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Diffstat (limited to 'json.h')
| -rw-r--r-- | json.h | 267 |
1 files changed, 267 insertions, 0 deletions
@@ -0,0 +1,267 @@ +/* + * json.h + * + * Home page of code is: https://www.smartmontools.org + * + * Copyright (C) 2017-22 Christian Franke + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#ifndef JSON_H_CVSID +#define JSON_H_CVSID "$Id: json.h 5292 2022-01-06 17:13:25Z chrfranke $" + +#include <stdint.h> +#include <stdio.h> +#include <initializer_list> +#include <map> +#include <memory> +#include <string> +#include <vector> + +/// Create and print JSON output. +class json +{ +public: + /// Return true if value is a safe JSON integer. + /// Same as Number.isSafeInteger(value) in JavaScript. + static bool is_safe_uint(unsigned long long value) + { return (value < (1ULL << 53)); } + + /// Replace space and non-alphanumerics with '_', upper to lower case. + static std::string str2key(const char * str); + + /// Replace space and non-alphanumerics with '_', upper to lower case + /// (std::string variant). + static std::string str2key(const std::string & str) + { return str2key(str.c_str()); } + + enum node_type { + nt_unset, nt_object, nt_array, + nt_bool, nt_int, nt_uint, nt_uint128, nt_string + }; + + // initializer_list<> elements. + struct initlist_value { + // cppcheck-suppress noExplicitConstructor + initlist_value(node_type t) : type(t) {} + // cppcheck-suppress noExplicitConstructor + initlist_value(bool v) : type(nt_bool), intval(v ? 1 : 0) {} + // cppcheck-suppress noExplicitConstructor + initlist_value(int v) : initlist_value((long long)v) {} + // cppcheck-suppress noExplicitConstructor + initlist_value(unsigned v) : initlist_value((unsigned long long)v) {} + // cppcheck-suppress noExplicitConstructor + initlist_value(long v) : initlist_value((long long)v) {} + // cppcheck-suppress noExplicitConstructor + initlist_value(unsigned long v) : initlist_value((unsigned long long)v) {} + // cppcheck-suppress noExplicitConstructor + initlist_value(long long v) : type(nt_int), intval((uint64_t)(int64_t)v) {} + // cppcheck-suppress noExplicitConstructor + initlist_value(unsigned long long v) : type(nt_uint), intval((uint64_t)v) {} + // cppcheck-suppress noExplicitConstructor + initlist_value(const char * v) : type(nt_string), strval(v) {} + // cppcheck-suppress noExplicitConstructor + initlist_value(const std::string & v) : type(nt_string), strval(v.c_str()) {} + node_type type; + uint64_t intval = 0; + const char * strval = nullptr; + }; + + struct initlist_key_value_pair { + initlist_key_value_pair(const char * k, const initlist_value & v) : keystr(k), value(v) {} + initlist_key_value_pair(const std::string & k, const initlist_value & v) + : keystr(k.c_str()), value(v) {} + initlist_key_value_pair(const char * k, const std::initializer_list<initlist_key_value_pair> & ilist) + : keystr(k), value(nt_object), object(ilist) {} + initlist_key_value_pair(const std::string & k, const std::initializer_list<initlist_key_value_pair> & ilist) + : keystr(k.c_str()), value(nt_object), object(ilist) {} + initlist_key_value_pair(const char * k, const std::initializer_list<initlist_value> & ilist) + : keystr(k), value(nt_array), array(ilist) {} + initlist_key_value_pair(const std::string & k, const std::initializer_list<initlist_value> & ilist) + : keystr(k.c_str()), value(nt_array), array(ilist) {} + const char * keystr; + initlist_value value; + std::initializer_list<initlist_key_value_pair> object; + std::initializer_list<initlist_value> array; + }; + +private: + struct node_info + { + std::string key; + int index = 0; + + node_info() = default; + explicit node_info(const char * keystr) : key(str2key(keystr)) { } + explicit node_info(int index_) : index(index_) { } + }; + + typedef std::vector<node_info> node_path; + +public: + /// Reference to a JSON element. + class ref + { + public: + ~ref(); + + /// Return reference to object element. + ref operator[](const char * keystr) const + { return ref(*this, keystr); } + + /// Return reference to object element (std::string variant). + ref operator[](const std::string & keystr) const + { return ref(*this, keystr.c_str()); } + + /// Return reference to array element. + ref operator[](int index) const + { return ref(*this, index); } + + // Assignment operators create or change element. + void operator=(bool value); + + void operator=(int value); + void operator=(unsigned value); + void operator=(long value); + void operator=(unsigned long value); + void operator=(long long value); + void operator=(unsigned long long value); + + void operator=(const char * value); + void operator=(const std::string & value); + + /// Return reference to element with KEY_SUFFIX appended to last key. + ref with_suffix(const char * key_suffix) const + { return ref(*this, "", key_suffix); } + + void set_uint128(uint64_t value_hi, uint64_t value_lo); + + // Output only if safe integer. + bool set_if_safe_uint64(uint64_t value); + bool set_if_safe_uint128(uint64_t value_hi, uint64_t value_lo); + bool set_if_safe_le128(const void * pvalue); + + // If unsafe integer, output also as string with key "NUMBER_s". + void set_unsafe_uint64(uint64_t value); + void set_unsafe_uint128(uint64_t value_hi, uint64_t value_lo); + void set_unsafe_le128(const void * pvalue); + + /// Braced-init-list support for nested objects. + void operator+=(std::initializer_list<initlist_key_value_pair> ilist); + /// Braced-init-list support for simple arrays. + void operator+=(std::initializer_list<initlist_value> ilist); + + private: + friend class json; + explicit ref(json & js); + ref(json & js, const char * keystr); + ref(const ref & base, const char * keystr); + ref(const ref & base, int index); + ref(const ref & base, const char * /*dummy*/, const char * key_suffix); + + void operator=(const initlist_value & value) + { m_js.set_initlist_value(m_path, value); } + + json & m_js; + node_path m_path; + }; + + /// Return reference to element of top level object. + ref operator[](const char * keystr) + { return ref(*this, keystr); } + + /// Return reference to element of top level object (std::string variant). + ref operator[](const std::string & keystr) + { return ref(*this, keystr.c_str()); } + + /// Braced-init-list support for top level object. + void operator+=(std::initializer_list<initlist_key_value_pair> ilist) + { ref(*this) += ilist; } + + /// Enable/disable JSON output. + void enable(bool yes = true) + { m_enabled = yes; } + + /// Return true if enabled. + bool is_enabled() const + { return m_enabled; } + + /// Enable/disable extra string output for safe integers also. + void set_verbose(bool yes = true) + { m_verbose = yes; } + + /// Return true if any 128-bit value has been output. + bool has_uint128_output() const + { return m_uint128_output; } + + /// Options for print(). + struct print_options { + bool pretty = false; //< Pretty-print output. + bool sorted = false; //< Sort object keys. + char format = 0; //< 'y': YAML, 'g': flat(grep, gron), other: JSON + }; + + /// Print JSON tree to a file. + void print(FILE * f, const print_options & options) const; + +private: + struct node + { + node(); + node(const node &) = delete; + explicit node(const std::string & key_); + ~node(); + void operator=(const node &) = delete; + + node_type type = nt_unset; + + uint64_t intval = 0, intval_hi = 0; + std::string strval; + + std::string key; + std::vector< std::unique_ptr<node> > childs; + typedef std::map<std::string, unsigned> keymap; + keymap key2index; + + class const_iterator + { + public: + const_iterator(const node * node_p, bool sorted); + bool at_end() const; + unsigned array_index() const; + void operator++(); + const node * operator*() const; + + private: + const node * m_node_p; + bool m_use_map; + unsigned m_child_idx = 0; + keymap::const_iterator m_key_iter; + }; + }; + + bool m_enabled = false; + bool m_verbose = false; + bool m_uint128_output = false; + + node m_root_node; + + node * find_or_create_node(const node_path & path, node_type type); + + void set_bool(const node_path & path, bool value); + void set_int64(const node_path & path, int64_t value); + void set_uint64(const node_path & path, uint64_t value); + void set_uint128(const node_path & path, uint64_t value_hi, uint64_t value_lo); + void set_cstring(const node_path & path, const char * value); + void set_string(const node_path & path, const std::string & value); + void set_initlist_value(const node_path & path, const initlist_value & value); + + static void print_json(FILE * f, bool pretty, bool sorted, const node * p, int level); + static void print_yaml(FILE * f, bool pretty, bool sorted, const node * p, int level_o, + int level_a, bool cont); + static void print_flat(FILE * f, const char * assign, bool sorted, const node * p, + std::string & path); +}; + +#endif // JSON_H_CVSID |