Merge bitcoin#19734: Move CDiskTxPos to its own file

7668db3 Move only: Move CDiskTxPos to its own file (Marcin Jachymiak)

Pull request description:

  Moves `CDiskTxPos` it its own file so it can be used without the `txindex.h` include elsewhere. Originally part of bitcoin#14053.

ACKs for top commit:
  jnewbery:
    utACK 7668db3
  promag:
    ACK 7668db3.

Tree-SHA512: b108e980ad04e43d1323410c3683a82bed70aee7795f5d8a2afbaf32a07ba598571f00b047bdde15048124b17178bcbd10654c48461beac988e9643cb2df664c

src/Makefile.am

@@ -178,6 +178,7 @@ BITCOIN_CORE_H = \
   httpserver.h \
   index/base.h \
   index/blockfilterindex.h \
+  index/disktxpos.h \
   index/txindex.h \
   indirectmap.h \
   init.h \

src/index/disktxpos.h

@@ -0,0 +1,37 @@
+// Copyright (c) 2019 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_INDEX_DISKTXPOS_H
+#define BITCOIN_INDEX_DISKTXPOS_H
+
+#include <chain.h>
+#include <flatfile.h>
+#include <primitives/block.h>
+#include <primitives/transaction.h>
+
+struct CDiskTxPos : public FlatFilePos
+{
+    unsigned int nTxOffset; // after header
+
+    SERIALIZE_METHODS(CDiskTxPos, obj)
+    {
+        READWRITEAS(FlatFilePos, obj);
+        READWRITE(VARINT(obj.nTxOffset));
+    }
+
+    CDiskTxPos(const FlatFilePos &blockIn, unsigned int nTxOffsetIn) : FlatFilePos(blockIn.nFile, blockIn.nPos), nTxOffset(nTxOffsetIn) {
+    }
+
+    CDiskTxPos() {
+        SetNull();
+    }
+
+    void SetNull() {
+        FlatFilePos::SetNull();
+        nTxOffset = 0;
+    }
+};
+
+
+#endif // BITCOIN_INDEX_DISKTXPOS_H

src/index/txindex.cpp

@@ -2,6 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <index/disktxpos.h>
 #include <index/txindex.h>
 #include <init.h>
 #include <ui_interface.h>
@@ -16,29 +17,6 @@ constexpr char DB_TXINDEX_BLOCK = 'T';
 
 std::unique_ptr<TxIndex> g_txindex;
 
-struct CDiskTxPos : public FlatFilePos
-{
-    unsigned int nTxOffset; // after header
-
-    SERIALIZE_METHODS(CDiskTxPos, obj)
-    {
-        READWRITEAS(FlatFilePos, obj);
-        READWRITE(VARINT(obj.nTxOffset));
-    }
-
-    CDiskTxPos(const FlatFilePos &blockIn, unsigned int nTxOffsetIn) : FlatFilePos(blockIn.nFile, blockIn.nPos), nTxOffset(nTxOffsetIn) {
-    }
-
-    CDiskTxPos() {
-        SetNull();
-    }
-
-    void SetNull() {
-        FlatFilePos::SetNull();
-        nTxOffset = 0;
-    }
-};
-
 /**
  * Access to the txindex database (indexes/txindex/)
  *