From 34935be1f41e5345f585303f40f9fb0255587bfa Mon Sep 17 00:00:00 2001
From: JoelKatz <DavidJoelSchwartz@GMail.com>
Date: Wed, 11 Jul 2012 18:25:47 -0700
Subject: [PATCH] More of the close time resolution code.

---
 src/LedgerTiming.cpp | 26 ++++++++++++++++++++++++++
 src/LedgerTiming.h   | 13 +++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/src/LedgerTiming.cpp b/src/LedgerTiming.cpp
index b6fb422379..b7a3b77344 100644
--- a/src/LedgerTiming.cpp
+++ b/src/LedgerTiming.cpp
@@ -1,6 +1,10 @@
 
 #include "LedgerTiming.h"
 
+#include <cassert>
+
+// NOTE: Last time must be repeated
+int ContinuousLedgerTiming::LedgerTimeResolution[] = { 10, 20, 30, 60, 90, 120, 120 };
 
 // Called when a ledger is open and no close is in progress -- when a transaction is received and no close
 // is in process, or when a close completes. Returns the number of seconds the ledger should be be open.
@@ -62,3 +66,25 @@ bool ContinuousLedgerTiming::haveConsensus(
 	// no consensus yet
 	return false;
 }
+
+int ContinuousLedgerTiming::getNextLedgerTimeResolution(int previousResolution, bool previousAgree, int ledgerSeq)
+{
+	assert(ledgerSeq);
+	if ((!previousAgree) && ((ledgerSeq % LEDGER_RES_DECREASE) == 0))
+	{ // reduce resolution
+		int i = 0;
+		while (LedgerTimeResolution[i] != previousResolution)
+			++i;
+		return LedgerTimeResolution[(i != 0) ? (i - 1) : i];
+	}
+
+	if ((previousAgree) && ((ledgerSeq % LEDGER_RES_INCREASE) == 0))
+	{ // increase resolution
+		int i = 0;
+		while (LedgerTimeResolution[i] != previousResolution)
+			++i;
+		return LedgerTimeResolution[i + 1];
+	}
+
+	return previousResolution;
+}
diff --git a/src/LedgerTiming.h b/src/LedgerTiming.h
index de463a085e..2b580a6057 100644
--- a/src/LedgerTiming.h
+++ b/src/LedgerTiming.h
@@ -10,6 +10,15 @@
 // The number of seconds we wait minimum to ensure participation
 #	define LEDGER_MIN_CONSENSUS		2
 
+// Initial resolution of ledger close time
+#	define LEDGER_TIME_ACCURACY		30
+
+// How often to increase resolution
+#	define LEDGER_RES_INCREASE		8
+
+// How often to decrease resolution
+#	define LEDGER_RES_DECREASE		1
+
 // Avalanche tuning
 #define AV_INIT_CONSENSUS_PCT		50	// percentage of nodes on our UNL that must vote yes
 
@@ -19,10 +28,13 @@
 #define AV_LATE_CONSENSUS_TIME		85	// percentage of previous close time before we advance
 #define AV_LATE_CONSENSUS_PCT		70	// percentage of nodes that most vote yes after advancing
 
+
 class ContinuousLedgerTiming
 {
 public:
 
+	static int LedgerTimeResolution[];
+
 	// Returns the number of seconds the ledger was or should be open
 	// Call when a consensus is reached and when any transaction is relayed to be added
 	static int shouldClose(
@@ -35,6 +47,7 @@ public:
 		int currentAgree,			int currentClosed,
 		int previousAgreeTime,		int currentAgreeTime);
 
+	static int getNextLedgerTimeResolution(int previousResolution, bool previousAgree, int ledgerSeq);
 };
 
 #endif