/*

 * Copyright (c) 2022 Fastly

 *

 * 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 substantial 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 "h2o.h"

#include <inttypes.h>

struct st_recycle_status_t {

    uint64_t chunks;

    uint64_t low_watermark;

};

struct st_memory_status_ctx_t {

    pthread_mutex_t mutex;

    struct st_recycle_status_t mem_pool, socket_ssl, socket_zerocopy;

    size_t socket_zerocopy_inflight;

};

static void recycle_status_per_thread(struct st_recycle_status_t *status, h2o_mem_recycle_t *recycle)

{

    status->chunks += recycle->chunks.size;

    status->low_watermark += recycle->low_watermark;

}

static void memory_status_per_thread(void *priv, h2o_context_t *ctx)

{

    struct st_memory_status_ctx_t *csc = priv;

    pthread_mutex_lock(&csc->mutex);

    recycle_status_per_thread(&csc->mem_pool, &h2o_mem_pool_allocator);

    recycle_status_per_thread(&csc->socket_ssl, &h2o_socket_ssl_buffer_allocator);

    recycle_status_per_thread(&csc->socket_zerocopy, &h2o_socket_zerocopy_buffer_allocator);

    csc->socket_zerocopy_inflight += h2o_socket_num_zerocopy_buffers_inflight;

    pthread_mutex_unlock(&csc->mutex);

}

static void *memory_status_init(void)

{

    struct st_memory_status_ctx_t *ret = h2o_mem_alloc(sizeof(*ret));

    *ret = (struct st_memory_status_ctx_t){PTHREAD_MUTEX_INITIALIZER};

    return ret;

}

static h2o_iovec_t memory_status_json(void *priv, h2o_globalconf_t *gconf, h2o_req_t *req)

{

    struct st_memory_status_ctx_t *csc = priv;

    h2o_iovec_t ret;

#define BUFSIZE 512

#define FMT(prefix)                                                                                                                \

    " \"memory." H2O_TO_STR(prefix) ".chunks\": %" PRIu64 ",\n \"memory." H2O_TO_STR(prefix) ".low_watermark\": %" PRIu64 ",\n"

#define ARGS(prefix) csc->prefix.chunks, csc->prefix.low_watermark

    ret.base = h2o_mem_alloc_pool(&req->pool, char, BUFSIZE);

    ret.len = snprintf(ret.base, BUFSIZE,

                       ",\n" FMT(mem_pool) FMT(socket.ssl) FMT(socket.zerocopy) " \"memory.socket.zerocopy.inflight\": %zu\n",

                       ARGS(mem_pool), ARGS(socket_ssl), ARGS(socket_zerocopy),

                       csc->socket_zerocopy_inflight * h2o_socket_zerocopy_buffer_allocator.conf->memsize);

#undef FMT

#undef ARGS

#undef BUFSIZE

    pthread_mutex_destroy(&csc->mutex);

    free(csc);

    return ret;

}

h2o_status_handler_t h2o_memory_status_handler = {

    {H2O_STRLIT("memory")},

    memory_status_json,

    memory_status_init,

    memory_status_per_thread,

};