Since this queries block heights for blocks that may or may not
exist, queries for non existing blocks would throw an exception,
and that would slow down the loop a lot. 7 seconds to go through
a 30 hash list.
Fix this by adding an optional return block height to block_exists
and using this instead. Actual errors will still throw an
exception.
This also cuts down on log exception spam.
Since these are needed at the same time as the output pubkeys,
this is a whole lot faster, and takes less space. Only outputs
of 0 amount store the commitment. When reading other outputs,
a fake commitment is regenerated on the fly. This avoids having
to rewrite the database to add space for fake commitments for
existing outputs.
This code relies on two things:
- LMDB must support fixed size records per key, rather than
per database (ie, all records on key 0 are the same size, all
records for non 0 keys are same size, but records from key 0
and non 0 keys do have different sizes).
- the commitment must be directly after the rest of the data
in outkey and output_data_t.
It sets the max number of threads to use for a parallel job.
This is different that the number of total threads, since monero
binaries typically start a lot of them.
This is a list of existing output amounts along with the number
of outputs of that amount in the blockchain.
The daemon command takes:
- no parameters: all outputs with at least 3 instances
- one parameter: all outputs with at least that many instances
- two parameters: all outputs within that many instances
The default starts at 3 to avoid massive spamming of all dust
outputs in the blockchain, and is the current minimum mixin
requirement.
An optional vector of amounts may be passed, to request
histogram only for those outputs.
This improves blockchain reorganization time by allowing one of the more
expensive DB lookups when popping a block to not have to seek through a
long dup list in the "output_amounts" db. This is most noticeable for
HDDs.
See ffcf6bdb95
Data should be removed in the reverse order it was added.
This matches the order of removal in
blockchain_storage::pop_transaction_from_global_index.
See f11def012f
The check was explicit in the original version, so it seems
safer to make it explicit here, especially as it is now done
implicitely in a different place, away from the original check.
This is a precaution for older Berkeley DB versions.
- smooth reports an issue running with 4.7:
DB_ENV->log_set_config: DB_LOG_IN_MEMORY: method not permitted
after handle's open method
- this works just fine with 5.3
- we do not use DB_LOG_IN_MEMORY, but we use DB_LOG_AUTO_REMOVE
- libdb docs say some flags must be set before open, and some
may be set at any time, but never say some must be set after
open
- moving the call to log_set_config before open works with 5.3
Therefore, it seems best to move the call before open.
Early DB versions did not store key images for inputs if the
transaction spending them had no outputs (ie, all fee). This
is not correct, as this would allow these outputs to be double
spent. This was fixed in 533acc30ed
a few months ago, but databases having synced blocks 2021612 and
685498 with a faulty version will be missing those key images
in the spent keys database. This code checks for this, and adds
those key images if they are missing.
It looks like some of the indices passed to the DB access functions
are already bumped by 1. Moreover, the existing code was not
throwing DB errors with 0 keys, and this is unlikely if it really
was using 0 keys. Last, this patch broke sync from scratch in at
least one case. So I'm calling it bad and reverting it.
This reverts commit bfc97401ae.
