Move CBlockIndex, CChain and related code out of main

1 files changed, 390 insertions, 0 deletions

diff --git a/src/chain.h b/src/chain.h
new file mode 100644
index 0000000000..91bdf38347
--- /dev/null
+++ b/src/chain.h
@@ -0,0 +1,390 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2014 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef H_BITCOIN_CHAIN
+#define H_BITCOIN_CHAIN
+
+#include "core.h"
+#include "pow.h"
+#include "uint256.h"
+
+#include <vector>
+
+#include <boost/foreach.hpp>
+
+struct CDiskBlockPos
+{
+    int nFile;
+    unsigned int nPos;
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+        READWRITE(VARINT(nFile));
+        READWRITE(VARINT(nPos));
+    }
+
+    CDiskBlockPos() {
+        SetNull();
+    }
+
+    CDiskBlockPos(int nFileIn, unsigned int nPosIn) {
+        nFile = nFileIn;
+        nPos = nPosIn;
+    }
+
+    friend bool operator==(const CDiskBlockPos &a, const CDiskBlockPos &b) {
+        return (a.nFile == b.nFile && a.nPos == b.nPos);
+    }
+
+    friend bool operator!=(const CDiskBlockPos &a, const CDiskBlockPos &b) {
+        return !(a == b);
+    }
+
+    void SetNull() { nFile = -1; nPos = 0; }
+    bool IsNull() const { return (nFile == -1); }
+};
+
+enum BlockStatus {
+    BLOCK_VALID_UNKNOWN      =    0,
+    BLOCK_VALID_HEADER       =    1, // parsed, version ok, hash satisfies claimed PoW, 1 <= vtx count <= max, timestamp not in future
+    BLOCK_VALID_TREE         =    2, // parent found, difficulty matches, timestamp >= median previous, checkpoint
+    BLOCK_VALID_TRANSACTIONS =    3, // only first tx is coinbase, 2 <= coinbase input script length <= 100, transactions valid, no duplicate txids, sigops, size, merkle root
+    BLOCK_VALID_CHAIN        =    4, // outputs do not overspend inputs, no double spends, coinbase output ok, immature coinbase spends, BIP30
+    BLOCK_VALID_SCRIPTS      =    5, // scripts/signatures ok
+    BLOCK_VALID_MASK         =   BLOCK_VALID_HEADER | BLOCK_VALID_TREE | BLOCK_VALID_TRANSACTIONS |
+                                 BLOCK_VALID_CHAIN | BLOCK_VALID_SCRIPTS,
+
+    BLOCK_HAVE_DATA          =    8, // full block available in blk*.dat
+    BLOCK_HAVE_UNDO          =   16, // undo data available in rev*.dat
+    BLOCK_HAVE_MASK          =   BLOCK_HAVE_DATA | BLOCK_HAVE_UNDO,
+
+    BLOCK_FAILED_VALID       =   32, // stage after last reached validness failed
+    BLOCK_FAILED_CHILD       =   64, // descends from failed block
+    BLOCK_FAILED_MASK        =   BLOCK_FAILED_VALID | BLOCK_FAILED_CHILD,
+};
+
+/** The block chain is a tree shaped structure starting with the
+ * genesis block at the root, with each block potentially having multiple
+ * candidates to be the next block. A blockindex may have multiple pprev pointing
+ * to it, but at most one of them can be part of the currently active branch.
+ */
+class CBlockIndex
+{
+public:
+    // pointer to the hash of the block, if any. memory is owned by this CBlockIndex
+    const uint256* phashBlock;
+
+    // pointer to the index of the predecessor of this block
+    CBlockIndex* pprev;
+
+    // pointer to the index of some further predecessor of this block
+    CBlockIndex* pskip;
+
+    // height of the entry in the chain. The genesis block has height 0
+    int nHeight;
+
+    // Which # file this block is stored in (blk?????.dat)
+    int nFile;
+
+    // Byte offset within blk?????.dat where this block's data is stored
+    unsigned int nDataPos;
+
+    // Byte offset within rev?????.dat where this block's undo data is stored
+    unsigned int nUndoPos;
+
+    // (memory only) Total amount of work (expected number of hashes) in the chain up to and including this block
+    uint256 nChainWork;
+
+    // Number of transactions in this block.
+    // Note: in a potential headers-first mode, this number cannot be relied upon
+    unsigned int nTx;
+
+    // (memory only) Number of transactions in the chain up to and including this block
+    unsigned int nChainTx; // change to 64-bit type when necessary; won't happen before 2030
+
+    // Verification status of this block. See enum BlockStatus
+    unsigned int nStatus;
+
+    // block header
+    int nVersion;
+    uint256 hashMerkleRoot;
+    unsigned int nTime;
+    unsigned int nBits;
+    unsigned int nNonce;
+
+    // (memory only) Sequencial id assigned to distinguish order in which blocks are received.
+    uint32_t nSequenceId;
+
+    void SetNull()
+    {
+        phashBlock = NULL;
+        pprev = NULL;
+        pskip = NULL;
+        nHeight = 0;
+        nFile = 0;
+        nDataPos = 0;
+        nUndoPos = 0;
+        nChainWork = 0;
+        nTx = 0;
+        nChainTx = 0;
+        nStatus = 0;
+        nSequenceId = 0;
+
+        nVersion       = 0;
+        hashMerkleRoot = 0;
+        nTime          = 0;
+        nBits          = 0;
+        nNonce         = 0;
+    }
+
+    CBlockIndex()
+    {
+        SetNull();
+    }
+
+    CBlockIndex(CBlockHeader& block)
+    {
+        SetNull();
+
+        nVersion       = block.nVersion;
+        hashMerkleRoot = block.hashMerkleRoot;
+        nTime          = block.nTime;
+        nBits          = block.nBits;
+        nNonce         = block.nNonce;
+    }
+
+    CDiskBlockPos GetBlockPos() const {
+        CDiskBlockPos ret;
+        if (nStatus & BLOCK_HAVE_DATA) {
+            ret.nFile = nFile;
+            ret.nPos  = nDataPos;
+        }
+        return ret;
+    }
+
+    CDiskBlockPos GetUndoPos() const {
+        CDiskBlockPos ret;
+        if (nStatus & BLOCK_HAVE_UNDO) {
+            ret.nFile = nFile;
+            ret.nPos  = nUndoPos;
+        }
+        return ret;
+    }
+
+    CBlockHeader GetBlockHeader() const
+    {
+        CBlockHeader block;
+        block.nVersion       = nVersion;
+        if (pprev)
+            block.hashPrevBlock = pprev->GetBlockHash();
+        block.hashMerkleRoot = hashMerkleRoot;
+        block.nTime          = nTime;
+        block.nBits          = nBits;
+        block.nNonce         = nNonce;
+        return block;
+    }
+
+    uint256 GetBlockHash() const
+    {
+        return *phashBlock;
+    }
+
+    int64_t GetBlockTime() const
+    {
+        return (int64_t)nTime;
+    }
+
+    uint256 GetBlockWork() const
+    {
+        return GetProofIncrement(nBits);
+    }
+
+    enum { nMedianTimeSpan=11 };
+
+    int64_t GetMedianTimePast() const
+    {
+        int64_t pmedian[nMedianTimeSpan];
+        int64_t* pbegin = &pmedian[nMedianTimeSpan];
+        int64_t* pend = &pmedian[nMedianTimeSpan];
+
+        const CBlockIndex* pindex = this;
+        for (int i = 0; i < nMedianTimeSpan && pindex; i++, pindex = pindex->pprev)
+            *(--pbegin) = pindex->GetBlockTime();
+
+        std::sort(pbegin, pend);
+        return pbegin[(pend - pbegin)/2];
+    }
+
+    /**
+     * Returns true if there are nRequired or more blocks of minVersion or above
+     * in the last Params().ToCheckBlockUpgradeMajority() blocks, starting at pstart 
+     * and going backwards.
+     */
+    static bool IsSuperMajority(int minVersion, const CBlockIndex* pstart,
+                                unsigned int nRequired);
+
+    std::string ToString() const
+    {
+        return strprintf("CBlockIndex(pprev=%p, nHeight=%d, merkle=%s, hashBlock=%s)",
+            pprev, nHeight,
+            hashMerkleRoot.ToString(),
+            GetBlockHash().ToString());
+    }
+
+    // Check whether this block index entry is valid up to the passed validity level.
+    bool IsValid(enum BlockStatus nUpTo = BLOCK_VALID_TRANSACTIONS) const
+    {
+        assert(!(nUpTo & ~BLOCK_VALID_MASK)); // Only validity flags allowed.
+        if (nStatus & BLOCK_FAILED_MASK)
+            return false;
+        return ((nStatus & BLOCK_VALID_MASK) >= nUpTo);
+    }
+
+    // Raise the validity level of this block index entry.
+    // Returns true if the validity was changed.
+    bool RaiseValidity(enum BlockStatus nUpTo)
+    {
+        assert(!(nUpTo & ~BLOCK_VALID_MASK)); // Only validity flags allowed.
+        if (nStatus & BLOCK_FAILED_MASK)
+            return false;
+        if ((nStatus & BLOCK_VALID_MASK) < nUpTo) {
+            nStatus = (nStatus & ~BLOCK_VALID_MASK) | nUpTo;
+            return true;
+        }
+        return false;
+    }
+
+    // Build the skiplist pointer for this entry.
+    void BuildSkip();
+
+    // Efficiently find an ancestor of this block.
+    CBlockIndex* GetAncestor(int height);
+    const CBlockIndex* GetAncestor(int height) const;
+};
+
+/** Used to marshal pointers into hashes for db storage. */
+class CDiskBlockIndex : public CBlockIndex
+{
+public:
+    uint256 hashPrev;
+
+    CDiskBlockIndex() {
+        hashPrev = 0;
+    }
+
+    explicit CDiskBlockIndex(CBlockIndex* pindex) : CBlockIndex(*pindex) {
+        hashPrev = (pprev ? pprev->GetBlockHash() : 0);
+    }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+        if (!(nType & SER_GETHASH))
+            READWRITE(VARINT(nVersion));
+
+        READWRITE(VARINT(nHeight));
+        READWRITE(VARINT(nStatus));
+        READWRITE(VARINT(nTx));
+        if (nStatus & (BLOCK_HAVE_DATA | BLOCK_HAVE_UNDO))
+            READWRITE(VARINT(nFile));
+        if (nStatus & BLOCK_HAVE_DATA)
+            READWRITE(VARINT(nDataPos));
+        if (nStatus & BLOCK_HAVE_UNDO)
+            READWRITE(VARINT(nUndoPos));
+
+        // block header
+        READWRITE(this->nVersion);
+        READWRITE(hashPrev);
+        READWRITE(hashMerkleRoot);
+        READWRITE(nTime);
+        READWRITE(nBits);
+        READWRITE(nNonce);
+    }
+
+    uint256 GetBlockHash() const
+    {
+        CBlockHeader block;
+        block.nVersion        = nVersion;
+        block.hashPrevBlock   = hashPrev;
+        block.hashMerkleRoot  = hashMerkleRoot;
+        block.nTime           = nTime;
+        block.nBits           = nBits;
+        block.nNonce          = nNonce;
+        return block.GetHash();
+    }
+
+
+    std::string ToString() const
+    {
+        std::string str = "CDiskBlockIndex(";
+        str += CBlockIndex::ToString();
+        str += strprintf("\n                hashBlock=%s, hashPrev=%s)",
+            GetBlockHash().ToString(),
+            hashPrev.ToString());
+        return str;
+    }
+};
+
+/** An in-memory indexed chain of blocks. */
+class CChain {
+private:
+    std::vector<CBlockIndex*> vChain;
+
+public:
+    /** Returns the index entry for the genesis block of this chain, or NULL if none. */
+    CBlockIndex *Genesis() const {
+        return vChain.size() > 0 ? vChain[0] : NULL;
+    }
+
+    /** Returns the index entry for the tip of this chain, or NULL if none. */
+    CBlockIndex *Tip() const {
+        return vChain.size() > 0 ? vChain[vChain.size() - 1] : NULL;
+    }
+
+    /** Returns the index entry at a particular height in this chain, or NULL if no such height exists. */
+    CBlockIndex *operator[](int nHeight) const {
+        if (nHeight < 0 || nHeight >= (int)vChain.size())
+            return NULL;
+        return vChain[nHeight];
+    }
+
+    /** Compare two chains efficiently. */
+    friend bool operator==(const CChain &a, const CChain &b) {
+        return a.vChain.size() == b.vChain.size() &&
+               a.vChain[a.vChain.size() - 1] == b.vChain[b.vChain.size() - 1];
+    }
+
+    /** Efficiently check whether a block is present in this chain. */
+    bool Contains(const CBlockIndex *pindex) const {
+        return (*this)[pindex->nHeight] == pindex;
+    }
+
+    /** Find the successor of a block in this chain, or NULL if the given index is not found or is the tip. */
+    CBlockIndex *Next(const CBlockIndex *pindex) const {
+        if (Contains(pindex))
+            return (*this)[pindex->nHeight + 1];
+        else
+            return NULL;
+    }
+
+    /** Return the maximal height in the chain. Is equal to chain.Tip() ? chain.Tip()->nHeight : -1. */
+    int Height() const {
+        return vChain.size() - 1;
+    }
+
+    /** Set/initialize a chain with a given tip. Returns the forking point. */
+    CBlockIndex *SetTip(CBlockIndex *pindex);
+
+    /** Return a CBlockLocator that refers to a block in this chain (by default the tip). */
+    CBlockLocator GetLocator(const CBlockIndex *pindex = NULL) const;
+
+    /** Find the last common block between this chain and a block index entry. */
+    const CBlockIndex *FindFork(const CBlockIndex *pindex) const;
+};
+
+#endif