backup.
+ */
+void lyjson_ctx_backup(struct lyjson_ctx *jsonctx);
+
+/**
+ * @brief REstore the JSON parser context's state from the backup created by ::lyjson_ctx_backup().
+ * @param[in] jsonctx JSON parser context to restore.
+ */
+void lyjson_ctx_restore(struct lyjson_ctx *jsonctx);
+
+/**
+ * @brief Remove the allocated working memory of the context.
+ *
+ * @param[in] jsonctx JSON context to clear.
+ */
+void lyjson_ctx_free(struct lyjson_ctx *jsonctx);
+
+#endif /* LY_JSON_H_ */