From f59e2408f94f01cf1fb9d6cf05e8d40c6304fc0c Mon Sep 17 00:00:00 2001
From: nicksavers <nicksavers@gmail.com>
Date: Sat, 7 Jun 2014 17:27:38 +0200
Subject: [PATCH] Remove call to Blockchain DB from Genesis and fix default
 calc values

---
 .../main/java/org/ethereum/core/Block.java    |  6 +++---
 .../main/java/org/ethereum/core/Genesis.java  | 21 +++++++++++++++++--
 .../java/org/ethereum/core/BlockTest.java     |  6 ++++--
 3 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/ethereumj-core/src/main/java/org/ethereum/core/Block.java b/ethereumj-core/src/main/java/org/ethereum/core/Block.java
index f6b452a0..fff0fe6a 100644
--- a/ethereumj-core/src/main/java/org/ethereum/core/Block.java
+++ b/ethereumj-core/src/main/java/org/ethereum/core/Block.java
@@ -226,7 +226,7 @@ public class Block {
 
         toStringBuff.setLength(0);
         toStringBuff.append("BlockData [");
-        toStringBuff.append("  hash=" + ByteUtil.toHexString(hash)).append("");
+        toStringBuff.append("  hash=" + ByteUtil.toHexString(this.getHash())).append("");
         toStringBuff.append(header.toFlatString());
         
         for (Transaction tx : getTransactionsList()){
@@ -313,8 +313,8 @@ public class Block {
 	 * @return
 	 */
 	public long calcGasLimit() {
-		if (this.header.getParentHash() == null)
-			return 1000000L;
+		if (Arrays.equals(this.header.getParentHash(), Genesis.PARENT_HASH))
+			return Genesis.GAS_LIMIT;
 		else {
 			Block parent = this.getParent();
 			return Math.max(MIN_GAS_LIMIT, (parent.header.getGasLimit() * (1024 - 1) + (parent.header.getGasUsed() * 6 / 5)) / 1024);
diff --git a/ethereumj-core/src/main/java/org/ethereum/core/Genesis.java b/ethereumj-core/src/main/java/org/ethereum/core/Genesis.java
index 5058384e..e54e39fc 100644
--- a/ethereumj-core/src/main/java/org/ethereum/core/Genesis.java
+++ b/ethereumj-core/src/main/java/org/ethereum/core/Genesis.java
@@ -9,10 +9,29 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.spongycastle.util.encoders.Hex;
 
+/**
+ * The genesis block is the first block in the chain and has fixed values according to 
+ * the protocol specification. The genesis block is 13 items, and is specified thus:
+ * 
+ * ( zerohash_256 , SHA3 RLP () , zerohash_160 , stateRoot, 0, 2^22 , 0, 0, 1000000, 0, 0, 0, SHA3 (42) , (), () )
+ * 
+ * - Where zerohash_256 refers to the parent hash, a 256-bit hash which is all zeroes; 
+ * - zerohash_160 refers to the coinbase address, a 160-bit hash which is all zeroes; 
+ * - 2^22 refers to the difficulty; 
+ * - 0 refers to the timestamp (the Unix epoch); 
+ * - the transaction trie root and extradata are both 0, being equivalent to the empty byte array. 
+ * - The sequences of both uncles and transactions are empty and represented by (). 
+ * - SHA3 (42) refers to the SHA3 hash of a byte array of length one whose first and only byte is of value 42. 
+ * - SHA3 RLP () value refers to the hash of the uncle lists in RLP, both empty lists.
+ * 
+ * See Yellow Paper: http://www.gavwood.com/Paper.pdf (Appendix I. Genesis Block)
+ */
 public class Genesis extends Block {
 	
 	Logger logger = LoggerFactory.getLogger(this.getClass());
 	
+	// The proof-of-concept series include a development premine, making the state root hash 
+	// some value stateRoot. The latest documentation should be consulted for the value of the state root.
 	private AccountState acct = new AccountState(BigInteger.ZERO, BigInteger.valueOf(2).pow(200));
 	private String[] premine = new String[] {
 			"2ef47100e0787b915105fd5e3f4ff6752079d5cb", 	// # (M)
@@ -53,8 +72,6 @@ public class Genesis extends Block {
 		}
 		logger.info("Genesis-hash: " + Hex.toHexString(this.getHash()));
 		logger.info("Genesis-stateRoot: " + Hex.toHexString(this.getStateRoot()));
-
-        Config.CHAIN_DB.put(getParentHash(), getEncoded());
     }
 	
 	public static Block getInstance() {
diff --git a/ethereumj-core/src/test/java/org/ethereum/core/BlockTest.java b/ethereumj-core/src/test/java/org/ethereum/core/BlockTest.java
index f0914fd7..a6edcbc3 100644
--- a/ethereumj-core/src/test/java/org/ethereum/core/BlockTest.java
+++ b/ethereumj-core/src/test/java/org/ethereum/core/BlockTest.java
@@ -94,13 +94,15 @@ public class BlockTest {
     	Block genesis = Genesis.getInstance();
     	byte[] diffBytes = genesis.calcDifficulty();
     	BigInteger difficulty = new BigInteger(1, diffBytes);
-    	System.out.println(difficulty.toString());
+    	System.out.println("Genesis difficulty = " + difficulty.toString());
     	fail("Yet to be implemented.");
     }
     
     @Test
     public void testCalcGasLimit() {
-    	// Block.calcGasLimit()
+    	Block genesis = Genesis.getInstance();
+    	long gasLimit = genesis.calcGasLimit();
+    	System.out.println("Genesis gasLimit = " + gasLimit);
     	fail("Yet to be implemented.");
     }
 }
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