#include "cache.h"
#include "common.h"

struct cache_op {
    u_int8_t key[CACHE_KEY];

    struct cache_nest *nest;

    u_int8_t obj_nest;
    u_int32_t obj_offset;
    u_int16_t obj_length:

    void *mmap_addr;
    
    // for linked lists
    struct cache_op *next;
};

int _cache_op_get (struct cache_op **op_info, struct cache *cache_info, u_int8_t key[CACHE_KEY_SIZE]) {
    struct cache_op *op;

    // first, search the read queue
    for (op = cache_info->rop_list; op; op = op->next) {
        if (memcmp(op->key, key, CACHE_KEY_SIZE))
            break;
    }

    if (!op) {
        // look for in-progress write ops
        for (int i = 0; i < CACHE_NEST_COUNT; i++) {
            op = ctx->nests[i].op;

            if (op && memcmp(op->key, key, CACHE_KEY_SIZE))
                break;
    }

    if (!op) {
        // look for queued write ops
        for (op = cache_info->wop_list; op; op = op->next) {
            if (memcmp(op->key, key, CACHE_KEY_SIZE))
                break;
        }
    }

    if (!op) {
        // alloc a new op struct
        op = calloc(1, sizeof(*op));
        
        // look it up in the index
        if (_cache_index_find(cache_info->index, key, &op->nest, &op->obj_offset, &op->obj_length) == 0) {
            // found it in some nest
            
            // XXX: enter read list and start read

        } else {
            // not in the cache, try and find an unused nest to write it
            if (_cache_nest_assign_op(cache_info, op, &op->nest) == 0) {
                // excellent, we can start writing directly
                
                // XXX: start writing

            } else {
                // enter the wait queue...
                
                // XXX: enter write queue
            }
        }
    } else {
        // XXX: start reading
    }
}