[OE-core] [PATCH 2/2] combo-layer: avoid too long command lines in update with history
Patrick Ohly
patrick.ohly at intel.com
Fri May 13 16:56:57 UTC 2016
As suspected, invoking "git archive" with all intended files as
parameters can run into command line length limitations. Splitting up
the parameters into multiple invocations (xargs-style) works and was
tested after encountering the situation in practice.
Signed-off-by: Patrick Ohly <patrick.ohly at intel.com>
---
scripts/combo-layer | 31 +++++++++++++++++++++++++++++--
1 file changed, 29 insertions(+), 2 deletions(-)
diff --git a/scripts/combo-layer b/scripts/combo-layer
index a0a737d..1ca2ce6 100755
--- a/scripts/combo-layer
+++ b/scripts/combo-layer
@@ -1266,8 +1266,35 @@ def apply_commit(parent, rev, largs, wargs, dest_dir, file_filter=None):
target = os.path.join(wargs["destdir"], dest_dir)
if not os.path.isdir(target):
os.makedirs(target)
- runcmd("git archive %s %s | tar -C %s -xf -" % (rev, ' '.join([pipes.quote(x) for x in update]), pipes.quote(target)), **largs)
- runcmd("git add -f".split() + [os.path.join(dest_dir, x) for x in update], **wargs)
+ quoted_target = pipes.quote(target)
+ # os.sysconf('SC_ARG_MAX') is lying: running a command with
+ # string length 629343 already failed with "Argument list too
+ # long" although SC_ARG_MAX = 2097152. "man execve" explains
+ # the limitations, but those are pretty complicated. So here
+ # we just hard-code a fixed value which is more likely to work.
+ max_cmdsize = 64 * 1024
+ while update:
+ quoted_args = []
+ unquoted_args = []
+ cmdsize = 100 + len(quoted_target)
+ while update:
+ quoted_next = pipes.quote(update[0])
+ size_next = len(quoted_next) + len(dest_dir) + 1
+ logger.debug('cmdline length %d + %d < %d?' % (cmdsize, size_next, os.sysconf('SC_ARG_MAX')))
+ if cmdsize + size_next < max_cmdsize:
+ quoted_args.append(quoted_next)
+ unquoted_args.append(update.pop(0))
+ cmdsize += size_next
+ else:
+ logger.debug('Breaking the cmdline at length %d' % cmdsize)
+ break
+ logger.debug('Final cmdline length %d / %d' % (cmdsize, os.sysconf('SC_ARG_MAX')))
+ cmd = "git archive %s %s | tar -C %s -xf -" % (rev, ' '.join(quoted_args), quoted_target)
+ logger.debug('First cmdline length %d' % len(cmd))
+ runcmd(cmd, **largs)
+ cmd = "git add -f".split() + [os.path.join(dest_dir, x) for x in unquoted_args]
+ logger.debug('Second cmdline length %d' % reduce(lambda x, y: x + len(y), cmd, 0))
+ runcmd(cmd, **wargs)
if delete:
for path in delete:
if dest_dir:
--
2.1.4
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