ngx_open_file_cache.c

来自「Nginx是一个高性能的HTTP和反向代理服务器」· C语言 代码 · 共 820 行 · 第 1/2 页

        cache->current--;

        if (file->count == 0) {

	    if (file->fd != NGX_INVALID_FILE) {
		if (ngx_close_file(file->fd) == NGX_FILE_ERROR) {
		    ngx_log_error(NGX_LOG_ALERT, pool->log, ngx_errno,
				  ngx_close_file_n " \"%s\" failed",
                                  file->name);
		}
	    }

            ngx_free(file->name);
            ngx_free(file);

        } else {
            file->close = 1;
        }
    }

    if (of->fd != NGX_INVALID_FILE) {
        if (ngx_close_file(of->fd) == NGX_FILE_ERROR) {
            ngx_log_error(NGX_LOG_ALERT, pool->log, ngx_errno,
                          ngx_close_file_n " \"%s\" failed", name->data);
        }
    }

    return NGX_ERROR;
}


static ngx_int_t
ngx_open_and_stat_file(u_char *name, ngx_open_file_info_t *of, ngx_log_t *log)
{
    ngx_fd_t         fd;
    ngx_file_info_t  fi;

    of->fd = NGX_INVALID_FILE;

    if (of->test_dir) {

        if (ngx_file_info(name, &fi) == -1) {
            of->err = ngx_errno;

            return NGX_ERROR;
        }

        of->uniq = ngx_file_uniq(&fi);
        of->mtime = ngx_file_mtime(&fi);
        of->size = ngx_file_size(&fi);
        of->is_dir = ngx_is_dir(&fi);
        of->is_file = ngx_is_file(&fi);
        of->is_link = ngx_is_link(&fi);
        of->is_exec = ngx_is_exec(&fi);

        if (of->is_dir) {
            return NGX_OK;
        }
    }

    fd = ngx_open_file(name, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0);

    if (fd == NGX_INVALID_FILE) {
        of->err = ngx_errno;
        return NGX_ERROR;
    }

    if (ngx_fd_info(fd, &fi) == NGX_FILE_ERROR) {
        ngx_log_error(NGX_LOG_CRIT, log, ngx_errno,
                      ngx_fd_info_n " \"%s\" failed", name);

        if (ngx_close_file(fd) == NGX_FILE_ERROR) {
            ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                          ngx_close_file_n " \"%s\" failed", name);
        }

        return NGX_ERROR;
    }

    if (ngx_is_dir(&fi)) {
        if (ngx_close_file(fd) == NGX_FILE_ERROR) {
            ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                          ngx_close_file_n " \"%s\" failed", name);
        }

        fd = NGX_INVALID_FILE;
    }

    of->fd = fd;
    of->uniq = ngx_file_uniq(&fi);
    of->mtime = ngx_file_mtime(&fi);
    of->size = ngx_file_size(&fi);
    of->is_dir = ngx_is_dir(&fi);
    of->is_file = ngx_is_file(&fi);
    of->is_link = ngx_is_link(&fi);
    of->is_exec = ngx_is_exec(&fi);

    return NGX_OK;
}


/*
 * we ignore any possible event setting error and
 * fallback to usual periodic file retests
 */

static void
ngx_open_file_add_event(ngx_open_file_cache_t *cache,
    ngx_cached_open_file_t *file, ngx_open_file_info_t *of, ngx_log_t *log)
{
    ngx_open_file_cache_event_t  *fev;

    if (!(ngx_event_flags & NGX_USE_VNODE_EVENT)
        || !of->events
        || file->event
        || of->fd == NGX_INVALID_FILE
        || file->uses < of->min_uses)
    {
        return;
    }

    file->event = ngx_calloc(sizeof(ngx_event_t), log);
    if (file->event== NULL) {
        return;
    }

    fev = ngx_alloc(sizeof(ngx_open_file_cache_event_t), log);
    if (fev == NULL) {
        ngx_free(file->event);
        file->event = NULL;
        return;
    }

    fev->fd = of->fd;
    fev->file = file;
    fev->cache = cache;

    file->event->handler = ngx_open_file_cache_remove;
    file->event->data = fev;

    /*
     * although vnode event may be called while ngx_cycle->poll
     * destruction, however, cleanup procedures are run before any
     * memory freeing and events will be canceled.
     */

    file->event->log = ngx_cycle->log;

    if (ngx_add_event(file->event, NGX_VNODE_EVENT, NGX_ONESHOT_EVENT)
        != NGX_OK)
    {
        ngx_free(file->event->data);
        ngx_free(file->event);
        file->event = NULL;
        return;
    }

    /*
     * we do not file->use_event here because there may be a race
     * condition between opening file and adding event, so we rely
     * upon event notification only after first file revalidation
     */

    return;
}


static void
ngx_open_file_cleanup(void *data)
{
    ngx_open_file_cache_cleanup_t  *c = data;

    c->file->count--;

    ngx_close_cached_file(c->cache, c->file, c->min_uses, c->log);

    /* drop one or two expired open files */
    ngx_expire_old_cached_files(c->cache, 1, c->log);
}


static void
ngx_close_cached_file(ngx_open_file_cache_t *cache,
    ngx_cached_open_file_t *file, ngx_uint_t min_uses, ngx_log_t *log)
{
    ngx_log_debug5(NGX_LOG_DEBUG_CORE, log, 0,
                   "close cached open file: %s, fd:%d, c:%d, u:%d, %d",
                   file->name, file->fd, file->count, file->uses, file->close);

    if (!file->close) {

        file->accessed = ngx_time();

        ngx_queue_remove(&file->queue);

        ngx_queue_insert_head(&cache->expire_queue, &file->queue);

        if (file->uses >= min_uses || file->count) {
            return;
        }
    }

    ngx_open_file_del_event(file);

    if (file->count) {
        return;
    }

    if (file->fd != NGX_INVALID_FILE) {

        if (ngx_close_file(file->fd) == NGX_FILE_ERROR) {
            ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                          ngx_close_file_n " \"%s\" failed", file->name);
        }

        file->fd = NGX_INVALID_FILE;
    }

    if (!file->close) {
        return;
    }

    ngx_free(file->name);
    ngx_free(file);
}


static void
ngx_open_file_del_event(ngx_cached_open_file_t *file)
{
    if (file->event == NULL) {
        return;
    }

    (void) ngx_del_event(file->event, NGX_VNODE_EVENT,
                         file->count ? NGX_FLUSH_EVENT : NGX_CLOSE_EVENT);

    ngx_free(file->event->data);
    ngx_free(file->event);
    file->event = NULL;
    file->use_event = 0;
}


static void
ngx_expire_old_cached_files(ngx_open_file_cache_t *cache, ngx_uint_t n,
    ngx_log_t *log)
{
    time_t                   now;
    ngx_queue_t             *q;
    ngx_cached_open_file_t  *file;

    now = ngx_time();

    /*
     * n == 1 deletes one or two inactive files
     * n == 0 deletes least recently used file by force
     *        and one or two inactive files
     */

    while (n < 3) {

        if (ngx_queue_empty(&cache->expire_queue)) {
            return;
        }

        q = ngx_queue_last(&cache->expire_queue);

        file = ngx_queue_data(q, ngx_cached_open_file_t, queue);

        if (n++ != 0 && now - file->accessed <= cache->inactive) {
            return;
        }

        ngx_queue_remove(q);

        ngx_rbtree_delete(&cache->rbtree, &file->node);

        cache->current--;

        ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0,
                       "expire cached open file: %s", file->name);

        if (!file->err && !file->is_dir) {
            file->close = 1;
            ngx_close_cached_file(cache, file, 0, log);

        } else {
            ngx_free(file->name);
            ngx_free(file);
        }
    }
}


static void
ngx_open_file_cache_rbtree_insert_value(ngx_rbtree_node_t *temp,
    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel)
{
    ngx_rbtree_node_t       **p;
    ngx_cached_open_file_t    *file, *file_temp;

    for ( ;; ) {

        if (node->key < temp->key) {

            p = &temp->left;

        } else if (node->key > temp->key) {

            p = &temp->right;

        } else { /* node->key == temp->key */

            file = (ngx_cached_open_file_t *) node;
            file_temp = (ngx_cached_open_file_t *) temp;

            p = (ngx_strcmp(file->name, file_temp->name) < 0)
                    ? &temp->left : &temp->right;
        }

        if (*p == sentinel) {
            break;
        }

        temp = *p;
    }

    *p = node;
    node->parent = temp;
    node->left = sentinel;
    node->right = sentinel;
    ngx_rbt_red(node);
}


static ngx_cached_open_file_t *
ngx_open_file_lookup(ngx_open_file_cache_t *cache, ngx_str_t *name,
    uint32_t hash)
{
    ngx_int_t                rc;
    ngx_rbtree_node_t       *node, *sentinel;
    ngx_cached_open_file_t  *file;

    node = cache->rbtree.root;
    sentinel = cache->rbtree.sentinel;

    while (node != sentinel) {

        if (hash < node->key) {
            node = node->left;
            continue;
        }

        if (hash > node->key) {
            node = node->right;
            continue;
        }

        /* hash == node->key */

        do {
            file = (ngx_cached_open_file_t *) node;

            rc = ngx_strcmp(name->data, file->name);

            if (rc == 0) {
                return file;
            }

            node = (rc < 0) ? node->left : node->right;

        } while (node != sentinel && hash == node->key);

        break;
    }

    return NULL;
}


static void
ngx_open_file_cache_remove(ngx_event_t *ev)
{
    ngx_cached_open_file_t       *file;
    ngx_open_file_cache_event_t  *fev;

    fev = ev->data;
    file = fev->file;

    ngx_queue_remove(&file->queue);

    ngx_rbtree_delete(&fev->cache->rbtree, &file->node);

    fev->cache->current--;

    /* NGX_ONESHOT_EVENT was already deleted */
    file->event = NULL;

    file->close = 1;

    ngx_close_cached_file(fev->cache, file, 0, ev->log);

    /* free memory only when fev->cache and fev->file are already not needed */

    ngx_free(ev->data);
    ngx_free(ev);
}