[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 2 of 3] remus: move makeheader from image.py to vm.py
# HG changeset patch # User Shriram Rajagopalan <rshriram@xxxxxxxxx> # Date 1308683504 25200 # Node ID 794ead1a2be0578d70c38f006e7ab61c7abe9203 # Parent ca4a8d0d504344a84f64bc7e939f8910baac236e remus: move makeheader from image.py to vm.py makeheader is the only function used from image.py. Move it to vm.py and remove image.py file. Signed-off-by: Shriram Rajagopalan <rshriram@xxxxxxxxx> diff -r ca4a8d0d5043 -r 794ead1a2be0 tools/python/xen/remus/image.py --- a/tools/python/xen/remus/image.py Tue Jun 21 12:11:41 2011 -0700 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,227 +0,0 @@ -# VM image file manipulation - -import logging, struct - -import vm - -SIGNATURE = 'LinuxGuestRecord' -LONGLEN = struct.calcsize('L') -INTLEN = struct.calcsize('i') -PAGE_SIZE = 4096 -# ~0L -P2M_EXT_SIG = 4294967295L -# frames per page -FPP = 1024 -LTAB_MASK = 0xf << 28 -BATCH_SIZE = 1024 -IDXLEN = INTLEN + BATCH_SIZE * LONGLEN - -logging.basicConfig(level=logging.DEBUG) -log = logging.getLogger() - -class VMParseException(Exception): pass - -class VMImage(object): - def __init__(self, img=None): - """img may be a path or a file object. - If compact is True, apply checkpoints to base image instead - of simply concatenating them. - """ - self.img = img - - self.dom = None - self.fd = None - self.header = None - self.nr_pfns = 0 - # p2m extension header (unparsed) - self.p2mext = None - - if self.img: - self.open(self.img) - - def open(self, img): - if isinstance(img, str): - self.fd = file(img, 'rb') - else: - self.fd = img - - self.readheader() - - def readheader(self): - sig = self.fd.read(len(SIGNATURE)) - if sig != SIGNATURE: - raise VMParseException("Bad signature in image") - - hlen = self.fd.read(INTLEN) - hlen, = struct.unpack('!i', hlen) - - self.header = self.fd.read(hlen) - self.dom = parseheader(self.header) - - def readp2mfl(self): - "read the P2M frame list" - pfnlen = self.fd.read(LONGLEN) - self.nr_pfns, = struct.unpack('L', pfnlen) - p2m0 = self.fd.read(LONGLEN) - - p2mhdr = p2m0 - p2m0, = struct.unpack('L', p2m0) - if p2m0 == P2M_EXT_SIG: - elen = self.fd.read(INTLEN) - elen, = struct.unpack('I', elen) - - self.p2mext = self.fd.read(elen) - - p2m0 = self.fd.read(LONGLEN) - p2m0, = struct.unpack('L', p2m0) - p2mfl = [p2m0] - - p2mfle = (self.nr_pfns + FPP - 1)/FPP - 1 - p2ms = self.fd.read(LONGLEN * p2mfle) - p2mfl.extend(struct.unpack('%dL' % p2mfle, p2ms)) - - self.p2mfl = p2mfl - - def flush(self): - self.ofd.write(self.tail) - -class Writer(object): - """compress a stream of checkpoints into a single image of the - last checkpoint""" - def __init__(self, fd, compact=False): - self.fd = fd - self.compact = compact - - self.vm = None - self.tail = None - # offset to first batch of pages - self.imgstart = 0 - # PFN mappings - self.pfns = [] - - def __del__(self): - self.close() - - def writeheader(self): - hlen = struct.pack('!i', len(self.vm.header)) - header = ''.join([SIGNATURE, hlen, self.vm.header]) - self.fd.write(header) - - def writep2mfl(self): - p2m = [struct.pack('L', self.vm.nr_pfns)] - if self.vm.p2mext: - p2m.extend([struct.pack('L', P2M_EXT_SIG), self.vm.p2mext]) - p2m.append(struct.pack('%dL' % len(self.vm.p2mfl), *self.vm.p2mfl)) - self.fd.write(''.join(p2m)) - - def writebatch(self, batch): - def offset(pfn): - isz = (pfn / BATCH_SIZE + 1) * IDXLEN - return self.imgstart + isz + pfn * PAGE_SIZE - - if not self.compact: - return self.fd.write(batch) - - batch = parsebatch(batch) - # sort pages for better disk seek behaviour - batch.sort(lambda x, y: cmp(x[0] & ~LTAB_MASK, y[0] & ~LTAB_MASK)) - - for pfndesc, page in batch: - pfn = pfndesc & ~LTAB_MASK - if pfn > self.vm.nr_pfns: - log.error('INVALID PFN: %d' % pfn) - if len(self.pfns) <= pfn: - self.pfns.extend([0] * (pfn - len(self.pfns) + 1)) - self.pfns[pfn] = pfndesc - self.fd.seek(offset(pfn)) - self.fd.write(page) - - #print "max offset: %d, %d" % (len(self.pfns), offset(self.pfns[-1])) - - def writeindex(self): - "Write batch header in front of each page" - hdrlen = INTLEN + BATCH_SIZE * LONGLEN - batches = (len(self.pfns) + BATCH_SIZE - 1) / BATCH_SIZE - - for i in xrange(batches): - offset = self.imgstart + i * (hdrlen + (PAGE_SIZE * BATCH_SIZE)) - pfnoff = i * BATCH_SIZE - # python auto-clamps overreads - pfns = self.pfns[pfnoff:pfnoff + BATCH_SIZE] - - self.fd.seek(offset) - self.fd.write(struct.pack('i', len(pfns))) - self.fd.write(struct.pack('%dL' % len(pfns), *pfns)) - - def slurp(self, ifd): - """Apply an incremental checkpoint to a loaded image. - accepts a path or a file object.""" - if isinstance(ifd, str): - ifd = file(ifd, 'rb') - - if not self.vm: - self.vm = VMImage(ifd) - self.writeheader() - - self.vm.readp2mfl() - self.writep2mfl() - self.imgstart = self.fd.tell() - - while True: - l, batch = readbatch(ifd) - if l <= 0: - break - self.writebatch(batch) - self.tail = batch + ifd.read() - - def flush(self): - if self.tail: - self.fd.seek(0, 2) - self.fd.write(self.tail) - if self.compact: - self.writeindex() - self.tail = None - - def close(self): - self.flush() - -def parseheader(header): - "parses a header sexpression" - return vm.parsedominfo(vm.strtosxpr(header)) - -def makeheader(dominfo): - "create an image header from a VM dominfo sxpr" - items = [SIGNATURE] - sxpr = vm.sxprtostr(dominfo) - items.append(struct.pack('!i', len(sxpr))) - items.append(sxpr) - return ''.join(items) - -def readbatch(fd): - batch = [] - batchlen = fd.read(INTLEN) - batch.append(batchlen) - batchlen, = struct.unpack('i', batchlen) - log.info("batch length: %d" % batchlen) - if batchlen <= 0: - return (batchlen, batch[0]) - - batchfns = fd.read(LONGLEN * batchlen) - batch.append(batchfns) - pages = fd.read(PAGE_SIZE * batchlen) - if len(pages) != PAGE_SIZE * batchlen: - log.error('SHORT READ: %d' % len(pages)) - batch.append(pages) - - return (batchlen, ''.join(batch)) - -def parsebatch(batch): - "parse a batch string into pages" - batchlen, batch = batch[:INTLEN], batch[INTLEN:] - batchlen, = struct.unpack('i', batchlen) - #print 'batch length: %d' % batchlen - pfnlen = batchlen * LONGLEN - pfns = struct.unpack('%dL' % batchlen, batch[:pfnlen]) - pagebuf = batch[pfnlen:] - pages = [pagebuf[i*PAGE_SIZE:(i+1)*PAGE_SIZE] for i in xrange(batchlen)] - return zip(pfns, pages) diff -r ca4a8d0d5043 -r 794ead1a2be0 tools/python/xen/remus/save.py --- a/tools/python/xen/remus/save.py Tue Jun 21 12:11:41 2011 -0700 +++ b/tools/python/xen/remus/save.py Tue Jun 21 12:11:44 2011 -0700 @@ -10,7 +10,7 @@ import xen.lowlevel.checkpoint -import vm, image +import vm class _proxy(object): "proxy simulates an object without inheritance" @@ -70,7 +70,7 @@ def start(self): vm.getshadowmem(self.vm) - hdr = image.makeheader(self.vm.dominfo) + hdr = vm.makeheader(self.vm.dominfo) self.fd.write(hdr) self.fd.flush() diff -r ca4a8d0d5043 -r 794ead1a2be0 tools/python/xen/remus/vm.py --- a/tools/python/xen/remus/vm.py Tue Jun 21 12:11:41 2011 -0700 +++ b/tools/python/xen/remus/vm.py Tue Jun 21 12:11:44 2011 -0700 @@ -1,6 +1,6 @@ #!/usr/bin/env python -import xmlrpclib +import xmlrpclib, struct from xen.xend.XendClient import server from xen.xend import sxp, osdep @@ -11,6 +11,7 @@ # need a nicer way to load disk drivers import vbd +SIGNATURE = 'LinuxGuestRecord' class VMException(Exception): pass class VM(object): @@ -162,3 +163,11 @@ # target is in MB, not KB target = (dom0cur - needed) / 1024 server.xend.domain.setMemoryTarget(0, target) + +def makeheader(dominfo): + "create an image header from a VM dominfo sxpr" + items = [SIGNATURE] + sxpr = sxprtostr(dominfo) + items.append(struct.pack('!i', len(sxpr))) + items.append(sxpr) + return ''.join(items) _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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