/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.

*

* 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 "uv.h"

#include "uv-common.h"

#ifdef _WIN32

#include "win/internal.h"

#include "win/handle-inl.h"

#define uv__make_close_pending(h) uv__want_endgame((h)->loop, (h))

#else

#include "unix/internal.h"

#endif

#include <assert.h>

#include <stdlib.h>

#include <string.h>

struct poll_ctx {

uv_fs_poll_t* parent_handle;

int busy_polling;

unsigned int interval;

uint64_t start_time;

uv_loop_t* loop;

uv_fs_poll_cb poll_cb;

uv_timer_t timer_handle;

uv_fs_t fs_req; /* TODO(bnoordhuis) mark fs_req internal */

uv_stat_t statbuf;

struct poll_ctx* previous; /* context from previous start()..stop() period */

char path[1]; /* variable length */

};

static int statbuf_eq(const uv_stat_t* a, const uv_stat_t* b);

static void poll_cb(uv_fs_t* req);

static void timer_cb(uv_timer_t* timer);

static void timer_close_cb(uv_handle_t* timer);

static uv_stat_t zero_statbuf;

int uv_fs_poll_init(uv_loop_t* loop, uv_fs_poll_t* handle) {

uv__handle_init(loop, (uv_handle_t*)handle, UV_FS_POLL);

handle->poll_ctx = NULL;

return 0;

}

int uv_fs_poll_start(uv_fs_poll_t* handle,

uv_fs_poll_cb cb,

const char* path,

unsigned int interval) {

struct poll_ctx* ctx;

uv_loop_t* loop;

size_t len;

int err;

if (uv_is_active((uv_handle_t*)handle))

return 0;

loop = handle->loop;

len = strlen(path);

ctx = uv__calloc(1, sizeof(*ctx) + len);

if (ctx == NULL)

return UV_ENOMEM;

ctx->loop = loop;

ctx->poll_cb = cb;

ctx->interval = interval ? interval : 1;

ctx->start_time = uv_now(loop);

ctx->parent_handle = handle;

memcpy(ctx->path, path, len + 1);

err = uv_timer_init(loop, &ctx->timer_handle);

if (err < 0)

goto error;

ctx->timer_handle.flags |= UV_HANDLE_INTERNAL;

uv__handle_unref(&ctx->timer_handle);

err = uv_fs_stat(loop, &ctx->fs_req, ctx->path, poll_cb);

if (err < 0)

goto error;

if (handle->poll_ctx != NULL)

ctx->previous = handle->poll_ctx;

handle->poll_ctx = ctx;

uv__handle_start(handle);

return 0;

error:

uv__free(ctx);

return err;

}

int uv_fs_poll_stop(uv_fs_poll_t* handle) {

struct poll_ctx* ctx;

if (!uv_is_active((uv_handle_t*)handle))

return 0;

ctx = handle->poll_ctx;

assert(ctx != NULL);

assert(ctx->parent_handle == handle);

/* Close the timer if it's active. If it's inactive, there's a stat request

* in progress and poll_cb will take care of the cleanup.

*/

if (uv_is_active((uv_handle_t*)&ctx->timer_handle))

uv_close((uv_handle_t*)&ctx->timer_handle, timer_close_cb);

uv__handle_stop(handle);

return 0;

}

int uv_fs_poll_getpath(uv_fs_poll_t* handle, char* buffer, size_t* size) {

struct poll_ctx* ctx;

size_t required_len;

if (buffer == NULL || size == NULL || *size == 0)

return UV_EINVAL;

if (!uv_is_active((uv_handle_t*)handle)) {

*size = 0;

return UV_EINVAL;

}

ctx = handle->poll_ctx;

assert(ctx != NULL);

required_len = strlen(ctx->path);

if (required_len >= *size) {

*size = required_len + 1;

return UV_ENOBUFS;

}

memcpy(buffer, ctx->path, required_len);

*size = required_len;

buffer[required_len] = '\0';

return 0;

}

void uv__fs_poll_close(uv_fs_poll_t* handle) {

uv_fs_poll_stop(handle);

if (handle->poll_ctx == NULL)

uv__make_close_pending((uv_handle_t*)handle);

}

static void timer_cb(uv_timer_t* timer) {

struct poll_ctx* ctx;

ctx = container_of(timer, struct poll_ctx, timer_handle);

assert(ctx->parent_handle != NULL);

assert(ctx->parent_handle->poll_ctx == ctx);

ctx->start_time = uv_now(ctx->loop);

if (uv_fs_stat(ctx->loop, &ctx->fs_req, ctx->path, poll_cb))

abort();

}

static void poll_cb(uv_fs_t* req) {

uv_stat_t* statbuf;

struct poll_ctx* ctx;

uint64_t interval;

uv_fs_poll_t* handle;

ctx = container_of(req, struct poll_ctx, fs_req);

handle = ctx->parent_handle;

if (!uv_is_active((uv_handle_t*)handle) || uv__is_closing(handle))

goto out;

if (req->result != 0) {

if (ctx->busy_polling != req->result) {

ctx->poll_cb(ctx->parent_handle,

req->result,

&ctx->statbuf,

&zero_statbuf);

ctx->busy_polling = req->result;

}

goto out;

}

statbuf = &req->statbuf;

if (ctx->busy_polling != 0)

if (ctx->busy_polling < 0 || !statbuf_eq(&ctx->statbuf, statbuf))

ctx->poll_cb(ctx->parent_handle, 0, &ctx->statbuf, statbuf);

ctx->statbuf = *statbuf;

ctx->busy_polling = 1;

out:

uv_fs_req_cleanup(req);

if (!uv_is_active((uv_handle_t*)handle) || uv__is_closing(handle)) {

uv_close((uv_handle_t*)&ctx->timer_handle, timer_close_cb);

return;

}

/* Reschedule timer, subtract the delay from doing the stat(). */

interval = ctx->interval;

interval -= (uv_now(ctx->loop) - ctx->start_time) % interval;

if (uv_timer_start(&ctx->timer_handle, timer_cb, interval, 0))

abort();

}

static void timer_close_cb(uv_handle_t* timer) {

struct poll_ctx* ctx;

struct poll_ctx* it;

struct poll_ctx* last;

uv_fs_poll_t* handle;

ctx = container_of(timer, struct poll_ctx, timer_handle);

handle = ctx->parent_handle;

if (ctx == handle->poll_ctx) {

handle->poll_ctx = ctx->previous;

if (handle->poll_ctx == NULL && uv__is_closing(handle))

uv__make_close_pending((uv_handle_t*)handle);

} else {

for (last = handle->poll_ctx, it = last->previous;

it != ctx;

last = it, it = it->previous) {

assert(last->previous != NULL);

}

last->previous = ctx->previous;

}

uv__free(ctx);

}

static int statbuf_eq(const uv_stat_t* a, const uv_stat_t* b) {

return a->st_ctim.tv_nsec == b->st_ctim.tv_nsec

&& a->st_mtim.tv_nsec == b->st_mtim.tv_nsec

&& a->st_birthtim.tv_nsec == b->st_birthtim.tv_nsec

&& a->st_ctim.tv_sec == b->st_ctim.tv_sec

&& a->st_mtim.tv_sec == b->st_mtim.tv_sec

&& a->st_birthtim.tv_sec == b->st_birthtim.tv_sec

&& a->st_size == b->st_size

&& a->st_mode == b->st_mode

&& a->st_uid == b->st_uid

&& a->st_gid == b->st_gid

&& a->st_ino == b->st_ino

&& a->st_dev == b->st_dev

&& a->st_flags == b->st_flags

&& a->st_gen == b->st_gen;

}

#if defined(_WIN32)

#include "win/internal.h"

#include "win/handle-inl.h"

void uv__fs_poll_endgame(uv_loop_t* loop, uv_fs_poll_t* handle) {

assert(handle->flags & UV_HANDLE_CLOSING);

assert(!(handle->flags & UV_HANDLE_CLOSED));

uv__handle_close(handle);

}

#endif /* _WIN32 */