Merge bitcoin#13961: util: Replace boost::signals2 with std::function

ddddce0 util: Replace boost::signals2 with std::function (MarcoFalke)

Pull request description:

  This removes the `#include <boost/signals2/signal.hpp>` from `util.h` (hopefully speeding up the build time and reducing the memory usage further after  bitcoin#13634)

  The whole translation interface is replaced by a function `G_TRANSLATION_FUN` that is set to nullptr in units that don't need translation. (Thus only set in the gui)

Tree-SHA512: 087c717358bbed8bdb409463e225239d667f1ced381abb10e7cd31a41dcdd2cebe20b43c2ee86f0f8e55d53301f75e963f07421a99a7ff4c0cad2c6a375c5ab1

# Conflicts:
#	src/bench/bench_dash.cpp
#	src/qt/dash.cpp
#	src/qt/splashscreen.cpp
#	src/qt/transactiontablemodel.cpp
#	src/test/test_dash.cpp
#	src/util/system.h
#	src/wallet/coinselection.cpp

src/bench/bench_dash.cpp

@@ -16,6 +16,8 @@
 
 #include <bls/bls.h>
 
+const std::function<std::string(const char*)> G_TRANSLATION_FUN = nullptr;
+
 static const int64_t DEFAULT_BENCH_EVALUATIONS = 5;
 static const char* DEFAULT_BENCH_FILTER = ".*";
 static const char* DEFAULT_BENCH_SCALING = "1.0";

src/dash-cli.cpp

@@ -26,6 +26,8 @@
 
 #include <univalue.h>
 
+const std::function<std::string(const char*)> G_TRANSLATION_FUN = nullptr;
+
 static const char DEFAULT_RPCCONNECT[] = "127.0.0.1";
 static const int DEFAULT_HTTP_CLIENT_TIMEOUT=900;
 static const bool DEFAULT_NAMED=false;

src/dash-tx.cpp

@@ -32,6 +32,8 @@ static bool fCreateBlank;
 static std::map<std::string,UniValue> registers;
 static const int CONTINUE_EXECUTION=-1;
 
+const std::function<std::string(const char*)> G_TRANSLATION_FUN = nullptr;
+
 static void SetupBitcoinTxArgs()
 {
     gArgs.AddArg("-?", "This help message", false, OptionsCategory::OPTIONS);

src/dashd.cpp

@@ -25,6 +25,8 @@
 
 #include <stdio.h>
 
+const std::function<std::string(const char*)> G_TRANSLATION_FUN = nullptr;
+
 /* Introduction text for doxygen: */
 
 /*! \mainpage Developer documentation

src/noui.cpp

@@ -13,6 +13,8 @@
 #include <stdint.h>
 #include <string>
 
+#include <boost/signals2/connection.hpp>
+
 static bool noui_ThreadSafeMessageBox(const std::string& message, const std::string& caption, unsigned int style)
 {
     bool fSecure = style & CClientUIInterface::SECURE;

src/qt/bitcoingui.cpp

@@ -61,6 +61,8 @@
 #include <QUrlQuery>
 #include <QVBoxLayout>
 
+#include <boost/bind.hpp>
+
 const std::string BitcoinGUI::DEFAULT_UIPLATFORM =
 #if defined(Q_OS_MAC)
         "macosx"

src/qt/dash.cpp

@@ -76,13 +76,10 @@ static void InitMessage(const std::string &message)
     LogPrintf("init message: %s\n", message);
 }
 
-/*
-   Translate string to current locale using Qt.
- */
-static std::string Translate(const char* psz)
-{
+/** Translate string to current locale using Qt. */
+const std::function<std::string(const char*)> G_TRANSLATION_FUN = [](const char* psz) {
     return QCoreApplication::translate("dash-core", psz).toStdString();
-}
+};
 
 static QString GetLangTerritory()
 {
@@ -628,7 +625,6 @@ int main(int argc, char *argv[])
     // Now that QSettings are accessible, initialize translations
     QTranslator qtTranslatorBase, qtTranslator, translatorBase, translator;
     initTranslations(qtTranslatorBase, qtTranslator, translatorBase, translator);
-    translationInterface.Translate.connect(Translate);
 
     if (gArgs.IsArgSet("-printcrashinfo")) {
         auto crashInfo = GetCrashInfoStrFromSerializedStr(gArgs.GetArg("-printcrashinfo", ""));

src/qt/splashscreen.cpp

@@ -18,15 +18,17 @@
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
 #include <interfaces/wallet.h>
-#include <util/system.h>
 #include <ui_interface.h>
+#include <util/system.h>
 #include <version.h>
 
 #include <QApplication>
 #include <QCloseEvent>
 #include <QDesktopWidget>
 #include <QPainter>
 
+#include <boost/bind.hpp>
+
 SplashScreen::SplashScreen(interfaces::Node& node, Qt::WindowFlags f, const NetworkStyle *networkStyle) :
     QWidget(0, f), curAlignment(0), m_node(node)
 {

src/qt/transactiontablemodel.cpp

@@ -13,17 +13,19 @@
 #include <core_io.h>
 #include <interfaces/handler.h>
 #include <interfaces/node.h>
-#include <validation.h>
 #include <sync.h>
 #include <uint256.h>
 #include <util/system.h>
+#include <validation.h>
 
 #include <QColor>
 #include <QDateTime>
 #include <QDebug>
 #include <QIcon>
 #include <QList>
 
+#include <boost/bind.hpp>
+
 // Amount column is right-aligned it contains numbers
 static int column_alignments[] = {
         Qt::AlignLeft|Qt::AlignVCenter, /* status */

src/test/test_dash.cpp

@@ -9,15 +9,16 @@
 #include <consensus/validation.h>
 #include <crypto/sha256.h>
 #include <index/txindex.h>
-#include <validation.h>
 #include <miner.h>
 #include <net_processing.h>
 #include <pow.h>
-#include <ui_interface.h>
-#include <streams.h>
-#include <rpc/server.h>
 #include <rpc/register.h>
+#include <rpc/server.h>
 #include <script/sigcache.h>
+#include <streams.h>
+#include <ui_interface.h>
+#include <validation.h>
+
 #include <util/validation.h>
 
 #include <coinjoin/coinjoin.h>
@@ -26,6 +27,8 @@
 #include <evo/cbtx.h>
 #include <llmq/quorums_init.h>
 
+const std::function<std::string(const char*)> G_TRANSLATION_FUN = nullptr;
+
 void CConnmanTest::AddNode(CNode& node)
 {
     LOCK(g_connman->cs_vNodes);

src/test/test_dash_fuzzy.cpp

@@ -6,20 +6,20 @@
 #include <config/dash-config.h>
 #endif
 
-#include <consensus/merkle.h>
-#include <primitives/block.h>
-#include <script/script.h>
 #include <addrman.h>
+#include <blockencodings.h>
 #include <chain.h>
 #include <coins.h>
 #include <compressor.h>
+#include <consensus/merkle.h>
 #include <net.h>
+#include <primitives/block.h>
 #include <protocol.h>
+#include <pubkey.h>
+#include <script/script.h>
 #include <streams.h>
 #include <undo.h>
 #include <version.h>
-#include <pubkey.h>
-#include <blockencodings.h>
 
 #include <stdint.h>
 #include <unistd.h>
@@ -28,6 +28,8 @@
 #include <memory>
 #include <vector>
 
+const std::function<std::string(const char*)> G_TRANSLATION_FUN = nullptr;
+
 enum TEST_ID {
     CBLOCK_DESERIALIZE=0,
     CTRANSACTION_DESERIALIZE,

src/util/system.cpp

@@ -99,8 +99,6 @@ const char * const BITCOIN_PID_FILENAME = "dashd.pid";
 
 ArgsManager gArgs;
 
-CTranslationInterface translationInterface;
-
 /** Init OpenSSL library multithreading support */
 static std::unique_ptr<CCriticalSection[]> ppmutexOpenSSL;
 void locking_callback(int mode, int i, const char* file, int line) NO_THREAD_SAFETY_ANALYSIS

src/util/system.h

@@ -22,8 +22,8 @@
 #include <sync.h>
 #include <util/threadnames.h>
 #include <tinyformat.h>
-#include <util/time.h>
 #include <util/memory.h>
+#include <util/time.h>
 #include <amount.h>
 
 #include <atomic>
@@ -36,7 +36,6 @@
 #include <unordered_set>
 #include <vector>
 
-#include <boost/signals2/signal.hpp>
 #include <boost/thread/condition_variable.hpp> // for boost::thread_interrupted
 
 // Debugging macros
@@ -59,27 +58,19 @@ extern int nWalletBackups;
 // Application startup time (used for uptime calculation)
 int64_t GetStartupTime();
 
-/** Signals for translation. */
-class CTranslationInterface
-{
-public:
-    /** Translate a message to the native language of the user. */
-    boost::signals2::signal<std::string (const char* psz)> Translate;
-};
-
-extern CTranslationInterface translationInterface;
-
 extern const char * const BITCOIN_CONF_FILENAME;
 extern const char * const BITCOIN_PID_FILENAME;
 
+/** Translate a message to the native language of the user. */
+const extern std::function<std::string(const char*)> G_TRANSLATION_FUN;
+
 /**
- * Translation function: Call Translate signal on UI interface, which returns a boost::optional result.
- * If no translation slot is registered, nothing is returned, and simply return the input.
+ * Translation function.
+ * If no translation function is set, simply return the input.
  */
 inline std::string _(const char* psz)
 {
-    boost::optional<std::string> rv = translationInterface.Translate(psz);
-    return rv ? (*rv) : psz;
+    return G_TRANSLATION_FUN ? (G_TRANSLATION_FUN)(psz) : psz;
 }
 
 void SetupEnvironment();

src/wallet/coinselection.cpp

@@ -3,6 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <wallet/coinselection.h>
+
 #include <util/system.h>
 #include <util/moneystr.h>