Boston, MA 02111-1307, USA.
*/
-/**
+/**
* @file include/gnunet_psyc_service.h
* @brief PSYC service; high-level access to the PSYC protocol
* note that clients of this API are NOT expected to
* 'places' and 'persons' are combined within the same
* abstraction, that of a "channel". Channels are identified
* and accessed in this API using a public/private key.
- * Higher-level applications should use NAMES within GADS
+ * Higher-level applications should use NAMES within GNS
* to obtain public keys, and the distinction between
* 'places' and 'persons' can then be made with the help
* of the naming system (and/or conventions).
* @c \#define for the maximum size of a variable).
* - PSYC defines standard variables, methods, etc. This
* library deliberately abstracts over all of these; a
- * higher-level API should combine the naming system (GADS)
+ * higher-level API should combine the naming system (GNS)
* and standard methods (message, join, part, warn,
* fail, error) and variables (action, color, time,
* tag, etc.). However, this API does take over the
#endif
#include "gnunet_util_lib.h"
-#include "gnunet_psyc_lib.h"
+#include "gnunet_env_lib.h"
#include "gnunet_multicast_service.h"
-/**
+/**
* Version number of GNUnet-PSYC API.
*/
#define GNUNET_PSYC_VERSION 0x00000000
+/**
+ * Policy flags for a channel.
+ */
+enum GNUNET_PSYC_ChannelFlags
+{
+ /**
+ * Admission must be confirmed by the master.
+ */
+ GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL = 1 << 0,
+
+ /**
+ * Past messages are only available to slaves who were admitted at the time
+ * they were sent to the channel.
+ */
+ GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY = 1 << 1,
+};
+
+/**
+ * PSYC channel policies.
+ */
+enum GNUNET_PSYC_Policy
+{
+ /**
+ * Anyone can join the channel, without announcing his presence;
+ * all messages are always public and can be distributed freely.
+ * Joins may be announced, but this is not required.
+ */
+ GNUNET_PSYC_CHANNEL_ANONYMOUS = 0,
+
+ /**
+ * The master must approve membership to the channel, messages must only be
+ * distributed to current channel slaves. This includes the channel
+ * state as well as transient messages.
+ */
+ GNUNET_PSYC_CHANNEL_PRIVATE
+ = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL
+ | GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY,
+
+#if IDEAS_FOR_FUTURE
+ /**
+ * Anyone can freely join the channel (no approval required);
+ * however, messages must only be distributed to current channel
+ * slaves, so the master must still acknowledge that the slave
+ * joined before transient messages are delivered. As approval is
+ * guaranteed, the presistent channel state can be synchronized freely
+ * immediately, prior to master confirmation.
+ */
+ GNUNET_PSYC_CHANNEL_OPEN
+ = GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY,
+
+ /**
+ * The master must approve joins to the channel, but past messages can be
+ * freely distributed to slaves.
+ */
+ GNUNET_PSYC_CHANNEL_CLOSED
+ = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL,
+,
+#endif
+
+};
+
+
enum GNUNET_PSYC_MessageFlags
{
/**
*/
GNUNET_PSYC_MESSAGE_LAST_FRAGMENT = 1 << 1,
- /**
+ /**
* OR'ed flags if message is not fragmented.
*/
GNUNET_PSYC_MESSAGE_NOT_FRAGMENTED
};
-/**
+/**
+ * M
+ */
+struct GNUNET_PSYC_MessageMethod
+{
+ /**
+ * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
+ */
+ struct GNUNET_MessageHeader header;
+
+ uint32_t reserved GNUNET_PACKED;
+
+ /**
+ * Number of modifiers in the message.
+ */
+ uint32_t mod_count GNUNET_PACKED;
+
+ /**
+ * OR'ed GNUNET_PSYC_MasterTransmitFlags
+ */
+ uint32_t flags GNUNET_PACKED;
+
+ /**
+ * Sending slave's public key. NULL if the message is from the master, or when
+ * transmitting a message.
+ */
+ struct GNUNET_CRYPTO_EccPublicSignKey slave_key;
+
+ /* Followed by NUL-terminated method name. */
+};
+
+
+struct GNUNET_PSYC_MessageModifier
+{
+ /**
+ * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
+ */
+ struct GNUNET_MessageHeader header;
+
+ /**
+ * Size of value.
+ */
+ uint32_t value_size GNUNET_PACKED;
+
+ /**
+ * Size of name, including NUL terminator.
+ */
+ uint16_t name_size GNUNET_PACKED;
+
+ /**
+ * enum GNUNET_ENV_Operator
+ */
+ uint8_t oper;
+
+ /* Followed by NUL-terminated name, then the value. */
+};
+
+
+enum GNUNET_PSYC_DataStatus
+{
+ /**
+ * To be continued.
+ */
+ GNUNET_PSYC_DATA_CONT = 0,
+
+ /**
+ * Reached the end of message.
+ */
+ GNUNET_PSYC_DATA_END = 1,
+
+ /**
+ * Cancelled before the end.
+ */
+ GNUNET_PSYC_DATA_CANCEL = 2
+};
+
+
+struct GNUNET_PSYC_MessageData
+{
+ /**
+ * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
+ */
+ struct GNUNET_MessageHeader header;
+
+ /**
+ * enum GNUNET_PSYC_DataStatus
+ */
+ uint8_t status;
+};
+
+/**
* Handle that identifies a join request.
*
* Used to match calls to #GNUNET_PSYC_JoinCallback to the
struct GNUNET_PSYC_JoinHandle;
-/**
- * Method called from PSYC upon receiving a message indicating a call
- * to a @e method.
+/**
+ * Method called from PSYC upon receiving a message indicating a call to a
+ * @e method.
*
* @param cls Closure.
* @param slave_key Who transmitted the message.
* - NULL for multicast messages from the master.
- * - The hash of the sending slave's public key for unicast requests from
- * one of the slaves to the master.
+ * - The sending slave's public key for unicast requests from one of the
+ * slaves to the master.
* @param message_id Unique message counter for this message.
* Unique only in combination with the given sender for this channel.
* @param method_name Method name from PSYC.
* @param modifier_count Number of elements in the @a modifiers array.
* @param modifiers State modifiers and transient variables for the message.
* @param data_offset Byte offset of @a data in the overall data of the method.
- * @param data_size Number of bytes in @a data.
* @param data Data stream given to the method (might not be zero-terminated
* if data is binary).
+ * @param data_size Number of bytes in @a data.
* @param frag Fragmentation status for the data.
*/
typedef int
(*GNUNET_PSYC_Method) (void *cls,
- const struct GNUNET_CRYPTO_EccPublicKey *slave_key,
+ const struct GNUNET_CRYPTO_EccPublicSignKey *slave_key,
uint64_t message_id,
const char *method_name,
size_t modifier_count,
- const GNUNET_ENV_Modifier *modifiers,
+ const struct GNUNET_ENV_Modifier *modifiers,
uint64_t data_offset,
- size_t data_size,
const void *data,
+ size_t data_size,
enum GNUNET_PSYC_MessageFlags flags);
-/**
+/**
* Method called from PSYC upon receiving a join request.
*
* @param cls Closure.
* @param method_name Method name in the join request.
* @param variable_count Number of elements in the @a variables array.
* @param variables Transient variables for the join request.
- * @param data_size Number of bytes in @a data.
* @param data Data stream given to the method (might not be zero-terminated
* if data is binary).
+ * @param data_size Number of bytes in @a data.
+ * @param jh Join handle to use with GNUNET_PSYC_join_decision()
*/
typedef int
(*GNUNET_PSYC_JoinCallback) (void *cls,
- const struct GNUNET_CRYPTO_EccPublicKey *slave_key,
+ const struct GNUNET_CRYPTO_EccPublicSignKey
+ *slave_key,
const char *method_name,
size_t variable_count,
- const GNUNET_ENV_Modifier *variables,
- size_t data_size,
+ const struct GNUNET_ENV_Modifier *variables,
const void *data,
+ size_t data_size,
struct GNUNET_PSYC_JoinHandle *jh);
-/**
+/**
* Function to call with the decision made for a join request.
*
* Must be called once and only once in response to an invocation of the
* multicast tree. Note that it is unnecessary to specify our own
* peer identity in this array.
* @param method_name Method name for the message transmitted with the response.
- * @param env Environment containing transient variables for the message, or NULL.
- * @param data_size Size of @a data.
+ * @param env Environment containing transient variables for the message,
+ * or NULL.
* @param data Data of the message.
+ * @param data_size Size of @a data.
*/
void
GNUNET_PSYC_join_decision (struct GNUNET_PSYC_JoinHandle *jh,
const struct GNUNET_PeerIdentity *relays,
const char *method_name,
const struct GNUNET_ENV_Environment *env,
- size_t data_size,
- const void *data);
+ const void *data,
+ size_t data_size);
-/**
+/**
* Handle for the master of a PSYC channel.
*/
struct GNUNET_PSYC_Master;
-/**
+/**
+ * Function called after the channel master started.
+ *
+ * @param cls Closure.
+ * @param last_message_id Last message ID sent to the channel.
+ */
+typedef void
+(*GNUNET_PSYC_MasterStartCallback) (void *cls, uint64_t max_message_id);
+
+
+/**
* Start a PSYC master channel.
*
* Will start a multicast group identified by the given ECC key. Messages
* @param channel_key ECC key that will be used to sign messages for this
* PSYC session. The public key is used to identify the PSYC channel.
* Note that end-users will usually not use the private key directly, but
- * rather look it up in GADS for places managed by other users, or select
+ * rather look it up in GNS for places managed by other users, or select
* a file with the private key(s) when setting up their own channels
* FIXME: we'll likely want to use NOT the p521 curve here, but a cheaper
* one in the future.
- * @param policy Group policy specifying join and history restrictions.
- * Used to automate group management decisions.
+ * @param policy Channel policy specifying join and history restrictions.
+ * Used to automate join decisions.
* @param method Function to invoke on messages received from slaves.
* @param join_cb Function to invoke when a peer wants to join.
+ * @param start_cb Function to invoke after the channel master started.
* @param cls Closure for @a method and @a join_cb.
* @return Handle for the channel master, NULL on error.
*/
struct GNUNET_PSYC_Master *
GNUNET_PSYC_master_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
const struct GNUNET_CRYPTO_EccPrivateKey *channel_key,
- enum GNUNET_MULTICAST_GroupPolicy policy,
+ enum GNUNET_PSYC_Policy policy,
GNUNET_PSYC_Method method,
GNUNET_PSYC_JoinCallback join_cb,
+ GNUNET_PSYC_MasterStartCallback start_cb,
void *cls);
-/**
+/**
* Function called to provide data for a transmission via PSYC.
*
* Note that returning #GNUNET_OK or #GNUNET_SYSERR (but not #GNUNET_NO)
* invalidates the respective transmission handle.
*
* @param cls Closure.
- * @param message_id Set to the unique message ID that was generated for
- * this message.
- * @param[in,out] data_size Initially set to the number of bytes available in @a data,
- * should be set to the number of bytes written to data (IN/OUT).
- * @param[out] data Where to write the body of the message to give to the method;
- * function must copy at most @a *data_size bytes to @a data.
+ * @param[in,out] data_size Initially set to the number of bytes available in
+ * @a data, should be set to the number of bytes written to data.
+ * @param[out] data Where to write the body of the message to give to the
+ * method. The function must copy at most @a data_size bytes to @a data.
* @return #GNUNET_SYSERR on error (fatal, aborts transmission)
- * #GNUNET_NO on success, if more data is to be transmitted later
- * (should be used if @a *data_size was not big enough to take all the data)
+ * #GNUNET_NO on success, if more data is to be transmitted later.
+ * Should be used if @a data_size was not big enough to take all the
+ * data. If 0 is returned in @a data_size the transmission is paused,
+ * and can be resumed with GNUNET_PSYC_master_transmit_resume().
* #GNUNET_YES if this completes the transmission (all data supplied)
*/
typedef int
-(*GNUNET_PSYC_MasterReadyNotify)(void *cls,
- uint64_t message_id,
- size_t *data_size,
- void *data);
+(*GNUNET_PSYC_MasterTransmitNotify) (void *cls,
+ size_t *data_size,
+ void *data);
+
+/**
+ * Flags for transmitting messages to a channel by the master.
+ */
+enum GNUNET_PSYC_MasterTransmitFlags
+{
+ GNUNET_PSYC_MASTER_TRANSMIT_NONE = 0,
+ /**
+ * Whether this message should reset the channel state,
+ * i.e. remove all previously stored state variables.
+ */
+ GNUNET_PSYC_MASTER_TRANSMIT_RESET_STATE = 1 << 0,
-/**
+ /**
+ * Whether we need to increment the group generation counter after
+ * transmitting this message.
+ */
+ GNUNET_PSYC_MASTER_TRANSMIT_INC_GROUP_GEN = 1 << 1,
+
+ /**
+ * Add PSYC header variable with the hash of the current channel state.
+ */
+ GNUNET_PSYC_MASTER_TRANSMIT_ADD_STATE_HASH = 1 << 2
+};
+
+
+/**
* Handle for a pending PSYC transmission operation.
*/
struct GNUNET_PSYC_MasterTransmitHandle;
-/**
+/**
* Send a message to call a method to all members in the PSYC channel.
*
* @param master Handle to the PSYC channel.
- * @param increment_group_generation #GNUNET_YES if we need to increment
- * the group generation counter after transmitting this message.
* @param method_name Which method should be invoked.
* @param env Environment containing state operations and transient variables
* for the message, or NULL.
* @param notify Function to call to obtain the arguments.
* @param notify_cls Closure for @a notify.
+ * @param flags Flags for the message being transmitted.
* @return Transmission handle, NULL on error (i.e. more than one request queued).
*/
struct GNUNET_PSYC_MasterTransmitHandle *
GNUNET_PSYC_master_transmit (struct GNUNET_PSYC_Master *master,
- int increment_group_generation,
const char *method_name,
const struct GNUNET_ENV_Environment *env,
- GNUNET_PSYC_MasterReadyNotify notify,
- void *notify_cls);
+ GNUNET_PSYC_MasterTransmitNotify notify,
+ void *notify_cls,
+ enum GNUNET_PSYC_MasterTransmitFlags flags);
+
+
+/**
+ * Resume transmission to the channel.
+ *
+ * @param th Handle of the request that is being resumed.
+ */
+void
+GNUNET_PSYC_master_transmit_resume (struct GNUNET_PSYC_MasterTransmitHandle *th);
-/**
+/**
* Abort transmission request to channel.
*
* @param th Handle of the request that is being aborted.
GNUNET_PSYC_master_transmit_cancel (struct GNUNET_PSYC_MasterTransmitHandle *th);
-/**
+/**
* Stop a PSYC master channel.
*
* @param master PSYC channel master to stop.
GNUNET_PSYC_master_stop (struct GNUNET_PSYC_Master *master);
-/**
+/**
* Handle for a PSYC channel slave.
*/
struct GNUNET_PSYC_Slave;
-/**
+/**
+ * Function called after the slave joined.
+ *
+ * @param cls Closure.
+ * @param max_message_id Last message ID sent to the channel.
+ */
+typedef void
+(*GNUNET_PSYC_SlaveJoinCallback) (void *cls, uint64_t max_message_id);
+
+
+/**
* Join a PSYC channel.
*
* The entity joining is always the local peer. The user must immediately use
- * the GNUNET_PSYC_slave_to_master() functions to transmit a @e join_msg to the
+ * the GNUNET_PSYC_slave_transmit() functions to transmit a @e join_msg to the
* channel; if the join request succeeds, the channel state (and @e recent
* method calls) will be replayed to the joining member. There is no explicit
* notification on failure (as the channel may simply take days to approve,
* @param cls Closure for @a method_cb and @a join_cb.
* @param method_name Method name for the join request.
* @param env Environment containing transient variables for the request, or NULL.
- * @param data_size Number of bytes in @a data.
* @param data Payload for the join message.
+ * @param data_size Number of bytes in @a data.
* @return Handle for the slave, NULL on error.
*/
struct GNUNET_PSYC_Slave *
GNUNET_PSYC_slave_join (const struct GNUNET_CONFIGURATION_Handle *cfg,
- const struct GNUNET_CRYPTO_EccPublicKey *channel_key,
+ const struct GNUNET_CRYPTO_EccPublicSignKey *channel_key,
const struct GNUNET_CRYPTO_EccPrivateKey *slave_key,
const struct GNUNET_PeerIdentity *origin,
size_t relay_count,
const struct GNUNET_PeerIdentity *relays,
GNUNET_PSYC_Method method,
GNUNET_PSYC_JoinCallback join_cb,
+ GNUNET_PSYC_SlaveJoinCallback slave_joined_cb,
void *cls,
const char *method_name,
const struct GNUNET_ENV_Environment *env,
- size_t data_size,
- const void *data);
+ const void *data,
+ size_t data_size);
-/**
+/**
* Part a PSYC channel.
*
* Will terminate the connection to the PSYC service. Polite clients should
- * first explicitly send a @e part request (via GNUNET_PSYC_slave_to_master()).
+ * first explicitly send a @e part request (via GNUNET_PSYC_slave_transmit()).
*
* @param slave Slave handle.
*/
GNUNET_PSYC_slave_part (struct GNUNET_PSYC_Slave *slave);
-/**
- * Function called to provide data for a transmission to the channel
- * master (aka the @e host of the channel).
+/**
+ * Function called to provide data for a transmission to the channel master
+ * (a.k.a. the @e host of the channel).
*
* Note that returning #GNUNET_OK or #GNUNET_SYSERR (but not #GNUNET_NO)
* invalidates the respective transmission handle.
*
* @param cls Closure.
- * @param[in,out] data_size Initially set to the number of bytes available in @a data,
- * should be set to the number of bytes written to data (IN/OUT).
+ * @param[in,out] data_size Initially set to the number of bytes available in
+ * @a data, should be set to the number of bytes written to data
+ * (IN/OUT).
* @param[out] data Where to write the body of the message to give to the method;
* function must copy at most @a *data_size bytes to @a data.
* @return #GNUNET_SYSERR on error (fatal, aborts transmission).
* #GNUNET_YES if this completes the transmission (all data supplied).
*/
typedef int
-(*GNUNET_PSYC_SlaveReadyNotify) (void *cls,
- size_t *data_size,
- char *data);
+(*GNUNET_PSYC_SlaveTransmitNotify) (void *cls,
+ size_t *data_size,
+ char *data);
+
+
+/**
+ * Flags for transmitting messages to the channel master by a slave.
+ */
+enum GNUNET_PSYC_SlaveTransmitFlags
+{
+ GNUNET_PSYC_SLAVE_TRANSMIT_NONE = 0
+};
-/**
+/**
* Handle for a pending PSYC transmission operation.
*/
struct GNUNET_PSYC_SlaveTransmitHandle;
-/**
+/**
* Request a message to be sent to the channel master.
*
* @param slave Slave handle.
* @param env Environment containing transient variables for the message, or NULL.
* @param notify Function to call when we are allowed to transmit (to get data).
* @param notify_cls Closure for @a notify.
+ * @param flags Flags for the message being transmitted.
* @return Transmission handle, NULL on error (i.e. more than one request queued).
*/
struct GNUNET_PSYC_SlaveTransmitHandle *
GNUNET_PSYC_slave_transmit (struct GNUNET_PSYC_Slave *slave,
const char *method_name,
const struct GNUNET_ENV_Environment *env,
- GNUNET_PSYC_SlaveReadyNotify notify,
- void *notify_cls);
+ GNUNET_PSYC_SlaveTransmitNotify notify,
+ void *notify_cls,
+ enum GNUNET_PSYC_SlaveTransmitFlags flags);
+
+/**
+ * Resume transmission to the master.
+ *
+ * @param th Handle of the request that is being resumed.
+ */
+void
+GNUNET_PSYC_slave_transmit_resume (struct GNUNET_PSYC_MasterTransmitHandle *th);
-/**
+
+/**
* Abort transmission request to master.
*
* @param th Handle of the request that is being aborted.
GNUNET_PSYC_slave_transmit_cancel (struct GNUNET_PSYC_SlaveTransmitHandle *th);
-/**
+/**
* Handle to access PSYC channel operations for both the master and slaves.
*/
struct GNUNET_PSYC_Channel;
-/**
- * Convert a channel @a master to a @e channel handle to access the @e channel APIs.
+/**
+ * Convert a channel @a master to a @e channel handle to access the @e channel
+ * APIs.
*
* @param master Channel master handle.
* @return Channel handle, valid for as long as @a master is valid.
GNUNET_PSYC_master_get_channel (struct GNUNET_PSYC_Master *master);
-/**
+/**
* Convert @a slave to a @e channel handle to access the @e channel APIs.
*
* @param slave Slave handle.
GNUNET_PSYC_slave_get_channel (struct GNUNET_PSYC_Slave *slave);
-/**
+/**
* Add a slave to the channel's membership list.
*
* Note that this will NOT generate any PSYC traffic, it will merely update the
*
* @param channel Channel handle.
* @param slave_key Identity of channel slave to add.
- * @param message_id Message ID for the message that changed the membership.
+ * @param announced_at ID of the message that announced the membership change.
+ * @param effective_since Addition of slave is in effect since this message ID.
*/
void
GNUNET_PSYC_channel_slave_add (struct GNUNET_PSYC_Channel *channel,
- const struct GNUNET_CRYPTO_EccPublicKey *slave_key,
- uint64_t message_id);
+ const struct GNUNET_CRYPTO_EccPublicSignKey
+ *slave_key,
+ uint64_t announced_at,
+ uint64_t effective_since);
-/**
+/**
* Remove a slave from the channel's membership list.
*
* Note that this will NOT generate any PSYC traffic, it will merely update the
*
* @param channel Channel handle.
* @param slave_key Identity of channel slave to remove.
- * @param message_id Message ID for the message that changed the membership.
+ * @param announced_at ID of the message that announced the membership change.
*/
void
GNUNET_PSYC_channel_slave_remove (struct GNUNET_PSYC_Channel *channel,
- const struct GNUNET_CRYPTO_EccPublicKey *slave_key,
- uint64_t message_id);
+ const struct GNUNET_CRYPTO_EccPublicSignKey
+ *slave_key,
+ uint64_t announced_at);
-/**
+/**
* Function called to inform a member about stored state values for a channel.
*
* @param cls Closure.
- * @param name Name of the state variable.
+ * @param name Name of the state variable. A NULL value indicates that there
+ * are no more state variables to be returned.
* @param value Value of the state variable.
* @param value_size Number of bytes in @a value.
*/
typedef void
(*GNUNET_PSYC_StateCallback) (void *cls,
const char *name,
- size_t value_size,
- const void *value);
+ const void *value,
+ size_t value_size);
+
+
+/**
+ * Function called when a requested operation has finished.
+ *
+ * @param cls Closure.
+ */
+typedef void
+(*GNUNET_PSYC_FinishCallback) (void *cls);
-/**
+/**
* Handle to a story telling operation.
*/
struct GNUNET_PSYC_Story;
-/**
+/**
* Request to be told the message history of the channel.
*
* Historic messages (but NOT the state at the time) will be replayed (given to
* @param start_message_id Earliest interesting point in history.
* @param end_message_id Last (exclusive) interesting point in history.
* @param method Function to invoke on messages received from the story.
- * @param method_cls Closure for @a method.
* @param finish_cb Function to call when the requested story has been fully
* told (counting message IDs might not suffice, as some messages
* might be secret and thus the listener would not know the story is
* finished without being told explicitly); once this function
* has been called, the client must not call
* GNUNET_PSYC_channel_story_tell_cancel() anymore.
- * @param finish_cb_cls Closure to finish_cb.
+ * @param cls Closure for the callbacks.
* @return Handle to cancel story telling operation.
*/
struct GNUNET_PSYC_Story *
uint64_t start_message_id,
uint64_t end_message_id,
GNUNET_PSYC_Method method,
- void *method_cls,
- void (*finish_cb)(void *),
- void *finish_cb_cls);
+ GNUNET_PSYC_FinishCallback *finish_cb,
+ void *cls);
-/**
+/**
* Abort story telling.
*
* This function must not be called from within method handlers (as given to
GNUNET_PSYC_channel_story_tell_cancel (struct GNUNET_PSYC_Story *story);
-/**
- * Call the given callback on all matching values (including variables) in the
- * channel state.
- *
- * The callback is invoked synchronously on all matching states (as the state is
- * fully replicated in the library in this process; channel states should be
- * small, large data is to be passed as streaming data to methods).
+/**
+ * Handle for a state query operation.
+ */
+struct GNUNET_PSYC_StateQuery;
+
+
+/**
+ * Retrieve the best matching channel state variable.
*
- * A name matches if it includes the @a state_name prefix, thus requesting the
- * empty state ("") will match all values; requesting "_a_b" will also return
- * values stored under "_a_b_c".
+ * If the requested variable name is not present in the state, the nearest
+ * less-specific name is matched; for example, requesting "_a_b" will match "_a"
+ * if "_a_b" does not exist.
*
* @param channel Channel handle.
- * @param state_name Name of the state to query (full name
- * might be longer, this is only the prefix that must match).
- * @param cb Function to call on the matching state values.
- * @param cb_cls Closure for @a cb.
- * @return Message ID for which the state was returned (last seen
- * message ID).
+ * @param full_name Full name of the requested variable, the actual variable
+ * returned might have a shorter name..
+ * @param cb Function called once when a matching state variable is found.
+ * Not called if there's no matching state variable.
+ * @param cb_cls Closure for the callbacks.
+ * @return Handle that can be used to cancel the query operation.
*/
-uint64_t
-GNUNET_PSYC_channel_state_get_all (struct GNUNET_PSYC_Channel *channel,
- const char *state_name,
- GNUNET_PSYC_StateCallback cb,
- void *cb_cls);
+struct GNUNET_PSYC_StateQuery *
+GNUNET_PSYC_channel_state_get (struct GNUNET_PSYC_Channel *channel,
+ const char *full_name,
+ GNUNET_PSYC_StateCallback cb,
+ void *cb_cls);
-/**
- * Obtain the current value of the best-matching value in the state
- * (including variables).
+/**
+ * Return all channel state variables whose name matches a given prefix.
*
- * Note that variables are only valid during a #GNUNET_PSYC_Method invocation, as
- * variables are only valid for the duration of a method invocation.
+ * A name matches if it starts with the given @a name_prefix, thus requesting
+ * the empty prefix ("") will match all values; requesting "_a_b" will also
+ * return values stored under "_a_b_c".
*
- * If the requested variable name does not have an exact state in
- * the state, the nearest less-specific name is matched; for example,
- * requesting "_a_b" will match "_a" if "_a_b" does not exist.
+ * The @a state_cb is invoked on all matching state variables asynchronously, as
+ * the state is stored in and retrieved from the PSYCstore,
*
* @param channel Channel handle.
- * @param variable_name Name of the variable to query.
- * @param[out] return_value_size Set to number of bytes in variable,
- * needed as variables might contain binary data and
- * might also not be 0-terminated; set to 0 on errors.
- * @return NULL on error (no matching state or variable), pointer
- * to the respective value otherwise.
- */
-const void *
-GNUNET_PSYC_channel_state_get (struct GNUNET_PSYC_Channel *channel,
- const char *variable_name,
- size_t *return_value_size);
+ * @param name_prefix Prefix of the state variable name to match.
+ * @param cb Function to call with the matching state variables.
+ * @param cb_cls Closure for the callbacks.
+ * @return Handle that can be used to cancel the query operation.
+ */
+struct GNUNET_PSYC_StateQuery *
+GNUNET_PSYC_channel_state_get_prefix (struct GNUNET_PSYC_Channel *channel,
+ const char *name_prefix,
+ GNUNET_PSYC_StateCallback cb,
+ void *cb_cls);
+
+
+/**
+ * Cancel a state query operation.
+ *
+ * @param query Handle for the operation to cancel.
+ */
+void
+GNUNET_PSYC_channel_state_get_cancel (struct GNUNET_PSYC_StateQuery *query);
#if 0 /* keep Emacsens' auto-indent happy */
projects / oweals / gnunet.git / blobdiff