[build] Add several util units

Adds the following util units and adds them to libbitcoin_util:

- `util/url.cpp` takes `urlDecode` from `httpserver.cpp`
- `util/error.cpp` takes `TransactionErrorString` from
  `node/transaction.cpp` and `AmountHighWarn` and `AmountErrMsg` from
  `ui_interface.cpp`
- `util/fees.cpp` takes `StringForFeeReason` and `FeeModeFromString` from `policy/fees.cpp`
- `util/rbf.cpp` takes `SignalsOptInRBF` from `policy/rbf.cpp`
- 'util/validation.cpp` takes `FormatStateMessage` and `strMessageMagic` from 'validation.cpp`

Author: jnewbery

src/Makefile.am

@@ -203,10 +203,15 @@ BITCOIN_CORE_H = \
   undo.h \
   util/bip32.h \
   util/bytevectorhash.h \
+  util/error.h \
+  util/fees.h \
   util/system.h \
   util/memory.h \
   util/moneystr.h \
+  util/rbf.h \
   util/time.h \
+  util/url.h \
+  util/validation.h \
   validation.h \
   validationinterface.h \
   versionbits.h \
@@ -471,10 +476,15 @@ libbitcoin_util_a_SOURCES = \
   threadinterrupt.cpp \
   util/bip32.cpp \
   util/bytevectorhash.cpp \
+  util/error.cpp \
+  util/fees.cpp \
   util/system.cpp \
   util/moneystr.cpp \
+  util/rbf.cpp \
   util/strencodings.cpp \
   util/time.cpp \
+  util/url.cpp \
+  util/validation.cpp \
   $(BITCOIN_CORE_H)
 
 if GLIBC_BACK_COMPAT

src/bitcoin-tx.cpp

@@ -18,6 +18,7 @@
 #include <script/script.h>
 #include <script/sign.h>
 #include <univalue.h>
+#include <util/rbf.h>
 #include <util/system.h>
 #include <util/moneystr.h>
 #include <util/strencodings.h>

src/httpserver.cpp

@@ -655,15 +655,3 @@ void UnregisterHTTPHandler(const std::string &prefix, bool exactMatch)
         pathHandlers.erase(i);
     }
 }
-
-std::string urlDecode(const std::string &urlEncoded) {
-    std::string res;
-    if (!urlEncoded.empty()) {
-        char *decoded = evhttp_uridecode(urlEncoded.c_str(), false, nullptr);
-        if (decoded) {
-            res = std::string(decoded);
-            free(decoded);
-        }
-    }
-    return res;
-}

src/httpserver.h

@@ -148,6 +148,4 @@ class HTTPEvent
     struct event* ev;
 };
 
-std::string urlDecode(const std::string &urlEncoded);
-
 #endif // BITCOIN_HTTPSERVER_H

src/init.cpp

@@ -47,6 +47,7 @@
 #include <ui_interface.h>
 #include <util/system.h>
 #include <util/moneystr.h>
+#include <util/validation.h>
 #include <validationinterface.h>
 #include <warnings.h>
 #include <walletinitinterface.h>

src/miner.cpp

@@ -23,6 +23,7 @@
 #include <timedata.h>
 #include <util/moneystr.h>
 #include <util/system.h>
+#include <util/validation.h>
 #include <validationinterface.h>
 
 #include <algorithm>

src/net_processing.cpp

@@ -29,6 +29,7 @@
 #include <util/system.h>
 #include <util/moneystr.h>
 #include <util/strencodings.h>
+#include <util/validation.h>
 
 #include <memory>
 

src/node/transaction.cpp

@@ -6,38 +6,13 @@
 #include <consensus/validation.h>
 #include <net.h>
 #include <txmempool.h>
+#include <util/validation.h>
 #include <validation.h>
 #include <validationinterface.h>
 #include <node/transaction.h>
 
 #include <future>
 
-std::string TransactionErrorString(const TransactionError err)
-{
-    switch (err) {
-        case TransactionError::OK:
-            return "No error";
-        case TransactionError::MISSING_INPUTS:
-            return "Missing inputs";
-        case TransactionError::ALREADY_IN_CHAIN:
-            return "Transaction already in block chain";
-        case TransactionError::P2P_DISABLED:
-            return "Peer-to-peer functionality missing or disabled";
-        case TransactionError::MEMPOOL_REJECTED:
-            return "Transaction rejected by AcceptToMemoryPool";
-        case TransactionError::MEMPOOL_ERROR:
-            return "AcceptToMemoryPool failed";
-        case TransactionError::INVALID_PSBT:
-            return "PSBT is not sane";
-        case TransactionError::PSBT_MISMATCH:
-            return "PSBTs not compatible (different transactions)";
-        case TransactionError::SIGHASH_MISMATCH:
-            return "Specified sighash value does not match existing value";
-        // no default case, so the compiler can warn about missing cases
-    }
-    assert(false);
-}
-
 TransactionError BroadcastTransaction(const CTransactionRef tx, uint256& hashTx, std::string& err_string, const CAmount& highfee)
 {
     std::promise<void> promise;

src/node/transaction.h

@@ -8,20 +8,7 @@
 #include <attributes.h>
 #include <primitives/transaction.h>
 #include <uint256.h>
-
-enum class TransactionError {
-    OK, //!< No error
-    MISSING_INPUTS,
-    ALREADY_IN_CHAIN,
-    P2P_DISABLED,
-    MEMPOOL_REJECTED,
-    MEMPOOL_ERROR,
-    INVALID_PSBT,
-    PSBT_MISMATCH,
-    SIGHASH_MISMATCH,
-};
-
-std::string TransactionErrorString(const TransactionError error);
+#include <util/error.h>
 
 /**
  * Broadcast a transaction

src/policy/fees.cpp

@@ -27,40 +27,6 @@ std::string StringForFeeEstimateHorizon(FeeEstimateHorizon horizon) {
     return horizon_string->second;
 }
 
-std::string StringForFeeReason(FeeReason reason) {
-    static const std::map<FeeReason, std::string> fee_reason_strings = {
-        {FeeReason::NONE, "None"},
-        {FeeReason::HALF_ESTIMATE, "Half Target 60% Threshold"},
-        {FeeReason::FULL_ESTIMATE, "Target 85% Threshold"},
-        {FeeReason::DOUBLE_ESTIMATE, "Double Target 95% Threshold"},
-        {FeeReason::CONSERVATIVE, "Conservative Double Target longer horizon"},
-        {FeeReason::MEMPOOL_MIN, "Mempool Min Fee"},
-        {FeeReason::PAYTXFEE, "PayTxFee set"},
-        {FeeReason::FALLBACK, "Fallback fee"},
-        {FeeReason::REQUIRED, "Minimum Required Fee"},
-        {FeeReason::MAXTXFEE, "MaxTxFee limit"}
-    };
-    auto reason_string = fee_reason_strings.find(reason);
-
-    if (reason_string == fee_reason_strings.end()) return "Unknown";
-
-    return reason_string->second;
-}
-
-bool FeeModeFromString(const std::string& mode_string, FeeEstimateMode& fee_estimate_mode) {
-    static const std::map<std::string, FeeEstimateMode> fee_modes = {
-        {"UNSET", FeeEstimateMode::UNSET},
-        {"ECONOMICAL", FeeEstimateMode::ECONOMICAL},
-        {"CONSERVATIVE", FeeEstimateMode::CONSERVATIVE},
-    };
-    auto mode = fee_modes.find(mode_string);
-
-    if (mode == fee_modes.end()) return false;
-
-    fee_estimate_mode = mode->second;
-    return true;
-}
-
 /**
  * We will instantiate an instance of this class to track transactions that were
  * included in a block. We will lump transactions into a bucket according to their