Merge #11687: External wallet files

be8ab7d08 Create new wallet databases as directories rather than files (Russell Yanofsky)
26c06f24e Allow wallet files not in -walletdir directory (Russell Yanofsky)
d8a99f65e Allow wallet files in multiple directories (Russell Yanofsky)

Pull request description:

  This change consists of three commits:

  * The first commit is a pure refactoring that removes the restriction that two wallets can only be opened at the same time if they are contained in the same directory.
  * The second commit removes the restriction that `-wallet` filenames can only refer to files in the `-walletdir` directory.
  * The third commit makes second commit a little safer by changing bitcoin to create wallet databases as directories rather than files, so they can be safely backed up.

  All three commits should be straightforward:

  *  The first commit adds around 20 lines of new code and then updates a bunch of function signatures (generally updating them to take plain fs::path parameters, instead of combinations of strings, fs::paths, and objects like CDBEnv and CWalletDBWrapper).
  * The second commit removes two `-wallet` filename checks and adds some test cases to the multiwallet unit test.
  * The third commit just changes the mapping from specified wallet paths to bdb environment & data paths.

    ---

  **Note:** For anybody looking at this PR for the first time, I think you can skip the comments before _20 Nov_ and start reading at https://github.com/bitcoin/bitcoin/pull/11687#issuecomment-345625565. Comments before  _20 Nov_ were about an earlier version of the PR that didn't include the third commit, and then confusion from not seeing the first commit.

Tree-SHA512: 00bbb120fe0df847cf57014f75f1f7f1f58b0b62fa0b3adab4560163ebdfe06ccdfff33b4231693f03c5dc23601cb41954a07bcea9a4919c8d42f7d62bcf6024

1 files changed, 13 insertions, 19 deletions

diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 4db45f16ef..3e2d1794d8 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -15,6 +15,7 @@
 #include <validationinterface.h>
 #include <script/ismine.h>
 #include <script/sign.h>
+#include <util.h>
 #include <wallet/crypter.h>
 #include <wallet/walletdb.h>
 #include <wallet/rpcwallet.h>
@@ -67,8 +68,6 @@ static const bool DEFAULT_WALLET_RBF = false;
 static const bool DEFAULT_WALLETBROADCAST = true;
 static const bool DEFAULT_DISABLE_WALLET = false;
 
-extern const char * DEFAULT_WALLET_DAT;
-
 static const int64_t TIMESTAMP_MIN = 0;
 
 class CBlockIndex;
@@ -737,6 +736,14 @@ private:
      */
     bool AddWatchOnly(const CScript& dest) override;
 
+    /**
+     * Wallet filename from wallet=<path> command line or config option.
+     * Used in debug logs and to send RPCs to the right wallet instance when
+     * more than one wallet is loaded.
+     */
+    std::string m_name;
+
+    /** Internal database handle. */
     std::unique_ptr<CWalletDBWrapper> dbw;
 
     /**
@@ -768,14 +775,7 @@ public:
 
     /** Get a name for this wallet for logging/debugging purposes.
      */
-    std::string GetName() const
-    {
-        if (dbw) {
-            return dbw->GetName();
-        } else {
-            return "dummy";
-        }
-    }
+    const std::string& GetName() const { return m_name; }
 
     void LoadKeyPool(int64_t nIndex, const CKeyPool &keypool);
 
@@ -789,14 +789,8 @@ public:
     MasterKeyMap mapMasterKeys;
     unsigned int nMasterKeyMaxID;
 
-    // Create wallet with dummy database handle
-    CWallet(): dbw(new CWalletDBWrapper())
-    {
-        SetNull();
-    }
-
-    // Create wallet with passed-in database handle
-    explicit CWallet(std::unique_ptr<CWalletDBWrapper> dbw_in) : dbw(std::move(dbw_in))
+    /** Construct wallet with specified name and database implementation. */
+    CWallet(std::string name, std::unique_ptr<CWalletDBWrapper> dbw) : m_name(std::move(name)), dbw(std::move(dbw))
     {
         SetNull();
     }
@@ -1116,7 +1110,7 @@ public:
     bool MarkReplaced(const uint256& originalHash, const uint256& newHash);
 
     /* Initializes the wallet, returns a new CWallet instance or a null pointer in case of an error */
-    static CWallet* CreateWalletFromFile(const std::string walletFile);
+    static CWallet* CreateWalletFromFile(const std::string& name, const fs::path& path);
 
     /**
      * Wallet post-init setup