484 lines
16 KiB
C++
484 lines
16 KiB
C++
// Copyright (c) 2009-2010 Satoshi Nakamoto
|
|
// Copyright (c) 2009-2016 The Bitcoin Core developers
|
|
// Distributed under the MIT software license, see the accompanying
|
|
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
|
|
|
|
#ifndef BITCOIN_COINS_H
|
|
#define BITCOIN_COINS_H
|
|
|
|
#include "compressor.h"
|
|
#include "core_memusage.h"
|
|
#include "hash.h"
|
|
#include "memusage.h"
|
|
#include "serialize.h"
|
|
#include "uint256.h"
|
|
|
|
#include <assert.h>
|
|
#include <stdint.h>
|
|
|
|
#include <boost/foreach.hpp>
|
|
#include <boost/unordered_map.hpp>
|
|
|
|
/**
|
|
* Pruned version of CTransaction: only retains metadata and unspent transaction outputs
|
|
*
|
|
* Serialized format:
|
|
* - VARINT(nVersion)
|
|
* - VARINT(nCode)
|
|
* - unspentness bitvector, for vout[2] and further; least significant byte first
|
|
* - the non-spent CTxOuts (via CTxOutCompressor)
|
|
* - VARINT(nHeight)
|
|
*
|
|
* The nCode value consists of:
|
|
* - bit 0: IsCoinBase()
|
|
* - bit 1: vout[0] is not spent
|
|
* - bit 2: vout[1] is not spent
|
|
* - The higher bits encode N, the number of non-zero bytes in the following bitvector.
|
|
* - In case both bit 1 and bit 2 are unset, they encode N-1, as there must be at
|
|
* least one non-spent output).
|
|
*
|
|
* Example: 0104835800816115944e077fe7c803cfa57f29b36bf87c1d358bb85e
|
|
* <><><--------------------------------------------><---->
|
|
* | \ | /
|
|
* version code vout[1] height
|
|
*
|
|
* - version = 1
|
|
* - code = 4 (vout[1] is not spent, and 0 non-zero bytes of bitvector follow)
|
|
* - unspentness bitvector: as 0 non-zero bytes follow, it has length 0
|
|
* - vout[1]: 835800816115944e077fe7c803cfa57f29b36bf87c1d35
|
|
* * 8358: compact amount representation for 60000000000 (600 BTC)
|
|
* * 00: special txout type pay-to-pubkey-hash
|
|
* * 816115944e077fe7c803cfa57f29b36bf87c1d35: address uint160
|
|
* - height = 203998
|
|
*
|
|
*
|
|
* Example: 0109044086ef97d5790061b01caab50f1b8e9c50a5057eb43c2d9563a4eebbd123008c988f1a4a4de2161e0f50aac7f17e7f9555caa486af3b
|
|
* <><><--><--------------------------------------------------><----------------------------------------------><---->
|
|
* / \ \ | | /
|
|
* version code unspentness vout[4] vout[16] height
|
|
*
|
|
* - version = 1
|
|
* - code = 9 (coinbase, neither vout[0] or vout[1] are unspent,
|
|
* 2 (1, +1 because both bit 1 and bit 2 are unset) non-zero bitvector bytes follow)
|
|
* - unspentness bitvector: bits 2 (0x04) and 14 (0x4000) are set, so vout[2+2] and vout[14+2] are unspent
|
|
* - vout[4]: 86ef97d5790061b01caab50f1b8e9c50a5057eb43c2d9563a4ee
|
|
* * 86ef97d579: compact amount representation for 234925952 (2.35 BTC)
|
|
* * 00: special txout type pay-to-pubkey-hash
|
|
* * 61b01caab50f1b8e9c50a5057eb43c2d9563a4ee: address uint160
|
|
* - vout[16]: bbd123008c988f1a4a4de2161e0f50aac7f17e7f9555caa4
|
|
* * bbd123: compact amount representation for 110397 (0.001 BTC)
|
|
* * 00: special txout type pay-to-pubkey-hash
|
|
* * 8c988f1a4a4de2161e0f50aac7f17e7f9555caa4: address uint160
|
|
* - height = 120891
|
|
*/
|
|
class CCoins
|
|
{
|
|
public:
|
|
//! whether transaction is a coinbase
|
|
bool fCoinBase;
|
|
|
|
//! unspent transaction outputs; spent outputs are .IsNull(); spent outputs at the end of the array are dropped
|
|
std::vector<CTxOut> vout;
|
|
|
|
//! at which height this transaction was included in the active block chain
|
|
int nHeight;
|
|
|
|
//! version of the CTransaction; accesses to this value should probably check for nHeight as well,
|
|
//! as new tx version will probably only be introduced at certain heights
|
|
int nVersion;
|
|
|
|
void FromTx(const CTransaction &tx, int nHeightIn) {
|
|
fCoinBase = tx.IsCoinBase();
|
|
vout = tx.vout;
|
|
nHeight = nHeightIn;
|
|
nVersion = tx.nVersion;
|
|
ClearUnspendable();
|
|
}
|
|
|
|
//! construct a CCoins from a CTransaction, at a given height
|
|
CCoins(const CTransaction &tx, int nHeightIn) {
|
|
FromTx(tx, nHeightIn);
|
|
}
|
|
|
|
void Clear() {
|
|
fCoinBase = false;
|
|
std::vector<CTxOut>().swap(vout);
|
|
nHeight = 0;
|
|
nVersion = 0;
|
|
}
|
|
|
|
//! empty constructor
|
|
CCoins() : fCoinBase(false), vout(0), nHeight(0), nVersion(0) { }
|
|
|
|
//!remove spent outputs at the end of vout
|
|
void Cleanup() {
|
|
while (vout.size() > 0 && vout.back().IsNull())
|
|
vout.pop_back();
|
|
if (vout.empty())
|
|
std::vector<CTxOut>().swap(vout);
|
|
}
|
|
|
|
void ClearUnspendable() {
|
|
BOOST_FOREACH(CTxOut &txout, vout) {
|
|
if (txout.scriptPubKey.IsUnspendable())
|
|
txout.SetNull();
|
|
}
|
|
Cleanup();
|
|
}
|
|
|
|
void swap(CCoins &to) {
|
|
std::swap(to.fCoinBase, fCoinBase);
|
|
to.vout.swap(vout);
|
|
std::swap(to.nHeight, nHeight);
|
|
std::swap(to.nVersion, nVersion);
|
|
}
|
|
|
|
//! equality test
|
|
friend bool operator==(const CCoins &a, const CCoins &b) {
|
|
// Empty CCoins objects are always equal.
|
|
if (a.IsPruned() && b.IsPruned())
|
|
return true;
|
|
return a.fCoinBase == b.fCoinBase &&
|
|
a.nHeight == b.nHeight &&
|
|
a.nVersion == b.nVersion &&
|
|
a.vout == b.vout;
|
|
}
|
|
friend bool operator!=(const CCoins &a, const CCoins &b) {
|
|
return !(a == b);
|
|
}
|
|
|
|
void CalcMaskSize(unsigned int &nBytes, unsigned int &nNonzeroBytes) const;
|
|
|
|
bool IsCoinBase() const {
|
|
return fCoinBase;
|
|
}
|
|
|
|
template<typename Stream>
|
|
void Serialize(Stream &s) const {
|
|
unsigned int nMaskSize = 0, nMaskCode = 0;
|
|
CalcMaskSize(nMaskSize, nMaskCode);
|
|
bool fFirst = vout.size() > 0 && !vout[0].IsNull();
|
|
bool fSecond = vout.size() > 1 && !vout[1].IsNull();
|
|
assert(fFirst || fSecond || nMaskCode);
|
|
unsigned int nCode = 8*(nMaskCode - (fFirst || fSecond ? 0 : 1)) + (fCoinBase ? 1 : 0) + (fFirst ? 2 : 0) + (fSecond ? 4 : 0);
|
|
// version
|
|
::Serialize(s, VARINT(this->nVersion));
|
|
// header code
|
|
::Serialize(s, VARINT(nCode));
|
|
// spentness bitmask
|
|
for (unsigned int b = 0; b<nMaskSize; b++) {
|
|
unsigned char chAvail = 0;
|
|
for (unsigned int i = 0; i < 8 && 2+b*8+i < vout.size(); i++)
|
|
if (!vout[2+b*8+i].IsNull())
|
|
chAvail |= (1 << i);
|
|
::Serialize(s, chAvail);
|
|
}
|
|
// txouts themself
|
|
for (unsigned int i = 0; i < vout.size(); i++) {
|
|
if (!vout[i].IsNull())
|
|
::Serialize(s, CTxOutCompressor(REF(vout[i])));
|
|
}
|
|
// coinbase height
|
|
::Serialize(s, VARINT(nHeight));
|
|
}
|
|
|
|
template<typename Stream>
|
|
void Unserialize(Stream &s) {
|
|
unsigned int nCode = 0;
|
|
// version
|
|
::Unserialize(s, VARINT(this->nVersion));
|
|
// header code
|
|
::Unserialize(s, VARINT(nCode));
|
|
fCoinBase = nCode & 1;
|
|
std::vector<bool> vAvail(2, false);
|
|
vAvail[0] = (nCode & 2) != 0;
|
|
vAvail[1] = (nCode & 4) != 0;
|
|
unsigned int nMaskCode = (nCode / 8) + ((nCode & 6) != 0 ? 0 : 1);
|
|
// spentness bitmask
|
|
while (nMaskCode > 0) {
|
|
unsigned char chAvail = 0;
|
|
::Unserialize(s, chAvail);
|
|
for (unsigned int p = 0; p < 8; p++) {
|
|
bool f = (chAvail & (1 << p)) != 0;
|
|
vAvail.push_back(f);
|
|
}
|
|
if (chAvail != 0)
|
|
nMaskCode--;
|
|
}
|
|
// txouts themself
|
|
vout.assign(vAvail.size(), CTxOut());
|
|
for (unsigned int i = 0; i < vAvail.size(); i++) {
|
|
if (vAvail[i])
|
|
::Unserialize(s, REF(CTxOutCompressor(vout[i])));
|
|
}
|
|
// coinbase height
|
|
::Unserialize(s, VARINT(nHeight));
|
|
Cleanup();
|
|
}
|
|
|
|
//! mark a vout spent
|
|
bool Spend(uint32_t nPos);
|
|
|
|
//! check whether a particular output is still available
|
|
bool IsAvailable(unsigned int nPos) const {
|
|
return (nPos < vout.size() && !vout[nPos].IsNull());
|
|
}
|
|
|
|
//! check whether the entire CCoins is spent
|
|
//! note that only !IsPruned() CCoins can be serialized
|
|
bool IsPruned() const {
|
|
BOOST_FOREACH(const CTxOut &out, vout)
|
|
if (!out.IsNull())
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
size_t DynamicMemoryUsage() const {
|
|
size_t ret = memusage::DynamicUsage(vout);
|
|
BOOST_FOREACH(const CTxOut &out, vout) {
|
|
ret += RecursiveDynamicUsage(out.scriptPubKey);
|
|
}
|
|
return ret;
|
|
}
|
|
};
|
|
|
|
class SaltedTxidHasher
|
|
{
|
|
private:
|
|
/** Salt */
|
|
const uint64_t k0, k1;
|
|
|
|
public:
|
|
SaltedTxidHasher();
|
|
|
|
/**
|
|
* This *must* return size_t. With Boost 1.46 on 32-bit systems the
|
|
* unordered_map will behave unpredictably if the custom hasher returns a
|
|
* uint64_t, resulting in failures when syncing the chain (#4634).
|
|
*/
|
|
size_t operator()(const uint256& txid) const {
|
|
return SipHashUint256(k0, k1, txid);
|
|
}
|
|
};
|
|
|
|
struct CCoinsCacheEntry
|
|
{
|
|
CCoins coins; // The actual cached data.
|
|
unsigned char flags;
|
|
|
|
enum Flags {
|
|
DIRTY = (1 << 0), // This cache entry is potentially different from the version in the parent view.
|
|
FRESH = (1 << 1), // The parent view does not have this entry (or it is pruned).
|
|
/* Note that FRESH is a performance optimization with which we can
|
|
* erase coins that are fully spent if we know we do not need to
|
|
* flush the changes to the parent cache. It is always safe to
|
|
* not mark FRESH if that condition is not guaranteed.
|
|
*/
|
|
};
|
|
|
|
CCoinsCacheEntry() : coins(), flags(0) {}
|
|
};
|
|
|
|
typedef boost::unordered_map<uint256, CCoinsCacheEntry, SaltedTxidHasher> CCoinsMap;
|
|
|
|
/** Cursor for iterating over CoinsView state */
|
|
class CCoinsViewCursor
|
|
{
|
|
public:
|
|
CCoinsViewCursor(const uint256 &hashBlockIn): hashBlock(hashBlockIn) {}
|
|
virtual ~CCoinsViewCursor();
|
|
|
|
virtual bool GetKey(uint256 &key) const = 0;
|
|
virtual bool GetValue(CCoins &coins) const = 0;
|
|
/* Don't care about GetKeySize here */
|
|
virtual unsigned int GetValueSize() const = 0;
|
|
|
|
virtual bool Valid() const = 0;
|
|
virtual void Next() = 0;
|
|
|
|
//! Get best block at the time this cursor was created
|
|
const uint256 &GetBestBlock() const { return hashBlock; }
|
|
private:
|
|
uint256 hashBlock;
|
|
};
|
|
|
|
/** Abstract view on the open txout dataset. */
|
|
class CCoinsView
|
|
{
|
|
public:
|
|
//! Retrieve the CCoins (unspent transaction outputs) for a given txid
|
|
virtual bool GetCoins(const uint256 &txid, CCoins &coins) const;
|
|
|
|
//! Just check whether we have data for a given txid.
|
|
//! This may (but cannot always) return true for fully spent transactions
|
|
virtual bool HaveCoins(const uint256 &txid) const;
|
|
|
|
//! Retrieve the block hash whose state this CCoinsView currently represents
|
|
virtual uint256 GetBestBlock() const;
|
|
|
|
//! Do a bulk modification (multiple CCoins changes + BestBlock change).
|
|
//! The passed mapCoins can be modified.
|
|
virtual bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock);
|
|
|
|
//! Get a cursor to iterate over the whole state
|
|
virtual CCoinsViewCursor *Cursor() const;
|
|
|
|
//! As we use CCoinsViews polymorphically, have a virtual destructor
|
|
virtual ~CCoinsView() {}
|
|
};
|
|
|
|
|
|
/** CCoinsView backed by another CCoinsView */
|
|
class CCoinsViewBacked : public CCoinsView
|
|
{
|
|
protected:
|
|
CCoinsView *base;
|
|
|
|
public:
|
|
CCoinsViewBacked(CCoinsView *viewIn);
|
|
bool GetCoins(const uint256 &txid, CCoins &coins) const;
|
|
bool HaveCoins(const uint256 &txid) const;
|
|
uint256 GetBestBlock() const;
|
|
void SetBackend(CCoinsView &viewIn);
|
|
bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock);
|
|
CCoinsViewCursor *Cursor() const;
|
|
};
|
|
|
|
|
|
class CCoinsViewCache;
|
|
|
|
/**
|
|
* A reference to a mutable cache entry. Encapsulating it allows us to run
|
|
* cleanup code after the modification is finished, and keeping track of
|
|
* concurrent modifications.
|
|
*/
|
|
class CCoinsModifier
|
|
{
|
|
private:
|
|
CCoinsViewCache& cache;
|
|
CCoinsMap::iterator it;
|
|
size_t cachedCoinUsage; // Cached memory usage of the CCoins object before modification
|
|
CCoinsModifier(CCoinsViewCache& cache_, CCoinsMap::iterator it_, size_t usage);
|
|
|
|
public:
|
|
CCoins* operator->() { return &it->second.coins; }
|
|
CCoins& operator*() { return it->second.coins; }
|
|
~CCoinsModifier();
|
|
friend class CCoinsViewCache;
|
|
};
|
|
|
|
/** CCoinsView that adds a memory cache for transactions to another CCoinsView */
|
|
class CCoinsViewCache : public CCoinsViewBacked
|
|
{
|
|
protected:
|
|
/* Whether this cache has an active modifier. */
|
|
bool hasModifier;
|
|
|
|
|
|
/**
|
|
* Make mutable so that we can "fill the cache" even from Get-methods
|
|
* declared as "const".
|
|
*/
|
|
mutable uint256 hashBlock;
|
|
mutable CCoinsMap cacheCoins;
|
|
|
|
/* Cached dynamic memory usage for the inner CCoins objects. */
|
|
mutable size_t cachedCoinsUsage;
|
|
|
|
public:
|
|
CCoinsViewCache(CCoinsView *baseIn);
|
|
~CCoinsViewCache();
|
|
|
|
// Standard CCoinsView methods
|
|
bool GetCoins(const uint256 &txid, CCoins &coins) const;
|
|
bool HaveCoins(const uint256 &txid) const;
|
|
uint256 GetBestBlock() const;
|
|
void SetBestBlock(const uint256 &hashBlock);
|
|
bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock);
|
|
|
|
/**
|
|
* Check if we have the given tx already loaded in this cache.
|
|
* The semantics are the same as HaveCoins(), but no calls to
|
|
* the backing CCoinsView are made.
|
|
*/
|
|
bool HaveCoinsInCache(const uint256 &txid) const;
|
|
|
|
/**
|
|
* Return a pointer to CCoins in the cache, or NULL if not found. This is
|
|
* more efficient than GetCoins. Modifications to other cache entries are
|
|
* allowed while accessing the returned pointer.
|
|
*/
|
|
const CCoins* AccessCoins(const uint256 &txid) const;
|
|
|
|
/**
|
|
* Return a modifiable reference to a CCoins. If no entry with the given
|
|
* txid exists, a new one is created. Simultaneous modifications are not
|
|
* allowed.
|
|
*/
|
|
CCoinsModifier ModifyCoins(const uint256 &txid);
|
|
|
|
/**
|
|
* Return a modifiable reference to a CCoins. Assumes that no entry with the given
|
|
* txid exists and creates a new one. This saves a database access in the case where
|
|
* the coins were to be wiped out by FromTx anyway. This should not be called with
|
|
* the 2 historical coinbase duplicate pairs because the new coins are marked fresh, and
|
|
* in the event the duplicate coinbase was spent before a flush, the now pruned coins
|
|
* would not properly overwrite the first coinbase of the pair. Simultaneous modifications
|
|
* are not allowed.
|
|
*/
|
|
CCoinsModifier ModifyNewCoins(const uint256 &txid, bool coinbase);
|
|
|
|
/**
|
|
* Push the modifications applied to this cache to its base.
|
|
* Failure to call this method before destruction will cause the changes to be forgotten.
|
|
* If false is returned, the state of this cache (and its backing view) will be undefined.
|
|
*/
|
|
bool Flush();
|
|
|
|
/**
|
|
* Removes the transaction with the given hash from the cache, if it is
|
|
* not modified.
|
|
*/
|
|
void Uncache(const uint256 &txid);
|
|
|
|
//! Calculate the size of the cache (in number of transactions)
|
|
unsigned int GetCacheSize() const;
|
|
|
|
//! Calculate the size of the cache (in bytes)
|
|
size_t DynamicMemoryUsage() const;
|
|
|
|
/**
|
|
* Amount of bitcoins coming in to a transaction
|
|
* Note that lightweight clients may not know anything besides the hash of previous transactions,
|
|
* so may not be able to calculate this.
|
|
*
|
|
* @param[in] tx transaction for which we are checking input total
|
|
* @return Sum of value of all inputs (scriptSigs)
|
|
*/
|
|
CAmount GetValueIn(const CTransaction& tx) const;
|
|
|
|
//! Check whether all prevouts of the transaction are present in the UTXO set represented by this view
|
|
bool HaveInputs(const CTransaction& tx) const;
|
|
|
|
/**
|
|
* Return priority of tx at height nHeight. Also calculate the sum of the values of the inputs
|
|
* that are already in the chain. These are the inputs that will age and increase priority as
|
|
* new blocks are added to the chain.
|
|
*/
|
|
double GetPriority(const CTransaction &tx, int nHeight, CAmount &inChainInputValue) const;
|
|
|
|
const CTxOut &GetOutputFor(const CTxIn& input) const;
|
|
|
|
friend class CCoinsModifier;
|
|
|
|
private:
|
|
CCoinsMap::const_iterator FetchCoins(const uint256 &txid) const;
|
|
|
|
/**
|
|
* By making the copy constructor private, we prevent accidentally using it when one intends to create a cache on top of a base cache.
|
|
*/
|
|
CCoinsViewCache(const CCoinsViewCache &);
|
|
};
|
|
|
|
#endif // BITCOIN_COINS_H
|