jack1/libjack/metadata.c

/*
   Copyright (C) 2013 Paul Davis

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation; either version 2.1 of the License, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
   License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <string.h>
#include <db.h>
#include <limits.h>

#include <jack/metadata.h>
#include <jack/uuid.h>

#include "internal.h"
#include "local.h"

const char* JACK_METADATA_PRETTY_NAME = "http://jackaudio.org/metadata/pretty-name";
const char* JACK_METADATA_HARDWARE    = "http://jackaudio.org/metadata/hardware";
const char* JACK_METADATA_CONNECTED   = "http://jackaudio.org/metadata/connected";
const char* JACK_METADATA_PORT_GROUP  = "http://jackaudio.org/metadata/port-group";
const char* JACK_METADATA_ICON_SMALL  = "http://jackaudio.org/metadata/icon-small";
const char* JACK_METADATA_ICON_LARGE  = "http://jackaudio.org/metadata/icon-large";

static DB* db = NULL;
static DB_ENV* db_env = NULL;

static int
jack_property_init (const char* server_name)
{
	int ret;
	char dbpath[PATH_MAX + 1];
	char server_dir[PATH_MAX + 1];

	/* idempotent */

	if (db_env) {
		return 0;
	}

	if ((ret = db_env_create (&db_env, 0)) != 0) {
		jack_error ("cannot initialize DB environment: %s\n", db_strerror (ret));
		return -1;
	}

	if ((ret = db_env->open (db_env, jack_server_dir (server_name, server_dir), DB_CREATE | DB_INIT_LOCK | DB_INIT_MPOOL | DB_THREAD, 0)) != 0) {
		jack_error ("cannot open DB environment: %s", db_strerror (ret));
		return -1;
	}

	if ((ret = db_create (&db, db_env, 0)) != 0) {
		jack_error ("Cannot initialize metadata DB (%s)", db_strerror (ret));
		return -1;
	}

	snprintf (dbpath, sizeof(dbpath), "%s/%s", jack_server_dir (server_name, server_dir), "metadata.db");

	if ((ret = db->open (db, NULL, dbpath, NULL, DB_HASH, DB_CREATE | DB_THREAD, 0666)) != 0) {
		jack_error ("Cannot open metadata DB at %s: %s", dbpath, db_strerror (ret));
		db->close (db, 0);
		db = NULL;
		return -1;
	}

	return 0;
}

static void jack_properties_uninit() __attribute__ ((destructor));

void
jack_properties_uninit ()
{
	if (db) {
		db->close (db, 0);
		db = NULL;
	}
	if (db_env) {
		db_env->close (db_env, 0);
		db_env = 0;
	}
}

void
jack_free_description (jack_description_t* desc, int free_actual_description_too)
{
	uint32_t n;

	for (n = 0; n < desc->property_cnt; ++n) {
		free ((char*)desc->properties[n].key);
		free ((char*)desc->properties[n].data);
		if (desc->properties[n].type) {
			free ((char*)desc->properties[n].type);
		}
	}

	free (desc->properties);

	if (free_actual_description_too) {
		free (desc);
	}
}

static int
jack_property_change_notify (jack_client_t* client, jack_uuid_t uuid, const char* key, jack_property_change_t change)
{
	jack_request_t req;

	/* the engine passes in a NULL client when it removes metadata during port or client removal
	 */

	if (client == NULL) {
		return 0;
	}

	req.type = PropertyChangeNotify;
	req.x.property.change = change;
	jack_uuid_copy (&req.x.property.uuid, uuid);
	req.x.property.keylen = key ? strlen (key) + 1 : 0;
	req.x.property.key = key;
	return jack_client_deliver_request (client, &req);
}

static void
make_key_dbt (DBT* dbt, jack_uuid_t subject, const char* key)
{
	char ustr[JACK_UUID_STRING_SIZE];
	size_t len1, len2;

	memset (dbt, 0, sizeof(DBT));
	memset (ustr, 0, JACK_UUID_STRING_SIZE);
	jack_uuid_unparse (subject, ustr);
	len1 = JACK_UUID_STRING_SIZE;
	len2 = strlen (key) + 1;
	dbt->size = len1 + len2;
	dbt->data = malloc (dbt->size);
	memcpy (dbt->data, ustr, len1);         // copy subject+null
	memcpy (dbt->data + len1, key, len2);   // copy key+null
}


int
jack_set_property (jack_client_t* client,
		   jack_uuid_t subject,
		   const char* key,
		   const char* value,
		   const char* type)
{
	DBT d_key;
	DBT data;
	int ret;
	size_t len1, len2;
	jack_property_change_t change;

	if (!key || key[0] == '\0') {
		jack_error ("empty key string for metadata not allowed");
		return -1;
	}

	if (!value || value[0] == '\0') {
		jack_error ("empty value string for metadata not allowed");
		return -1;
	}

	if (jack_property_init (NULL)) {
		return -1;
	}

	/* build a key */

	make_key_dbt (&d_key, subject, key);

	/* build data */

	memset (&data, 0, sizeof(data));

	len1 = strlen (value) + 1;
	if (type && type[0] != '\0') {
		len2 = strlen (type) + 1;
	} else {
		len2 = 0;
	}

	data.size = len1 + len2;
	data.data = malloc (data.size);
	memcpy (data.data, value, len1);

	if (len2) {
		memcpy (data.data + len1, type, len2);
	}

	if (db->exists (db, NULL, &d_key, 0) == DB_NOTFOUND) {
		change = PropertyCreated;
	} else {
		change = PropertyChanged;
	}

	if ((ret = db->put (db, NULL, &d_key, &data, 0)) != 0) {
		char ustr[JACK_UUID_STRING_SIZE];
		jack_uuid_unparse (subject, ustr);
		jack_error ("Cannot store metadata for %s/%s (%s)", ustr, key, db_strerror (ret));
		if (d_key.size > 0) {
			free (d_key.data);
		}
		if (data.size  > 0) {
			free (data.data);
		}
		return -1;
	}

	jack_property_change_notify (client, subject, key, change);

	if (d_key.size > 0) {
		free (d_key.data);
	}
	if (data.size  > 0) {
		free (data.data);
	}

	return 0;
}

int
jack_get_property (jack_uuid_t subject,
		   const char* key,
		   char**      value,
		   char**      type)
{
	DBT d_key;
	DBT data;
	int ret;
	size_t len1, len2;

	if (key == NULL || key[0] == '\0') {
		return -1;
	}

	if (jack_property_init (NULL)) {
		return -1;
	}

	/* build a key */

	make_key_dbt (&d_key, subject, key);

	/* setup data DBT */

	memset (&data, 0, sizeof(data));
	data.flags = DB_DBT_MALLOC;

	if ((ret = db->get (db, NULL, &d_key, &data, 0)) != 0) {
		if (ret != DB_NOTFOUND) {
			char ustr[JACK_UUID_STRING_SIZE];
			jack_uuid_unparse (subject, ustr);
			jack_error ("Cannot  metadata for %s/%s (%s)", ustr, key, db_strerror (ret));
		}
		if (d_key.size > 0) {
			free (d_key.data);
		}
		if (data.size  > 0) {
			free (data.data);
		}
		return -1;
	}

	/* result must have at least 2 chars plus 2 nulls to be valid
	 */

	if (data.size < 4) {
		if (d_key.size > 0) {
			free (d_key.data);
		}
		if (data.size  > 0) {
			free (data.data);
		}
		return -1;
	}

	len1 = strlen (data.data) + 1;
	(*value) = (char*)malloc (len1);
	memcpy (*value, data.data, len1);

	if (len1 < data.size) {
		len2 = strlen (data.data + len1) + 1;

		(*type) = (char*)malloc (len2);
		memcpy (*type, data.data + len1, len2);
	} else {
		/* no type specified, assume default */
		*type = NULL;
	}

	if (d_key.size > 0) {
		free (d_key.data);
	}
	if (data.size  > 0) {
		free (data.data);
	}

	return 0;
}

int
jack_get_properties (jack_uuid_t subject,
		     jack_description_t* desc)
{
	DBT key;
	DBT data;
	DBC* cursor;
	int ret;
	size_t len1, len2;
	size_t cnt = 0;
	char ustr[JACK_UUID_STRING_SIZE];
	size_t props_size = 0;
	jack_property_t* prop;

	desc->properties = NULL;
	desc->property_cnt = 0;

	memset (ustr, 0, JACK_UUID_STRING_SIZE);
	jack_uuid_unparse (subject, ustr);

	if (jack_property_init (NULL)) {
		return -1;
	}


	if ((ret = db->cursor (db, NULL, &cursor, 0)) != 0) {
		jack_error ("Cannot create cursor for metadata search (%s)", db_strerror (ret));
		return -1;
	}

	memset (&key, 0, sizeof(key));
	memset (&data, 0, sizeof(data));
	data.flags = DB_DBT_MALLOC;

	while ((ret = cursor->get (cursor, &key, &data, DB_NEXT)) == 0) {

		/* require 2 extra chars (data+null) for key,
		   which is composed of UUID str plus a key name
		 */

		if (key.size < JACK_UUID_STRING_SIZE + 2) {
			/* if (key.size  > 0) free(key.data); */
			if (data.size > 0) {
				free (data.data);
			}
			continue;
		}

		if (memcmp (ustr, key.data, JACK_UUID_STRING_SIZE) != 0) {
			/* not relevant */
			/* if (key.size  > 0) free(key.data); */
			if (data.size > 0) {
				free (data.data);
			}
			continue;
		}

		/* result must have at least 2 chars plus 2 nulls to be valid
		 */

		if (data.size < 4) {
			/* if (key.size  > 0) free(key.data); */
			if (data.size > 0) {
				free (data.data);
			}
			continue;
		}

		/* realloc array if necessary */

		if (cnt == props_size) {
			if (props_size == 0) {
				props_size = 8; /* a rough guess at a likely upper bound for the number of properties */
			} else {
				props_size *= 2;
			}

			desc->properties = (jack_property_t*)realloc (desc->properties, sizeof(jack_property_t) * props_size);
		}

		prop = &desc->properties[cnt];

		/* store UUID/subject */

		jack_uuid_copy (&desc->subject, subject);

		/* copy key (without leading UUID as subject */

		len1 = key.size - JACK_UUID_STRING_SIZE;
		prop->key = malloc (len1);
		memcpy ((char*)prop->key, key.data + JACK_UUID_STRING_SIZE, len1);

		/* copy data (which contains 1 or 2 null terminated strings, the value
		   and optionally a MIME type.
		 */

		len1 = strlen (data.data) + 1;
		prop->data = (char*)malloc (len1);
		memcpy ((char*)prop->data, data.data, len1);

		if (len1 < data.size) {
			len2 = strlen (data.data + len1) + 1;

			prop->type = (char*)malloc (len2);
			memcpy ((char*)prop->type, data.data + len1, len2);
		} else {
			/* no type specified, assume default */
			prop->type = NULL;
		}

		/* if (key.size  > 0) free(key.data);  */
		if (data.size > 0) {
			free (data.data);
		}

		++cnt;
	}

	cursor->close (cursor);
	desc->property_cnt = cnt;

	return cnt;
}

int
jack_get_all_properties (jack_description_t** descriptions)
{
	DBT key;
	DBT data;
	DBC* cursor;
	int ret;
	size_t dcnt = 0;
	size_t dsize = 0;
	size_t n = 0;
	jack_description_t* desc = NULL;
	jack_uuid_t uuid = JACK_UUID_EMPTY_INITIALIZER;
	jack_description_t* current_desc = NULL;
	jack_property_t* current_prop = NULL;
	size_t len1, len2;

	if (jack_property_init (NULL)) {
		return -1;
	}

	if ((ret = db->cursor (db, NULL, &cursor, 0)) != 0) {
		jack_error ("Cannot create cursor for metadata search (%s)", db_strerror (ret));
		return -1;
	}

	memset (&key, 0, sizeof(key));
	memset (&data, 0, sizeof(data));
	data.flags = DB_DBT_MALLOC;

	dsize = 8; /* initial guess at number of descriptions we need */
	dcnt = 0;
	desc = (jack_description_t*)malloc (dsize * sizeof(jack_description_t));

	while ((ret = cursor->get (cursor, &key, &data, DB_NEXT)) == 0) {

		/* require 2 extra chars (data+null) for key,
		   which is composed of UUID str plus a key name
		 */

		if (key.size < JACK_UUID_STRING_SIZE + 2) {
			/* if (key.size  > 0) free(key.data);  */
			if (data.size > 0) {
				free (data.data);
			}
			continue;
		}

		if (jack_uuid_parse (key.data, &uuid) != 0) {
			continue;
		}

		/* do we have an existing description for this UUID */

		for (n = 0; n < dcnt; ++n) {
			if (jack_uuid_compare (uuid, desc[n].subject) == 0) {
				break;
			}
		}

		if (n == dcnt) {
			/* we do not have an existing description, so grow the array */

			if (dcnt == dsize) {
				dsize *= 2;
				desc = (jack_description_t*)realloc (desc, sizeof(jack_description_t) * dsize);
			}

			/* initialize */

			desc[n].property_size = 0;
			desc[n].property_cnt = 0;
			desc[n].properties = NULL;

			/* set up UUID */

			jack_uuid_copy (&desc[n].subject, uuid);
			dcnt++;
		}

		current_desc = &desc[n];

		/* see if there is room for the new property or if we need to realloc
		 */

		if (current_desc->property_cnt == current_desc->property_size) {
			if (current_desc->property_size == 0) {
				current_desc->property_size = 8;
			} else {
				current_desc->property_size *= 2;
			}

			current_desc->properties = (jack_property_t*)realloc (current_desc->properties, sizeof(jack_property_t) * current_desc->property_size);
		}

		current_prop = &current_desc->properties[current_desc->property_cnt++];

		/* copy key (without leading UUID) */

		len1 = key.size - JACK_UUID_STRING_SIZE;
		current_prop->key = malloc (len1);
		memcpy ((char*)current_prop->key, key.data + JACK_UUID_STRING_SIZE, len1);

		/* copy data (which contains 1 or 2 null terminated strings, the value
		   and optionally a MIME type.
		 */

		len1 = strlen (data.data) + 1;
		current_prop->data = (char*)malloc (len1);
		memcpy ((char*)current_prop->data, data.data, len1);

		if (len1 < data.size) {
			len2 = strlen (data.data + len1) + 1;

			current_prop->type = (char*)malloc (len2);
			memcpy ((char*)current_prop->type, data.data + len1, len2);
		} else {
			/* no type specified, assume default */
			current_prop->type = NULL;
		}

		/* if (key.size  > 0) free(key.data);  */
		if (data.size > 0) {
			free (data.data);
		}
	}

	cursor->close (cursor);

	(*descriptions) = desc;

	return dcnt;
}


int
jack_get_description (jack_uuid_t subject,
		      jack_description_t* desc)
{
	return 0;
}

int
jack_get_all_descriptions (jack_description_t** descs)
{
	return 0;
}

int
jack_set_property_change_callback (jack_client_t *client,
				   JackPropertyChangeCallback callback, void *arg)
{
	if (client->control->active) {
		jack_error ("You cannot set callbacks on an active client.");
		return -1;
	}
	client->property_cb = callback;
	client->property_cb_arg = arg;
	client->control->property_cbset = (callback != NULL);
	return 0;
}

int
jack_remove_property (jack_client_t* client, jack_uuid_t subject, const char* key)
{
	DBT d_key;
	int ret;

	if (jack_property_init (NULL)) {
		return -1;
	}

	make_key_dbt (&d_key, subject, key);
	if ((ret = db->del (db, NULL, &d_key, 0)) != 0) {
		jack_error ("Cannot delete key %s (%s)", key, db_strerror (ret));
		if (d_key.size > 0) {
			free (d_key.data);
		}
		return -1;
	}

	jack_property_change_notify (client, subject, key, PropertyDeleted);

	if (d_key.size > 0) {
		free (d_key.data);
	}

	return 0;
}

int
jack_remove_properties (jack_client_t* client, jack_uuid_t subject)
{
	DBT key;
	DBT data;
	DBC* cursor;
	int ret;
	char ustr[JACK_UUID_STRING_SIZE];
	int retval = 0;
	uint32_t cnt = 0;

	memset (ustr, 0, JACK_UUID_STRING_SIZE);
	jack_uuid_unparse (subject, ustr);

	if (jack_property_init (NULL)) {
		return -1;
	}

	if ((ret = db->cursor (db, NULL, &cursor, 0)) != 0) {
		jack_error ("Cannot create cursor for metadata search (%s)", db_strerror (ret));
		return -1;
	}

	memset (&key, 0, sizeof(key));
	memset (&data, 0, sizeof(data));
	data.flags = DB_DBT_MALLOC;

	while ((ret = cursor->get (cursor, &key, &data, DB_NEXT)) == 0) {

		/* require 2 extra chars (data+null) for key,
		   which is composed of UUID str plus a key name
		 */

		if (key.size < JACK_UUID_STRING_SIZE + 2) {
			/* if (key.size  > 0) free(key.data); */
			if (data.size > 0) {
				free (data.data);
			}
			continue;
		}

		if (memcmp (ustr, key.data, JACK_UUID_STRING_SIZE) != 0) {
			/* not relevant */
			/* if (key.size  > 0) free(key.data); */
			if (data.size > 0) {
				free (data.data);
			}
			continue;
		}

		if ((ret = cursor->del (cursor, 0)) != 0) {
			jack_error ("cannot delete property (%s)", db_strerror (ret));
			/* don't return -1 here since this would leave things
			   even more inconsistent. wait till the cursor is finished
			 */
			retval = -1;
		}
		cnt++;

		/* if (key.size  > 0) free(key.data);  */
		if (data.size > 0) {
			free (data.data);
		}
	}

	cursor->close (cursor);

	if (cnt) {
		jack_property_change_notify (client, subject, NULL, PropertyDeleted);
	}

	if (retval) {
		return -1;
	}

	return cnt;
}

int
jack_remove_all_properties (jack_client_t* client)
{
	int ret;
	jack_uuid_t empty_uuid = JACK_UUID_EMPTY_INITIALIZER;

	if (jack_property_init (NULL)) {
		return -1;
	}

	if ((ret = db->truncate (db, NULL, NULL, 0)) != 0) {
		jack_error ("Cannot clear properties (%s)", db_strerror (ret));
		return -1;
	}

	jack_property_change_notify (client, empty_uuid, NULL, PropertyDeleted);

	return 0;
}