daos_api.h File Reference

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Enumerations
enum	{ DAOS_TF_RDONLY = (1 << 0) , DAOS_TF_ZERO_COPY = (1 << 1) }

Functions
d_rank_list_t *	daos_rank_list_parse (const char *str, const char *sep)
int	daos_tx_open (daos_handle_t coh, daos_handle_t *th, uint64_t flags, daos_event_t *ev)
int	daos_tx_commit (daos_handle_t th, daos_event_t *ev)
int	daos_tx_open_snap (daos_handle_t coh, daos_epoch_t epoch, daos_handle_t *th, daos_event_t *ev)
int	daos_tx_abort (daos_handle_t th, daos_event_t *ev)
int	daos_tx_close (daos_handle_t th, daos_event_t *ev)
int	daos_tx_restart (daos_handle_t th, daos_event_t *ev)
int	daos_tx_hdl2epoch (daos_handle_t th, daos_epoch_t *epoch)
int	daos_hlc2timespec (uint64_t hlc, struct timespec *ts)
int	daos_hlc2timestamp (uint64_t hlc, time_t *ts)

Detailed Description

DAOS API methods

Definition in file daos_api.h.

Enumeration Type Documentation

anonymous enum

anonymous enum

Flags for daos_tx_open

Enumerator
DAOS_TF_RDONLY	The transaction is read only.
DAOS_TF_ZERO_COPY	Do not copy caller data buffers during modifications associated with the transaction. The buffers must remain unchanged until the daos_tx_commit operation for the transaction completes. Key buffers are always copied, regardless of this flag. They can be released or repurposed after corresponding operations complete.

Definition at line 20 of file daos_api.h.

Function Documentation

daos_hlc2timespec()

int daos_hlc2timespec	(	uint64_t	hlc,
		struct timespec *	ts )

Convert daos hybrid logical clock (HLC) time to system struct timespec.

Parameters

[in]	hlc	64-bit HLC value returned by libdaos API (such as found in daos_cont_info_t)
[out]	ts	pointer to timespec structure to fill with system time converted from HLC.

Returns

0 if Success, negative if failed.

Return values

-DER_INVAL

Invalid parameter

daos_hlc2timestamp()

int daos_hlc2timestamp	(	uint64_t	hlc,
		time_t *	ts )

Convert daos hybrid logical clock (HLC) time to seconds timestamp.

Parameters

[in]	hlc	64-bit HLC value returned by libdaos API (such as found in daos_cont_info_t)
[out]	ts	pointer to time_t value to assign with seconds since the UNIX epoch, converted from daos HLC.

Returns

0 if Success, negative if failed.

Return values

-DER_INVAL

Invalid parameter

daos_rank_list_parse()

d_rank_list_t * daos_rank_list_parse	(	const char *	str,
		const char *	sep )

Generate a rank list from a string with a separator argument. This is a convenience function to generate the rank list.

Parameters

[in]	str	string with the rank list
[in]	sep	separator of the ranks in str. dmg uses ":" as the separator.

Returns

allocated rank list that user is responsible to free with d_rank_list_free().

daos_tx_abort()

int daos_tx_abort	(	daos_handle_t	th,
		daos_event_t *	ev )

Abort all modifications on the transaction. The transaction handle cannot be used for any new IO.

Parameters

[in]	th	Transaction handle to abort.
[in]	ev	Completion event, it is optional and can be NULL. The function will run in blocking mode if ev is NULL.

Returns

0 if Success, negative if failed.

daos_tx_close()

int daos_tx_close	(	daos_handle_t	th,
		daos_event_t *	ev )

Close the transaction handle. This is a local operation, no RPC involved.

Parameters

[in]	th	Transaction handle to free.
[in]	ev	Completion event, it is optional and can be NULL. The function will run in blocking mode if ev is NULL.

Returns

0 if Success, negative if failed.

daos_tx_commit()

int daos_tx_commit	(	daos_handle_t	th,
		daos_event_t *	ev )

Commit the transaction. If the operation succeeds, the transaction handle cannot be used for any new IO. If -DER_TX_RESTART is returned, the caller needs to restart the transaction with the same transaction handle, by calling daos_tx_restart, re-executing the caller code for this transaction, and calling daos_tx_commit again.

Parameters

[in]	th	Transaction handle to commit.
[in]	ev	Completion event, it is optional and can be NULL. The function will run in blocking mode if ev is NULL.

Returns

0 if Success, negative if failed. Possible error values include: -DER_NO_HDL invalid transaction handle. -DER_INVAL Invalid parameter -DER_TX_RESTART transaction needs to restart (e.g., due to conflicts).

daos_tx_hdl2epoch()

int daos_tx_hdl2epoch	(	daos_handle_t	th,
		daos_epoch_t *	epoch )

Return the epoch associated with the transaction handle. An epoch may not be available at the beginning of the transaction, but one shall be available after the transaction successfully commits.

This function is specific to the current implementation. It should only be used for testing and debugging purposes.

Parameters

[in]	th	Transaction handle.
[out]	epoch	Returned epoch value.

Returns

0 if Success, negative if failed.

Return values

-DER_UNINIT

An epoch is not available yet.

daos_tx_open()

int daos_tx_open	(	daos_handle_t	coh,
		daos_handle_t *	th,
		uint64_t	flags,
		daos_event_t *	ev )

Open a transaction on a container handle. The resulting transaction handle can be used for IOs in this container that need to be committed transactionally.

Invoking operations of one TX with events from multiple event queues, including with NULL events from multiple threads, is not currently supported.

Parameters

[in]	coh	Container handle.
[out]	th	Returned transaction handle.
[in]	flags	Transaction flags (DAOS_TF_RDONLY, etc.).
[in]	ev	Completion event, it is optional and can be NULL. The function will run in blocking mode if ev is NULL.

Returns

0 if Success, negative if failed.

daos_tx_open_snap()

int daos_tx_open_snap	(	daos_handle_t	coh,
		daos_epoch_t	epoch,
		daos_handle_t *	th,
		daos_event_t *	ev )

Create a read-only transaction from a snapshot. This does not create the snapshot, but only a read transaction to be able to read from a snapshot created with daos_cont_create_snap. If the user passes an epoch that is not snapshoted, or the snapshot was deleted, reads using that transaction may get undefined results.

Parameters

[in]	coh	Container handle.
[in]	epoch	Epoch of snapshot to read from.
[out]	th	Returned read only transaction handle.
[in]	ev	Completion event, it is optional and can be NULL. The function will run in blocking mode if ev is NULL.

Returns

0 if Success, negative if failed.

daos_tx_restart()

int daos_tx_restart	(	daos_handle_t	th,
		daos_event_t *	ev )

Restart the transaction after encountering a -DER_TX_RESTART error. This drops all the IOs that have been issued via the transaction handle. Whether the restarted transaction observes any conflicting modifications committed after this transaction was originally opened is undefined. If callers would like to retry transactions for their own purposes, they shall open new transactions instead. This is a local operation, no RPC involved.

Parameters

[in]	th	Transaction handle to be restarted.
[in]	ev	Completion event, it is optional and can be NULL. The function will run in blocking mode if ev is NULL.

Returns

0 if Success, negative if failed.