This commit is the first stage of several that are planned to convert
the blockchain package into a concurrent safe package that will
ultimately allow support for multi-peer download and concurrent chain
processing. The goal is to update btcd proper after each step so it can
take advantage of the enhancements as they are developed.
In addition to the aforementioned benefit, this staged approach has been
chosen since it is absolutely critical to maintain consensus.
Separating the changes into several stages makes it easier for reviewers
to logically follow what is happening and therefore helps prevent
consensus bugs. Naturally there are significant automated tests to help
prevent consensus issues as well.
The main focus of this stage is to convert the blockchain package to use
the new database interface and implement the chain-related functionality
which it no longer handles. It also aims to improve efficiency in
various areas by making use of the new database and chain capabilities.
The following is an overview of the chain changes:
- Update to use the new database interface
- Add chain-related functionality that the old database used to handle
- Main chain structure and state
- Transaction spend tracking
- Implement a new pruned unspent transaction output (utxo) set
- Provides efficient direct access to the unspent transaction outputs
- Uses a domain specific compression algorithm that understands the
standard transaction scripts in order to significantly compress them
- Removes reliance on the transaction index and paves the way toward
eventually enabling block pruning
- Modify the New function to accept a Config struct instead of
inidividual parameters
- Replace the old TxStore type with a new UtxoViewpoint type that makes
use of the new pruned utxo set
- Convert code to treat the new UtxoViewpoint as a rolling view that is
used between connects and disconnects to improve efficiency
- Make best chain state always set when the chain instance is created
- Remove now unnecessary logic for dealing with unset best state
- Make all exported functions concurrent safe
- Currently using a single chain state lock as it provides a straight
forward and easy to review path forward however this can be improved
with more fine grained locking
- Optimize various cases where full blocks were being loaded when only
the header is needed to help reduce the I/O load
- Add the ability for callers to get a snapshot of the current best
chain stats in a concurrent safe fashion
- Does not block callers while new blocks are being processed
- Make error messages that reference transaction outputs consistently
use <transaction hash>:<output index>
- Introduce a new AssertError type an convert internal consistency
checks to use it
- Update tests and examples to reflect the changes
- Add a full suite of tests to ensure correct functionality of the new
code
The following is an overview of the btcd changes:
- Update to use the new database and chain interfaces
- Temporarily remove all code related to the transaction index
- Temporarily remove all code related to the address index
- Convert all code that uses transaction stores to use the new utxo
view
- Rework several calls that required the block manager for safe
concurrency to use the chain package directly now that it is
concurrent safe
- Change all calls to obtain the best hash to use the new best state
snapshot capability from the chain package
- Remove workaround for limits on fetching height ranges since the new
database interface no longer imposes them
- Correct the gettxout RPC handler to return the best chain hash as
opposed the hash the txout was found in
- Optimize various RPC handlers:
- Change several of the RPC handlers to use the new chain snapshot
capability to avoid needlessly loading data
- Update several handlers to use new functionality to avoid accessing
the block manager so they are able to return the data without
blocking when the server is busy processing blocks
- Update non-verbose getblock to avoid deserialization and
serialization overhead
- Update getblockheader to request the block height directly from
chain and only load the header
- Update getdifficulty to use the new cached data from chain
- Update getmininginfo to use the new cached data from chain
- Update non-verbose getrawtransaction to avoid deserialization and
serialization overhead
- Update gettxout to use the new utxo store versus loading
full transactions using the transaction index
The following is an overview of the utility changes:
- Update addblock to use the new database and chain interfaces
- Update findcheckpoint to use the new database and chain interfaces
- Remove the dropafter utility which is no longer supported
NOTE: The transaction index and address index will be reimplemented in
another commit.
Contains the following upstream commits:
- d4852101d4
- This commit has already been independently applied so it is mostly a
NOOP
- f389742b39
In addition, gofmt -s has been run again to simplify the new additions
to Decred and and all simplifications are included in the merge commit.
Contains the following upstream commits:
- ef9c50be57
- eb882f39f8
In addition to merging the fixes in the commits, this also fixes a few
more misspellings that were introduced in the new Decred code.
Upstream commit 3942a116e4
This merge also includes a few Decred specific modifications and
corrects some old btcjson references that should have been updated to
dcrjson.
Corrected or added many comments.
Update test code to follow format go vet wants.
The code doesn't pass the checks 100% yet. That will come in a later
commit but these all seemed related so I'd rather get them in now.
First, it removes the documentation section from all the README.md files
and instead puts a web-based godoc badge and link at the top with the
other badges. This is being done since the local godoc tool no longer
ships with Go by default, so the instructions no longer work without
first installing godoc. Due to this, pretty much everyone uses the
web-based godoc these days anyways. Anyone who has manually installed
godoc won't need instructions.
Second, it makes sure the ISC license badge is at the top with the other
badges and removes the textual reference in the overview section.
Finally, it's modifies the Installation section to Installation and
Updating and adds a '-u' to the 'go get' command since it works for both
and thus is simpler.
This commit converts all block height references to int32 instead of
int64. The current target block production rate is 10 mins per block
which means it will take roughly 40,800 years to reach the maximum
height an int32 affords. Even if the target rate were lowered to one
block per minute, it would still take roughly another 4,080 years to
reach the maximum.
In the mean time, there is no reason to use a larger type which results
in higher memory and disk space usage. However, for now, in order to
avoid having to reserialize a bunch of database information, the heights
are still serialized to the database as 8-byte uint64s.
This is being mainly being done in preparation for further upcoming
infrastructure changes which will use the smaller and more efficient
4-byte serialization in the database as well.
This commit removes the error returns from the BlockHeader.BlockSha,
MsgBlock.BlockSha, and MsgTx.TxSha functions since they can never fail and
end up causing a lot of unneeded error checking throughout the code base.
It also updates all call sites for the change.
This commit contains three classes of optimizations:
- Reducing the number of unnecessary hash copies
- Improve the performance of the DoubleSha256 function
- A couple of minor optimizations of the ShaHash functions
The first class is a result of the Bytes function on a ShaHash making a
copy of the bytes before returning them. It really should have been named
CloneBytes, but that would break the API now.
To address this, a comment has been added to the function which explicitly
calls out the copy behavior. In addition, all call sites of .Bytes on a
ShaHash in the code base have been updated to simply slice the array when
a copy is not needed. This saves a significant amount of data copying.
The second optimization modifies the DoubleSha256 function to directly use
fastsha256.Sum256 instead of the hasher interface. This reduces the
number of allocations needed. A benchmark for the function has been added
as well.
old: BenchmarkDoubleSha256 500000 3691 ns/op 192 B/op 3 allocs/op
new: BenchmarkDoubleSha256 500000 3081 ns/op 32 B/op 1 allocs/op
The final optimizations are for the ShaHash IsEqual and SetBytes functions
which have been modified to make use of the fact the type is an array and
remove an unneeded subslice.
- Delete spent TX in setclearSpentData when unspent by block
disconnect on reorg; return an error when there's more than
one record to delete in the spent TX as that should never
happen.
- Test spent TX deletion when reorg causes block disconnect.
- Test for correct NewestSha results after DropAfterBlockBySha.
- Fix DropAfterBlockBySha to update info for NewestSha.
- Updated copyright statements in modified files
Fix#303 by changing the addrindex key prefix to 3 characters so that
it's easy to check length when dropping the index. To drop the old
index, check to make sure we aren't dropping any entries that end in
"sx" or "tx" as those aren't part of the addrindex. Update test to
deal with the new prefix length.
Fix#346 by changing the pointers in the mempool's addrindex map to
wire.ShaHash 32-byte values. This lets them be deleted even if the
transaction data changes places in memory upon expanding the maps.
Change the way addrindex uint32s are stored to big-endian in order to
sort the transactions on disk in chronological/dependency order.
Change the "searchrawtransactions" RPC call to return transactions
from the database before the memory pool so that they're returned in
order. This commit DOES NOT do topological sorting of the memory pool
transactions to ensure they're returned in dependency order. This may
be a good idea for a future enhancement.
Add addrindex versioning to automatically drop the old/incompatible
version of the index and rebuild with the new sort method and key
prefix.
- Use explicit index values for byte slices
- Fix a bug in FetchTxsForAddr that allocated an extra 10 bytes
for each address index
- Add missing iterator release in error path
- Check for iterator errors.
This change converts the leveldb database's ExistsSha() and
ExistsTxSha to use the goleveldb API. Has() only returns if
the key exists and does not need to read the entire value into
memory resulting in less disk i/o and much less GC.
This commit contains the entire btcdb repository along with several
changes needed to move all of the files into the database directory in
order to prepare it for merging. This does NOT update btcd or any of the
other packages to use the new location as that will be done separately.
- All import paths in the old btcdb test files have been changed to the
new location
- All references to btcdb as the package name have been chagned to
database
- The coveralls badge has been removed since it unfortunately doesn't
support coverage of sub-packages
This is ongoing work toward #214.
