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Diffstat (limited to 'fs/vendor/frozen.h')
| -rw-r--r-- | fs/vendor/frozen.h | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/fs/vendor/frozen.h b/fs/vendor/frozen.h new file mode 100644 index 0000000..97643be --- /dev/null +++ b/fs/vendor/frozen.h @@ -0,0 +1,329 @@ +/* + * Copyright (c) 2004-2013 Sergey Lyubka <valenok@gmail.com> + * Copyright (c) 2018 Cesanta Software Limited + * All rights reserved + * + * Licensed under the Apache License, Version 2.0 (the ""License""); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an ""AS IS"" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef CS_FROZEN_FROZEN_H_ +#define CS_FROZEN_FROZEN_H_ + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +#include <stdarg.h> +#include <stddef.h> +#include <stdio.h> + +#if defined(_WIN32) && _MSC_VER < 1700 +typedef int bool; +enum { false = 0, true = 1 }; +#else +#include <stdbool.h> +#endif + +/* JSON token type */ +enum json_token_type { + JSON_TYPE_INVALID = 0, /* memsetting to 0 should create INVALID value */ + JSON_TYPE_STRING, + JSON_TYPE_NUMBER, + JSON_TYPE_TRUE, + JSON_TYPE_FALSE, + JSON_TYPE_NULL, + JSON_TYPE_OBJECT_START, + JSON_TYPE_OBJECT_END, + JSON_TYPE_ARRAY_START, + JSON_TYPE_ARRAY_END, + + JSON_TYPES_CNT +}; + +/* + * Structure containing token type and value. Used in `json_walk()` and + * `json_scanf()` with the format specifier `%T`. + */ +struct json_token { + const char *ptr; /* Points to the beginning of the value */ + int len; /* Value length */ + enum json_token_type type; /* Type of the token, possible values are above */ +}; + +#define JSON_INVALID_TOKEN \ + { 0, 0, JSON_TYPE_INVALID } + +/* Error codes */ +#define JSON_STRING_INVALID -1 +#define JSON_STRING_INCOMPLETE -2 + +/* + * Callback-based SAX-like API. + * + * Property name and length is given only if it's available: i.e. if current + * event is an object's property. In other cases, `name` is `NULL`. For + * example, name is never given: + * - For the first value in the JSON string; + * - For events JSON_TYPE_OBJECT_END and JSON_TYPE_ARRAY_END + * + * E.g. for the input `{ "foo": 123, "bar": [ 1, 2, { "baz": true } ] }`, + * the sequence of callback invocations will be as follows: + * + * - type: JSON_TYPE_OBJECT_START, name: NULL, path: "", value: NULL + * - type: JSON_TYPE_NUMBER, name: "foo", path: ".foo", value: "123" + * - type: JSON_TYPE_ARRAY_START, name: "bar", path: ".bar", value: NULL + * - type: JSON_TYPE_NUMBER, name: "0", path: ".bar[0]", value: "1" + * - type: JSON_TYPE_NUMBER, name: "1", path: ".bar[1]", value: "2" + * - type: JSON_TYPE_OBJECT_START, name: "2", path: ".bar[2]", value: NULL + * - type: JSON_TYPE_TRUE, name: "baz", path: ".bar[2].baz", value: "true" + * - type: JSON_TYPE_OBJECT_END, name: NULL, path: ".bar[2]", value: "{ \"baz\": + *true }" + * - type: JSON_TYPE_ARRAY_END, name: NULL, path: ".bar", value: "[ 1, 2, { + *\"baz\": true } ]" + * - type: JSON_TYPE_OBJECT_END, name: NULL, path: "", value: "{ \"foo\": 123, + *\"bar\": [ 1, 2, { \"baz\": true } ] }" + */ +typedef void (*json_walk_callback_t)(void *callback_data, const char *name, + size_t name_len, const char *path, + const struct json_token *token); + +/* + * Parse `json_string`, invoking `callback` in a way similar to SAX parsers; + * see `json_walk_callback_t`. + * Return number of processed bytes, or a negative error code. + */ +int json_walk(const char *json_string, int json_string_length, + json_walk_callback_t callback, void *callback_data); + +/* + * JSON generation API. + * struct json_out abstracts output, allowing alternative printing plugins. + */ +struct json_out { + int (*printer)(struct json_out *, const char *str, size_t len); + union { + struct { + char *buf; + size_t size; + size_t len; + } buf; + void *data; + FILE *fp; + } u; +}; + +extern int json_printer_buf(struct json_out *, const char *, size_t); +extern int json_printer_file(struct json_out *, const char *, size_t); + +#define JSON_OUT_BUF(buf, len) \ + { \ + json_printer_buf, { \ + { buf, len, 0 } \ + } \ + } +#define JSON_OUT_FILE(fp) \ + { \ + json_printer_file, { \ + { (char *) fp, 0, 0 } \ + } \ + } + +typedef int (*json_printf_callback_t)(struct json_out *, va_list *ap); + +/* + * Generate formatted output into a given sting buffer. + * This is a superset of printf() function, with extra format specifiers: + * - `%B` print json boolean, `true` or `false`. Accepts an `int`. + * - `%Q` print quoted escaped string or `null`. Accepts a `const char *`. + * - `%.*Q` same as `%Q`, but with length. Accepts `int`, `const char *` + * - `%V` print quoted base64-encoded string. Accepts a `const char *`, `int`. + * - `%H` print quoted hex-encoded string. Accepts a `int`, `const char *`. + * - `%M` invokes a json_printf_callback_t function. That callback function + * can consume more parameters. + * + * Return number of bytes printed. If the return value is bigger than the + * supplied buffer, that is an indicator of overflow. In the overflow case, + * overflown bytes are not printed. + */ +int json_printf(struct json_out *, const char *fmt, ...); +int json_vprintf(struct json_out *, const char *fmt, va_list ap); + +/* + * Same as json_printf, but prints to a file. + * File is created if does not exist. File is truncated if already exists. + */ +int json_fprintf(const char *file_name, const char *fmt, ...); +int json_vfprintf(const char *file_name, const char *fmt, va_list ap); + +/* + * Print JSON into an allocated 0-terminated string. + * Return allocated string, or NULL on error. + * Example: + * + * ```c + * char *str = json_asprintf("{a:%H}", 3, "abc"); + * printf("%s\n", str); // Prints "616263" + * free(str); + * ``` + */ +char *json_asprintf(const char *fmt, ...); +char *json_vasprintf(const char *fmt, va_list ap); + +/* + * Helper %M callback that prints contiguous C arrays. + * Consumes void *array_ptr, size_t array_size, size_t elem_size, char *fmt + * Return number of bytes printed. + */ +int json_printf_array(struct json_out *, va_list *ap); + +/* + * Scan JSON string `str`, performing scanf-like conversions according to `fmt`. + * This is a `scanf()` - like function, with following differences: + * + * 1. Object keys in the format string may be not quoted, e.g. "{key: %d}" + * 2. Order of keys in an object is irrelevant. + * 3. Several extra format specifiers are supported: + * - %B: consumes `int *` (or `char *`, if `sizeof(bool) == sizeof(char)`), + * expects boolean `true` or `false`. + * - %Q: consumes `char **`, expects quoted, JSON-encoded string. Scanned + * string is malloc-ed, caller must free() the string. + * - %V: consumes `char **`, `int *`. Expects base64-encoded string. + * Result string is base64-decoded, malloced and NUL-terminated. + * The length of result string is stored in `int *` placeholder. + * Caller must free() the result. + * - %H: consumes `int *`, `char **`. + * Expects a hex-encoded string, e.g. "fa014f". + * Result string is hex-decoded, malloced and NUL-terminated. + * The length of the result string is stored in `int *` placeholder. + * Caller must free() the result. + * - %M: consumes custom scanning function pointer and + * `void *user_data` parameter - see json_scanner_t definition. + * - %T: consumes `struct json_token *`, fills it out with matched token. + * + * Return number of elements successfully scanned & converted. + * Negative number means scan error. + */ +int json_scanf(const char *str, int str_len, const char *fmt, ...); +int json_vscanf(const char *str, int str_len, const char *fmt, va_list ap); + +/* json_scanf's %M handler */ +typedef void (*json_scanner_t)(const char *str, int len, void *user_data); + +/* + * Helper function to scan array item with given path and index. + * Fills `token` with the matched JSON token. + * Return -1 if no array element found, otherwise non-negative token length. + */ +int json_scanf_array_elem(const char *s, int len, const char *path, int index, + struct json_token *token); + +/* + * Unescape JSON-encoded string src,slen into dst, dlen. + * src and dst may overlap. + * If destination buffer is too small (or zero-length), result string is not + * written but the length is counted nevertheless (similar to snprintf). + * Return the length of unescaped string in bytes. + */ +int json_unescape(const char *src, int slen, char *dst, int dlen); + +/* + * Escape a string `str`, `str_len` into the printer `out`. + * Return the number of bytes printed. + */ +int json_escape(struct json_out *out, const char *str, size_t str_len); + +/* + * Read the whole file in memory. + * Return malloc-ed file content, or NULL on error. The caller must free(). + */ +char *json_fread(const char *file_name); + +/* + * Update given JSON string `s,len` by changing the value at given `json_path`. + * The result is saved to `out`. If `json_fmt` == NULL, that deletes the key. + * If path is not present, missing keys are added. Array path without an + * index pushes a value to the end of an array. + * Return 1 if the string was changed, 0 otherwise. + * + * Example: s is a JSON string { "a": 1, "b": [ 2 ] } + * json_setf(s, len, out, ".a", "7"); // { "a": 7, "b": [ 2 ] } + * json_setf(s, len, out, ".b", "7"); // { "a": 1, "b": 7 } + * json_setf(s, len, out, ".b[]", "7"); // { "a": 1, "b": [ 2,7 ] } + * json_setf(s, len, out, ".b", NULL); // { "a": 1 } + */ +int json_setf(const char *s, int len, struct json_out *out, + const char *json_path, const char *json_fmt, ...); + +int json_vsetf(const char *s, int len, struct json_out *out, + const char *json_path, const char *json_fmt, va_list ap); + +/* + * Pretty-print JSON string `s,len` into `out`. + * Return number of processed bytes in `s`. + */ +int json_prettify(const char *s, int len, struct json_out *out); + +/* + * Prettify JSON file `file_name`. + * Return number of processed bytes, or negative number of error. + * On error, file content is not modified. + */ +int json_prettify_file(const char *file_name); + +/* + * Iterate over an object at given JSON `path`. + * On each iteration, fill the `key` and `val` tokens. It is OK to pass NULL + * for `key`, or `val`, in which case they won't be populated. + * Return an opaque value suitable for the next iteration, or NULL when done. + * + * Example: + * + * ```c + * void *h = NULL; + * struct json_token key, val; + * while ((h = json_next_key(s, len, h, ".foo", &key, &val)) != NULL) { + * printf("[%.*s] -> [%.*s]\n", key.len, key.ptr, val.len, val.ptr); + * } + * ``` + */ +void *json_next_key(const char *s, int len, void *handle, const char *path, + struct json_token *key, struct json_token *val); + +/* + * Iterate over an array at given JSON `path`. + * Similar to `json_next_key`, but fills array index `idx` instead of `key`. + */ +void *json_next_elem(const char *s, int len, void *handle, const char *path, + int *idx, struct json_token *val); + +#ifndef JSON_MAX_PATH_LEN +#define JSON_MAX_PATH_LEN 256 +#endif + +#ifndef JSON_MINIMAL +#define JSON_MINIMAL 0 +#endif + +#ifndef JSON_ENABLE_BASE64 +#define JSON_ENABLE_BASE64 !JSON_MINIMAL +#endif + +#ifndef JSON_ENABLE_HEX +#define JSON_ENABLE_HEX !JSON_MINIMAL +#endif + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* CS_FROZEN_FROZEN_H_ */ |