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View File Name : instance.cc

/*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 * 
 *  Libmemcached library
 *
 *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
 *  Copyright (C) 2006-2009 Brian Aker All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are
 *  met:
 *
 *      * Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *      * Redistributions in binary form must reproduce the above
 *  copyright notice, this list of conditions and the following disclaimer
 *  in the documentation and/or other materials provided with the
 *  distribution.
 *
 *      * The names of its contributors may not be used to endorse or
 *  promote products derived from this software without specific prior
 *  written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <libmemcached/common.h>

static inline void _server_init(memcached_instance_st* self, Memcached *root,
                                const memcached_string_t& hostname,
                                in_port_t port,
                                uint32_t weight, memcached_connection_t type)
{
  self->options.is_shutting_down= false;
  self->options.is_dead= false;
  self->options.ready= false;
  self->_events= 0;
  self->_revents= 0;
  self->cursor_active_= 0;
  self->port_= port;
  self->fd= INVALID_SOCKET;
  self->io_bytes_sent= 0;
  self->request_id= 0;
  self->server_failure_counter= 0;
  self->server_failure_counter_query_id= 0;
  self->server_timeout_counter= 0;
  self->server_timeout_counter_query_id= 0;
  self->weight= weight ? weight : 1; // 1 is the default weight value
  self->io_wait_count.read= 0;
  self->io_wait_count.write= 0;
  self->io_wait_count.timeouts= 0;
  self->io_wait_count._bytes_read= 0;
  self->major_version= UINT8_MAX;
  self->micro_version= UINT8_MAX;
  self->minor_version= UINT8_MAX;
  self->type= type;
  self->error_messages= NULL;
  self->read_ptr= self->read_buffer;
  self->read_buffer_length= 0;
  self->read_data_length= 0;
  self->write_buffer_offset= 0;
  self->address_info= NULL;
  self->address_info_next= NULL;

  self->state= MEMCACHED_SERVER_STATE_NEW;
  self->next_retry= 0;

  self->root= root;
  if (root)
  {
    self->version= ++root->server_info.version;
  }
  else
  {
    self->version= UINT_MAX;
  }
  self->limit_maxbytes= 0;
  self->hostname(hostname);
}

static memcached_instance_st* _server_create(memcached_instance_st* self, const memcached_st *memc)
{
  if (self == NULL)
  {
   self= libmemcached_xmalloc(memc, memcached_instance_st);

    if (self == NULL)
    {
      return NULL; /*  MEMCACHED_MEMORY_ALLOCATION_FAILURE */
    }

    self->options.is_allocated= true;
  }
  else
  {
    self->options.is_allocated= false;
  }

  self->options.is_initialized= true;

  return self;
}

void memcached_instance_st::events(short arg)
{
  if ((_events | arg) == _events)
  {
    return;
  }

  _events|= arg;
}

void memcached_instance_st::revents(short arg)
{
  if (arg)
  {
    options.ready= true;
  }

  _revents= arg;
  _events&= short(~arg);
}

memcached_instance_st* __instance_create_with(memcached_st *memc,
                                                    memcached_instance_st* self,
                                                    const memcached_string_t& hostname,
                                                    const in_port_t port,
                                                    uint32_t weight, 
                                                    const memcached_connection_t type)
{
  if (memcached_is_valid_servername(hostname) == false)
  {
    memcached_set_error(*memc, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT, memcached_literal_param("Invalid hostname provided"));
    return NULL;
  }

  self= _server_create(self, memc);

  if (self == NULL)
  {
    return NULL;
  }

  _server_init(self, const_cast<memcached_st *>(memc), hostname, port, weight, type);

  if (memc and memcached_is_udp(memc))
  { 
    self->write_buffer_offset= UDP_DATAGRAM_HEADER_LENGTH;
    memcached_io_init_udp_header(self, 0);
  }

  return self;
}

void __instance_free(memcached_instance_st* self)
{
  memcached_quit_server(self, false);

  self->clear_addrinfo();
  assert(self->address_info_next == NULL);

  memcached_error_free(*self);

  if (memcached_is_allocated(self))
  {
    libmemcached_free(self->root, self);
  }
  else
  {
    self->options.is_initialized= false;
  }
}

void memcached_instance_free(memcached_instance_st* self)
{
  if (self)
  {
    __instance_free(self);
  }
}

memcached_return_t memcached_server_cursor(const memcached_st* shell,
                                           const memcached_server_fn *callback,
                                           void *context,
                                           uint32_t number_of_callbacks)
{
  const Memcached* memc= memcached2Memcached(shell);
  memcached_return_t rc;
  if (memcached_failed(rc= initialize_const_query(memc)))
  {
    return rc;
  }

  size_t errors= 0;
  for (uint32_t x= 0; x < memcached_instance_list_count(memc); x++)
  {
    memcached_instance_st* instance= memcached_instance_by_position(memc, x);

    for (uint32_t y= 0; y < number_of_callbacks; y++)
    {
      memcached_return_t ret= (*callback[y])(memc, instance, context);

      if (memcached_failed(ret))
      {
        errors++;
        continue;
      }
    }
  }

  return errors ? MEMCACHED_SOME_ERRORS : MEMCACHED_SUCCESS;
}

memcached_return_t memcached_server_execute(memcached_st *memc,
                                            memcached_server_execute_fn callback,
                                            void *context)
{
  if (callback == NULL)
  {
    return MEMCACHED_INVALID_ARGUMENTS;
  }

  bool some_errors= false;;
  for (uint32_t x= 0; x < memcached_instance_list_count(memc); x++)
  {
    memcached_instance_st* instance= memcached_instance_fetch(memc, x);

    memcached_return_t rc= (*callback)(memc, instance, context);
    if (rc == MEMCACHED_INVALID_ARGUMENTS)
    {
      return rc;
    }
    else if (memcached_fatal(rc))
    {
      some_errors= true;
    }
  }

  (void)some_errors;
  return MEMCACHED_SUCCESS;
}

const memcached_instance_st * memcached_server_by_key(memcached_st *shell,
                                                     const char *key,
                                                     size_t key_length,
                                                     memcached_return_t *error)
{
  Memcached* memc= memcached2Memcached(shell);
  memcached_return_t unused;
  if (error == NULL)
  {
    error= &unused;
  }


  memcached_return_t rc;
  if (memcached_failed(rc= initialize_const_query(memc)))
  {
    *error= rc;
    return NULL;
  }

  if (memcached_failed((memcached_key_test(*memc, (const char **)&key, &key_length, 1))))
  {
    *error= memcached_last_error(memc);
    return NULL;
  }

  uint32_t server_key= memcached_generate_hash(memc, key, key_length);
  return memcached_instance_by_position(memc, server_key);
}

/*
  If we do not have a valid object to clone from, we toss an error.
*/
static memcached_instance_st* memcached_instance_clone(memcached_instance_st* source)
{
  /* We just do a normal create if source is missing */
  if (source == NULL)
  {
    return NULL;
  }

  memcached_string_t hostname_= { memcached_string_make_from_cstr(source->hostname()) };
  return __instance_create_with(source->root,
                                NULL,
                                hostname_,
                                source->port(), source->weight,
                                source->type);
}

void set_last_disconnected_host(memcached_instance_st* self)
{
  assert(self->root);
  if (self->root)
  {
    if (memcached_server_get_last_disconnect(self->root) and
        memcached_server_get_last_disconnect(self->root)->version == self->version)
    {
      return;
    }

    // const_cast
    memcached_st *root= (memcached_st *)self->root;

    memcached_instance_free((memcached_instance_st*)(root->last_disconnected_server));

    // We set is_parsing so that no lookup happens
    root->state.is_parsing= true;
    root->last_disconnected_server= memcached_instance_clone(self);
    root->state.is_parsing= false;

    ((memcached_instance_st*)memcached_server_get_last_disconnect(root))->version= self->version;
  }
}

const memcached_instance_st * memcached_server_get_last_disconnect(const memcached_st *shell)
{
  const Memcached* self= memcached2Memcached(shell);
  if (self)
  {
    return (const memcached_instance_st *)self->last_disconnected_server;
  }

  return 0;
}

void memcached_instance_next_retry(const memcached_instance_st * self, const time_t absolute_time)
{
  WATCHPOINT_ASSERT(self);
  if (self)
  {
    ((memcached_instance_st*)self)->next_retry= absolute_time;
  }
}

bool memcached_instance_st::valid() const
{
  if (fd == INVALID_SOCKET)
  {
    return false;
  }

  return true;
}

bool memcached_instance_st::is_shutting_down() const
{
  return options.is_shutting_down;
}