contrib: add script dump_to_sqlite.sh for direct SQLite3 UTXO dump

Author: theStack

contrib/README.md

@@ -53,3 +53,7 @@ to a SQLite3 database. The coins are stored in a table with the following schema
 ```
 CREATE TABLE utxos(txid TEXT, vout INT, value INT, coinbase INT, height INT, scriptpubkey TEXT)
 ```
+
+### [Dump-to-SQLite](/contrib/utxo-tools/dump_to_sqlite.sh) ###
+This script creates an UTXO set dump in SQLite3 format on the fly from a running bitcoind instance,
+i.e. with the intermediate step of storing the compact-serialized UTXO set on disk is skipped.

contrib/utxo-tools/dump_to_sqlite.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -e
+if [ $# -ne 2 ]; then
+    echo "Usage: $0 <bitcoin-cli-path> <output-file>"
+    exit 1
+fi
+
+BITCOIN_CLI=$1
+OUTPUT_FILE=$2
+UTXO_TO_SQLITE=`dirname $0`/utxo_to_sqlite.py
+
+# create named pipe in unique temporary folder
+TEMPPATH=$(mktemp -d)
+FIFOPATH=$TEMPPATH/utxos.fifo
+mkfifo $FIFOPATH
+
+# start dumping UTXO set to the pipe in background
+$BITCOIN_CLI dumptxoutset $FIFOPATH latest &
+BITCOIN_CLI_PID=$!
+
+# start UTXO to SQLite conversion tool, reading from pipe
+$UTXO_TO_SQLITE $FIFOPATH $OUTPUT_FILE
+
+# wait and cleanup
+wait $BITCOIN_CLI_PID
+rm -r $TEMPPATH