wire: Remove errs from BlockHeader/MsgBlock/MsgTx.

This commit removes the error returns from the BlockHeader.BlockSha,
MsgBlock.BlockSha, and MsgTx.TxSha functions since they can never fail and
end up causing a lot of unneeded error checking throughout the code base.

It also updates all call sites for the change.

database/ldb/insertremove_test.go

@@ -91,7 +91,7 @@ endtest:
 					t.Errorf("referenced tx not found %v ", origintxsha)
 				}
 			}
-			txshaname, _ := tx.TxSha()
+			txshaname := tx.TxSha()
 			txlookupList = append(txlookupList, &txshaname)
 			txOutList = append(txOutList, &txshaname)
 		}

database/ldb/operational_test.go

@@ -367,7 +367,7 @@ func testBackout(t *testing.T) {
 
 	block := testDb.blocks[119]
 	mblock := block.MsgBlock()
-	txsha, err := mblock.Transactions[0].TxSha()
+	txsha := mblock.Transactions[0].TxSha()
 	exists, err := testDb.db.ExistsTxSha(&txsha)
 	if err != nil {
 		t.Errorf("ExistsTxSha: unexpected error %v ", err)

database/ldb/tx.go

@@ -482,7 +482,7 @@ func (db *LevelDb) FetchTxsForAddr(addr btcutil.Address, skip int,
 			continue
 		}
 
-		txSha, _ := tx.TxSha()
+		txSha := tx.TxSha()
 		txReply := &database.TxListReply{Sha: &txSha, Tx: tx,
 			BlkSha: blkSha, Height: blkHeight, TxSpent: []bool{}, Err: err}
 

database/memdb/memdb.go

@@ -184,7 +184,7 @@ func (db *MemDb) DropAfterBlockBySha(sha *wire.ShaHash) error {
 		transactions := db.blocks[i].Transactions
 		for j := len(transactions) - 1; j >= 0; j-- {
 			tx := transactions[j]
-			txHash, _ := tx.TxSha()
+			txHash := tx.TxSha()
 			db.removeTx(tx, &txHash)
 		}
 
@@ -291,11 +291,7 @@ func (db *MemDb) FetchBlockShaByHeight(height int64) (*wire.ShaHash, error) {
 	}
 
 	msgBlock := db.blocks[height]
-	blockHash, err := msgBlock.BlockSha()
-	if err != nil {
-		return nil, err
-	}
-
+	blockHash := msgBlock.BlockSha()
 	return &blockHash, nil
 }
 
@@ -337,10 +333,7 @@ func (db *MemDb) FetchHeightRange(startHeight, endHeight int64) ([]wire.ShaHash,
 		}
 
 		msgBlock := db.blocks[i]
-		blockHash, err := msgBlock.BlockSha()
-		if err != nil {
-			return nil, err
-		}
+		blockHash := msgBlock.BlockSha()
 		hashList = append(hashList, blockHash)
 	}
 
@@ -390,10 +383,7 @@ func (db *MemDb) FetchTxBySha(txHash *wire.ShaHash) ([]*database.TxListReply, er
 	replyList := make([]*database.TxListReply, len(txns))
 	for i, txD := range txns {
 		msgBlock := db.blocks[txD.blockHeight]
-		blockSha, err := msgBlock.BlockSha()
-		if err != nil {
-			return nil, err
-		}
+		blockSha := msgBlock.BlockSha()
 
 		spentBuf := make([]bool, len(txD.spentBuf))
 		copy(spentBuf, txD.spentBuf)
@@ -455,11 +445,7 @@ func (db *MemDb) fetchTxByShaList(txShaList []*wire.ShaHash, includeSpent bool)
 			// the reply error appropriately and go to the next
 			// requested transaction if anything goes wrong.
 			msgBlock := db.blocks[txD.blockHeight]
-			blockSha, err := msgBlock.BlockSha()
-			if err != nil {
-				reply.Err = err
-				continue
-			}
+			blockSha := msgBlock.BlockSha()
 
 			// Make a copy of the spent buf to return so the caller
 			// can't accidentally modify it.
@@ -685,11 +671,7 @@ func (db *MemDb) NewestSha() (*wire.ShaHash, int64, error) {
 		return &zeroHash, -1, nil
 	}
 
-	blockSha, err := db.blocks[numBlocks-1].BlockSha()
-	if err != nil {
-		return nil, -1, err
-	}
-
+	blockSha := db.blocks[numBlocks-1].BlockSha()
 	return &blockSha, int64(numBlocks - 1), nil
 }
 

database/memdb/memdb_test.go

@@ -55,10 +55,7 @@ func TestClosed(t *testing.T) {
 	}
 
 	genesisCoinbaseTx := chaincfg.MainNetParams.GenesisBlock.Transactions[0]
-	coinbaseHash, err := genesisCoinbaseTx.TxSha()
-	if err != nil {
-		t.Errorf("TxSha: unexpected error %v", err)
-	}
+	coinbaseHash := genesisCoinbaseTx.TxSha()
 	if _, err := db.ExistsTxSha(&coinbaseHash); err != memdb.ErrDbClosed {
 		t.Errorf("ExistsTxSha: unexpected error %v", err)
 	}