JSONSerialization.c

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/*
 * Objectively: Ultra-lightweight object oriented framework for GNU C.
 * Copyright (C) 2014 Jay Dolan <jay@jaydolan.com>
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 *
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 *
 * 3. This notice may not be removed or altered from any source distribution.
 */
 
#include <assert.h>
#include <stdlib.h>
#include <string.h>
 
#include "Boole.h"
#include "JSONSerialization.h"
#include "MutableData.h"
#include "MutableDictionary.h"
#include "MutableArray.h"
#include "Null.h"
#include "Number.h"
#include "String.h"
 
#define _Class _JSONSerialization
 
#pragma mark - JSONSerialization
 
typedef struct {
    MutableData *data;
    int options;
    size_t depth;
} JSONWriter;
 
static void writeElement(JSONWriter *writer, const ident obj);
 
static void writeNull(JSONWriter *writer, const Null *null) {
 
    $(writer->data, appendBytes, (uint8_t *) "null", 4);
}
 
static void writeBoole(JSONWriter *writer, const Boole *boolean) {
 
    if (boolean->value) {
        $(writer->data, appendBytes, (uint8_t *) "true", 4);
    } else {
        $(writer->data, appendBytes, (uint8_t *) "false", 5);
    }
}
 
static void writeString(JSONWriter *writer, const String *string) {
 
    $(writer->data, appendBytes, (uint8_t *) "\"", 1);
    $(writer->data, appendBytes, (uint8_t *) string->chars, string->length);
    $(writer->data, appendBytes, (uint8_t *) "\"", 1);
}
 
static void writeNumber(JSONWriter *writer, const Number *number) {
 
    String *string = $(alloc(String), initWithFormat, "%g", number->value);
 
    $(writer->data, appendBytes, (uint8_t *) string->chars, string->length);
 
    release(string);
}
 
static void writeLabel(JSONWriter *writer, const String *label) {
 
    writeString(writer, label);
    $(writer->data, appendBytes, (uint8_t *) ": ", 2);
}
 
static void writePretty(JSONWriter *writer) {
 
    if (writer->options & JSON_WRITE_PRETTY) {
        $(writer->data, appendBytes, (uint8_t *) "\n", 1);
        for (size_t i = 0; i < writer->depth; i++) {
            $(writer->data, appendBytes, (uint8_t *) "  ", 2);
        }
    }
}
 
static void writeObject(JSONWriter *writer, const Dictionary *object) {
 
    $(writer->data, appendBytes, (uint8_t * ) "{", 1);
    writer->depth++;
 
    Array *keys = $(object, allKeys);
    if (writer->options & JSON_WRITE_SORTED) {
        Array *sorted = $(keys, sortedArray, StringCompare);
        release(keys);
        keys = sorted;
    }
 
    for (size_t i = 0; i < keys->count; i++) {
 
        writePretty(writer);
 
        const ident key = $(keys, objectAtIndex, i);
        writeLabel(writer, (String *) key);
 
        const ident obj = $(object, objectForKey, key);
        writeElement(writer, obj);
 
        if (i < keys->count - 1) {
            $(writer->data, appendBytes, (uint8_t *) ",", 1);
        }
    }
 
    release(keys);
 
    writer->depth--;
    writePretty(writer);
 
    $(writer->data, appendBytes, (uint8_t * ) "}", 1);
}
 
static void writeArray(JSONWriter *writer, const Array *array) {
 
    $(writer->data, appendBytes, (uint8_t * ) "[", 1);
    writer->depth++;
 
    for (size_t i = 0; i < array->count; i++) {
 
        writePretty(writer);
        
        writeElement(writer, $(array, objectAtIndex, i));
 
        if (i < array->count - 1) {
            $(writer->data, appendBytes, (uint8_t *) ",", 1);
        }
    }
 
    writer->depth--;
    writePretty(writer);
 
    $(writer->data, appendBytes, (uint8_t * ) "]", 1);
}
 
static void writeElement(JSONWriter *writer, const ident obj) {
 
    const Object *object = cast(Object, obj);
    if (object) {
        if ($(object, isKindOfClass, _Dictionary())) {
            writeObject(writer, (const Dictionary *) object);
        } else if ($(object, isKindOfClass, _Array())) {
            writeArray(writer, (const Array *) object);
        } else if ($(object, isKindOfClass, _String())) {
            writeString(writer, (const String *) object);
        } else if ($(object, isKindOfClass, _Number())) {
            writeNumber(writer, (const Number *) object);
        } else if ($(object, isKindOfClass, _Boole())) {
            writeBoole(writer, (const Boole *) object);
        } else if ($(object, isKindOfClass, _Null())) {
            writeNull(writer, (const Null *) object);
        }
    }
}
 
static Data *dataFromObject(const ident obj, int options) {
 
    if (obj) {
        JSONWriter writer = {
            .data = $(alloc(MutableData), init),
            .options = options
        };
 
        writeObject(&writer, obj);
 
        return (Data *) writer.data;
    }
 
    return NULL;
}
 
typedef struct {
    const Data *data;
    int options;
    uint8_t *b;
} JSONReader;
 
static ident readElement(JSONReader *reader);
 
static int readByte(JSONReader *reader) {
 
    if (reader->b) {
        if (reader->b - reader->data->bytes < reader->data->length) {
            return (int) *(++(reader->b));
        }
    } else {
        if (reader->data->bytes) {
            return (int) *(reader->b = reader->data->bytes);
        }
    }
 
    return -1;
}
 
static int readByteUntil(JSONReader *reader, const char *stop) {
 
    int b;
 
    while (true) {
        b = readByte(reader);
        if (b == -1 || strchr(stop, b)) {
            break;
        }
    }
 
    return b;
}
 
static void consumeBytes(JSONReader *reader, const char *bytes) {
 
    for (size_t i = 1; i < strlen(bytes); i++) {
        int b = readByte(reader);
        assert(b == bytes[i]);
    }
}
 
static String *readString(JSONReader *reader) {
 
    uint8_t *bytes = reader->b;
 
    const int b = readByteUntil(reader, "\"");
    assert(b == '"');
 
    const size_t length = reader->b - bytes - 1;
    return $$(String, stringWithBytes, bytes + 1, length, STRING_ENCODING_UTF8);
}
 
static Number *readNumber(JSONReader *reader) {
 
    uint8_t *bytes = reader->b;
 
    uint8_t *end;
    double d = strtod((char *) bytes, (char **) &end);
 
    assert(end > bytes);
    reader->b = end - 1;
 
    return $$(Number, numberWithValue, d);
}
 
static _Bool *readBoole(JSONReader *reader) {
 
    Boole *boolean = NULL;
 
    switch (*reader->b) {
        case 't':
            consumeBytes(reader, "true");
            boolean = $$(Boole, True);
            break;
        case 'f':
            consumeBytes(reader, "false");
            boolean = $$(Boole, False);
            break;
        default:
            assert(false);
    }
 
    return retain(boolean);
}
 
static Null *readNull(JSONReader *reader) {
 
    consumeBytes(reader, "null");
 
    Null *null = $$(Null, null);
 
    return retain(null);
}
 
static String *readLabel(JSONReader *reader) {
 
    const int b = readByteUntil(reader, "\"}");
    if (b == '"') {
        return readString(reader);
    } if (b == '}') {
        reader->b--;
    }
 
    return NULL;
}
 
static Dictionary *readObject(JSONReader *reader) {
 
    MutableDictionary *object = $(alloc(MutableDictionary), init);
 
    while (true) {
 
        String *key = readLabel(reader);
        if (key == NULL) {
            const int b = readByteUntil(reader, "}");
            assert(b == '}');
            break;
        }
 
        const int b = readByteUntil(reader, ":");
        assert(b == ':');
 
        ident obj = readElement(reader);
        assert(obj);
 
        $(object, setObjectForKey, obj, key);
 
        release(key);
        release(obj);
    }
 
    return (Dictionary *) object;
}
 
static Array *readArray(JSONReader *reader) {
 
    MutableArray *array = $(alloc(MutableArray), init);
 
    while (true) {
 
        Object *obj = readElement(reader);
        if (obj == NULL) {
            const int b = readByteUntil(reader, "]");
            assert(b == ']');
            break;
        }
 
        $(array, addObject, obj);
 
        release(obj);
    }
 
    return (Array *) array;
}
 
static ident readElement(JSONReader *reader) {
 
    const int b = readByteUntil(reader, "{[\"tfn0123456789.-]}");
    if (b == '{') {
        return readObject(reader);
    } else if (b == '[') {
        return readArray(reader);
    } else if (b == '\"') {
        return readString(reader);
    } else if (b == 't' || b == 'f') {
        return readBoole(reader);
    } else if (b == 'n') {
        return readNull(reader);
    } else if (b == '.' || b == '-' || isdigit(b)) {
        return readNumber(reader);
    } else if (b == ']' || b == '}') {
        reader->b--;
    }
 
    return NULL;
}
 
static ident objectFromData(const Data *data, int options) {
 
    if (data && data->length) {
        JSONReader reader = {
            .data = data,
            .options = options
        };
 
        return readElement(&reader);
    }
 
    return NULL;
}
 
#pragma mark - Class lifecycle
 
static void initialize(Class *clazz) {
 
    ((JSONSerializationInterface *) clazz->interface)->dataFromObject = dataFromObject;
    ((JSONSerializationInterface *) clazz->interface)->objectFromData = objectFromData;
}
 
Class *_JSONSerialization(void) {
    static Class *clazz;
    static Once once;
 
    do_once(&once, {
        clazz = _initialize(&(const ClassDef) {
            .name = "JSONSerialization",
            .superclass = _Object(),
            .instanceSize = sizeof(JSONSerialization),
            .interfaceOffset = offsetof(JSONSerialization, interface),
            .interfaceSize = sizeof(JSONSerializationInterface),
            .initialize = initialize,
        });
    });
 
    return clazz;
}
 
#undef _Class