1 files changed, 44 insertions, 7 deletions

diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index fb048311de..10979b43b0 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2018 The Bitcoin Core developers
+// Copyright (c) 2017-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -197,6 +197,7 @@ struct Sections {
         case RPCArg::Type::STR:
         case RPCArg::Type::NUM:
         case RPCArg::Type::AMOUNT:
+        case RPCArg::Type::RANGE:
         case RPCArg::Type::BOOL: {
             if (outer_type == OuterType::NAMED_ARG) return; // Nothing more to do for non-recursive types on first recursion
             auto left = indent;
@@ -311,6 +312,17 @@ std::string RPCExamples::ToDescriptionString() const
     return m_examples.empty() ? m_examples : "\nExamples:\n" + m_examples;
 }
 
+bool RPCHelpMan::IsValidNumArgs(size_t num_args) const
+{
+    size_t num_required_args = 0;
+    for (size_t n = m_args.size(); n > 0; --n) {
+        if (!m_args.at(n - 1).IsOptional()) {
+            num_required_args = n;
+            break;
+        }
+    }
+    return num_required_args <= num_args && num_args <= m_args.size();
+}
 std::string RPCHelpMan::ToString() const
 {
     std::string ret;
@@ -319,12 +331,7 @@ std::string RPCHelpMan::ToString() const
     ret += m_name;
     bool was_optional{false};
     for (const auto& arg : m_args) {
-        bool optional;
-        if (arg.m_fallback.which() == 1) {
-            optional = true;
-        } else {
-            optional = RPCArg::Optional::NO != boost::get<RPCArg::Optional>(arg.m_fallback);
-        }
+        const bool optional = arg.IsOptional();
         ret += " ";
         if (optional) {
             if (!was_optional) ret += "( ";
@@ -366,6 +373,15 @@ std::string RPCHelpMan::ToString() const
     return ret;
 }
 
+bool RPCArg::IsOptional() const
+{
+    if (m_fallback.which() == 1) {
+        return true;
+    } else {
+        return RPCArg::Optional::NO != boost::get<RPCArg::Optional>(m_fallback);
+    }
+}
+
 std::string RPCArg::ToDescriptionString() const
 {
     std::string ret;
@@ -387,6 +403,10 @@ std::string RPCArg::ToDescriptionString() const
             ret += "numeric or string";
             break;
         }
+        case Type::RANGE: {
+            ret += "numeric or array";
+            break;
+        }
         case Type::BOOL: {
             ret += "boolean";
             break;
@@ -446,6 +466,8 @@ std::string RPCArg::ToStringObj(const bool oneline) const
         return res + "\"hex\"";
     case Type::NUM:
         return res + "n";
+    case Type::RANGE:
+        return res + "n or [n,n]";
     case Type::AMOUNT:
         return res + "amount";
     case Type::BOOL:
@@ -476,6 +498,7 @@ std::string RPCArg::ToString(const bool oneline) const
         return "\"" + m_name + "\"";
     }
     case Type::NUM:
+    case Type::RANGE:
     case Type::AMOUNT:
     case Type::BOOL: {
         return m_name;
@@ -505,3 +528,17 @@ std::string RPCArg::ToString(const bool oneline) const
     }
     assert(false);
 }
+
+std::pair<int64_t, int64_t> ParseRange(const UniValue& value)
+{
+    if (value.isNum()) {
+        return {0, value.get_int64()};
+    }
+    if (value.isArray() && value.size() == 2 && value[0].isNum() && value[1].isNum()) {
+        int64_t low = value[0].get_int64();
+        int64_t high = value[1].get_int64();
+        if (low > high) throw JSONRPCError(RPC_INVALID_PARAMETER, "Range specified as [begin,end] must not have begin after end");
+        return {low, high};
+    }
+    throw JSONRPCError(RPC_INVALID_PARAMETER, "Range must be specified as end or as [begin,end]");
+}