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Merge #7756: Add cursor to iterate over utxo set, use this in `gettxo…

…utsetinfo`

509cb00 txdb: Add Cursor() method to CCoinsView to iterate over UTXO set (Wladimir J. van der Laan)
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laanwj committed Apr 15, 2016
2 parents be14ca5 + 509cb00 commit 9e47fcec1798e1db9a32ae243605e8245ffdb273
Showing with 148 additions and 57 deletions.
  1. +6 −2 src/coins.cpp
  2. +20 −13 src/coins.h
  3. +57 −1 src/rpc/blockchain.cpp
  4. +0 −2 src/test/coins_tests.cpp
  5. +40 −38 src/txdb.cpp
  6. +25 −1 src/txdb.h
View
@@ -45,7 +45,7 @@ bool CCoinsView::GetCoins(const uint256 &txid, CCoins &coins) const { return fal
bool CCoinsView::HaveCoins(const uint256 &txid) const { return false; }
uint256 CCoinsView::GetBestBlock() const { return uint256(); }
bool CCoinsView::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return false; }
bool CCoinsView::GetStats(CCoinsStats &stats) const { return false; }
CCoinsViewCursor *CCoinsView::Cursor() const { return 0; }
CCoinsViewBacked::CCoinsViewBacked(CCoinsView *viewIn) : base(viewIn) { }
@@ -54,7 +54,7 @@ bool CCoinsViewBacked::HaveCoins(const uint256 &txid) const { return base->HaveC
uint256 CCoinsViewBacked::GetBestBlock() const { return base->GetBestBlock(); }
void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; }
bool CCoinsViewBacked::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return base->BatchWrite(mapCoins, hashBlock); }
bool CCoinsViewBacked::GetStats(CCoinsStats &stats) const { return base->GetStats(stats); }
CCoinsViewCursor *CCoinsViewBacked::Cursor() const { return base->Cursor(); }
CCoinsKeyHasher::CCoinsKeyHasher() : salt(GetRandHash()) {}
@@ -300,3 +300,7 @@ CCoinsModifier::~CCoinsModifier()
cache.cachedCoinsUsage += it->second.coins.DynamicMemoryUsage();
}
}
CCoinsViewCursor::~CCoinsViewCursor()
{
}
View
@@ -297,19 +297,26 @@ struct CCoinsCacheEntry
typedef boost::unordered_map<uint256, CCoinsCacheEntry, CCoinsKeyHasher> CCoinsMap;
struct CCoinsStats
/** Cursor for iterating over CoinsView state */
class CCoinsViewCursor
{
int nHeight;
uint256 hashBlock;
uint64_t nTransactions;
uint64_t nTransactionOutputs;
uint64_t nSerializedSize;
uint256 hashSerialized;
CAmount nTotalAmount;
public:
CCoinsViewCursor(const uint256 &hashBlockIn): hashBlock(hashBlockIn) {}
virtual ~CCoinsViewCursor();
CCoinsStats() : nHeight(0), nTransactions(0), nTransactionOutputs(0), nSerializedSize(0), nTotalAmount(0) {}
};
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
@@ -329,8 +336,8 @@ class CCoinsView
//! The passed mapCoins can be modified.
virtual bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock);
//! Calculate statistics about the unspent transaction output set
virtual bool GetStats(CCoinsStats &stats) const;
//! Get a cursor to iterate over the whole state
virtual CCoinsViewCursor *Cursor() const;
//! As we use CCoinsViews polymorphically, have a virtual destructor
virtual ~CCoinsView() {}
@@ -350,7 +357,7 @@ class CCoinsViewBacked : public CCoinsView
uint256 GetBestBlock() const;
void SetBackend(CCoinsView &viewIn);
bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock);
bool GetStats(CCoinsStats &stats) const;
CCoinsViewCursor *Cursor() const;
};
View
@@ -18,11 +18,14 @@
#include "txmempool.h"
#include "util.h"
#include "utilstrencodings.h"
#include "hash.h"
#include <stdint.h>
#include <univalue.h>
#include <boost/thread/thread.hpp> // boost::thread::interrupt
using namespace std;
extern void TxToJSON(const CTransaction& tx, const uint256 hashBlock, UniValue& entry);
@@ -432,6 +435,59 @@ UniValue getblock(const UniValue& params, bool fHelp)
return blockToJSON(block, pblockindex);
}
struct CCoinsStats
{
int nHeight;
uint256 hashBlock;
uint64_t nTransactions;
uint64_t nTransactionOutputs;
uint64_t nSerializedSize;
uint256 hashSerialized;
CAmount nTotalAmount;
CCoinsStats() : nHeight(0), nTransactions(0), nTransactionOutputs(0), nSerializedSize(0), nTotalAmount(0) {}
};
//! Calculate statistics about the unspent transaction output set
static bool GetUTXOStats(CCoinsView *view, CCoinsStats &stats)
{
boost::scoped_ptr<CCoinsViewCursor> pcursor(view->Cursor());
CHashWriter ss(SER_GETHASH, PROTOCOL_VERSION);
stats.hashBlock = pcursor->GetBestBlock();
{
LOCK(cs_main);
stats.nHeight = mapBlockIndex.find(stats.hashBlock)->second->nHeight;
}
ss << stats.hashBlock;
CAmount nTotalAmount = 0;
while (pcursor->Valid()) {
boost::this_thread::interruption_point();
uint256 key;
CCoins coins;
if (pcursor->GetKey(key) && pcursor->GetValue(coins)) {
stats.nTransactions++;
for (unsigned int i=0; i<coins.vout.size(); i++) {
const CTxOut &out = coins.vout[i];
if (!out.IsNull()) {
stats.nTransactionOutputs++;
ss << VARINT(i+1);
ss << out;
nTotalAmount += out.nValue;
}
}
stats.nSerializedSize += 32 + pcursor->GetValueSize();
ss << VARINT(0);
} else {
return error("%s: unable to read value", __func__);
}
pcursor->Next();
}
stats.hashSerialized = ss.GetHash();
stats.nTotalAmount = nTotalAmount;
return true;
}
UniValue gettxoutsetinfo(const UniValue& params, bool fHelp)
{
if (fHelp || params.size() != 0)
@@ -458,7 +514,7 @@ UniValue gettxoutsetinfo(const UniValue& params, bool fHelp)
CCoinsStats stats;
FlushStateToDisk();
if (pcoinsTip->GetStats(stats)) {
if (GetUTXOStats(pcoinsTip, stats)) {
ret.push_back(Pair("height", (int64_t)stats.nHeight));
ret.push_back(Pair("bestblock", stats.hashBlock.GetHex()));
ret.push_back(Pair("transactions", (int64_t)stats.nTransactions));
View
@@ -61,8 +61,6 @@ class CCoinsViewTest : public CCoinsView
hashBestBlock_ = hashBlock;
return true;
}
bool GetStats(CCoinsStats& stats) const { return false; }
};
class CCoinsViewCacheTest : public CCoinsViewCache
View
@@ -94,50 +94,52 @@ bool CBlockTreeDB::ReadLastBlockFile(int &nFile) {
return Read(DB_LAST_BLOCK, nFile);
}
bool CCoinsViewDB::GetStats(CCoinsStats &stats) const {
CCoinsViewCursor *CCoinsViewDB::Cursor() const
{
CCoinsViewDBCursor *i = new CCoinsViewDBCursor(const_cast<CDBWrapper*>(&db)->NewIterator(), GetBestBlock());
/* It seems that there are no "const iterators" for LevelDB. Since we
only need read operations on it, use a const-cast to get around
that restriction. */
boost::scoped_ptr<CDBIterator> pcursor(const_cast<CDBWrapper*>(&db)->NewIterator());
pcursor->Seek(DB_COINS);
i->pcursor->Seek(DB_COINS);
// Cache key of first record
i->pcursor->GetKey(i->keyTmp);
return i;
}
CHashWriter ss(SER_GETHASH, PROTOCOL_VERSION);
stats.hashBlock = GetBestBlock();
ss << stats.hashBlock;
CAmount nTotalAmount = 0;
while (pcursor->Valid()) {
boost::this_thread::interruption_point();
std::pair<char, uint256> key;
CCoins coins;
if (pcursor->GetKey(key) && key.first == DB_COINS) {
if (pcursor->GetValue(coins)) {
stats.nTransactions++;
for (unsigned int i=0; i<coins.vout.size(); i++) {
const CTxOut &out = coins.vout[i];
if (!out.IsNull()) {
stats.nTransactionOutputs++;
ss << VARINT(i+1);
ss << out;
nTotalAmount += out.nValue;
}
}
stats.nSerializedSize += 32 + pcursor->GetValueSize();
ss << VARINT(0);
} else {
return error("CCoinsViewDB::GetStats() : unable to read value");
}
} else {
break;
}
pcursor->Next();
bool CCoinsViewDBCursor::GetKey(uint256 &key) const
{
// Return cached key
if (keyTmp.first == DB_COINS) {
key = keyTmp.second;
return true;
}
{
LOCK(cs_main);
stats.nHeight = mapBlockIndex.find(stats.hashBlock)->second->nHeight;
return false;
}
bool CCoinsViewDBCursor::GetValue(CCoins &coins) const
{
return pcursor->GetValue(coins);
}
unsigned int CCoinsViewDBCursor::GetValueSize() const
{
return pcursor->GetValueSize();
}
bool CCoinsViewDBCursor::Valid() const
{
return keyTmp.first == DB_COINS;
}
void CCoinsViewDBCursor::Next()
{
pcursor->Next();
if (pcursor->Valid()) {
bool ok = pcursor->GetKey(keyTmp);
assert(ok); // If GetKey fails here something must be wrong with underlying database, we cannot handle that here
} else {
keyTmp.first = 0; // Invalidate cached key after last record so that Valid() and GetKey() return false
}
stats.hashSerialized = ss.GetHash();
stats.nTotalAmount = nTotalAmount;
return true;
}
bool CBlockTreeDB::WriteBatchSync(const std::vector<std::pair<int, const CBlockFileInfo*> >& fileInfo, int nLastFile, const std::vector<const CBlockIndex*>& blockinfo) {
View
@@ -26,6 +26,8 @@ static const int64_t nMaxDbCache = sizeof(void*) > 4 ? 16384 : 1024;
//! min. -dbcache in (MiB)
static const int64_t nMinDbCache = 4;
class CCoinsViewDBCursor;
/** CCoinsView backed by the coin database (chainstate/) */
class CCoinsViewDB : public CCoinsView
{
@@ -38,7 +40,29 @@ class CCoinsViewDB : public CCoinsView
bool HaveCoins(const uint256 &txid) const;
uint256 GetBestBlock() const;
bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock);
bool GetStats(CCoinsStats &stats) const;
CCoinsViewCursor *Cursor() const;
};
/** Specialization of CCoinsViewCursor to iterate over a CCoinsViewDB */
class CCoinsViewDBCursor: public CCoinsViewCursor
{
public:
~CCoinsViewDBCursor() {}
bool GetKey(uint256 &key) const;
bool GetValue(CCoins &coins) const;
unsigned int GetValueSize() const;
bool Valid() const;
void Next();
private:
CCoinsViewDBCursor(CDBIterator* pcursorIn, const uint256 &hashBlockIn):
CCoinsViewCursor(hashBlockIn), pcursor(pcursorIn) {}
boost::scoped_ptr<CDBIterator> pcursor;
std::pair<char, uint256> keyTmp;
friend class CCoinsViewDB;
};
/** Access to the block database (blocks/index/) */

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