From 97072d6685564dd50aab4c145b1758ccc10863b3 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter.wuille@gmail.com>
Date: Tue, 25 Apr 2017 11:29:41 -0700
Subject: [PATCH] Remove unused CCoins methods

---
 src/coins.cpp |  32 ----------
 src/coins.h   | 167 --------------------------------------------------
 2 files changed, 199 deletions(-)

diff --git a/src/coins.cpp b/src/coins.cpp
index 38b8df171..09fd2b13d 100644
--- a/src/coins.cpp
+++ b/src/coins.cpp
@@ -10,38 +10,6 @@
 
 #include <assert.h>
 
-/**
- * calculate number of bytes for the bitmask, and its number of non-zero bytes
- * each bit in the bitmask represents the availability of one output, but the
- * availabilities of the first two outputs are encoded separately
- */
-void CCoins::CalcMaskSize(unsigned int &nBytes, unsigned int &nNonzeroBytes) const {
-    unsigned int nLastUsedByte = 0;
-    for (unsigned int b = 0; 2+b*8 < vout.size(); b++) {
-        bool fZero = true;
-        for (unsigned int i = 0; i < 8 && 2+b*8+i < vout.size(); i++) {
-            if (!vout[2+b*8+i].IsNull()) {
-                fZero = false;
-                continue;
-            }
-        }
-        if (!fZero) {
-            nLastUsedByte = b + 1;
-            nNonzeroBytes++;
-        }
-    }
-    nBytes += nLastUsedByte;
-}
-
-bool CCoins::Spend(uint32_t nPos) 
-{
-    if (nPos >= vout.size() || vout[nPos].IsNull())
-        return false;
-    vout[nPos].SetNull();
-    Cleanup();
-    return true;
-}
-
 bool CCoinsView::GetCoins(const COutPoint &outpoint, Coin &coin) const { return false; }
 bool CCoinsView::HaveCoins(const COutPoint &outpoint) const { return false; }
 uint256 CCoinsView::GetBestBlock() const { return uint256(); }
diff --git a/src/coins.h b/src/coins.h
index ae85a199c..bd2f2caf2 100644
--- a/src/coins.h
+++ b/src/coins.h
@@ -82,58 +82,6 @@ public:
     }
 };
 
-/** 
- * 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:
@@ -146,98 +94,9 @@ public:
     //! at which height this transaction was included in the active block chain
     int nHeight;
 
-    void FromTx(const CTransaction &tx, int nHeightIn) {
-        fCoinBase = tx.IsCoinBase();
-        vout = tx.vout;
-        nHeight = nHeightIn;
-        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;
-    }
-
     //! empty constructor
     CCoins() : fCoinBase(false), vout(0), nHeight(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);
-    }
-
-    //! 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.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
-        int nVersionDummy = 0;
-        ::Serialize(s, VARINT(nVersionDummy));
-        // 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;
@@ -270,32 +129,6 @@ public:
         }
         // 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;
     }
 };