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Commit a transaction

Source: R/txn.R
mdbx_txn_commit.Rd

Makes the transaction's writes durable and visible to other readers, and ends the transaction.

Usage

mdbx_txn_commit(txn)

Arguments

txn

An mdbx_txn object, from mdbx_txn_begin().

Value

NULL, invisibly.

Details

Unlike mdbx_txn_abort(), this is not idempotent: committing an already-finished transaction is an error, because the second call cannot do what it appears to. Note also that a commit which cannot complete is turned into an abort by 'libmdbx' — if this raises an error, the transaction has still ended, and its writes are gone.

Some failures inside a transaction end it there and then. A rejected key or value size (mdbx_put() returning MDBX_BAD_VALSIZE) is just that one operation failing, and the transaction carries on. A failure that exhausts the map (MDBX_MAP_FULL) instead marks the transaction unusable: every later operation fails with MDBX_BAD_TXN, and the commit reports that the whole transaction was rolled back rather than committed. mdbx_txn_state() reads "failed" from the moment that happens, and "aborted" once the rollback has ended it.

See also

mdbx_txn_begin(), mdbx_txn_abort()

Examples

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

txn <- mdbx_txn_begin(env, write = TRUE)
mdbx_txn_commit(txn)
mdbx_txn_state(txn)
#> [1] "committed"

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