This can generate non decomposed outputs for very large block
rewards (or not so large ones if a miner decides to not quantize
the block rewards). Out of an abundance of caution, we refuse
to generate those. They are still accepted by the consensus code,
however.
d5d46e6 tests: obligatory hardfork unit build fix after interface change (moneromooo-monero)
25672d3 wallet: pass std::function by const ref, not value (moneromooo-monero)
0be6e08 wallet: do not leak owned amounts to the daemon unless --trusted-daemon (moneromooo-monero)
12146da wallet: change sweep_dust to sweep_unmixable (moneromooo-monero)
600a3cf New RPC and daemon command to get output histogram (moneromooo-monero)
f9a2fd2 wallet: handle rare case where fee adjustment can bump to the next kB (moneromooo-monero)
f26651a wallet: factor fee calculation (moneromooo-monero)
This allows appropriate action to be taken, like displaying
the reason to the user.
Do just that in simplewallet, which should help a lot in
determining why users fail to send.
Also make it so a tx which is accepted but not relayed is
seen as a success rather than a failure.
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 was meant to go in v2, but the miner tx slipped through
the cracks as it doesn't go through the main tx verification
since it doesn't get added to the pool.
tx_pool.h doxygen documentation completed.
Many notes made on areas for improvement, be that functionality or
code clarity.
Commented code and unused code removed.
The functions in src/cryptonote_core/checkpoints_create.{h,cpp} should
be member functions of the checkpoints class, if nothing else for the
sake of keeping their documentation together.
This commit covers moving those functions to be member functions of the
checkpoints class as well as documenting those functions.
All functions in src/cryptonote_core/checkpoints.h are now documented in
doxygen style.
checkpoints.cpp has been reviewed, one function has been marked for
discussion on correctness.
All functions are now documented in doxygen format. Comments have been
updated to reflect the current state of the code. Many areas for
improvement in clarity and design have been noted, as well as cruft to
be removed. These changes are not reflected in this commit both to
allow time for comment and to keep commits organized by purpose.
This is already the default for the daemon, but by checking a command
line argument and calling a Blockchain member function setter.
Initialize the variable to false so it's not dependent on an external
command-line argument check. This allows utilities like
blockchain_import to have a reasonable default without code changes.
c2a1fee simplewallet: prompt for private keys when generating wallets (moneromooo-monero)
4513b4c simplewallet: add a new --restore-from-keys option (moneromooo-monero)
We also replace the --fakechain option with an optional structure
containing details about configuration for the core/blockchain,
for test purposes. This seems more future friendly.
7658ac0 blockchain: revert handle_get_objects adding block id on tx not found (moneromooo-monero)
3a0f4d8 berkeleydb: fix delete/free mismatch (moneromooo-monero)
1642be2 minor bugfixes and refactoring (Thomas Winget)
098dcf2 unit_tests: fix mnemonics unit test testing invalid seeds (moneromooo-monero)
Locking just one db turns out to not have been a good idea, since
the pool and p2p state fdles have to be used anyway.
Also ensure the directory exists before tring to lock.
- Blockchain should store if it's running on testnet or not
- moved loading compiled-in block hashes to its own function for clarity
- on handle_get_objects, should now correctly return false if a block's
transactions are missing
- replace instances of BOOST_FOREACH with C++11 for loops in Blockchain.
7fc6fa3 wallet: forbid dust altogether in output selection where appropriate (moneromooo-monero)
5e1a739 blockchain: log number of outputs available for a new tx (moneromooo-monero)
bcac101 daemon: fix a few issues reported by valgrind (moneromooo-monero)
a7e8174 tx_pool: fix serialization of new relayed data (moneromooo-monero)
601ad76 hardfork: fix mixup in indexing variable in get_voting_info (moneromooo-monero)
444e22f blockchain: remove unused timer (moneromooo-monero)
7edfdd8 blockchain: fix m_sync_counter uninitialized variable use (moneromooo-monero)
d97582c epee: use generate_random_bytes for new random uuids (moneromooo-monero)
17c7c9c epee: remove dodgy random code that nobody uses (moneromooo-monero)
A boost lock is used to determine whether more than one process
wants to access the database. The boost file_lock doesn't seem
to like locking directories, so we use an arbitrary file in it.
This allows to still run two daemons if they have different
database directories (ie, LMDB/BDB, different data directories).
This is intended to avoid cases where a timed out tx will be
re-relayed by another peer for which it has not timed out yet,
which would cause the tx to stay in the network's pool for a
long time (until all peers time it out before another one
tries to relay it again).
This ensures this will be done without fail, as the error prone
matching of every return with a call to KILL_IOSERVICE leads to
hard to debug corruption when one is missing.
- only try to stop if actually started
- print number of threads before zeroing it
This fixes the suspiciously doubled "Mining has been stopped"
message on exit.
b39aae7 Tweak 45800a25e9 (hyc)
4a5a5ff blockchain: always stop the ioservice before returning (moneromooo-monero)
78b65cf db_lmdb: safety close db at exit (moneromooo-monero)
45800a2 db_lmdb: fix a strdup/delete[] mistmatch (moneromooo-monero)
If the block reward was too high, the verification failed flag
was set, but the function continued. The code which was supposed
to trap this flag and return failure failed to trap it, and,
while the block was not added to the chain, the function would
return success.
The reason for avoiding returning when the block reward problem
was detected was to be able to return any transactions to the
pool if needed. This is now mooted by moving the transaction
return code to a separate function, which is now called at all
appropriate points, making the logic much simpler, and hopefully
correct now.
We also move the hard fork version check after the prev_id check,
as block which does not go on the top of the chain might not
have the expected version there, without being invalid just for
this reason.
Last, we trap the case where a block fails to be added due to
using already spent key images, to set the verification failed
flag.
This fixes some double spending tests.
This may or may not be unneeded in normal (non test) circumstances,
to be determined later. Keeping these for now may be slower, but safer.
Block reward may now be less than the full amount allowed.
This was breaking the bitflipping test.
We now keep track of whether a block which was accepted by the core
has a lower than allowed block reward, and allow this in the test.
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.
The core tests use the blockchain, and reset it to be able
to add test data to it. This does not play nice with the
databases, since those will save that data without an explicit
save call.
We add a fakechain flag that the tests will set, which tells
the core and blockchain code to use a separate database, as
well as skip a few things like checkpoints and fixup, which
only make sense for real data.
This fixes coretests, which does not register daemon specific arguments,
but uses core, which uses those arguments. Also gets rid of an unwanted
dependency on daemon code from core.
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.
This allows them to be saved as a fixed (one byte) chunk whatever
the value. Using a varint will use two bytes as the high bit gets
set.
This is backward compatible with current usage (0-2 values).
d887c18 hardfork: fix more major/minor issues (moneromooo-monero)
3b47ca2 hardfork: fix rescan on load (moneromooo-monero)
4cea2b1 Add IP blocking for misbehaving nodes (adapted from Boolberry) (Javier Smooth)
9c64b12 quiet down p2p logging a bit (Javier Smooth)
53c75ab blockchain: log versions as numbers, not characters (moneromooo-monero)
edade8d hardfork: fix actual/voting confusion (moneromooo-monero)
Also add some more tests, and rename some instances of
"version" and "add" for clarity.
NOTE: the starting height values are sometimes wrong.
I suspect this is due to the hard fork reorg code being
buggy, since they're good when syncing after the fact.
However, they're not actually used by the consensus code,
so I'm ignoring this for now, but this needs debugging.
The last relayed time of a transaction is maintained, and
transactions will be relayed again if they are still in the
pool after a certain amount of time, which increases with
the transaction's age. All such transactions are resent,
whether or not they originated on the local node.
Use the correct block time for realtime fuzz on locktime
Use the correct block time to calculate next_difficulty on alt chains (will not work as-is with voting)
Lock unit tests to original block time for now
43bca0d blockchain_utilities: new blockchain_dump diagnostic tool (moneromooo-monero)
5f397e4 Add functions to iterate through blocks, txes, outputs, key images (moneromooo-monero)
0a5a5e8 db_bdb: record numbers for recno databases start at 1 (moneromooo-monero)
50dfdc0 db_bdb: DB_KEYEMPTY is also not found for non-top recon fields (moneromooo-monero)
572780e blockchain_db: use the DNE exceptions where appropriate (moneromooo-monero)
The wallet and the daemon applied different height considerations
when selecting outputs to use. This can leak information on which
input in a ring signature is the real one.
Found and originally fixed by smooth on Aeon.
Using major version would cause older daemons to reject those
blocks as they fail to deserialize blocks with a major version
which is not 1. There is no such restriction on the minor
version, so switching allows older daemons to coexist with
newer ones till the actual fork date, when most will hopefully
have updated already.
Also, for the same reason, we consider a vote for 0 to be a
vote for 1, since older daemons set minor version to 0.
This allows knowing the hard fork a block must obey in order to be
added to the blockchain. The previous semantics would use that new
block's version vote to determine this hard fork, which made it
impossible to use the rules to validate transactions entering the
tx pool (and made it impossible to validate a block before adding
it to the blockchain).
The height function apparently used to return the index of
the last block, rather than the height of the chain. This now
seems to be incorrect, judging the the code, so we remove the
now wrong comment, as well as a couple +/- 1 adjustments
which now cause the median calculation to differ from the
original blockchain_storage version.
It was only used by the older blockchain_storage.
We also move the code to the calling blockchain level, to avoid
replicating the code in every DB implementation. This also makes
the get_random_out method obsolete, and we delete it.
Pros:
- smaller on the blockchain
- shorter integrated addresses
Cons:
- less sparseness
- less ability to embed actual information
The boolean argument to encrypt payment ids is now gone from the
RPC calls, since the decision is made based on the length of the
payment id passed.
A payment ID may be encrypted using the tx secret key and the
receiver's public view key. The receiver can decrypt it with
the tx public key and the receiver's secret view key.
Using integrated addresses now cause the payment IDs to be
encrypted. Payment IDs used manually are not encrypted by default,
but can be encrypted using the new 'encrypt_payment_id' field
in the transfer and transfer_split RPC calls. It is not possible
to use an encrypted payment ID by specifying a manual simplewallet
transfer/transfer_new command, though this is just a limitation
due to input parsing.
Bockchain:
1. Optim: Multi-thread long-hash computation when encountering groups of blocks.
2. Optim: Cache verified txs and return result from cache instead of re-checking whenever possible.
3. Optim: Preload output-keys when encoutering groups of blocks. Sort by amount and global-index before bulk querying database and multi-thread when possible.
4. Optim: Disable double spend check on block verification, double spend is already detected when trying to add blocks.
5. Optim: Multi-thread signature computation whenever possible.
6. Patch: Disable locking (recursive mutex) on called functions from check_tx_inputs which causes slowdowns (only seems to happen on ubuntu/VMs??? Reason: TBD)
7. Optim: Removed looped full-tx hash computation when retrieving transactions from pool (???).
8. Optim: Cache difficulty/timestamps (735 blocks) for next-difficulty calculations so that only 2 db reads per new block is needed when a new block arrives (instead of 1470 reads).
Berkeley-DB:
1. Fix: 32-bit data errors causing wrong output global indices and failure to send blocks to peers (etc).
2. Fix: Unable to pop blocks on reorganize due to transaction errors.
3. Patch: Large number of transaction aborts when running multi-threaded bulk queries.
4. Patch: Insufficient locks error when running full sync.
5. Patch: Incorrect db stats when returning from an immediate exit from "pop block" operation.
6. Optim: Add bulk queries to get output global indices.
7. Optim: Modified output_keys table to store public_key+unlock_time+height for single transaction lookup (vs 3)
8. Optim: Used output_keys table retrieve public_keys instead of going through output_amounts->output_txs+output_indices->txs->output:public_key
9. Optim: Added thread-safe buffers used when multi-threading bulk queries.
10. Optim: Added support for nosync/write_nosync options for improved performance (*see --db-sync-mode option for details)
11. Mod: Added checkpoint thread and auto-remove-logs option.
12. *Now usable on 32-bit systems like RPI2.
LMDB:
1. Optim: Added custom comparison for 256-bit key tables (minor speed-up, TBD: get actual effect)
2. Optim: Modified output_keys table to store public_key+unlock_time+height for single transaction lookup (vs 3)
3. Optim: Used output_keys table retrieve public_keys instead of going through output_amounts->output_txs+output_indices->txs->output:public_key
4. Optim: Added support for sync/writemap options for improved performance (*see --db-sync-mode option for details)
5. Mod: Auto resize to +1GB instead of multiplier x1.5
ETC:
1. Minor optimizations for slow-hash for ARM (RPI2). Incomplete.
2. Fix: 32-bit saturation bug when computing next difficulty on large blocks.
[PENDING ISSUES]
1. Berkely db has a very slow "pop-block" operation. This is very noticeable on the RPI2 as it sometimes takes > 10 MINUTES to pop a block during reorganization.
This does not happen very often however, most reorgs seem to take a few seconds but it possibly depends on the number of outputs present. TBD.
2. Berkeley db, possible bug "unable to allocate memory". TBD.
[NEW OPTIONS] (*Currently all enabled for testing purposes)
1. --fast-block-sync arg=[0:1] (default: 1)
a. 0 = Compute long hash per block (may take a while depending on CPU)
b. 1 = Skip long-hash and verify blocks based on embedded known good block hashes (faster, minimal CPU dependence)
2. --db-sync-mode arg=[[safe|fast|fastest]:[sync|async]:[nblocks_per_sync]] (default: fastest:async:1000)
a. safe = fdatasync/fsync (or equivalent) per stored block. Very slow, but safest option to protect against power-out/crash conditions.
b. fast/fastest = Enables asynchronous fdatasync/fsync (or equivalent). Useful for battery operated devices or STABLE systems with UPS and/or systems with battery backed write cache/solid state cache.
Fast - Write meta-data but defer data flush.
Fastest - Defer meta-data and data flush.
Sync - Flush data after nblocks_per_sync and wait.
Async - Flush data after nblocks_per_sync but do not wait for the operation to finish.
3. --prep-blocks-threads arg=[n] (default: 4 or system max threads, whichever is lower)
Max number of threads to use when computing long-hash in groups.
4. --show-time-stats arg=[0:1] (default: 1)
Show benchmark related time stats.
5. --db-auto-remove-logs arg=[0:1] (default: 1)
For berkeley-db only. Auto remove logs if enabled.
**Note: lmdb and berkeley-db have changes to the tables and are not compatible with official git head version.
At the moment, you need a full resync to use this optimized version.
[PERFORMANCE COMPARISON]
**Some figures are approximations only.
Using a baseline machine of an i7-2600K+SSD+(with full pow computation):
1. The optimized lmdb/blockhain core can process blocks up to 585K for ~1.25 hours + download time, so it usually takes 2.5 hours to sync the full chain.
2. The current head with memory can process blocks up to 585K for ~4.2 hours + download time, so it usually takes 5.5 hours to sync the full chain.
3. The current head with lmdb can process blocks up to 585K for ~32 hours + download time and usually takes 36 hours to sync the full chain.
Averate procesing times (with full pow computation):
lmdb-optimized:
1. tx_ave = 2.5 ms / tx
2. block_ave = 5.87 ms / block
memory-official-repo:
1. tx_ave = 8.85 ms / tx
2. block_ave = 19.68 ms / block
lmdb-official-repo (0f4a036437)
1. tx_ave = 47.8 ms / tx
2. block_ave = 64.2 ms / block
**Note: The following data denotes processing times only (does not include p2p download time)
lmdb-optimized processing times (with full pow computation):
1. Desktop, Quad-core / 8-threads 2600k (8Mb) - 1.25 hours processing time (--db-sync-mode=fastest:async:1000).
2. Laptop, Dual-core / 4-threads U4200 (3Mb) - 4.90 hours processing time (--db-sync-mode=fastest:async:1000).
3. Embedded, Quad-core / 4-threads Z3735F (2x1Mb) - 12.0 hours processing time (--db-sync-mode=fastest:async:1000).
lmdb-optimized processing times (with per-block-checkpoint)
1. Desktop, Quad-core / 8-threads 2600k (8Mb) - 10 minutes processing time (--db-sync-mode=fastest:async:1000).
berkeley-db optimized processing times (with full pow computation)
1. Desktop, Quad-core / 8-threads 2600k (8Mb) - 1.8 hours processing time (--db-sync-mode=fastest:async:1000).
2. RPI2. Improved from estimated 3 months(???) into 2.5 days (*Need 2AMP supply + Clock:1Ghz + [usb+ssd] to achieve this speed) (--db-sync-mode=fastest:async:1000).
berkeley-db optimized processing times (with per-block-checkpoint)
1. RPI2. 12-15 hours (*Need 2AMP supply + Clock:1Ghz + [usb+ssd] to achieve this speed) (--db-sync-mode=fastest:async:1000).
Add public method blockchain_storage::debug_pop_block_from_blockchain()
Ensure blockchain_import calls destructors before exit.
To test:
DATABASE=memory make release
// create blockchain.bin from blockchain.raw if needed
build/release/bin/blockchain_import --block-stop 1000
// try popping a single block
build/release/bin/blockchain_import --pop-blocks 1
b43716c Do store transaction's blob size in transaction_chain_entry (Sergey Kazenyuk)
3be518f Use single get_transaction_hash to get both id and blob size (Sergey Kazenyuk)
There will need to be some more refactoring for these changes to be
considered complete/correct, but for now it's working.
new daemon cli argument "--db-type", works for LMDB and BerkeleyDB.
A good deal of refactoring is also present in this commit, namely
Blockchain no longer instantiates BlockchainDB, but rather is passed a
pointer to an already-instantiated BlockchainDB on init().
Add support to:
- BlockchainDB, BlockchainLMDB
- blockchain_import utility to open LMDB database with one or more
LMDB flags.
Sample use:
$ blockchain_import --database lmdb#nosync
$ blockchain_import --database lmdb#nosync,nometasync
In order to make things more general, BlockchainDB now has get_db_name()
which should return a string with the "name" of that type of db.
This "name" will be the subfolder name that holds that db type's files
within the monero folder.
Small bugfix: blockchain_converter was not correctly appending this in
the prior hard-coded-string implementation of the subfolder data
directory concept.
Ostensibly janitorial work, but should be more relevant later down the
line. Things that depend on core cryptonote things (i.e.
cryptonote_core) don't necessarily depend on BlockchainDB and thus
have no need to have BlockchainDB baked in with them.
The RPC calls the daemon executable uses to talk to the running daemon
instance have mostly been added back in. Rate limiting has not been
added in upstream, but is on its way in a separate effort, so those
calls are still NOPed out.
many RPC functions added by the daemonize changes
(and related changes on the upstream dev branch that were not merged)
were commented out (apart from return). Other than that, this *should*
work...at any rate, it builds, and that's something.
new update of the pr with network limits
more debug options:
discarding downloaded blocks all or after given height.
trying to trigger the locking errors.
debug levels polished/tuned to sane values.
debug/logging improved.
warning: this pr should be correct code, but it could make
an existing (in master version) locking error appear more often.
it's a race on the list (map) of peers, e.g. between closing/deleting
them versus working on them in net-limit sleep in sending chunk.
the bug is not in this code/this pr, but in the master version.
the locking problem of master will be fixed in other pr.
problem is ub, and in practice is seems to usually cause program abort
(tested on debian stable with updated gcc). see --help for option
to add sleep to trigger the error faster.
Update of the PR with network limits
works very well for all speeds
(but remember that low download speed can stop upload
because we then slow down downloading of blockchain
requests too)
more debug options
fixed pedantic warnings in our code
should work again on Mac OS X and FreeBSD
fixed warning about size_t
tested on Debian, Ubuntu, Windows(testing now)
TCP options and ToS (QoS) flag
FIXED peer number limit
FIXED some spikes in ingress/download
FIXED problems when other up and down limit
commands and options for network limiting
works very well e.g. for 50 KiB/sec up and down
ToS (QoS) flag
peer number limit
TODO some spikes in ingress/download
TODO problems when other up and down limit
added "otshell utils" - simple logging (with colors, text files channels)
Usage:
default is lmdb for blockchain branch:
$ make release
same as:
$ DATABASE=lmdb make release
for original in-memory implementation:
$ DATABASE=memory make release
It expects the total number of blocks of main chain, not last block id
(off-by-one error).
This again behaves like the same height assertion done in original
implementation in blockchain_storage::handle_alternative_block().
This allows a reorganization to proceed after an alternative block has
been added.
difficulty.
This fixes the continual reorganization between a main and alternate
chain, using the same two latest blocks from each.
The check that cumulative difficulty of the alternate chain is bigger
than main's was not using main's last block, but incorrectly using the
passed-in block's previous block. main_chain_cumulative_difficulty was
being used in two different ways. This has been split up to keep use
of main_chain_cumulative_difficulty consistent.
Remove have_block() check from Blockchain::handle_block_to_main_chain().
Add logging to have_block().
This allows blockchain reorganization to proceed further.
have_block() check here causes an error after a blockchain reorganize
begins with error: "Attempting to add block to main chain, but it's
already either there or in an alternate chain."
While reorganizing to become the main chain, a block in the
alternative chain would be refused due to have_block() rightfully
finding it in the alternative chain. The reorganization would end in
rollback, restoring to previous blockchain.
Original implementation didn't call it here, and it doesn't appear
necessary to be called from here in this implementation either. When
needed, it appears it's called prior to handle_block_to_main_chain().
Complete method BlockchainLMDB::remove_output()
- use output index as the key for:
m_output_indices, m_output_txs, m_output_keys
- call new method BlockchainLMDB::remove_amount_output_index()
Add method to remove amount output index.
- BlockchainLMDB::remove_amount_output_index()
- for m_output_amounts
This also fixes the segfault when blockchain reorganization is
attempted.
Use last block id, not number of blocks (off-by-one error).
Fixes error at start of blockchain reorganization: "Attempt to get
cumulative difficulty from height <XXXXXX> failed -- difficulty not in
db"
Implement BlockchainLMDB::get_output_global_index()
- returns global output index for a given amount and amount output
index.
Add information to debug statement for failed ring signature check
within Blockchain::check_tx_inputs()
Fixes bitmonerod RPC call "/getrandom_outs.bin" to return correct
output keys, used in creating a transaction with mixins.
TODO: get_output_global_index() could be refactored with part of
get_output_tx_and_index() as the latter uses the former's
functionality. Keep track of LMDB read transaction.
Fix Blockchain::get_tx_outputs_gindexs() to return amount output
indices.
Implement BlockchainLMDB::get_tx_amount_output_indices() and call it
from the function instead of BlockchainLMDB::get_tx_output_indices()
Previously, Blockchain::get_tx_outputs_gindexs() was instead returning
global output indices, which are internal to LMDB databases.
Allows bitmonerod RPC /get_o_indexes.bin to return the amount output
indices as expected.
Allows simplewallet refresh to set correct amount output indices for
incoming transfers. simplewallet can now construct and send valid
transactions (currently only without mixins).
This is a fix that doesn't require altering the structure of the
current LMDB databases.
TODO:
This can be done more efficiently by adding another LMDB database
(key-value table).
It's not used during regular transaction validation by bitmonerod. I
think it's currently used only or mainly by simplewallet for just its
own incoming transactions. So the current behavior is not a primary
bottleneck.
Currently, it's using the "output_amounts" database, walking through a
given amount's list of values, comparing each one to a given global
output index. The iteration number of the match is the desired result:
the amount output index. This is done for each global output index of
the transaction.
A tx's amount output indices can be stored in various other ways
allowing for faster lookup. Since a tx is only written once, there are
no special future write requirements for its list of indices.
As it is useful for functions calling BlockchainDB functions to know
whether an exception is expected (attempting to get a block that doesn't
exist and counting it missing if not, to save time checking if it
does, for example), the inline functions throw{0,1} need to keep the
exception type information.
Slight comment update due to copy/paste failure.
Fixes problem of obtaining incorrect outputs used for tx input.
Reverts to earlier intended behavior that was fixed in previous
commit's split of get_output_tx_and_index into two functions.
Ideally, the log would go in the exception's ctor, but
two log levels are used, so I'd need to specify the level
in the ctor, which isn't great as it's not really related
to the exception.
hard-coded config folder, hard-coded BlockchainDB subclass.
Needs finessing, but should be testable this way.
update for rebase (warptangent 2015-01-04)
fix conflicts with upstream CMakeLists.txt files
src/CMakeLists.txt (edit original commit)
src/blockchain_converter/CMakeLists.txt (add)
