format_cap.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2010, Digium, Inc.
 *
 * David Vossel <dvossel@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*!
 * \file
 * \brief Format Capability API
 *
 * \author David Vossel <dvossel@digium.com>
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 369013 $");

#include "asterisk/_private.h"
#include "asterisk/format.h"
#include "asterisk/format_cap.h"
#include "asterisk/frame.h"
#include "asterisk/astobj2.h"
#include "asterisk/utils.h"


struct ast_format_cap {
   /* The capabilities structure is just an ao2 container of ast_formats */
   struct ao2_container *formats;
   struct ao2_iterator it;
   /*! TRUE if the formats container created without a lock. */
   int nolock;
};

/*! format exists within capabilities structure if it is identical to
 * another format, or if the format is a proper subset of another format. */
static int cmp_cb(void *obj, void *arg, int flags)
{
   struct ast_format *format1 = arg;
   struct ast_format *format2 = obj;
   enum ast_format_cmp_res res = ast_format_cmp(format1, format2);

   return ((res == AST_FORMAT_CMP_EQUAL) ||
         (res == AST_FORMAT_CMP_SUBSET)) ?
            CMP_MATCH | CMP_STOP :
            0;
}

static int hash_cb(const void *obj, const int flags)
{
   const struct ast_format *format = obj;
   return format->id;
}

static struct ast_format_cap *cap_alloc_helper(int nolock)
{
   struct ast_format_cap *cap = ast_calloc(1, sizeof(*cap));

   if (!cap) {
      return NULL;
   }
   cap->nolock = nolock;
   cap->formats = ao2_container_alloc_options(
      nolock ? AO2_ALLOC_OPT_LOCK_NOLOCK : AO2_ALLOC_OPT_LOCK_MUTEX,
      283, hash_cb, cmp_cb);
   if (!cap->formats) {
      ast_free(cap);
      return NULL;
   }

   return cap;
}

struct ast_format_cap *ast_format_cap_alloc_nolock(void)
{
   return cap_alloc_helper(1);
}

struct ast_format_cap *ast_format_cap_alloc(void)
{
   return cap_alloc_helper(0);
}

void *ast_format_cap_destroy(struct ast_format_cap *cap)
{
   if (!cap) {
      return NULL;
   }
   ao2_ref(cap->formats, -1);
   ast_free(cap);
   return NULL;
}

void ast_format_cap_add(struct ast_format_cap *cap, const struct ast_format *format)
{
   struct ast_format *fnew;

   if (!format || !format->id) {
      return;
   }
   if (!(fnew = ao2_alloc(sizeof(struct ast_format), NULL))) {
      return;
   }
   ast_format_copy(fnew, format);
   ao2_link(cap->formats, fnew);
   ao2_ref(fnew, -1);
}

void ast_format_cap_add_all_by_type(struct ast_format_cap *cap, enum ast_format_type type)
{
   int x;
   size_t f_len = 0;
   const struct ast_format_list *f_list = ast_format_list_get(&f_len);

   for (x = 0; x < f_len; x++) {
      if (AST_FORMAT_GET_TYPE(f_list[x].format.id) == type) {
         ast_format_cap_add(cap, &f_list[x].format);
      }
   }
   ast_format_list_destroy(f_list);
}

void ast_format_cap_add_all(struct ast_format_cap *cap)
{
   int x;
   size_t f_len = 0;
   const struct ast_format_list *f_list = ast_format_list_get(&f_len);

   for (x = 0; x < f_len; x++) {
      ast_format_cap_add(cap, &f_list[x].format);
   }
   ast_format_list_destroy(f_list);
}

static int append_cb(void *obj, void *arg, int flag)
{
   struct ast_format_cap *result = (struct ast_format_cap *) arg;
   struct ast_format *format = (struct ast_format *) obj;

   if (!ast_format_cap_iscompatible(result, format)) {
      ast_format_cap_add(result, format);
   }

   return 0;
}

void ast_format_cap_append(struct ast_format_cap *dst, const struct ast_format_cap *src)
{
   ao2_callback(src->formats, OBJ_NODATA, append_cb, dst);
}

static int copy_cb(void *obj, void *arg, int flag)
{
   struct ast_format_cap *result = (struct ast_format_cap *) arg;
   struct ast_format *format = (struct ast_format *) obj;

   ast_format_cap_add(result, format);
   return 0;
}

void ast_format_cap_copy(struct ast_format_cap *dst, const struct ast_format_cap *src)
{
   ast_format_cap_remove_all(dst);
   ao2_callback(src->formats, OBJ_NODATA, copy_cb, dst);
}

struct ast_format_cap *ast_format_cap_dup(const struct ast_format_cap *cap)
{
   struct ast_format_cap *dst;
   if (cap->nolock) {
      dst = ast_format_cap_alloc_nolock();
   } else {
      dst = ast_format_cap_alloc();
   }
   if (!dst) {
      return NULL;
   }
   ao2_callback(cap->formats, OBJ_NODATA, copy_cb, dst);
   return dst;
}

int ast_format_cap_is_empty(const struct ast_format_cap *cap)
{
   if (!cap) {
      return 1;
   }
   return ao2_container_count(cap->formats) == 0 ? 1 : 0;
}

static int find_exact_cb(void *obj, void *arg, int flag)
{
   struct ast_format *format1 = (struct ast_format *) arg;
   struct ast_format *format2 = (struct ast_format *) obj;

   return (ast_format_cmp(format1, format2) == AST_FORMAT_CMP_EQUAL) ? CMP_MATCH : 0;
}

int ast_format_cap_remove(struct ast_format_cap *cap, struct ast_format *format)
{
   struct ast_format *fremove;

   fremove = ao2_callback(cap->formats, OBJ_POINTER | OBJ_UNLINK, find_exact_cb, format);
   if (fremove) {
      ao2_ref(fremove, -1);
      return 0;
   }

   return -1;
}

struct multiple_by_id_data {
   struct ast_format *format;
   int match_found;
};

static int multiple_by_id_cb(void *obj, void *arg, int flag)
{
   struct multiple_by_id_data *data = arg;
   struct ast_format *format = obj;
   int res;

   res = (format->id == data->format->id) ? CMP_MATCH : 0;
   if (res) {
      data->match_found = 1;
   }

   return res;
}

int ast_format_cap_remove_byid(struct ast_format_cap *cap, enum ast_format_id id)
{
   struct ast_format format = {
      .id = id,
   };
   struct multiple_by_id_data data = {
      .format = &format,
      .match_found = 0,
   };

   ao2_callback(cap->formats,
      OBJ_NODATA | OBJ_MULTIPLE | OBJ_UNLINK,
      multiple_by_id_cb,
      &data);

   /* match_found will be set if at least one item was removed */
   if (data.match_found) {
      return 0;
   }

   return -1;
}

static int multiple_by_type_cb(void *obj, void *arg, int flag)
{
   int *type = arg;
   struct ast_format *format = obj;
   return ((AST_FORMAT_GET_TYPE(format->id)) == *type) ? CMP_MATCH : 0;
}

void ast_format_cap_remove_bytype(struct ast_format_cap *cap, enum ast_format_type type)
{
   ao2_callback(cap->formats,
      OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE,
      multiple_by_type_cb,
      &type);
}

void ast_format_cap_remove_all(struct ast_format_cap *cap)
{
   ao2_callback(cap->formats, OBJ_NODATA | OBJ_MULTIPLE | OBJ_UNLINK, NULL, NULL);
}

void ast_format_cap_set(struct ast_format_cap *cap, struct ast_format *format)
{
   ast_format_cap_remove_all(cap);
   ast_format_cap_add(cap, format);
}

int ast_format_cap_get_compatible_format(const struct ast_format_cap *cap, const struct ast_format *format, struct ast_format *result)
{
   struct ast_format *f;
   struct ast_format_cap *tmp_cap = (struct ast_format_cap *) cap;

   f = ao2_find(tmp_cap->formats, format, OBJ_POINTER);
   if (f) {
      ast_format_copy(result, f);
      ao2_ref(f, -1);
      return 1;
   }
   ast_format_clear(result);
   return 0;
}

int ast_format_cap_iscompatible(const struct ast_format_cap *cap, const struct ast_format *format)
{
   struct ast_format *f;
   struct ast_format_cap *tmp_cap = (struct ast_format_cap *) cap;

   if (!tmp_cap) {
      return 0;
   }

   f = ao2_find(tmp_cap->formats, format, OBJ_POINTER);
   if (f) {
      ao2_ref(f, -1);
      return 1;
   }

   return 0;
}

struct byid_data {
   struct ast_format *result;
   enum ast_format_id id;
};
static int find_best_byid_cb(void *obj, void *arg, int flag)
{
   struct ast_format *format = obj;
   struct byid_data *data = arg;

   if (data->id != format->id) {
      return 0;
   }
   if (!data->result->id || (ast_format_rate(data->result) < ast_format_rate(format))) {
      ast_format_copy(data->result, format);
   }
   return 0;
}

int ast_format_cap_best_byid(const struct ast_format_cap *cap, enum ast_format_id id, struct ast_format *result)
{
   struct byid_data data;
   data.result = result;
   data.id = id;

   ast_format_clear(result);
   ao2_callback(cap->formats,
      OBJ_MULTIPLE | OBJ_NODATA,
      find_best_byid_cb,
      &data);
   return result->id ? 1 : 0;
}

/*! \internal
 * \brief this struct is just used for the ast_format_cap_joint function so we can provide
 * both a format and a result ast_format_cap structure as arguments to the find_joint_cb
 * ao2 callback function.
 */
struct find_joint_data {
   /*! format to compare to for joint capabilities */
   struct ast_format *format;
   /*! if joint formmat exists with above format, add it to the result container */
   struct ast_format_cap *joint_cap;
   int joint_found;
};

static int find_joint_cb(void *obj, void *arg, int flag)
{
   struct ast_format *format = obj;
   struct find_joint_data *data = arg;

   struct ast_format tmp = { 0, };
   if (!ast_format_joint(format, data->format, &tmp)) {
      if (data->joint_cap) {
         ast_format_cap_add(data->joint_cap, &tmp);
      }
      data->joint_found++;
   }

   return 0;
}

int ast_format_cap_has_joint(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2)
{
   struct ao2_iterator it;
   struct ast_format *tmp;
   struct find_joint_data data = {
      .joint_found = 0,
      .joint_cap = NULL,
   };

   it = ao2_iterator_init(cap1->formats, 0);
   while ((tmp = ao2_iterator_next(&it))) {
      data.format = tmp;
      ao2_callback(cap2->formats,
         OBJ_MULTIPLE | OBJ_NODATA,
         find_joint_cb,
         &data);
      ao2_ref(tmp, -1);
   }
   ao2_iterator_destroy(&it);

   return data.joint_found ? 1 : 0;
}

int ast_format_cap_identical(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2)
{
   struct ao2_iterator it;
   struct ast_format *tmp;

   if (ao2_container_count(cap1->formats) != ao2_container_count(cap2->formats)) {
      return 0; /* if they are not the same size, they are not identical */
   }

   it = ao2_iterator_init(cap1->formats, 0);
   while ((tmp = ao2_iterator_next(&it))) {
      if (!ast_format_cap_iscompatible(cap2, tmp)) {
         ao2_ref(tmp, -1);
         ao2_iterator_destroy(&it);
         return 0;
      }
      ao2_ref(tmp, -1);
   }
   ao2_iterator_destroy(&it);

   return 1;
}

struct ast_format_cap *ast_format_cap_joint(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2)
{
   struct ao2_iterator it;
   struct ast_format_cap *result = ast_format_cap_alloc_nolock();
   struct ast_format *tmp;
   struct find_joint_data data = {
      .joint_found = 0,
      .joint_cap = result,
   };
   if (!result) {
      return NULL;
   }

   it = ao2_iterator_init(cap1->formats, 0);
   while ((tmp = ao2_iterator_next(&it))) {
      data.format = tmp;
      ao2_callback(cap2->formats,
         OBJ_MULTIPLE | OBJ_NODATA,
         find_joint_cb,
         &data);
      ao2_ref(tmp, -1);
   }
   ao2_iterator_destroy(&it);

   if (ao2_container_count(result->formats)) {
      return result;
   }

   result = ast_format_cap_destroy(result);
   return NULL;
}

static int joint_copy_helper(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2, struct ast_format_cap *result, int append)
{
   struct ao2_iterator it;
   struct ast_format *tmp;
   struct find_joint_data data = {
      .joint_cap = result,
      .joint_found = 0,
   };
   if (!append) {
      ast_format_cap_remove_all(result);
   }
   it = ao2_iterator_init(cap1->formats, 0);
   while ((tmp = ao2_iterator_next(&it))) {
      data.format = tmp;
      ao2_callback(cap2->formats,
         OBJ_MULTIPLE | OBJ_NODATA,
         find_joint_cb,
         &data);
      ao2_ref(tmp, -1);
   }
   ao2_iterator_destroy(&it);

   return ao2_container_count(result->formats) ? 1 : 0;
}

int ast_format_cap_joint_append(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2, struct ast_format_cap *result)
{
   return joint_copy_helper(cap1, cap2, result, 1);
}

int ast_format_cap_joint_copy(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2, struct ast_format_cap *result)
{
   return joint_copy_helper(cap1, cap2, result, 0);
}

struct ast_format_cap *ast_format_cap_get_type(const struct ast_format_cap *cap, enum ast_format_type ftype)
{
   struct ao2_iterator it;
   struct ast_format_cap *result = ast_format_cap_alloc_nolock();
   struct ast_format *tmp;

   if (!result) {
      return NULL;
   }

   /* for each format in cap1, see if that format is
    * compatible with cap2. If so copy it to the result */
   it = ao2_iterator_init(cap->formats, 0);
   while ((tmp = ao2_iterator_next(&it))) {
      if (AST_FORMAT_GET_TYPE(tmp->id) == ftype) {
         /* copy format */
         ast_format_cap_add(result, tmp);
      }
      ao2_ref(tmp, -1);
   }
   ao2_iterator_destroy(&it);

   if (ao2_container_count(result->formats)) {
      return result;
   }
   result = ast_format_cap_destroy(result);

   return NULL;
}


int ast_format_cap_has_type(const struct ast_format_cap *cap, enum ast_format_type type)
{
   struct ao2_iterator it;
   struct ast_format *tmp;

   it = ao2_iterator_init(cap->formats, 0);
   while ((tmp = ao2_iterator_next(&it))) {
      if (AST_FORMAT_GET_TYPE(tmp->id) == type) {
         ao2_ref(tmp, -1);
         ao2_iterator_destroy(&it);
         return 1;
      }
      ao2_ref(tmp, -1);
   }
   ao2_iterator_destroy(&it);

   return 0;
}

void ast_format_cap_iter_start(struct ast_format_cap *cap)
{
   /* We can unconditionally lock even if the container has no lock. */
   ao2_lock(cap->formats);
   cap->it = ao2_iterator_init(cap->formats, AO2_ITERATOR_DONTLOCK);
}

void ast_format_cap_iter_end(struct ast_format_cap *cap)
{
   ao2_iterator_destroy(&cap->it);
   /* We can unconditionally unlock even if the container has no lock. */
   ao2_unlock(cap->formats);
}

int ast_format_cap_iter_next(struct ast_format_cap *cap, struct ast_format *format)
{
   struct ast_format *tmp = ao2_iterator_next(&cap->it);

   if (!tmp) {
      return -1;
   }
   ast_format_copy(format, tmp);
   ao2_ref(tmp, -1);

   return 0;
}

char *ast_getformatname_multiple(char *buf, size_t size, struct ast_format_cap *cap)
{
   int x;
   unsigned len;
   char *start, *end = buf;
   struct ast_format tmp_fmt;
   size_t f_len;
   const struct ast_format_list *f_list = ast_format_list_get(&f_len);

   if (!size) {
      f_list = ast_format_list_destroy(f_list);
      return buf;
   }
   snprintf(end, size, "(");
   len = strlen(end);
   end += len;
   size -= len;
   start = end;
   for (x = 0; x < f_len; x++) {
      ast_format_copy(&tmp_fmt, &f_list[x].format);
      if (ast_format_cap_iscompatible(cap, &tmp_fmt)) {
         snprintf(end, size, "%s|", f_list[x].name);
         len = strlen(end);
         end += len;
         size -= len;
      }
   }
   if (start == end) {
      ast_copy_string(start, "nothing)", size);
   } else if (size > 1) {
      *(end - 1) = ')';
   }
   f_list = ast_format_list_destroy(f_list);
   return buf;
}

uint64_t ast_format_cap_to_old_bitfield(const struct ast_format_cap *cap)
{
   uint64_t res = 0;
   struct ao2_iterator it;
   struct ast_format *tmp;

   it = ao2_iterator_init(cap->formats, 0);
   while ((tmp = ao2_iterator_next(&it))) {
      res |= ast_format_to_old_bitfield(tmp);
      ao2_ref(tmp, -1);
   }
   ao2_iterator_destroy(&it);
   return res;
}

void ast_format_cap_from_old_bitfield(struct ast_format_cap *dst, uint64_t src)
{
   uint64_t tmp = 0;
   int x;
   struct ast_format tmp_format = { 0, };

   ast_format_cap_remove_all(dst);
   for (x = 0; x < 64; x++) {
      tmp = (1ULL << x);
      if (tmp & src) {
         ast_format_cap_add(dst, ast_format_from_old_bitfield(&tmp_format, tmp));
      }
   }
}