Add %iB for UTXO height.

This lets us do analysis like "how long to UTXO entries last".

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

doc/bitcoin-iterate.1

@@ -2,12 +2,12 @@
 .\"     Title: bitcoin-iterate
 .\"    Author: [see the "AUTHOR" section]
 .\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
-.\"      Date: 06/21/2015
+.\"      Date: 12/29/2015
 .\"    Manual: \ \&
 .\"    Source: \ \&
 .\"  Language: English
 .\"
-.TH "BITCOIN\-ITERATE" "1" "06/21/2015" "\ \&" "\ \&"
+.TH "BITCOIN\-ITERATE" "1" "12/29/2015" "\ \&" "\ \&"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -101,6 +101,7 @@ Print out the format string for each transaction input (in the order they are in
 %il: input script length
 %is: input script as a hex string
 %iN: input number within transaction
+%iB: input UTXO block number (0 for coinbase)
 %iX: input as a hex string
 .fi
 .if n \{\
@@ -198,6 +199,9 @@ bitcoin\-iterate \-\-output=%ol
 \fBExample\ \&6.\ \&Print out <block number>,<transaction hash>,<script> for each output\fR
 .sp
 bitcoin\-iterate \-\-output=%bn,%th,%os
+.SH "NOTES"
+.sp
+Use of \fB%tF\fR or \fB%iB\fR significantly slows iteration, as this requires \fBbitcoin\-iterate\fR to track unspent outputs\&.
 .SH "BUGS"
 .sp
 This manpage documents how it should work, not how it does work\&.

doc/bitcoin-iterate.1.txt

@@ -68,6 +68,7 @@ OPTIONS
   %il: input script length
   %is: input script as a hex string
   %iN: input number within transaction
+  %iB: input UTXO block number (0 for coinbase)
   %iX: input as a hex string
 
 *--output*='FORMAT'::
@@ -143,6 +144,11 @@ bitcoin-iterate --output=%ol
 bitcoin-iterate --output=%bn,%th,%os
 ===================================================================
 
+NOTES
+-----
+Use of *%tF* or *%iB* significantly slows iteration, as this requires
+*bitcoin-iterate* to track unspent outputs.
+
 BUGS
 ----
 This manpage documents how it should work, not how it does work.

iterate.c

@@ -70,6 +70,9 @@ struct utxo {
 	/* txid */
 	u8 tx[SHA256_DIGEST_LENGTH];
 
+	/* Height. */
+	unsigned int height;
+
 	/* Number of outputs. */
 	u32 num_outputs;
 
@@ -105,6 +108,7 @@ static void add_utxo(struct utxo_map *utxo_map,
 
 	memcpy(utxo->tx, t->sha256, sizeof(utxo->tx));
 	utxo->num_outputs = utxo->unspent_outputs = t->output_count;
+	utxo->height = b->height;
 	for (i = 0; i < utxo->num_outputs; i++)
 		utxo->amount[i] = t->output[i].amount;
 
@@ -352,6 +356,14 @@ static void print_format(const char *format,
 			case 'X':
 				dump_tx_input(i);
 				break;
+			case 'B':
+				/* Coinbase doesn't have valid input. */
+				if (i - t->input != 0) {
+					struct utxo *utxo = utxo_map_get(utxo_map, i->hash);
+					printf("%u", utxo->height);
+				} else
+					printf("0");
+				break;
 			default:
 				goto bad_fmt;
 			}
@@ -450,6 +462,7 @@ int main(int argc, char *argv[])
 			   "  %is: input script as a hex string\n"
 			   "  %iN: input number\n"
 			   "  %iX: input in hex\n"
+			   "  %iB: input UTXO block number (0 for coinbase)\n"
 			   "Valid output format:\n"
 			   "  %oa: output amount\n"
 			   "  %ol: output script length\n"
@@ -631,11 +644,13 @@ int main(int argc, char *argv[])
 	needs_utxo = false;
 
 	/* We need it for fee calculation (can be asked by tx, input
-	 * or output) */
+	 * or output) or UTXO block number */
 	if (txfmt && strstr(txfmt, "%tF"))
 		needs_utxo = true;
 	if (inputfmt && strstr(inputfmt, "%tF"))
 		needs_utxo = true;
+	if (inputfmt && strstr(inputfmt, "%iB"))
+		needs_utxo = true;
 	if (outputfmt && strstr(outputfmt, "%tF"))
 		needs_utxo = true;