src/vpp-api/client/stat_client.c - fdio/vpp - Gitiles

 /*
  *------------------------------------------------------------------
  * stat_client.c - Library for access to VPP statistics segment
  *
  * Copyright (c) 2018 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *------------------------------------------------------------------
  */

 #include <stdio.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <stdbool.h>
 #include <sys/stat.h>
 #include <regex.h>
 #include <assert.h>
 #include <vppinfra/vec.h>
 #include <vppinfra/lock.h>
 #include "stat_client.h"
 #include <stdatomic.h>
 #include <vpp/stats/stat_segment.h>

 struct stat_client_main_t
 {
   uint64_t current_epoch;
   stat_segment_shared_header_t *shared_header;
   stat_segment_directory_entry_t *directory_vector;
   ssize_t memory_size;
 };

 stat_client_main_t stat_client_main;

 stat_client_main_t *
 stat_client_get (void)
 {
   stat_client_main_t *sm;
   sm = (stat_client_main_t *) malloc (sizeof (stat_client_main_t));
   clib_memset (sm, 0, sizeof (stat_client_main_t));
   return sm;
 }

 void
 stat_client_free (stat_client_main_t * sm)
 {
   free (sm);
 }

 static int
 recv_fd (int sock)
 {
   struct msghdr msg = { 0 };
   struct cmsghdr *cmsg;
   int fd = -1;
   char iobuf[1];
   struct iovec io = {.iov_base = iobuf,.iov_len = sizeof (iobuf) };
   union
   {
     char buf[CMSG_SPACE (sizeof (fd))];
     struct cmsghdr align;
   } u;
   msg.msg_iov = &io;
   msg.msg_iovlen = 1;
   msg.msg_control = u.buf;
   msg.msg_controllen = sizeof (u.buf);

   ssize_t size;
   if ((size = recvmsg (sock, &msg, 0)) < 0)
     {
       perror ("recvmsg failed");
       return -1;
     }
   cmsg = CMSG_FIRSTHDR (&msg);
   if (cmsg && cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS)
     {
       memmove (&fd, CMSG_DATA (cmsg), sizeof (fd));
     }
   return fd;
 }

 static stat_segment_directory_entry_t *
 get_stat_vector_r (stat_client_main_t * sm)
 {
   ASSERT (sm->shared_header);
   return stat_segment_pointer (sm->shared_header,
 			       sm->shared_header->directory_offset);
 }

 static stat_segment_directory_entry_t *
 get_stat_vector (void)
 {
   stat_client_main_t *sm = &stat_client_main;
   return get_stat_vector_r (sm);
 }

 int
 stat_segment_connect_r (char *socket_name, stat_client_main_t * sm)
 {
   int mfd = -1;
   int sock;

   clib_memset (sm, 0, sizeof (*sm));
   if ((sock = socket (AF_UNIX, SOCK_SEQPACKET, 0)) < 0)
     {
       perror ("Stat client couldn't open socket");
       return -1;
     }

   struct sockaddr_un un = { 0 };
   un.sun_family = AF_UNIX;
   strncpy ((char *) un.sun_path, socket_name, sizeof (un.sun_path) - 1);
   if (connect (sock, (struct sockaddr *) &un, sizeof (struct sockaddr_un)) <
       0)
     {
       close (sock);
       return -1;
     }

   if ((mfd = recv_fd (sock)) < 0)
     {
       close (sock);
       fprintf (stderr, "Receiving file descriptor failed\n");
       return -1;
     }
   close (sock);

   /* mmap shared memory segment. */
   void *memaddr;
   struct stat st = { 0 };

   if (fstat (mfd, &st) == -1)
     {
       perror ("mmap fstat failed");
       return -1;
     }
   if ((memaddr =
        mmap (NULL, st.st_size, PROT_READ, MAP_SHARED, mfd, 0)) == MAP_FAILED)
     {
       perror ("mmap map failed");
       return -1;
     }

   sm->memory_size = st.st_size;
   sm->shared_header = memaddr;
   sm->directory_vector =
     stat_segment_pointer (memaddr, sm->shared_header->directory_offset);

   return 0;
 }

 int
 stat_segment_connect (char *socket_name)
 {
   stat_client_main_t *sm = &stat_client_main;
   return stat_segment_connect_r (socket_name, sm);
 }

 void
 stat_segment_disconnect_r (stat_client_main_t * sm)
 {
   munmap (sm->shared_header, sm->memory_size);
   return;
 }

 void
 stat_segment_disconnect (void)
 {
   stat_client_main_t *sm = &stat_client_main;
   return stat_segment_disconnect_r (sm);
 }

 double
 stat_segment_heartbeat_r (stat_client_main_t * sm)
 {
   stat_segment_directory_entry_t *vec = get_stat_vector_r (sm);
   double *hb = stat_segment_pointer (sm->shared_header, vec[4].offset);
   return *hb;
 }

 double
 stat_segment_heartbeat (void)
 {
   stat_client_main_t *sm = &stat_client_main;
   return stat_segment_heartbeat_r (sm);
 }

 stat_segment_data_t
 copy_data (stat_segment_directory_entry_t * ep, stat_client_main_t * sm)
 {
   stat_segment_data_t result = { 0 };
   int i;
   vlib_counter_t **combined_c;	/* Combined counter */
   counter_t **simple_c;		/* Simple counter */
   counter_t *error_base;
   uint64_t *offset_vector;

   assert (sm->shared_header);

   result.type = ep->type;
   result.name = strdup (ep->name);
   switch (ep->type)
     {
     case STAT_DIR_TYPE_SCALAR_INDEX:
       result.scalar_value = ep->value;
       break;

     case STAT_DIR_TYPE_COUNTER_VECTOR_SIMPLE:
       if (ep->offset == 0)
 	return result;
       simple_c = stat_segment_pointer (sm->shared_header, ep->offset);
       result.simple_counter_vec = vec_dup (simple_c);
       offset_vector =
 	stat_segment_pointer (sm->shared_header, ep->offset_vector);
       for (i = 0; i < vec_len (simple_c); i++)
 	{
 	  counter_t *cb =
 	    stat_segment_pointer (sm->shared_header, offset_vector[i]);
 	  result.simple_counter_vec[i] = vec_dup (cb);
 	}
       break;

     case STAT_DIR_TYPE_COUNTER_VECTOR_COMBINED:
       if (ep->offset == 0)
 	return result;
       combined_c = stat_segment_pointer (sm->shared_header, ep->offset);
       result.combined_counter_vec = vec_dup (combined_c);
       offset_vector =
 	stat_segment_pointer (sm->shared_header, ep->offset_vector);
       for (i = 0; i < vec_len (combined_c); i++)
 	{
 	  vlib_counter_t *cb =
 	    stat_segment_pointer (sm->shared_header, offset_vector[i]);
 	  result.combined_counter_vec[i] = vec_dup (cb);
 	}
       break;

     case STAT_DIR_TYPE_ERROR_INDEX:
       error_base =
 	stat_segment_pointer (sm->shared_header,
 			      sm->shared_header->error_offset);
       result.error_value = error_base[ep->index];
       break;

     default:
       fprintf (stderr, "Unknown type: %d", ep->type);
     }
   return result;
 }

 void
 stat_segment_data_free (stat_segment_data_t * res)
 {
   int i, j;
   for (i = 0; i < vec_len (res); i++)
     {
       switch (res[i].type)
 	{
 	case STAT_DIR_TYPE_COUNTER_VECTOR_SIMPLE:
 	  for (j = 0; j < vec_len (res[i].simple_counter_vec); j++)
 	    vec_free (res[i].simple_counter_vec[j]);
 	  vec_free (res[i].simple_counter_vec);
 	  break;
 	case STAT_DIR_TYPE_COUNTER_VECTOR_COMBINED:
 	  for (j = 0; j < vec_len (res[i].combined_counter_vec); j++)
 	    vec_free (res[i].combined_counter_vec[j]);
 	  vec_free (res[i].combined_counter_vec);
 	  break;
 	default:
 	  ;
 	}
       free (res[i].name);
     }
   vec_free (res);
 }


 typedef struct
 {
   uint64_t epoch;
 } stat_segment_access_t;

 static void
 stat_segment_access_start (stat_segment_access_t * sa,
 			   stat_client_main_t * sm)
 {
   stat_segment_shared_header_t *shared_header = sm->shared_header;
   sa->epoch = shared_header->epoch;
   while (shared_header->in_progress != 0)
     ;
 }

 static bool
 stat_segment_access_end (stat_segment_access_t * sa, stat_client_main_t * sm)
 {
   stat_segment_shared_header_t *shared_header = sm->shared_header;

   if (shared_header->epoch != sa->epoch || shared_header->in_progress)
     return false;
   return true;
 }

 uint32_t *
 stat_segment_ls_r (uint8_t ** patterns, stat_client_main_t * sm)
 {
   stat_segment_access_t sa;

   uint32_t *dir = 0;
   regex_t regex[vec_len (patterns)];

   int i, j;
   for (i = 0; i < vec_len (patterns); i++)
     {
       int rv = regcomp (&regex[i], (char *) patterns[i], 0);
       if (rv)
 	{
 	  fprintf (stderr, "Could not compile regex %s\n", patterns[i]);
 	  return dir;
 	}
     }

   stat_segment_access_start (&sa, sm);

   stat_segment_directory_entry_t *counter_vec = get_stat_vector_r (sm);
   for (j = 0; j < vec_len (counter_vec); j++)
     {
       for (i = 0; i < vec_len (patterns); i++)
 	{
 	  int rv = regexec (&regex[i], counter_vec[j].name, 0, NULL, 0);
 	  if (rv == 0)
 	    {
 	      vec_add1 (dir, j);
 	      break;
 	    }
 	}
       if (vec_len (patterns) == 0)
 	vec_add1 (dir, j);
     }

   for (i = 0; i < vec_len (patterns); i++)
     regfree (&regex[i]);

   if (!stat_segment_access_end (&sa, sm))
     {
       /* Failed, clean up */
       vec_free (dir);
       return 0;

     }

   /* Update last version */
   sm->current_epoch = sa.epoch;
   return dir;
 }

 uint32_t *
 stat_segment_ls (uint8_t ** patterns)
 {
   stat_client_main_t *sm = &stat_client_main;
   return stat_segment_ls_r ((uint8_t **) patterns, sm);
 }

 stat_segment_data_t *
 stat_segment_dump_r (uint32_t * stats, stat_client_main_t * sm)
 {
   int i;
   stat_segment_directory_entry_t *ep;
   stat_segment_data_t *res = 0;
   stat_segment_access_t sa;

   /* Has directory been update? */
   if (sm->shared_header->epoch != sm->current_epoch)
     return 0;

   stat_segment_access_start (&sa, sm);
   for (i = 0; i < vec_len (stats); i++)
     {
       /* Collect counter */
       ep = vec_elt_at_index (sm->directory_vector, stats[i]);
       vec_add1 (res, copy_data (ep, sm));
     }

   if (stat_segment_access_end (&sa, sm))
     return res;

   fprintf (stderr, "Epoch changed while reading, invalid results\n");
   // TODO increase counter
   return 0;
 }

 stat_segment_data_t *
 stat_segment_dump (uint32_t * stats)
 {
   stat_client_main_t *sm = &stat_client_main;
   return stat_segment_dump_r (stats, sm);
 }

 /* Wrapper for accessing vectors from other languages */
 int
 stat_segment_vec_len (void *vec)
 {
   return vec_len (vec);
 }

 void
 stat_segment_vec_free (void *vec)
 {
   vec_free (vec);
 }

 /* Create a vector from a string (or add to existing) */
 u8 **
 stat_segment_string_vector (u8 ** string_vector, char *string)
 {
   u8 *name = 0;
   name = vec_dup ((u8 *) string);
   vec_add1 (string_vector, (u8 *) name);
   return string_vector;
 }

 stat_segment_data_t *
 stat_segment_dump_entry_r (uint32_t index, stat_client_main_t * sm)
 {
   stat_segment_directory_entry_t *ep;
   stat_segment_data_t *res = 0;
   stat_segment_access_t sa;

   stat_segment_access_start (&sa, sm);

   /* Collect counter */
   ep = vec_elt_at_index (sm->directory_vector, index);
   vec_add1 (res, copy_data (ep, sm));

   if (stat_segment_access_end (&sa, sm))
     return res;
   return 0;
 }

 stat_segment_data_t *
 stat_segment_dump_entry (uint32_t index)
 {
   stat_client_main_t *sm = &stat_client_main;
   return stat_segment_dump_entry_r (index, sm);
 }

 char *
 stat_segment_index_to_name (uint32_t index)
 {
   char *name;
   stat_segment_directory_entry_t *counter_vec = get_stat_vector ();
   stat_segment_directory_entry_t *ep;
   ep = vec_elt_at_index (counter_vec, index);
   name = strdup (ep->name);
   return name;
 }

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	*------------------------------------------------------------------
	* stat_client.c - Library for access to VPP statistics segment
	*
	* Copyright (c) 2018 Cisco and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*------------------------------------------------------------------
	*/

	#include <stdio.h>
	#include <errno.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <sys/un.h>
	#include <stdbool.h>
	#include <sys/stat.h>
	#include <regex.h>
	#include <assert.h>
	#include <vppinfra/vec.h>
	#include <vppinfra/lock.h>
	#include "stat_client.h"
	#include <stdatomic.h>
	#include <vpp/stats/stat_segment.h>

	struct stat_client_main_t
	{
	uint64_t current_epoch;
	stat_segment_shared_header_t *shared_header;
	stat_segment_directory_entry_t *directory_vector;
	ssize_t memory_size;
	};

	stat_client_main_t stat_client_main;

	stat_client_main_t *
	stat_client_get (void)
	{
	stat_client_main_t *sm;
	sm = (stat_client_main_t *) malloc (sizeof (stat_client_main_t));
	clib_memset (sm, 0, sizeof (stat_client_main_t));
	return sm;
	}

	void
	stat_client_free (stat_client_main_t * sm)
	{
	free (sm);
	}

	static int
	recv_fd (int sock)
	{
	struct msghdr msg = { 0 };
	struct cmsghdr *cmsg;
	int fd = -1;
	char iobuf[1];
	struct iovec io = {.iov_base = iobuf,.iov_len = sizeof (iobuf) };
	union
	{
	char buf[CMSG_SPACE (sizeof (fd))];
	struct cmsghdr align;
	} u;
	msg.msg_iov = &io;
	msg.msg_iovlen = 1;
	msg.msg_control = u.buf;
	msg.msg_controllen = sizeof (u.buf);

	ssize_t size;
	if ((size = recvmsg (sock, &msg, 0)) < 0)
	{
	perror ("recvmsg failed");
	return -1;
	}
	cmsg = CMSG_FIRSTHDR (&msg);
	if (cmsg && cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS)
	{
	memmove (&fd, CMSG_DATA (cmsg), sizeof (fd));
	}
	return fd;
	}

	static stat_segment_directory_entry_t *
	get_stat_vector_r (stat_client_main_t * sm)
	{
	ASSERT (sm->shared_header);
	return stat_segment_pointer (sm->shared_header,
	sm->shared_header->directory_offset);
	}

	static stat_segment_directory_entry_t *
	get_stat_vector (void)
	{
	stat_client_main_t *sm = &stat_client_main;
	return get_stat_vector_r (sm);
	}

	int
	stat_segment_connect_r (char socket_name, stat_client_main_t sm)
	{
	int mfd = -1;
	int sock;

	clib_memset (sm, 0, sizeof (*sm));
	if ((sock = socket (AF_UNIX, SOCK_SEQPACKET, 0)) < 0)
	{
	perror ("Stat client couldn't open socket");
	return -1;
	}

	struct sockaddr_un un = { 0 };
	un.sun_family = AF_UNIX;
	strncpy ((char *) un.sun_path, socket_name, sizeof (un.sun_path) - 1);
	if (connect (sock, (struct sockaddr *) &un, sizeof (struct sockaddr_un)) <
	0)
	{
	close (sock);
	return -1;
	}

	if ((mfd = recv_fd (sock)) < 0)
	{
	close (sock);
	fprintf (stderr, "Receiving file descriptor failed\n");
	return -1;
	}
	close (sock);

	/* mmap shared memory segment. */
	void *memaddr;
	struct stat st = { 0 };

	if (fstat (mfd, &st) == -1)
	{
	perror ("mmap fstat failed");
	return -1;
	}
	if ((memaddr =
	mmap (NULL, st.st_size, PROT_READ, MAP_SHARED, mfd, 0)) == MAP_FAILED)
	{
	perror ("mmap map failed");
	return -1;
	}

	sm->memory_size = st.st_size;
	sm->shared_header = memaddr;
	sm->directory_vector =
	stat_segment_pointer (memaddr, sm->shared_header->directory_offset);

	return 0;
	}

	int
	stat_segment_connect (char *socket_name)
	{
	stat_client_main_t *sm = &stat_client_main;
	return stat_segment_connect_r (socket_name, sm);
	}

	void
	stat_segment_disconnect_r (stat_client_main_t * sm)
	{
	munmap (sm->shared_header, sm->memory_size);
	return;
	}

	void
	stat_segment_disconnect (void)
	{
	stat_client_main_t *sm = &stat_client_main;
	return stat_segment_disconnect_r (sm);
	}

	double
	stat_segment_heartbeat_r (stat_client_main_t * sm)
	{
	stat_segment_directory_entry_t *vec = get_stat_vector_r (sm);
	double *hb = stat_segment_pointer (sm->shared_header, vec[4].offset);
	return *hb;
	}

	double
	stat_segment_heartbeat (void)
	{
	stat_client_main_t *sm = &stat_client_main;
	return stat_segment_heartbeat_r (sm);
	}

	stat_segment_data_t
	copy_data (stat_segment_directory_entry_t * ep, stat_client_main_t * sm)
	{
	stat_segment_data_t result = { 0 };
	int i;
	vlib_counter_t *combined_c; / Combined counter */
	counter_t *simple_c; / Simple counter */
	counter_t *error_base;
	uint64_t *offset_vector;

	assert (sm->shared_header);

	result.type = ep->type;
	result.name = strdup (ep->name);
	switch (ep->type)
	{
	case STAT_DIR_TYPE_SCALAR_INDEX:
	result.scalar_value = ep->value;
	break;

	case STAT_DIR_TYPE_COUNTER_VECTOR_SIMPLE:
	if (ep->offset == 0)
	return result;
	simple_c = stat_segment_pointer (sm->shared_header, ep->offset);
	result.simple_counter_vec = vec_dup (simple_c);
	offset_vector =
	stat_segment_pointer (sm->shared_header, ep->offset_vector);
	for (i = 0; i < vec_len (simple_c); i++)
	{
	counter_t *cb =
	stat_segment_pointer (sm->shared_header, offset_vector[i]);
	result.simple_counter_vec[i] = vec_dup (cb);
	}
	break;

	case STAT_DIR_TYPE_COUNTER_VECTOR_COMBINED:
	if (ep->offset == 0)
	return result;
	combined_c = stat_segment_pointer (sm->shared_header, ep->offset);
	result.combined_counter_vec = vec_dup (combined_c);
	offset_vector =
	stat_segment_pointer (sm->shared_header, ep->offset_vector);
	for (i = 0; i < vec_len (combined_c); i++)
	{
	vlib_counter_t *cb =
	stat_segment_pointer (sm->shared_header, offset_vector[i]);
	result.combined_counter_vec[i] = vec_dup (cb);
	}
	break;

	case STAT_DIR_TYPE_ERROR_INDEX:
	error_base =
	stat_segment_pointer (sm->shared_header,
	sm->shared_header->error_offset);
	result.error_value = error_base[ep->index];
	break;

	default:
	fprintf (stderr, "Unknown type: %d", ep->type);
	}
	return result;
	}

	void
	stat_segment_data_free (stat_segment_data_t * res)
	{
	int i, j;
	for (i = 0; i < vec_len (res); i++)
	{
	switch (res[i].type)
	{
	case STAT_DIR_TYPE_COUNTER_VECTOR_SIMPLE:
	for (j = 0; j < vec_len (res[i].simple_counter_vec); j++)
	vec_free (res[i].simple_counter_vec[j]);
	vec_free (res[i].simple_counter_vec);
	break;
	case STAT_DIR_TYPE_COUNTER_VECTOR_COMBINED:
	for (j = 0; j < vec_len (res[i].combined_counter_vec); j++)
	vec_free (res[i].combined_counter_vec[j]);
	vec_free (res[i].combined_counter_vec);
	break;
	default:
	;
	}
	free (res[i].name);
	}
	vec_free (res);
	}


	typedef struct
	{
	uint64_t epoch;
	} stat_segment_access_t;

	static void
	stat_segment_access_start (stat_segment_access_t * sa,
	stat_client_main_t * sm)
	{
	stat_segment_shared_header_t *shared_header = sm->shared_header;
	sa->epoch = shared_header->epoch;
	while (shared_header->in_progress != 0)
	;
	}

	static bool
	stat_segment_access_end (stat_segment_access_t * sa, stat_client_main_t * sm)
	{
	stat_segment_shared_header_t *shared_header = sm->shared_header;

	if (shared_header->epoch != sa->epoch \|\| shared_header->in_progress)
	return false;
	return true;
	}

	uint32_t *
	stat_segment_ls_r (uint8_t ** patterns, stat_client_main_t * sm)
	{
	stat_segment_access_t sa;

	uint32_t *dir = 0;
	regex_t regex[vec_len (patterns)];

	int i, j;
	for (i = 0; i < vec_len (patterns); i++)
	{
	int rv = regcomp (&regex[i], (char *) patterns[i], 0);
	if (rv)
	{
	fprintf (stderr, "Could not compile regex %s\n", patterns[i]);
	return dir;
	}
	}

	stat_segment_access_start (&sa, sm);

	stat_segment_directory_entry_t *counter_vec = get_stat_vector_r (sm);
	for (j = 0; j < vec_len (counter_vec); j++)
	{
	for (i = 0; i < vec_len (patterns); i++)
	{
	int rv = regexec (&regex[i], counter_vec[j].name, 0, NULL, 0);
	if (rv == 0)
	{
	vec_add1 (dir, j);
	break;
	}
	}
	if (vec_len (patterns) == 0)
	vec_add1 (dir, j);
	}

	for (i = 0; i < vec_len (patterns); i++)
	regfree (&regex[i]);

	if (!stat_segment_access_end (&sa, sm))
	{
	/* Failed, clean up */
	vec_free (dir);
	return 0;

	}

	/* Update last version */
	sm->current_epoch = sa.epoch;
	return dir;
	}

	uint32_t *
	stat_segment_ls (uint8_t ** patterns)
	{
	stat_client_main_t *sm = &stat_client_main;
	return stat_segment_ls_r ((uint8_t **) patterns, sm);
	}

	stat_segment_data_t *
	stat_segment_dump_r (uint32_t * stats, stat_client_main_t * sm)
	{
	int i;
	stat_segment_directory_entry_t *ep;
	stat_segment_data_t *res = 0;
	stat_segment_access_t sa;

	/* Has directory been update? */
	if (sm->shared_header->epoch != sm->current_epoch)
	return 0;

	stat_segment_access_start (&sa, sm);
	for (i = 0; i < vec_len (stats); i++)
	{
	/* Collect counter */
	ep = vec_elt_at_index (sm->directory_vector, stats[i]);
	vec_add1 (res, copy_data (ep, sm));
	}

	if (stat_segment_access_end (&sa, sm))
	return res;

	fprintf (stderr, "Epoch changed while reading, invalid results\n");
	// TODO increase counter
	return 0;
	}

	stat_segment_data_t *
	stat_segment_dump (uint32_t * stats)
	{
	stat_client_main_t *sm = &stat_client_main;
	return stat_segment_dump_r (stats, sm);
	}

	/* Wrapper for accessing vectors from other languages */
	int
	stat_segment_vec_len (void *vec)
	{
	return vec_len (vec);
	}

	void
	stat_segment_vec_free (void *vec)
	{
	vec_free (vec);
	}

	/* Create a vector from a string (or add to existing) */
	u8 **
	stat_segment_string_vector (u8 ** string_vector, char *string)
	{
	u8 *name = 0;
	name = vec_dup ((u8 *) string);
	vec_add1 (string_vector, (u8 *) name);
	return string_vector;
	}

	stat_segment_data_t *
	stat_segment_dump_entry_r (uint32_t index, stat_client_main_t * sm)
	{
	stat_segment_directory_entry_t *ep;
	stat_segment_data_t *res = 0;
	stat_segment_access_t sa;

	stat_segment_access_start (&sa, sm);

	/* Collect counter */
	ep = vec_elt_at_index (sm->directory_vector, index);
	vec_add1 (res, copy_data (ep, sm));

	if (stat_segment_access_end (&sa, sm))
	return res;
	return 0;
	}

	stat_segment_data_t *
	stat_segment_dump_entry (uint32_t index)
	{
	stat_client_main_t *sm = &stat_client_main;
	return stat_segment_dump_entry_r (index, sm);
	}

	char *
	stat_segment_index_to_name (uint32_t index)
	{
	char *name;
	stat_segment_directory_entry_t *counter_vec = get_stat_vector ();
	stat_segment_directory_entry_t *ep;
	ep = vec_elt_at_index (counter_vec, index);
	name = strdup (ep->name);
	return name;
	}

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/