[RFC 13/16] Add a svnrdump-simulator replaying a dump file for testing.

[Florian Achleitner <florian.achleitner.2.6.31@gmail.com>]

To ease testing without depending on a reachable svn server, this
compact python script mimics parts of svnrdumps behaviour.
It requires the remote url to start with sim://.
Start and end revisions are evaluated.
If the requested revision doesn't exist, as it is the case with
incremental imports, if no new commit was added, it returns 1
(like svnrdump).
To allow using the same dump file for simulating multiple
incremental imports the highest revision can be limited by setting
the environment variable SVNRMAX to that value. This simulates the
situation where higher revs don't exist yet.

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
---
 contrib/svn-fe/svnrdump_sim.py |   53 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100755 contrib/svn-fe/svnrdump_sim.py

diff --git a/contrib/svn-fe/svnrdump_sim.py b/contrib/svn-fe/svnrdump_sim.py
new file mode 100755
index 0000000..ab4ccf1
--- /dev/null
+++ b/contrib/svn-fe/svnrdump_sim.py
@@ -0,0 +1,53 @@
+#!/usr/bin/python
+"""
+Simulates svnrdump by replaying an existing dump from a file, taking care
+of the specified revision range.
+To simulate incremental imports the environment variable SVNRMAX can be set
+to the highest revision that should be available.
+"""
+import sys, os
+
+
+def getrevlimit():
+	var = 'SVNRMAX'
+	if os.environ.has_key(var):
+		return os.environ[var]
+	return None
+	
+def writedump(url, lower, upper):
+	if url.startswith('sim://'):
+		filename = url[6:]
+		if filename[-1] == '/': filename = filename[:-1] #remove terminating slash
+	else:
+		raise ValueError('sim:// url required')
+	f = open(filename, 'r');
+	state = 'header'
+	wroterev = False
+	while(True):
+		l = f.readline()
+		if l == '': break
+		if state == 'header' and l.startswith('Revision-number: '):
+			state = 'prefix'
+		if state == 'prefix' and l == 'Revision-number: %s\n' % lower:
+			state = 'selection'
+		if not upper == 'HEAD' and state == 'selection' and l == 'Revision-number: %s\n' % upper:
+			break;
+
+		if state == 'header' or state == 'selection':
+			if state == 'selection': wroterev = True
+			sys.stdout.write(l)
+	return wroterev
+
+if __name__ == "__main__":
+	if not (len(sys.argv) in (3, 4, 5)):
+		print "usage: %s dump URL -rLOWER:UPPER"
+		sys.exit(1)
+	if not sys.argv[1] == 'dump': raise NotImplementedError('only "dump" is suppported.')
+	url = sys.argv[2]
+	r = ('0', 'HEAD')
+	if len(sys.argv) == 4 and sys.argv[3][0:2] == '-r':
+		r = sys.argv[3][2:].lstrip().split(':')
+	if not getrevlimit() is None: r[1] = getrevlimit()
+	if writedump(url, r[0], r[1]): ret = 0
+	else: ret = 1
+	sys.exit(ret)
-- 
1.7.9.5