From b4a72a75b4795dffbe973b0ae287343df2dac13c Mon Sep 17 00:00:00 2001
From: Jeff Garzik <jgarzik@bitpay.com>
Date: Sat, 23 Aug 2014 22:59:16 -0400
Subject: [PATCH] contrib/linearize: split output files based on
 new-timestamp-year or max-file-size

---
 contrib/linearize/README.md             |  3 ++
 contrib/linearize/example-linearize.cfg |  1 +
 contrib/linearize/linearize-data.py     | 44 ++++++++++++++++++++-----
 3 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/contrib/linearize/README.md b/contrib/linearize/README.md
index 8d06d53b10..b5c6e7824e 100644
--- a/contrib/linearize/README.md
+++ b/contrib/linearize/README.md
@@ -26,4 +26,7 @@ output.
 
 Optional config file setting for linearize-data:
 * "netmagic": network magic number
+* "max_out_sz": maximum output file size (default 1000*1000*1000)
+* "split_year": Split files when a new year is first seen, in addition to
+reaching a maximum file size.
 
diff --git a/contrib/linearize/example-linearize.cfg b/contrib/linearize/example-linearize.cfg
index 9c3270d653..071345f23a 100644
--- a/contrib/linearize/example-linearize.cfg
+++ b/contrib/linearize/example-linearize.cfg
@@ -13,4 +13,5 @@ netmagic=f9beb4d9
 input=/home/example/.bitcoin/blocks
 output_file=/home/example/Downloads/bootstrap.dat
 hashlist=hashlist.txt
+split_year=1
 
diff --git a/contrib/linearize/linearize-data.py b/contrib/linearize/linearize-data.py
index 77bae6e3c6..ea94f25fae 100755
--- a/contrib/linearize/linearize-data.py
+++ b/contrib/linearize/linearize-data.py
@@ -14,8 +14,7 @@ import base64
 import httplib
 import sys
 import hashlib
-
-MAX_OUT_SZ = 128 * 1024 * 1024
+import datetime
 
 settings = {}
 
@@ -41,9 +40,7 @@ def wordreverse(in_buf):
 	out_words.reverse()
 	return ''.join(out_words)
 
-def calc_hdr_hash(rawblock):
-	blk_hdr = rawblock[:80]
-
+def calc_hdr_hash(blk_hdr):
 	hash1 = hashlib.sha256()
 	hash1.update(blk_hdr)
 	hash1_o = hash1.digest()
@@ -54,13 +51,18 @@ def calc_hdr_hash(rawblock):
 
 	return hash2_o
 
-def calc_hash_str(rawblock):
-	hash = calc_hdr_hash(rawblock)
+def calc_hash_str(blk_hdr):
+	hash = calc_hdr_hash(blk_hdr)
 	hash = bufreverse(hash)
 	hash = wordreverse(hash)
 	hash_str = hash.encode('hex')
 	return hash_str
 
+def get_blk_year(blk_hdr):
+	members = struct.unpack("<I", blk_hdr[68:68+4])
+	dt = datetime.datetime.fromtimestamp(members[0])
+	return dt.year
+
 def get_block_hashes(settings):
 	blkindex = []
 	f = open(settings['hashlist'], "r")
@@ -86,9 +88,14 @@ def copydata(settings, blkindex, blkset):
 	outF = None
 	blkCount = 0
 
+	lastYear = 0
+	splitYear = False
 	fileOutput = True
+	maxOutSz = settings['max_out_sz']
 	if 'output' in settings:
 		fileOutput = False
+	if settings['split_year'] != 0:
+		splitYear = True
 
 	while True:
 		if not inF:
@@ -111,17 +118,30 @@ def copydata(settings, blkindex, blkset):
 		su = struct.unpack("<I", inLenLE)
 		inLen = su[0]
 		rawblock = inF.read(inLen)
+		blk_hdr = rawblock[:80]
 
-		hash_str = calc_hash_str(rawblock)
+		hash_str = calc_hash_str(blk_hdr)
 		if not hash_str in blkset:
 			print("Skipping unknown block " + hash_str)
 			continue
 
-		if not fileOutput and ((outsz + inLen) > MAX_OUT_SZ):
+		if not fileOutput and ((outsz + inLen) > maxOutSz):
 			outF.close()
 			outF = None
 			outFn = outFn + 1
 			outsz = 0
+
+		if splitYear:
+			blkYear = get_blk_year(blk_hdr)
+			if blkYear > lastYear:
+				print("New year " + str(blkYear) + " @ " + hash_str)
+				lastYear = blkYear
+				if outF:
+					outF.close()
+					outF = None
+					outFn = outFn + 1
+					outsz = 0
+
 		if not outF:
 			if fileOutput:
 				fname = settings['output_file']
@@ -164,7 +184,13 @@ if __name__ == '__main__':
 		settings['input'] = 'input'
 	if 'hashlist' not in settings:
 		settings['hashlist'] = 'hashlist.txt'
+	if 'split_year' not in settings:
+		settings['split_year'] = 0
+	if 'max_out_sz' not in settings:
+		settings['max_out_sz'] = 1000L * 1000 * 1000
 
+	settings['max_out_sz'] = long(settings['max_out_sz'])
+	settings['split_year'] = int(settings['split_year'])
 	settings['netmagic'] = settings['netmagic'].decode('hex')
 
 	if 'output_file' not in settings and 'output' not in settings: