[PATCH] 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://.
Eventual slashes at the end of the url are stripped.
The url specifies the path of the svn dump file (as created by
svnrdump). Selectable parts of it, or the whole file, are written
to stdout. The part is selectable by giving start and end revision
on the command line.

Start and end revisions can be specified on the command line
(-rSTART:END, like for svnrdump).
Only revisions between START and excluding END are replayed from
the dumpfile specified by the url. END can also be HEAD.

If the start revision specified on the command line doesn't exist
in the dump file, it returns 1.
This emulates the behaviour of svnrdump when START>HEAD, i.e. the
requested start revision doesn't exist on the server.

To allow using the same dump file for simulating multiple
incremental imports the highest visible revision can be limited by
setting the environment variable SVNRMAX to that value. This
effectively limits HEAD to simulate 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..4701d76
--- /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)
\ No newline at end of file
-- 
1.7.9.5