From 7650449a6777710cf818d41862626164da0cd412 Mon Sep 17 00:00:00 2001
From: "Wladimir J. van der Laan" <laanwj@gmail.com>
Date: Sat, 18 Jul 2015 07:44:19 +0200
Subject: [PATCH] univalue: Avoid unnecessary roundtrip through double for
 numbers

JSON makes no distinction between numbers and reals, and our code
doesn't need to do so either.

This removes VREAL, as well as its specific post-processing in
`UniValue::write`. Non-monetary amounts do not need to be forcibly
formatted with 8 decimals, so the extra roundtrip was unnecessary
(and potentially loses precision).
---
 qa/rpc-tests/rest.py            | 3 ++-
 src/rpcserver.cpp               | 2 +-
 src/test/univalue_tests.cpp     | 6 +++---
 src/univalue/univalue.cpp       | 5 ++---
 src/univalue/univalue.h         | 3 +--
 src/univalue/univalue_write.cpp | 7 -------
 6 files changed, 9 insertions(+), 17 deletions(-)

diff --git a/qa/rpc-tests/rest.py b/qa/rpc-tests/rest.py
index 1a2d326cc..b0cde7268 100755
--- a/qa/rpc-tests/rest.py
+++ b/qa/rpc-tests/rest.py
@@ -14,6 +14,7 @@ from struct import *
 import binascii
 import json
 import StringIO
+import decimal
 
 try:
     import http.client as httplib
@@ -243,7 +244,7 @@ class RESTTest (BitcoinTestFramework):
         response_header_json = http_get_call(url.hostname, url.port, '/rest/headers/1/'+bb_hash+self.FORMAT_SEPARATOR+"json", "", True)
         assert_equal(response_header_json.status, 200)
         response_header_json_str = response_header_json.read()
-        json_obj = json.loads(response_header_json_str)
+        json_obj = json.loads(response_header_json_str, parse_float=decimal.Decimal)
         assert_equal(len(json_obj), 1) #ensure that there is one header in the json response
         assert_equal(json_obj[0]['hash'], bb_hash) #request/response hash should be the same
 
diff --git a/src/rpcserver.cpp b/src/rpcserver.cpp
index c5402e0df..201fc5eba 100644
--- a/src/rpcserver.cpp
+++ b/src/rpcserver.cpp
@@ -120,7 +120,7 @@ void RPCTypeCheckObj(const UniValue& o,
 
 CAmount AmountFromValue(const UniValue& value)
 {
-    if (!value.isReal() && !value.isNum())
+    if (!value.isNum())
         throw JSONRPCError(RPC_TYPE_ERROR, "Amount is not a number");
     CAmount amount;
     if (!ParseFixedPoint(value.getValStr(), 8, &amount))
diff --git a/src/test/univalue_tests.cpp b/src/test/univalue_tests.cpp
index 16bc8d30f..67cb9b962 100644
--- a/src/test/univalue_tests.cpp
+++ b/src/test/univalue_tests.cpp
@@ -49,7 +49,7 @@ BOOST_AUTO_TEST_CASE(univalue_constructor)
 
     double vd = -7.21;
     UniValue v7(vd);
-    BOOST_CHECK(v7.isReal());
+    BOOST_CHECK(v7.isNum());
     BOOST_CHECK_EQUAL(v7.getValStr(), "-7.21");
 
     string vs("yawn");
@@ -127,7 +127,7 @@ BOOST_AUTO_TEST_CASE(univalue_set)
     BOOST_CHECK_EQUAL(v.getValStr(), "zum");
 
     BOOST_CHECK(v.setFloat(-1.01));
-    BOOST_CHECK(v.isReal());
+    BOOST_CHECK(v.isNum());
     BOOST_CHECK_EQUAL(v.getValStr(), "-1.01");
 
     BOOST_CHECK(v.setInt((int)1023));
@@ -272,7 +272,7 @@ BOOST_AUTO_TEST_CASE(univalue_object)
     objTypes["distance"] = UniValue::VNUM;
     objTypes["time"] = UniValue::VNUM;
     objTypes["calories"] = UniValue::VNUM;
-    objTypes["temperature"] = UniValue::VREAL;
+    objTypes["temperature"] = UniValue::VNUM;
     objTypes["cat1"] = UniValue::VNUM;
     objTypes["cat2"] = UniValue::VNUM;
     BOOST_CHECK(obj.checkObject(objTypes));
diff --git a/src/univalue/univalue.cpp b/src/univalue/univalue.cpp
index 6920c44c9..1d49a2cfc 100644
--- a/src/univalue/univalue.cpp
+++ b/src/univalue/univalue.cpp
@@ -86,7 +86,7 @@ bool UniValue::setFloat(double val)
     oss << std::setprecision(16) << val;
 
     bool ret = setNumStr(oss.str());
-    typ = VREAL;
+    typ = VNUM;
     return ret;
 }
 
@@ -210,7 +210,6 @@ const char *uvTypeName(UniValue::VType t)
     case UniValue::VARR: return "array";
     case UniValue::VSTR: return "string";
     case UniValue::VNUM: return "number";
-    case UniValue::VREAL: return "number";
     }
 
     // not reached
@@ -280,7 +279,7 @@ int64_t UniValue::get_int64() const
 
 double UniValue::get_real() const
 {
-    if (typ != VREAL && typ != VNUM)
+    if (typ != VNUM)
         throw std::runtime_error("JSON value is not a number as expected");
     double retval;
     if (!ParseDouble(getValStr(), &retval))
diff --git a/src/univalue/univalue.h b/src/univalue/univalue.h
index 54239741e..4742b56f3 100644
--- a/src/univalue/univalue.h
+++ b/src/univalue/univalue.h
@@ -16,7 +16,7 @@
 
 class UniValue {
 public:
-    enum VType { VNULL, VOBJ, VARR, VSTR, VNUM, VREAL, VBOOL, };
+    enum VType { VNULL, VOBJ, VARR, VSTR, VNUM, VBOOL, };
 
     UniValue() { typ = VNULL; }
     UniValue(UniValue::VType initialType, const std::string& initialStr = "") {
@@ -78,7 +78,6 @@ public:
     bool isBool() const { return (typ == VBOOL); }
     bool isStr() const { return (typ == VSTR); }
     bool isNum() const { return (typ == VNUM); }
-    bool isReal() const { return (typ == VREAL); }
     bool isArray() const { return (typ == VARR); }
     bool isObject() const { return (typ == VOBJ); }
 
diff --git a/src/univalue/univalue_write.cpp b/src/univalue/univalue_write.cpp
index d360c253b..bce3997af 100644
--- a/src/univalue/univalue_write.cpp
+++ b/src/univalue/univalue_write.cpp
@@ -61,13 +61,6 @@ string UniValue::write(unsigned int prettyIndent,
     case VSTR:
         s += "\"" + json_escape(val) + "\"";
         break;
-    case VREAL:
-        {
-            std::stringstream ss;
-            ss << std::showpoint << std::fixed << std::setprecision(8) << get_real();
-            s += ss.str();
-        }
-        break;
     case VNUM:
         s += val;
         break;