Commit Graph

394 Commits

Author SHA1 Message Date
Felix Lange
5f7826270c all: unify big.Int zero checks, use common/math in more places (#3716)
* common/math: optimize PaddedBigBytes, use it more

name              old time/op    new time/op    delta
PaddedBigBytes-8    71.1ns ± 5%    46.1ns ± 1%  -35.15%  (p=0.000 n=20+19)

name              old alloc/op   new alloc/op   delta
PaddedBigBytes-8     48.0B ± 0%     32.0B ± 0%  -33.33%  (p=0.000 n=20+20)

* all: unify big.Int zero checks

Various checks were in use. This commit replaces them all with Int.Sign,
which is cheaper and less code.

eg templates:

    func before(x *big.Int) bool { return x.BitLen() == 0 }
    func after(x *big.Int) bool  { return x.Sign() == 0 }

    func before(x *big.Int) bool { return x.BitLen() > 0 }
    func after(x *big.Int) bool  { return x.Sign() != 0 }

    func before(x *big.Int) int { return x.Cmp(common.Big0) }
    func after(x *big.Int) int  { return x.Sign() }

* common/math, crypto/secp256k1: make ReadBits public in package math
2017-02-28 15:09:11 +01:00
Felix Lange
d0eba23af3 all: disable log message colors outside of geth
Also tweak behaviour so colors are only enabled when stderr is a terminal.
2017-02-27 15:33:12 +01:00
Felix Lange
5c8fe28b72 common: move big integer math to common/math (#3699)
* common: remove CurrencyToString

Move denomination values to params instead.

* common: delete dead code

* common: move big integer operations to common/math

This commit consolidates all big integer operations into common/math and
adds tests and documentation.

There should be no change in semantics for BigPow, BigMin, BigMax, S256,
U256, Exp and their behaviour is now locked in by tests.

The BigD, BytesToBig and Bytes2Big functions don't provide additional
value, all uses are replaced by new(big.Int).SetBytes().

BigToBytes is now called PaddedBigBytes, its minimum output size
parameter is now specified as the number of bytes instead of bits. The
single use of this function is in the EVM's MSTORE instruction.

Big and String2Big are replaced by ParseBig, which is slightly stricter.
It previously accepted leading zeros for hexadecimal inputs but treated
decimal inputs as octal if a leading zero digit was present.

ParseUint64 is used in places where String2Big was used to decode a
uint64.

The new functions MustParseBig and MustParseUint64 are now used in many
places where parsing errors were previously ignored.

* common: delete unused big integer variables

* accounts/abi: replace uses of BytesToBig with use of encoding/binary

* common: remove BytesToBig

* common: remove Bytes2Big

* common: remove BigTrue

* cmd/utils: add BigFlag and use it for error-checked integer flags

While here, remove environment variable processing for DirectoryFlag
because we don't use it.

* core: add missing error checks in genesis block parser

* common: remove String2Big

* cmd/evm: use utils.BigFlag

* common/math: check for 256 bit overflow in ParseBig

This is supposed to prevent silent overflow/truncation of values in the
genesis block JSON. Without this check, a genesis block that set a
balance larger than 256 bits would lead to weird behaviour in the VM.

* cmd/utils: fixup import
2017-02-26 22:21:51 +01:00
Péter Szilágyi
d4fd06c3dc
all: blidly swap out glog to our log15, logs need rework 2017-02-23 12:16:44 +02:00
Jeffrey Wilcke
024d41d0c2 core, core/state, core/vm: remove exported account getters (#3618)
Removed exported statedb object accessors, reducing the chance for nasty
bugs to creep in. It's also ugly and unnecessary to have these methods.
2017-02-22 23:29:59 +01:00
Péter Szilágyi
b7f010de52 tests: cleanup tester blockchain after test run (#3692) 2017-02-20 11:54:23 +01:00
Jeffrey Wilcke
c12f4df910 params: core, core/vm, miner: 64bit gas instructions
Reworked the EVM gas instructions to use 64bit integers rather than
arbitrary size big ints. All gas operations, be it additions,
multiplications or divisions, are checked and guarded against 64 bit
integer overflows.

In additon, most of the protocol paramaters in the params package have
been converted to uint64 and are now constants rather than variables.

* common/math: added overflow check ops
* core: vmenv, env renamed to evm
* eth, internal/ethapi, les: unmetered eth_call and cancel methods
* core/vm: implemented big.Int pool for evm instructions
* core/vm: unexported intPool methods & verification methods
* core/vm: added memoryGasCost overflow check and test
2017-02-13 21:44:25 +01:00
Jeffrey Wilcke
57f4e90257 Revert "params: core, core/vm, miner: 64bit gas instructions (#3514)"
This reverts commit 8b57c49490.
2017-02-13 15:15:12 +01:00
Jeffrey Wilcke
8b57c49490 params: core, core/vm, miner: 64bit gas instructions (#3514)
Reworked the EVM gas instructions to use 64bit integers rather than
arbitrary size big ints. All gas operations, be it additions,
multiplications or divisions, are checked and guarded against 64 bit
integer overflows.

In additon, most of the protocol paramaters in the params package have
been converted to uint64 and are now constants rather than variables.

* common/math: added overflow check ops
* core: vmenv, env renamed to evm
* eth, internal/ethapi, les: unmetered eth_call and cancel methods
* core/vm: implemented big.Int pool for evm instructions
* core/vm: unexported intPool methods & verification methods
* core/vm: added memoryGasCost overflow check and test
2017-02-02 15:25:42 +01:00
Nick Johnson
17d92233d9 cmd/geth, core: add support for recording SHA3 preimages (#3543) 2017-01-17 12:19:50 +01:00
Jeffrey Wilcke
3160fd24ba tests: unskip test 2017-01-12 10:32:21 +01:00
Péter Szilágyi
18c77744ff
all: fix spelling errors 2017-01-06 19:44:35 +02:00
Felix Lange
f2da6581ba all: fix issues reported by honnef.co/go/simple/cmd/gosimple 2017-01-06 18:18:07 +01:00
Felix Lange
7731061903 core/vm: move Log to core/types
This significantly reduces the dependency closure of ethclient, which no
longer depends on core/vm as of this change.

All uses of vm.Logs are replaced by []*types.Log. NewLog is gone too,
the constructor simply returned a literal.
2017-01-06 14:15:22 +01:00
Jeffrey Wilcke
bbc4ea4ae8 core/vm: improved EVM run loop & instruction calling (#3378)
The run loop, which previously contained custom opcode executes have been
removed and has been simplified to a few checks.

Each operation consists of 4 elements: execution function, gas cost function,
stack validation function and memory size function. The execution function
implements the operation's runtime behaviour, the gas cost function implements
the operation gas costs function and greatly depends on the memory and stack,
the stack validation function validates the stack and makes sure that enough
items can be popped off and pushed on and the memory size function calculates
the memory required for the operation and returns it.

This commit also allows the EVM to go unmetered. This is helpful for offline
operations such as contract calls.
2017-01-05 11:52:10 +01:00
Jeffrey Wilcke
3fc7c97827 core, core/vm: implemented a generic environment (#3348)
Environment is now a struct (not an interface). This
reduces a lot of tech-debt throughout the codebase where a virtual
machine environment had to be implemented in order to test or run it.

The new environment is suitable to be used en the json tests, core
consensus and light client.
2016-12-06 02:16:03 +01:00
Felix Lange
bca7bfa927 tests: update from github.com/ethereum/tests @ f21c49dc816e 2016-11-24 22:54:50 +01:00
Jeffrey Wilcke
12d654a6fc core, core/state: fixed consensus issue added touch revert
Implemented proper touch revert journal entries and copied a Parity
consensus bug in order to remain in sync with the current longest chain.
2016-11-24 22:12:54 +01:00
Zsolt Felfoldi
b10bcd924b core/types: turn off nonce checking for Call messages 2016-11-14 14:16:06 +01:00
Jeffrey Wilcke
a91908e567 tests: updated 2016-11-13 23:26:07 +01:00
Jeffrey Wilcke
4dca5d4db7 core/types, params: EIP#155 2016-11-13 14:55:30 +01:00
Jeffrey Wilcke
5cd86443ee tests: added new EIP158 tests 2016-11-13 10:44:06 +01:00
Jeffrey Wilcke
445feaeef5 core, core/state, trie: EIP158, reprice & skip empty account write
This commit implements EIP158 part 1, 2, 3 & 4

1. If an account is empty it's no longer written to the trie. An empty
  account is defined as (balance=0, nonce=0, storage=0, code=0).
2. Delete an empty account if it's touched
3. An empty account is redefined as either non-existent or empty.
4. Zero value calls and zero value suicides no longer consume the 25k
  reation costs.

params: moved core/config to params

Signed-off-by: Jeffrey Wilcke <jeffrey@ethereum.org>
2016-11-13 10:44:04 +01:00
Jeffrey Wilcke
64af2aafda core, core/vm: added gas price variance table
This implements 1b & 1c of EIP150 by adding a new GasTable which must be
returned from the RuleSet config method. This table is used to determine
the gas prices for the current epoch.

Please note that when the CreateBySuicide gas price is set it is assumed
that we're in the new epoch phase.

In addition this PR will serve as temporary basis while refactorisation
in being done in the EVM64 PR, which will substentially overhaul the gas
price code.
2016-10-14 18:09:17 +02:00
Felix Lange
eeb2a1a6e3 Merge pull request #3094 from fjl/tests-update
tests: update test files from github.com/ethereum/tests @ 45bc1d21d3c1
2016-10-06 16:19:53 +02:00
Felix Lange
1b7b2ba216 tests: update test files from github.com/ethereum/tests @ 45bc1d21d3c1
Two new tests are skipped because they're buggy. Making some newer
random state tests work required implementing the 'compressed return
value encoding'.
2016-10-06 15:36:21 +02:00
Felix Lange
1f1ea18b54 core/state: implement reverts by journaling all changes
This commit replaces the deep-copy based state revert mechanism with a
linear complexity journal. This commit also hides several internal
StateDB methods to limit the number of ways in which calling code can
use the journal incorrectly.

As usual consultation and bug fixes to the initial implementation were
provided by @karalabe, @obscuren and @Arachnid. Thank you!
2016-10-06 15:32:16 +02:00
Péter Szilágyi
cb84e3f029 cmd, core, internal, light, tests: avoid hashing the code in the VM 2016-10-01 16:01:58 +03:00
Felix Lange
a59a93f476 core/state: track all accounts in canon state
This change introduces a global, per-state cache that keeps account data
in the canon state. Thanks to @karalabe for lots of fixes.
2016-09-26 10:09:52 +02:00
Nick Johnson
781915f183 core/vm: Refactor tracing to make Tracer the main interface
This CL makes several refactors:
 - Define a Tracer interface, implementing the `CaptureState` method
 - Add the VM environment as the first argument of
   `Tracer.CaptureState`
 - Rename existing functionality `StructLogger` an make it an
   implementation of `Tracer`
 - Delete `StructLogCollector` and make `StructLogger` collect the logs
   directly
 - Change all callers to use the new `StructLogger` where necessary and
   extract logs from that.
 - Deletes the apparently obsolete and likely nonfunctional 'TraceCall'
   from the eth API.

Callers that only wish accumulated logs can use the `StructLogger`
implementation straightforwardly. Callers that wish to efficiently
capture VM traces and operate on them without excessive copying can now
implement the `Tracer` interface to receive VM state at each step and
do with it as they wish.

This CL also removes the accumulation of logs from the vm.Environment;
this was necessary as part of the refactor, but also simplifies it by
removing a responsibility that doesn't directly belong to the
Environment.
2016-08-22 09:26:15 +01:00
Péter Szilágyi
2c2e389b77 cmd, core, eth, miner, params, tests: finalize the DAO fork 2016-07-15 16:52:55 +03:00
Péter Szilágyi
461cdb593b core, params, tests: add DAO hard-fork balance moves 2016-07-15 16:52:55 +03:00
zsfelfoldi
00787fe781 core: added CheckNonce() to Message interface 2016-07-11 12:35:23 +02:00
Péter Szilágyi
6362a9d610 Revert "test, cmd/evm, core, core/vm: illegal code hash implementation"
This reverts commit 7a5b571c67.
2016-06-29 11:44:51 +03:00
Jeffrey Wilcke
7a5b571c67 test, cmd/evm, core, core/vm: illegal code hash implementation
This implements a generic approach to enabling soft forks by allowing
anyone to put in hashes of contracts that should not be interacted from.
This will help "The DAO" in their endevour to stop any whithdrawals from
any DAO contract by convincing the mining community to accept their code
hash.
2016-06-22 11:38:25 +03:00
zsfelfoldi
f9917c8c7b core: improved chainDb using sequential keys 2016-06-07 16:38:56 +02:00
Felix Lange
ca18202eb9 eth: enable bad block reports
We used to have reporting of bad blocks, but it was disabled
before the Frontier release. We need it back because users
are usually unable to provide the full RLP data of a bad
block when it occurs.

A shortcoming of this particular implementation is that the
origin peer is not tracked for blocks received during eth/63
sync. No origin peer info is still better than no report at
all though.
2016-05-25 02:02:51 +02:00
Felix Lange
6fdd0893c3 all: fix go vet warnings 2016-04-15 11:17:27 +02:00
Felix Lange
d04a2e7557 all: update license information 2016-04-15 09:48:05 +02:00
Felix Lange
83877a0f9d tests: remove eth, node, accounts dependencies
Unlocking the accounts in the test doesn't help with anything.
2016-04-12 15:34:39 +02:00
Jeffrey Wilcke
f0cbebb19f core: added basic chain configuration
Added chain configuration options and write out during genesis database
insertion. If no "config" was found, nothing is written to the database.

Configurations are written on a per genesis base. This means
that any chain (which is identified by it's genesis hash) can have their
own chain settings.
2016-04-01 01:01:10 +02:00
Jeffrey Wilcke
14013372ae core: Added EVM configuration options
The EVM is now initialised with an additional configured object that
allows you to turn on debugging options.
2016-03-23 23:02:42 +01:00
Jeffrey Wilcke
342ae7ce7d core, core/vm, tests: changed the initialisation behaviour of the EVM
The EVM was previously initialised and created for every CALL, CALLCODE,
DELEGATECALL and CREATE. This PR changes this behaviour so that the same
EVM can be used through the session and beyond as long as the
Environment sticks around.
2016-03-23 00:04:00 +01:00
Péter Szilágyi
a6903ad6a5 Merge pull request #2260 from karalabe/ethash-cache-fixes
Godeps, eth, tests: update ethash, used shared for testing
2016-02-24 17:58:12 +02:00
Péter Szilágyi
0a5ee08e2b Godeps, eth, tests: update ethash, used shared for testing 2016-02-24 13:29:47 +02:00
Ricardo Catalinas Jiménez
436fc8d76a all: Rename crypto.Sha3{,Hash}() to crypto.Keccak256{,Hash}()
As we aren't really using the standarized SHA-3
2016-02-21 22:34:34 +00:00
Jeffrey Wilcke
5b283663b4 core: Added new TD strategy which mitigate the risk for selfish mining
Assuming the following scenario where a miner has 15% of all hashing
power and the ability to exert a moderate control over the network to
the point where if the attacker sees a message A, it can't stop A from
propagating, but what it **can** do is send a message B and ensure that
most nodes see B before A. The attacker can then selfish mine and
augment selfish mining strategy by giving his own blocks an advantage.

This change makes the time at which a block is received less relevant
and so the level of control an attacker has over the network no longer
makes a difference.

This change changes the current td algorithm `B_td > C_td` to the new
algorithm `B_td > C_td || B_td == C_td && rnd < 0.5`.
2016-02-18 10:12:13 +01:00
Jeffrey Wilcke
b6d88a0e9f core, core/vm, crypto: fixes for homestead
* Removed some strange code that didn't apply state reverting properly
* Refactored code setting from vm & state transition to the executioner
* Updated tests
2016-02-18 10:11:48 +01:00
Jeffrey Wilcke
4f4d2b6474 tests: updated homestead tests 2016-02-18 10:08:18 +01:00
Gustav Simonsson
371871d685 parmas, crypto, core, core/vm: homestead consensus protocol changes
* change gas cost for contract creating txs
* invalidate signature with s value greater than secp256k1 N / 2
* OOG contract creation if not enough gas to store code
* new difficulty adjustment algorithm
* new DELEGATECALL op code
2016-02-18 10:08:11 +01:00
Péter Szilágyi
1e806c4c77 cmd, common, core, eth, node, rpc, tests, whisper, xeth: use protocol stacks 2015-11-27 11:06:12 +02:00
Gustav Simonsson
220b0bf6e5 Update common test files 2015-11-20 12:53:36 +01:00
Péter Szilágyi
9dc5de51a2 tests: fix data race in bad-block-report disabling during tests 2015-11-05 13:29:50 +02:00
Drake Burroughs
05ea8926c3 cmd/utils, crypto: add --lightkdf flag for lighter KDF 2015-10-28 18:46:39 +01:00
Gustav Simonsson
145366c07e tests: update JSON files, add new wrappers 2015-10-23 14:25:18 +02:00
Jeffrey Wilcke
80f26086ee core, tests: get_hash fix
Make sure that we're fetching the hash from the current chain and not
the canonical chain.
2015-10-21 02:31:46 +02:00
Felix Lange
de8d5aaa92 core, core/state: move gas tracking out of core/state
The amount of gas available for tx execution was tracked in the
StateObject representing the coinbase account. This commit makes the gas
counter a separate type in package core, which avoids unintended
consequences of intertwining the counter with state logic.
2015-10-17 10:24:34 +02:00
Gustav Simonsson
1b1f293082 core/state, core, miner: handle missing root error from state.New 2015-10-16 02:22:06 +02:00
Gustav Simonsson
e1616f77c7 core, core/vm, cmd/evm: remove redundant balance check 2015-10-06 12:42:34 +02:00
Jeffrey Wilcke
7c7692933c cmd/geth, cmd/utils, core, rpc: renamed to blockchain
* Renamed ChainManager to BlockChain
* Checkpointing is no longer required and never really properly worked
when the state was corrupted.
2015-10-04 01:13:56 +02:00
Jeffrey Wilcke
361082ec4b cmd/evm, core/vm, test: refactored VM and core
* Moved `vm.Transfer` to `core` package and changed execution to call
`env.Transfer` instead of `core.Transfer` directly.
* core/vm: byte code VM moved to jump table instead of switch
* Moved `vm.Transfer` to `core` package and changed execution to call
  `env.Transfer` instead of `core.Transfer` directly.
* Byte code VM now shares the same code as the JITVM
* Renamed Context to Contract
* Changed initialiser of state transition & unexported methods
* Removed the Execution object and refactor `Call`, `CallCode` &
  `Create` in to their own functions instead of being methods.
* Removed the hard dep on the state for the VM. The VM now
  depends on a Database interface returned by the environment. In the
  process the core now depends less on the statedb by usage of the env
* Moved `Log` from package `core/state` to package `core/vm`.
2015-10-04 01:13:54 +02:00
Jeffrey Wilcke
49ae538506 Merge pull request #1405 from fjl/lean-trie
core, trie: new trie
2015-10-01 04:34:38 -07:00
Felix Lange
a2d5a60418 core, core/state: batch-based state sync 2015-09-22 22:57:37 +02:00
Gustav Simonsson
5621308949 tests: add test for StateTests/stCallCodes.json 2015-09-21 11:34:02 +02:00
Gustav Simonsson
47ca6904b3 tests: use lastblockhash field to validate reorgs and block headers 2015-09-18 17:48:31 +02:00
Gustav Simonsson
075815e5ff tests: update common test wrappers and test files 2015-09-18 13:08:36 +02:00
Felix Lange
8c4dab77ba all: move common.Database to package ethdb 2015-09-14 23:36:30 +02:00
Péter Szilágyi
cdc2662c40 core: split out TD from database and all internals 2015-09-11 17:42:25 +03:00
Gustav Simonsson
fe8093b71f Add TestBcForkUncleTests and update JSON files 2015-08-31 16:45:00 +02:00
Gustav Simonsson
7324176f70 Add tests for uncle timestamps and refactor timestamp type 2015-08-25 04:46:11 +02:00
Jeffrey Wilcke
36f7fe61c3 core, tests: Double SUICIDE fix 2015-08-20 18:22:50 +02:00
Jeffrey Wilcke
9cacec70f9 cmd/evm, core/vm, tests: changed DisableVm to EnableVm 2015-08-11 18:43:22 +02:00
Jeffrey Wilcke
2fcf7f1241 Merge pull request #1604 from obscuren/db-merge
core, eth, trie, xeth: merged state, chain, extra databases in one
2015-08-09 05:16:37 -07:00
Jeffrey Wilcke
a23478c0be core, eth, trie, xeth: merged state, chain, extra databases in one 2015-08-07 22:29:02 +02:00
Jeffrey Wilcke
ac697326a6 core/vm: reduced big int allocations
Reduced big int allocation by making stack items modifiable. Instead of
adding items such as `common.Big0` to the stack, `new(big.Int)` is
added instead. One must expect that any item that is added to the stack
might change.
2015-08-07 12:52:23 +02:00
Jeffrey Wilcke
184e9ae9a8 core, tests: reduced state copy by N calls
Reduced the amount of state copied that are required by N calls by doing
a balance check prior to any state modifications.
2015-08-07 12:52:23 +02:00
Jeffrey Wilcke
846f34f78b core/vm, tests: implemented semi-jit vm
* changed stack and removed stack ptr. Let go decide on slice reuse.
2015-08-07 12:52:17 +02:00
Jeffrey Wilcke
71d32f54f7 core, miner: added difficulty bomb 2015-08-05 13:09:09 +02:00
Jeffrey Wilcke
03c39d4fc0 tests: updated 2015-07-29 15:01:42 +02:00
Jeffrey Wilcke
1fad8798ec Merge pull request #1515 from fjl/license-fixes
all: fix license headers one more time
2015-07-28 04:29:42 -07:00
Jeffrey Wilcke
9afda6ab8c core: 5 ether block reward 2015-07-25 17:47:20 +02:00
Felix Lange
bfbcfbe4a9 all: fix license headers one more time
I forgot to update one instance of "go-ethereum" in commit 3f047be5a.
2015-07-23 18:35:11 +02:00
Felix Lange
3f047be5aa all: update license headers to distiguish GPL/LGPL
All code outside of cmd/ is licensed as LGPL. The headers
now reflect this by calling the whole work "the go-ethereum library".
2015-07-22 18:51:45 +02:00
Felix Lange
593b1b65e7 tests: document RLP tests 2015-07-17 15:42:23 +02:00
Felix Lange
5da82077d1 cmd/ethtest, tests: add support for RLP JSON tests 2015-07-17 15:13:24 +02:00
Jeffrey Wilcke
a32c51effd cmd, core, eth, common: genesis preparation
Implemented the --genesis flag thru which we can set a custom genesis
block, including the official Ethereum genesis block.
2015-07-10 17:37:41 +02:00
Gustav Simonsson
b08abe64e4 Unskip SimpleTx3, check err in pre/post state validations 2015-07-08 13:09:22 +02:00
Gustav Simonsson
0b53a5c673 Update Ethereum JSON test files and wrappers 2015-07-08 13:08:42 +02:00
Felix Lange
bdae4fd573 all: add some godoc synopsis comments 2015-07-07 14:12:45 +02:00
Felix Lange
ea54283b30 all: update license information 2015-07-07 14:12:44 +02:00
Jeffrey Wilcke
35cd355c14 cmd,eth,rpc,tests: default coinbase 2015-07-07 10:32:05 +02:00
Gustav Simonsson
b7e8d954ef Add TestBcGasPricer, comments and unskip tests 2015-07-06 13:56:56 +02:00
Jeffrey Wilcke
aa4502060b Merge pull request #1400 from obscuren/badblock-reporting
core, miner, tests: added test, implemented bad block reporting
2015-07-06 02:03:50 -07:00
Jeffrey Wilcke
bcc1660abc core, miner, tests: added test, implemented bad block reporting 2015-07-05 15:14:31 +02:00
Gustav Simonsson
0f04af5916 Fix core error forwarding, unify OOG VM err 2015-07-04 09:27:42 +02:00
Jeffrey Wilcke
ab16ce70fc core, miner, tests: renamed state methods
* Update => SyncIntermediate
* Added SyncObjects

SyncIntermediate only updates whatever has changed, but, as a side
effect, requires much more disk space.

SyncObjects will only sync whatever is required for a block and will not
save intermediate state to disk. As drawback this requires more time
when more txs come in.
2015-07-04 02:51:36 +02:00
Gustav Simonsson
ff97059a99 Update Ethereum JSON tests, skip failing 2015-07-03 09:40:07 +02:00
Gustav Simonsson
4c490db6af Use uint64 for block header timestamp 2015-06-30 10:52:11 +02:00
Felix Lange
1d42888d30 core/types: make blocks immutable 2015-06-29 18:51:47 +02:00
Felix Lange
654564e164 core/types: make transactions immutable 2015-06-29 18:51:47 +02:00