Break circular dependency main ↔ txdb

Break the circular dependency between main and txdb by:

- Moving `CBlockFileInfo` from `main.h` to `chain.h`. I think this makes
  sense, as the other block-file stuff is there too.

- Moving `CDiskTxPos` from `main.h` to `txdb.h`. This type seems
  specific to txdb.

- Pass a functor `insertBlockIndex` to `LoadBlockIndexGuts`. This leaves
  it up to the caller how to insert block indices.

src/chain.h

@@ -14,6 +14,60 @@
 
 #include <vector>
 
+class CBlockFileInfo
+{
+public:
+    unsigned int nBlocks;      //!< number of blocks stored in file
+    unsigned int nSize;        //!< number of used bytes of block file
+    unsigned int nUndoSize;    //!< number of used bytes in the undo file
+    unsigned int nHeightFirst; //!< lowest height of block in file
+    unsigned int nHeightLast;  //!< highest height of block in file
+    uint64_t nTimeFirst;       //!< earliest time of block in file
+    uint64_t nTimeLast;        //!< latest time of block in file
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+        READWRITE(VARINT(nBlocks));
+        READWRITE(VARINT(nSize));
+        READWRITE(VARINT(nUndoSize));
+        READWRITE(VARINT(nHeightFirst));
+        READWRITE(VARINT(nHeightLast));
+        READWRITE(VARINT(nTimeFirst));
+        READWRITE(VARINT(nTimeLast));
+    }
+
+     void SetNull() {
+         nBlocks = 0;
+         nSize = 0;
+         nUndoSize = 0;
+         nHeightFirst = 0;
+         nHeightLast = 0;
+         nTimeFirst = 0;
+         nTimeLast = 0;
+     }
+
+     CBlockFileInfo() {
+         SetNull();
+     }
+
+     std::string ToString() const;
+
+     /** update statistics (does not update nSize) */
+     void AddBlock(unsigned int nHeightIn, uint64_t nTimeIn) {
+         if (nBlocks==0 || nHeightFirst > nHeightIn)
+             nHeightFirst = nHeightIn;
+         if (nBlocks==0 || nTimeFirst > nTimeIn)
+             nTimeFirst = nTimeIn;
+         nBlocks++;
+         if (nHeightIn > nHeightLast)
+             nHeightLast = nHeightIn;
+         if (nTimeIn > nTimeLast)
+             nTimeLast = nTimeIn;
+     }
+};
+
 struct CDiskBlockPos
 {
     int nFile;

src/main.cpp

@@ -3706,7 +3706,7 @@ CBlockIndex * InsertBlockIndex(uint256 hash)
 bool static LoadBlockIndexDB()
 {
     const CChainParams& chainparams = Params();
-    if (!pblocktree->LoadBlockIndexGuts())
+    if (!pblocktree->LoadBlockIndexGuts(InsertBlockIndex))
         return false;
 
     boost::this_thread::interruption_point();

src/main.h

@@ -307,30 +307,6 @@ struct CNodeStateStats {
     std::vector<int> vHeightInFlight;
 };
 
-struct CDiskTxPos : public CDiskBlockPos
-{
-    unsigned int nTxOffset; // after header
-
-    ADD_SERIALIZE_METHODS;
-
-    template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
-        READWRITE(*(CDiskBlockPos*)this);
-        READWRITE(VARINT(nTxOffset));
-    }
-
-    CDiskTxPos(const CDiskBlockPos &blockIn, unsigned int nTxOffsetIn) : CDiskBlockPos(blockIn.nFile, blockIn.nPos), nTxOffset(nTxOffsetIn) {
-    }
-
-    CDiskTxPos() {
-        SetNull();
-    }
-
-    void SetNull() {
-        CDiskBlockPos::SetNull();
-        nTxOffset = 0;
-    }
-};
 
 
 /** 
@@ -469,61 +445,6 @@ bool DisconnectBlock(const CBlock& block, CValidationState& state, const CBlockI
 /** Check a block is completely valid from start to finish (only works on top of our current best block, with cs_main held) */
 bool TestBlockValidity(CValidationState& state, const CChainParams& chainparams, const CBlock& block, CBlockIndex* pindexPrev, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
 
-
-class CBlockFileInfo
-{
-public:
-    unsigned int nBlocks;      //!< number of blocks stored in file
-    unsigned int nSize;        //!< number of used bytes of block file
-    unsigned int nUndoSize;    //!< number of used bytes in the undo file
-    unsigned int nHeightFirst; //!< lowest height of block in file
-    unsigned int nHeightLast;  //!< highest height of block in file
-    uint64_t nTimeFirst;       //!< earliest time of block in file
-    uint64_t nTimeLast;        //!< latest time of block in file
-
-    ADD_SERIALIZE_METHODS;
-
-    template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
-        READWRITE(VARINT(nBlocks));
-        READWRITE(VARINT(nSize));
-        READWRITE(VARINT(nUndoSize));
-        READWRITE(VARINT(nHeightFirst));
-        READWRITE(VARINT(nHeightLast));
-        READWRITE(VARINT(nTimeFirst));
-        READWRITE(VARINT(nTimeLast));
-    }
-
-     void SetNull() {
-         nBlocks = 0;
-         nSize = 0;
-         nUndoSize = 0;
-         nHeightFirst = 0;
-         nHeightLast = 0;
-         nTimeFirst = 0;
-         nTimeLast = 0;
-     }
-
-     CBlockFileInfo() {
-         SetNull();
-     }
-
-     std::string ToString() const;
-
-     /** update statistics (does not update nSize) */
-     void AddBlock(unsigned int nHeightIn, uint64_t nTimeIn) {
-         if (nBlocks==0 || nHeightFirst > nHeightIn)
-             nHeightFirst = nHeightIn;
-         if (nBlocks==0 || nTimeFirst > nTimeIn)
-             nTimeFirst = nTimeIn;
-         nBlocks++;
-         if (nHeightIn > nHeightLast)
-             nHeightLast = nHeightIn;
-         if (nTimeIn > nTimeLast)
-             nTimeLast = nTimeIn;
-     }
-};
-
 /** RAII wrapper for VerifyDB: Verify consistency of the block and coin databases */
 class CVerifyDB {
 public:

src/txdb.cpp

@@ -5,10 +5,8 @@
 
 #include "txdb.h"
 
-#include "chain.h"
 #include "chainparams.h"
 #include "hash.h"
-#include "main.h"
 #include "pow.h"
 #include "uint256.h"
 
@@ -177,7 +175,7 @@ bool CBlockTreeDB::ReadFlag(const std::string &name, bool &fValue) {
     return true;
 }
 
-bool CBlockTreeDB::LoadBlockIndexGuts()
+bool CBlockTreeDB::LoadBlockIndexGuts(boost::function<CBlockIndex*(const uint256&)> insertBlockIndex)
 {
     boost::scoped_ptr<CDBIterator> pcursor(NewIterator());
 
@@ -191,8 +189,8 @@ bool CBlockTreeDB::LoadBlockIndexGuts()
             CDiskBlockIndex diskindex;
             if (pcursor->GetValue(diskindex)) {
                 // Construct block index object
-                CBlockIndex* pindexNew = InsertBlockIndex(diskindex.GetBlockHash());
-                pindexNew->pprev          = InsertBlockIndex(diskindex.hashPrev);
+                CBlockIndex* pindexNew = insertBlockIndex(diskindex.GetBlockHash());
+                pindexNew->pprev          = insertBlockIndex(diskindex.hashPrev);
                 pindexNew->nHeight        = diskindex.nHeight;
                 pindexNew->nFile          = diskindex.nFile;
                 pindexNew->nDataPos       = diskindex.nDataPos;

src/txdb.h

@@ -8,15 +8,17 @@
 
 #include "coins.h"
 #include "dbwrapper.h"
+#include "chain.h"
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
 
-class CBlockFileInfo;
+#include <boost/function.hpp>
+
 class CBlockIndex;
-struct CDiskTxPos;
+class CCoinsViewDBCursor;
 class uint256;
 
 //! -dbcache default (MiB)
@@ -26,7 +28,30 @@ static const int64_t nMaxDbCache = sizeof(void*) > 4 ? 16384 : 1024;
 //! min. -dbcache in (MiB)
 static const int64_t nMinDbCache = 4;
 
-class CCoinsViewDBCursor;
+struct CDiskTxPos : public CDiskBlockPos
+{
+    unsigned int nTxOffset; // after header
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+        READWRITE(*(CDiskBlockPos*)this);
+        READWRITE(VARINT(nTxOffset));
+    }
+
+    CDiskTxPos(const CDiskBlockPos &blockIn, unsigned int nTxOffsetIn) : CDiskBlockPos(blockIn.nFile, blockIn.nPos), nTxOffset(nTxOffsetIn) {
+    }
+
+    CDiskTxPos() {
+        SetNull();
+    }
+
+    void SetNull() {
+        CDiskBlockPos::SetNull();
+        nTxOffset = 0;
+    }
+};
 
 /** CCoinsView backed by the coin database (chainstate/) */
 class CCoinsViewDB : public CCoinsView
@@ -83,7 +108,7 @@ public:
     bool WriteTxIndex(const std::vector<std::pair<uint256, CDiskTxPos> > &list);
     bool WriteFlag(const std::string &name, bool fValue);
     bool ReadFlag(const std::string &name, bool &fValue);
-    bool LoadBlockIndexGuts();
+    bool LoadBlockIndexGuts(boost::function<CBlockIndex*(const uint256&)> insertBlockIndex);
 };
 
 #endif // BITCOIN_TXDB_H