shavit-credits/scripting/include/json.inc
2023-06-20 11:54:27 +02:00

815 lines
24 KiB
C++

/**
* vim: set ts=4 :
* =============================================================================
* sm-json
* A pure SourcePawn JSON encoder/decoder.
* https://github.com/clugg/sm-json
*
* sm-json (C)2022 James Dickens. (clug)
* SourceMod (C)2004-2008 AlliedModders LLC. All rights reserved.
* =============================================================================
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License, version 3.0, as published by the
* Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, AlliedModders LLC gives you permission to link the
* code of this program (as well as its derivative works) to "Half-Life 2," the
* "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
* by the Valve Corporation. You must obey the GNU General Public License in
* all respects for all other code used. Additionally, AlliedModders LLC grants
* this exception to all derivative works. AlliedModders LLC defines further
* exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
* or <http://www.sourcemod.net/license.php>.
*/
#if defined _json_included
#endinput
#endif
#define _json_included
#include <string>
#include <json/definitions>
#include <json/helpers/decode>
#include <json/helpers/errors>
#include <json/helpers/string>
#include <json/object>
#include <json/array>
/**
* Calculates the buffer size required to store an encoded JSON instance.
*
* @param obj Object to encode.
* @param options Bitwise combination of `JSON_ENCODE_*` options.
* @param depth The current depth of the encoder.
* @return The required buffer size.
*/
stock int json_encode_size(JSON_Object obj, int options = JSON_NONE, int depth = 0)
{
bool pretty_print = (options & JSON_ENCODE_PRETTY) != 0;
bool is_array = obj.IsArray;
int size = 1; // for opening bracket
// used in key iterator
int json_size = obj.Iterate();
JSON_Object child = null;
bool is_empty = true;
int str_length = 0;
int key_length = 0;
for (int i = 0; i < json_size; i += 1) {
key_length = is_array ? JSON_INT_BUFFER_SIZE : obj.GetKeySize(i);
char[] key = new char[key_length];
if (is_array) {
IntToString(i, key, key_length);
} else {
obj.GetKey(i, key, key_length);
}
// skip keys that are marked as hidden
if (obj.GetHidden(key)) {
continue;
}
JSONCellType type = obj.GetType(key);
// skip keys of unknown type
if (type == JSON_Type_Invalid) {
continue;
}
if (pretty_print) {
size += strlen(JSON_PP_NEWLINE);
size += (depth + 1) * strlen(JSON_PP_INDENT);
}
if (! is_array) {
// add the size of the key and + 1 for :
size += json_cell_string_size(key) + 1;
if (pretty_print) {
size += strlen(JSON_PP_AFTER_COLON);
}
}
switch (type) {
case JSON_Type_String: {
str_length = obj.GetSize(key);
char[] value = new char[str_length];
obj.GetString(key, value, str_length);
size += json_cell_string_size(value);
}
case JSON_Type_Int: {
size += JSON_INT_BUFFER_SIZE;
}
#if SM_INT64_SUPPORTED
case JSON_Type_Int64: {
size += JSON_INT64_BUFFER_SIZE;
}
#endif
case JSON_Type_Float: {
size += JSON_FLOAT_BUFFER_SIZE;
}
case JSON_Type_Bool: {
size += JSON_BOOL_BUFFER_SIZE;
}
case JSON_Type_Object: {
child = obj.GetObject(key);
size += child != null ? json_encode_size(child, options, depth + 1) : JSON_NULL_BUFFER_SIZE;
}
}
// increment for comma
size += 1;
is_empty = false;
}
if (! is_empty) {
// remove the final comma
size -= 1;
if (pretty_print) {
size += strlen(JSON_PP_NEWLINE);
size += depth * strlen(JSON_PP_INDENT);
}
}
size += 2; // closing bracket + NULL
return size;
}
/**
* Encodes a JSON instance into its string representation.
*
* @param obj Object to encode.
* @param output String buffer to store output.
* @param max_size Maximum size of string buffer.
* @param options Bitwise combination of `JSON_ENCODE_*` options.
* @param depth The current depth of the encoder.
*/
stock void json_encode(
JSON_Object obj,
char[] output,
int max_size,
int options = JSON_NONE,
int depth = 0
)
{
bool pretty_print = (options & JSON_ENCODE_PRETTY) != 0;
bool is_array = obj.IsArray;
strcopy(output, max_size, is_array ? "[" : "{");
// used in key iterator
int json_size = obj.Iterate();
int builder_size = 0;
int str_length = 1;
JSON_Object child = null;
int cell_length = 0;
bool is_empty = true;
int key_length = 0;
for (int i = 0; i < json_size; i += 1) {
key_length = is_array ? JSON_INT_BUFFER_SIZE : obj.GetKeySize(i);
char[] key = new char[key_length];
if (is_array) {
IntToString(i, key, key_length);
} else {
obj.GetKey(i, key, key_length);
}
// skip keys that are marked as hidden
if (obj.GetHidden(key)) {
continue;
}
JSONCellType type = obj.GetType(key);
// skip keys of unknown type
if (type == JSON_Type_Invalid) {
continue;
}
// determine the length of the char[] needed to represent our cell data
cell_length = 0;
switch (type) {
case JSON_Type_String: {
str_length = obj.GetSize(key);
char[] value = new char[str_length];
obj.GetString(key, value, str_length);
cell_length = json_cell_string_size(value);
}
case JSON_Type_Int: {
cell_length = JSON_INT_BUFFER_SIZE;
}
#if SM_INT64_SUPPORTED
case JSON_Type_Int64: {
cell_length = JSON_INT64_BUFFER_SIZE;
}
#endif
case JSON_Type_Float: {
cell_length = JSON_FLOAT_BUFFER_SIZE;
}
case JSON_Type_Bool: {
cell_length = JSON_BOOL_BUFFER_SIZE;
}
case JSON_Type_Object: {
child = obj.GetObject(key);
cell_length = child != null ? max_size : JSON_NULL_BUFFER_SIZE;
}
}
// fit the contents into the cell
char[] cell = new char[cell_length];
switch (type) {
case JSON_Type_String: {
char[] value = new char[str_length];
obj.GetString(key, value, str_length);
json_cell_string(value, cell, cell_length);
}
case JSON_Type_Int: {
int value = obj.GetInt(key);
IntToString(value, cell, cell_length);
}
#if SM_INT64_SUPPORTED
case JSON_Type_Int64: {
int value[2];
obj.GetInt64(key, value);
Int64ToString(value, cell, cell_length);
}
#endif
case JSON_Type_Float: {
float value = obj.GetFloat(key);
FloatToString(value, cell, cell_length);
// trim trailing 0s from float output up until decimal point
int last_char = strlen(cell) - 1;
while (cell[last_char] == '0' && cell[last_char - 1] != '.') {
cell[last_char--] = '\0';
}
}
case JSON_Type_Bool: {
bool value = obj.GetBool(key);
strcopy(cell, cell_length, value ? "true" : "false");
}
case JSON_Type_Object: {
if (child != null) {
json_encode(child, cell, cell_length, options, depth + 1);
} else {
strcopy(cell, cell_length, "null");
}
}
}
// make the builder fit our key:value
// use previously determined cell length and + 1 for ,
builder_size = cell_length + 1;
if (! is_array) {
// get the length of the key and + 1 for :
builder_size += json_cell_string_size(key) + 1;
if (pretty_print) {
builder_size += strlen(JSON_PP_AFTER_COLON);
}
}
char[] builder = new char[builder_size];
strcopy(builder, builder_size, "");
// add the key if we're working with an object
if (! is_array) {
json_cell_string(key, builder, builder_size);
StrCat(builder, builder_size, ":");
if (pretty_print) {
StrCat(builder, builder_size, JSON_PP_AFTER_COLON);
}
}
// add the value and a trailing comma
StrCat(builder, builder_size, cell);
StrCat(builder, builder_size, ",");
// prepare pretty printing then send builder to output afterwards
if (pretty_print) {
StrCat(output, max_size, JSON_PP_NEWLINE);
for (int j = 0; j < depth + 1; j += 1) {
StrCat(output, max_size, JSON_PP_INDENT);
}
}
StrCat(output, max_size, builder);
is_empty = false;
}
if (! is_empty) {
// remove the final comma
output[strlen(output) - 1] = '\0';
if (pretty_print) {
StrCat(output, max_size, JSON_PP_NEWLINE);
for (int j = 0; j < depth; j += 1) {
StrCat(output, max_size, JSON_PP_INDENT);
}
}
}
// append closing bracket
StrCat(output, max_size, is_array ? "]" : "}");
}
/**
* Decodes a JSON string into a JSON instance.
*
* @param buffer Buffer to decode.
* @param options Bitwise combination of `JSON_DECODE_*` options.
* @param pos Current position of the decoder as bytes
* offset into the buffer.
* @param depth Current nested depth of the decoder.
* @return JSON instance or null if decoding failed becase
* the buffer didn't contain valid JSON.
* @error If the buffer does not contain valid JSON,
* an error will be thrown.
*/
stock JSON_Object json_decode(
const char[] buffer,
int options = JSON_NONE,
int &pos = 0,
int depth = 0
)
{
int length = strlen(buffer);
// skip preceding whitespace
if (! json_skip_whitespace(buffer, length, pos)) {
json_set_last_error("buffer ended early at position %d", pos);
return null;
}
bool is_array = false;
JSON_Array arr = null;
JSON_Object obj = null;
if (buffer[pos] == '{') {
is_array = false;
obj = new JSON_Object();
if ((options & JSON_DECODE_ORDERED_KEYS) > 0) {
obj.EnableOrderedKeys();
}
} else if (buffer[pos] == '[') {
is_array = true;
arr = new JSON_Array();
} else {
json_set_last_error("no object or array found at position %d", pos);
return null;
}
bool allow_single_quotes = (options & JSON_DECODE_SINGLE_QUOTES) > 0;
bool empty_checked = false;
// while we haven't reached the end of our structure
while (
(! is_array && buffer[pos] != '}')
|| (is_array && buffer[pos] != ']')
) {
// pos is either an opening structure or comma, so increment past it
pos += 1;
// skip any whitespace preceding the element
if (! json_skip_whitespace(buffer, length, pos)) {
json_set_last_error("buffer ended early at position %d", pos);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
// if we haven't checked for empty yet and we are at the end
// of an object or array, we can stop here (empty structure)
if (! empty_checked) {
if (
(! is_array && buffer[pos] == '}')
|| (is_array && buffer[pos] == ']')
) {
break;
}
empty_checked = true;
}
int key_length = 1;
if (! is_array) {
// if dealing with an object, look for the key and determine length
if (! json_is_string(buffer[pos], allow_single_quotes)) {
json_set_last_error("expected key string at position %d", pos);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
key_length = json_extract_string_size(
buffer,
length,
pos,
is_array
);
}
char[] key = new char[key_length];
if (! is_array) {
// extract the key from the buffer
json_extract_string(buffer, length, pos, key, key_length, is_array);
// skip any whitespace following the key
if (! json_skip_whitespace(buffer, length, pos)) {
json_set_last_error("buffer ended early at position %d", pos);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
// ensure that we find a colon
if (buffer[pos++] != ':') {
json_set_last_error(
"expected colon after key at position %d",
pos
);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
// skip any whitespace following the colon
if (! json_skip_whitespace(buffer, length, pos)) {
json_set_last_error("buffer ended early at position %d", pos);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
}
int cell_length = 1;
JSONCellType cell_type = JSON_Type_Invalid;
if (buffer[pos] == '{' || buffer[pos] == '[') {
cell_type = JSON_Type_Object;
} else if (json_is_string(buffer[pos], allow_single_quotes)) {
cell_type = JSON_Type_String;
cell_length = json_extract_string_size(
buffer,
length,
pos,
is_array
);
} else {
// in this particular instance, we use JSON_Type_Invalid to
// represent any type that isn't an object or string
cell_length = json_extract_until_end_size(
buffer,
length,
pos,
is_array
);
}
char[] cell = new char[cell_length];
switch (cell_type) {
case JSON_Type_Object: {
// if we are dealing with an object or array, decode recursively
JSON_Object value = json_decode(
buffer,
options,
pos,
depth + 1
);
// decoding failed, error will be logged in json_decode
if (value == null) {
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
if (is_array) {
arr.PushObject(value);
} else {
obj.SetObject(key, value);
}
}
case JSON_Type_String: {
// if we are dealing with a string, attempt to extract it
if (! json_extract_string(
buffer,
length,
pos,
cell,
cell_length,
is_array
)) {
json_set_last_error(
"couldn't extract string at position %d",
pos
);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
if (is_array) {
arr.PushString(cell);
} else {
obj.SetString(key, cell);
}
}
case JSON_Type_Invalid: {
if (! json_extract_until_end(
buffer,
length,
pos,
cell,
cell_length,
is_array
)) {
json_set_last_error(
"couldn't extract until end at position %d",
pos
);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
if (strlen(cell) == 0) {
json_set_last_error(
"empty cell encountered at position %d",
pos
);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
if (json_is_int(cell)) {
int value = StringToInt(cell);
#if SM_INT64_SUPPORTED
if (json_is_int64(cell, value)) {
int values[2];
StringToInt64(cell, values);
if (is_array) {
arr.PushInt64(values);
} else {
obj.SetInt64(key, values);
}
} else {
if (is_array) {
arr.PushInt(value);
} else {
obj.SetInt(key, value);
}
}
#else
if (is_array) {
arr.PushInt(value);
} else {
obj.SetInt(key, value);
}
#endif
} else if (json_is_float(cell)) {
float value = StringToFloat(cell);
if (is_array) {
arr.PushFloat(value);
} else {
obj.SetFloat(key, value);
}
} else if (StrEqual(cell, "true") || StrEqual(cell, "false")) {
bool value = StrEqual(cell, "true");
if (is_array) {
arr.PushBool(value);
} else {
obj.SetBool(key, value);
}
} else if (StrEqual(cell, "null")) {
if (is_array) {
arr.PushObject(null);
} else {
obj.SetObject(key, null);
}
} else {
json_set_last_error(
"unknown type encountered at position %d: %s",
pos,
cell
);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
}
}
if (! json_skip_whitespace(buffer, length, pos)) {
json_set_last_error("buffer ended early at position %d", pos);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
}
// skip remaining whitespace and ensure we're at the end of the buffer
pos += 1;
if (json_skip_whitespace(buffer, length, pos) && depth == 0) {
json_set_last_error(
"unexpected data after structure end at position %d",
pos
);
json_cleanup_and_delete(obj);
json_cleanup_and_delete(arr);
return null;
}
return is_array ? view_as<JSON_Object>(arr) : obj;
}
/**
* Encodes the object with the options provided and writes
* the output to the file at the path specified.
*
* @param obj Object to encode/write to file.
* @param path Path of file to write to.
* @param options Options to pass to `json_encode`.
* @return True on success, false otherwise.
*/
stock bool json_write_to_file(
JSON_Object obj,
const char[] path,
int options = JSON_NONE
)
{
File f = OpenFile(path, "wb");
if (f == null) {
return false;
}
int size = json_encode_size(obj, options);
char[] buffer = new char[size];
json_encode(obj, buffer, size, options);
bool success = f.WriteString(buffer, false);
delete f;
return success;
}
/**
* Reads and decodes the contents of a JSON file.
*
* @param path Path of file to read from.
* @param options Options to pass to `json_decode`.
* @return The decoded object on success, null otherwise.
*/
stock JSON_Object json_read_from_file(const char[] path, int options = JSON_NONE)
{
File f = OpenFile(path, "rb");
if (f == null) {
return null;
}
f.Seek(0, SEEK_END);
int size = f.Position + 1;
char[] buffer = new char[size];
f.Seek(0, SEEK_SET);
f.ReadString(buffer, size);
delete f;
return json_decode(buffer, options);
}
/**
* Creates a shallow copy of the specified object.
*
* @param obj Object to copy.
* @return A shallow copy of the specified object.
*/
stock JSON_Object json_copy_shallow(JSON_Object obj)
{
bool isArray = obj.IsArray;
JSON_Object result = isArray
? view_as<JSON_Object>(new JSON_Array())
: new JSON_Object();
if (isArray) {
view_as<JSON_Array>(result).Concat(view_as<JSON_Array>(obj));
} else {
result.Merge(obj);
}
return result;
}
/**
* Creates a deep copy of the specified object.
*
* @param obj Object to copy.
* @return A deep copy of the specified object.
*/
stock JSON_Object json_copy_deep(JSON_Object obj)
{
JSON_Object result = json_copy_shallow(obj);
int length = obj.Iterate();
int key_length = 0;
for (int i = 0; i < length; i += 1) {
key_length = obj.GetKeySize(i);
char[] key = new char[key_length];
obj.GetKey(i, key, key_length);
// only deep copy objects
JSONCellType type = obj.GetType(key);
if (type != JSON_Type_Object) {
continue;
}
JSON_Object value = obj.GetObject(key);
result.SetObject(key, json_copy_deep(value));
}
return result;
}
/**
* Recursively cleans up the instance and any instances stored within.
*
* @param obj Object to clean up.
*/
stock void json_cleanup(JSON_Object obj)
{
if (obj == null) {
return;
}
int length = obj.Iterate();
int key_length = 0;
for (int i = 0; i < length; i += 1) {
key_length = obj.GetKeySize(i);
char[] key = new char[key_length];
obj.GetKey(i, key, key_length);
// only clean up objects
JSONCellType type = obj.GetType(key);
if (type != JSON_Type_Object) {
continue;
}
JSON_Object value = obj.GetObject(key);
if (value != null) {
json_cleanup(value);
}
}
delete obj.Snap;
obj.Super.Cleanup();
}
/**
* Cleans up an object and sets the passed variable to null.
*
* @param obj Object to clean up.
*/
stock void json_cleanup_and_delete(JSON_Object &obj)
{
json_cleanup(obj);
obj = null;
}