This speeds up wallet refresh by directly retrieving a tx's amount output indices.
It removes the indirection and walking the amount output duplicate list
for every amount in each requested tx.
"tx_outputs" is used by:
Amount output indices are needed for wallet refresh.
Global output indices are needed for removing a tx.
Both amount output indices and global output indices are now stored in
an array of 64-bit unsigned ints:
tx_outputs[<tx_hash>] -> [ <a1_oi, a1_gi, a2_oi, a2_gi, ...> ]
Previously it was:
tx_outputs[<tx_hash>] -> duplicate list of <a1_gi, a2_gi, a3_gi, ...>
The amount output list had to be walked for every amount in order to
find each amount's output index, by comparing the amount's global output
index with each one in the duplicate list until a match was found.
See also d045dfa7ce
bdec7cb BlockchainLMDB: Use DB error helper consistently (warptangent)
c5932eb BlockchainLMDB: Add DB error to exception (warptangent)
a49c355 Blockchain: Omit verbose time stats messages by default (warptangent)
When keys are contiguous and monotonically increasing, this gets
denser page utilization (doesn't leave padding in page splits).
Can't be used for keys that are inserted in random order (e.g. hashes)
In total this only saves around 1.5% of space compared to original
DB code. The previous patch accounted for 0.8% savings on its own;
the blocks tables just aren't that big.
1995923 BlockchainLMDB: Deal with DB exceptions at block level with particularity (warptangent)
c16cc20 BlockchainLMDB: Add sanity check for inconsistent state (warptangent)
9118d0a BlockchainLMDB: Call destructor on allocated txn if setup fails (warptangent)
f5581c3 BlockchainLMDB: Replace remaining txn pointer NULLs with nullptr (warptangent)
Add another DB error exception type to distinguish failed txn setup from
general use of txn.
This keeps the error handling flow the same as before the block-level
txn setup changes that moved control up a layer to BlockchainDB.
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
