From 7708968cff5596910f42f76aa8f2abe0bda2024f Mon Sep 17 00:00:00 2001
From: JoelKatz <DavidJoelSchwartz@GMail.com>
Date: Sun, 2 Dec 2012 15:23:17 -0800
Subject: [PATCH] Stuctures for feature enabling.

---
 src/cpp/ripple/Ledger.cpp             | 7 +++++++
 src/cpp/ripple/Ledger.h               | 2 ++
 src/cpp/ripple/LedgerFormats.cpp      | 4 ++++
 src/cpp/ripple/LedgerFormats.h        | 2 ++
 src/cpp/ripple/SerializeProto.h       | 2 ++
 src/cpp/ripple/TransactionFormats.cpp | 4 ++++
 src/cpp/ripple/TransactionFormats.h   | 2 ++
 7 files changed, 23 insertions(+)

diff --git a/src/cpp/ripple/Ledger.cpp b/src/cpp/ripple/Ledger.cpp
index a498fee1c..8e3c47c6b 100644
--- a/src/cpp/ripple/Ledger.cpp
+++ b/src/cpp/ripple/Ledger.cpp
@@ -918,6 +918,13 @@ uint256 Ledger::getAccountRootIndex(const uint160& uAccountID)
 	return s.getSHA512Half();
 }
 
+uint256 Ledger::getLedgerFeatureIndex()
+{ // get the index of the node that holds the last 256 ledgers
+	Serializer s(2);
+	s.add16(spaceFeature);
+	return s.getSHA512Half();
+}
+
 uint256 Ledger::getLedgerHashIndex()
 { // get the index of the node that holds the last 256 ledgers
 	Serializer s(2);
diff --git a/src/cpp/ripple/Ledger.h b/src/cpp/ripple/Ledger.h
index 23292254b..a9b560571 100644
--- a/src/cpp/ripple/Ledger.h
+++ b/src/cpp/ripple/Ledger.h
@@ -193,6 +193,8 @@ public:
 	static int getLedgerHashOffset(uint32 desiredLedgerIndex);
 	static int getLedgerHashOffset(uint32 desiredLedgerIndex, uint32 currentLedgerIndex);
 
+	static uint256 getLedgerFeatureIndex();
+
 	// index calculation functions
 	static uint256 getAccountRootIndex(const uint160& uAccountID);
 
diff --git a/src/cpp/ripple/LedgerFormats.cpp b/src/cpp/ripple/LedgerFormats.cpp
index 98c70857a..e727afc58 100644
--- a/src/cpp/ripple/LedgerFormats.cpp
+++ b/src/cpp/ripple/LedgerFormats.cpp
@@ -98,6 +98,10 @@ static bool LEFInit()
 		<< SOElement(sfHashes,				SOE_REQUIRED)
 		;
 
+	DECLARE_LEF(EnabledFeatures, ltFEATURES)
+		<< SOElement(sfEnabledFeatures, SOE_REQUIRED)
+		;
+
 		return true;
 }
 
diff --git a/src/cpp/ripple/LedgerFormats.h b/src/cpp/ripple/LedgerFormats.h
index 2c3f3cd5a..5f16c63f4 100644
--- a/src/cpp/ripple/LedgerFormats.h
+++ b/src/cpp/ripple/LedgerFormats.h
@@ -15,6 +15,7 @@ enum LedgerEntryType
 	ltOFFER				= 'o',
 	ltCONTRACT			= 'c',
 	ltLEDGER_HASHES		= 'h',
+	ltFEATURES			= 'f',
 };
 
 // Used as a prefix for computing ledger indexes (keys).
@@ -30,6 +31,7 @@ enum LedgerNameSpace
 	spaceBookDir		= 'B',	// Directory of order books.
 	spaceContract		= 'c',
 	spaceSkipList		= 's',
+	spaceFeature		= 'f',
 };
 
 enum LedgerSpecificFlags
diff --git a/src/cpp/ripple/SerializeProto.h b/src/cpp/ripple/SerializeProto.h
index a10ab314b..dc736adfc 100644
--- a/src/cpp/ripple/SerializeProto.h
+++ b/src/cpp/ripple/SerializeProto.h
@@ -84,6 +84,7 @@
 	FIELD(BookDirectory,		HASH256, 16)
 	FIELD(InvoiceID,			HASH256, 17)
 	FIELD(Nickname,				HASH256, 18)
+	FIELD(Feature,				HASH256, 19)
 
 	// 160-bit (common)
 	FIELD(TakerPaysCurrency,	HASH160, 1)
@@ -154,5 +155,6 @@
 	FIELD(Necessary,			ARRAY, 6)
 	FIELD(Sufficient,			ARRAY, 7)
 	FIELD(AffectedNodes,		ARRAY, 8)
+	FIELD(EnabledFeatures,		ARRAY, 9)
 
 // vim:ts=4
diff --git a/src/cpp/ripple/TransactionFormats.cpp b/src/cpp/ripple/TransactionFormats.cpp
index f54cb1868..5f0feb40e 100644
--- a/src/cpp/ripple/TransactionFormats.cpp
+++ b/src/cpp/ripple/TransactionFormats.cpp
@@ -71,6 +71,10 @@ static bool TFInit()
 		<< SOElement(sfTarget,			SOE_REQUIRED)
 		;
 
+	DECLARE_TF(EnableFeature, ttFEATURE)
+		<< SOElement(sfFeature,			SOE_REQUIRED)
+		;
+
 	return true;
 }
 
diff --git a/src/cpp/ripple/TransactionFormats.h b/src/cpp/ripple/TransactionFormats.h
index 091978ba1..6f399c591 100644
--- a/src/cpp/ripple/TransactionFormats.h
+++ b/src/cpp/ripple/TransactionFormats.h
@@ -19,6 +19,8 @@ enum TransactionType
 	ttCONTRACT_REMOVE	= 10,  // can we use the same msg as offer cancel
 
 	ttTRUST_SET		= 20,
+
+	ttFEATURE		= 100,
 };
 
 class TransactionFormat