telodendria/src/Db.c

/*
 * Copyright (C) 2022 Jordan Bancino <@jordan:bancino.net>
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include <Db.h>

#include <Memory.h>
#include <Json.h>

#include <pthread.h>

struct Db
{
    const char *dir;
    size_t cacheSize;
    size_t maxCache;
    pthread_mutex_t lock;

    HashMap *cache;
};

struct DbRef
{
    HashMap *json;
    pthread_mutex_t lock;

    unsigned long ts;
    char *file;
};

static ssize_t DbComputeSize(HashMap *);

static ssize_t
DbComputeSizeOfValue(JsonValue * val)
{
    MemoryInfo *a;
    ssize_t total = 0;

    size_t i;

    union
    {
        char *str;
        Array *arr;
    } u;

    if (!val)
    {
        return -1;
    }

    a = MemoryInfoGet(val);
    if (a)
    {
        total += MemoryInfoGetSize(a);
    }

    switch (JsonValueType(val))
    {
        case JSON_OBJECT:
            total += DbComputeSize(JsonValueAsObject(val));
            break;
        case JSON_ARRAY:
            u.arr = JsonValueAsArray(val);
            a = MemoryInfoGet(u.arr);

            if (a)
            {
                total += MemoryInfoGetSize(a);
            }

            for (i = 0; i < ArraySize(u.arr); i++)
            {
                total += DbComputeSizeOfValue(ArrayGet(u.arr, i));
            }
            break;
        case JSON_STRING:
            u.str = JsonValueAsString(val);
            a = MemoryInfoGet(u.str);
            if (a)
            {
                total += MemoryInfoGetSize(a);
            }
            break;
        case JSON_NULL:
        case JSON_INTEGER:
        case JSON_FLOAT:
        case JSON_BOOLEAN:
        default:
            /* These don't use any extra heap space */
            break;
    }
    return total;
}

static ssize_t
DbComputeSize(HashMap * json)
{
    char *key;
    JsonValue *val;
    MemoryInfo *a;
    size_t total;

    if (!json)
    {
        return -1;
    }

    total = 0;

    a = MemoryInfoGet(json);
    if (a)
    {
        total += MemoryInfoGetSize(a);
    }

    while (HashMapIterate(json, &key, (void **) &val))
    {
        a = MemoryInfoGet(key);
        if (a)
        {
            total += MemoryInfoGetSize(a);
        }

        total += DbComputeSizeOfValue(val);
    }

    return total;
}

Db *
DbOpen(const char *dir, size_t cache)
{
    Db *db;

    if (!dir)
    {
        return NULL;
    }

    db = Malloc(sizeof(Db));
    if (!db)
    {
        return NULL;
    }

    db->dir = dir;
    db->maxCache = cache;

    pthread_mutex_init(&db->lock, NULL);

    if (db->maxCache)
    {
        db->cache = HashMapCreate();
        if (!db->cache)
        {
            return NULL;
        }
    }

    return db;
}

void
DbClose(Db * db)
{
    if (!db)
    {
        return;
    }

    pthread_mutex_destroy(&db->lock);
    HashMapFree(db->cache);

    Free(db);
}

DbRef *
DbCreate(Db * db, char *prefix, char *key)
{
    if (!db || !prefix || !key)
    {
        return NULL;
    }

    return NULL;
}

DbRef *
DbLock(Db * db, char *prefix, char *key)
{
    if (!db || !prefix || !key)
    {
        return NULL;
    }

    pthread_mutex_lock(&db->lock);

    pthread_mutex_unlock(&db->lock);
    return NULL;
}

void
DbUnlock(Db * db, DbRef * ref)
{
    if (!db || !ref)
    {
        return;
    }

    pthread_mutex_lock(&db->lock);

    pthread_mutex_unlock(&db->lock);

    return;
}

HashMap *
DbJson(DbRef * ref)
{
    return ref ? ref->json : NULL;
}