State of a transaction

What this reports is whether the transaction can still be used, not whether its native handle happens to be allocated. Three of the five answers exist because those differ: a transaction 'libmdbx' has marked erroneous, one poisoned by an assertion failure, and one inherited across a fork() are each refused by every operation, and reporting them as "active" described only this package's own bookkeeping.

Usage

mdbx_txn_state(txn)

Arguments

txn

An mdbx_txn object, from mdbx_txn_begin().

Value

One of:

"active"

Open and usable.

"committed"

Ended by mdbx_txn_commit(); its writes are durable.

"aborted"

Ended by mdbx_txn_abort(), by the garbage collector, or by its environment closing; its writes are gone.

"failed"

Still open, but 'libmdbx' has marked it erroneous — MDBX_MAP_FULL is the usual cause. Every operation now fails with MDBX_BAD_TXN and committing reports a rollback, so the only thing left to do with it is end it.

"poisoned"

Abandoned after a 'libmdbx' assertion failure, in this transaction or in the environment that owns it. Aborting it is still safe, and does not re-enter 'libmdbx'; afterwards it reads as "aborted" like any other ended transaction.

"invalid"

The handle has been reclaimed, or was inherited across a fork() and belongs to another process — see mdbx-concurrency.

See also

mdbx_txn_begin()

Examples

path <- tempfile(fileext = ".mdbx")
env <- mdbx_env_open(path)

txn <- mdbx_txn_begin(env)
mdbx_txn_state(txn)
#> [1] "active"
mdbx_txn_abort(txn)
mdbx_txn_state(txn)
#> [1] "aborted"

mdbx_env_close(env)
unlink(c(path, paste0(path, "-lck")))