[Zodb-checkins] SVN: ZODB/branches/3.4/src/ZEO/simul.py Lots of
fiddling to work w/ current trace file format.
Tim Peters
tim.one at comcast.net
Fri Jul 22 21:49:27 EDT 2005
Log message for revision 37389:
Lots of fiddling to work w/ current trace file format.
Output isn't obviously wholly insane, but isn't a reasonably
close enough match to stats.py output either yet.
Changed:
U ZODB/branches/3.4/src/ZEO/simul.py
-=-
Modified: ZODB/branches/3.4/src/ZEO/simul.py
===================================================================
--- ZODB/branches/3.4/src/ZEO/simul.py 2005-07-22 23:35:44 UTC (rev 37388)
+++ ZODB/branches/3.4/src/ZEO/simul.py 2005-07-23 01:49:26 UTC (rev 37389)
@@ -42,13 +42,12 @@
print >>sys.stderr, __doc__
def main():
- # Parse options
- MB = 1000*1000
+ # Parse options.
+ MB = 1024**2
cachelimit = 20*MB
simclass = ZEOCacheSimulation
- theta = omicron = None
try:
- opts, args = getopt.getopt(sys.argv[1:], "bflyz2cOaTUs:o:t:")
+ opts, args = getopt.getopt(sys.argv[1:], "bflyz2cOaTUs:")
except getopt.error, msg:
usage(msg)
return 2
@@ -69,10 +68,6 @@
simclass = TwoQSimluation
elif o == '-c':
simclass = CircularCacheSimulation
- elif o == '-o':
- omicron = float(a)
- elif o == '-t':
- theta = float(a)
elif o == '-O':
simclass = OracleSimulation
elif o == '-a':
@@ -89,13 +84,9 @@
return 2
filename = args[0]
- if omicron is not None and simclass != CircularCacheSimulation:
- usage("-o flag only useful with -c (CircularCacheSimulation)")
- return 2
-
- # Open file
+ # Open file.
if filename.endswith(".gz"):
- # Open gzipped file
+ # Open gzipped file.
try:
import gzip
except ImportError:
@@ -107,57 +98,55 @@
print >> sys.stderr, "can't open %s: %s" % (filename, msg)
return 1
elif filename == "-":
- # Read from stdin
+ # Read from stdin.
f = sys.stdin
else:
- # Open regular file
+ # Open regular file.
try:
f = open(filename, "rb")
except IOError, msg:
print >> sys.stderr, "can't open %s: %s" % (filename, msg)
return 1
- # Create simulation object
- if omicron is not None or theta is not None:
- sim = simclass(cachelimit, omicron, theta)
- elif simclass is OracleSimulation:
+ # Create simulation object.
+ if simclass is OracleSimulation:
sim = simclass(cachelimit, filename)
else:
sim = simclass(cachelimit)
- # Print output header
+ # Print output header.
sim.printheader()
- # Read trace file, simulating cache behavior
- records = 0
+ # Read trace file, simulating cache behavior.
f_read = f.read
- struct_unpack = struct.unpack
+ unpack = struct.unpack
while 1:
- # Read a record and decode it
- r = f_read(8)
- if len(r) < 8:
+ # Read a record and decode it.
+ r = f_read(26)
+ if len(r) < 26:
break
- ts, code = struct_unpack(">ii", r)
+ ts, code, oidlen, start_tid, end_tid = unpack(">iiH8s8s", r)
if ts == 0:
- # Must be a misaligned record caused by a crash
+ # Must be a misaligned record caused by a crash; skip 8 bytes
+ # and try again. Why 8? Lost in the mist of history.
+ f.seek(f.tell() - 18)
continue
- r = f_read(16)
- if len(r) < 16:
+ oid = f_read(oidlen)
+ if len(oid) < oidlen:
break
- records += 1
- oid, serial = struct_unpack(">8s8s", r)
- # Decode the code
+ # Decode the code.
dlen, version, code, current = (code & 0x7fffff00,
code & 0x80,
code & 0x7e,
code & 0x01)
- # And pass it to the simulation
- sim.event(ts, dlen, version, code, current, oid, serial)
+ # And pass it to the simulation.
+ sim.event(ts, dlen, version, code, current, oid, start_tid)
- # Finish simulation
+ f.close()
+ # Finish simulation.
sim.finish()
- # Exit code from main()
+ # Exit code from main().
return 0
class Simulation:
@@ -195,32 +184,33 @@
self.ts0 = None
def event(self, ts, dlen, _version, code, _current, oid, _serial):
- # Record first and last timestamp seen
+ # Record first and last timestamp seen.
if self.ts0 is None:
self.ts0 = ts
if self.epoch is None:
self.epoch = ts
self.ts1 = ts
- # Simulate cache behavior. Use load hits, updates and stores
- # only (each load miss is followed immediately by a store
- # unless the object in fact did not exist). Updates always write.
- if dlen and code & 0x70 in (0x20, 0x30, 0x50):
- if code == 0x3A:
- # Update
+ # Simulate cache behavior.
+ action = code & 0x70 # ignore high bit (version flag)
+ if dlen:
+ if action == 0x20:
+ # Load.
+ self.loads += 1
+ self.total_loads += 1
+ self.load(oid, dlen)
+ elif action == 0x50:
+ # Store.
self.writes += 1
self.total_writes += 1
self.write(oid, dlen)
else:
- # Load hit or store -- these are really the load requests
- self.loads += 1
- self.total_loads += 1
- self.load(oid, dlen)
- elif code & 0x70 == 0x10:
- # Invalidate
+ assert False, (hex(code), dlen)
+ elif action == 0x10:
+ # Invalidate.
self.inval(oid)
- elif code == 0x00:
- # Restart
+ elif action == 0x00:
+ # Restart.
self.report()
self.restart()
@@ -982,78 +972,34 @@
# are written at the current pointer, evicting whatever was
# there previously.
- # For each cache hit, there is some distance between the current
- # pointer offset and the offset of the cached data record. The
- # cache can be configured to copy objects to the current offset
- # depending on how far away they are now. The omicron parameter
- # specifies a percentage
+ extras = "evicts", "inuse"
- extras = "evicts", "copies", "inuse", "skips"
-
- def __init__(self, cachelimit, omicron=None, skip=None):
+ def __init__(self, cachelimit):
Simulation.__init__(self, cachelimit)
- self.omicron = omicron or 0
- self.skip = skip or 0
self.total_evicts = 0
- self.total_copies = 0
- self.total_skips = 0
- # Current offset in file
+ # Current offset in file.
self.offset = 0
- # Map offset in file to tuple of size, oid
+ # Map offset in file to (size, oid) pair.
self.filemap = {0: (self.cachelimit, None)}
- # Map oid to offset, node
- self.cache = {}
- # LRU list of oids
- self.head = Node(None, None)
- self.head.linkbefore(self.head)
+ # Map oid to file offset.
+ self.oid2ofs = {}
- def extraheader(self):
- print "omicron = %s, theta = %s" % (self.omicron, self.skip)
-
def restart(self):
Simulation.restart(self)
self.evicts = 0
- self.copies = 0
- self.skips = 0
def load(self, oid, size):
- p = self.cache.get(oid)
- if p is None:
- self.add(oid, size)
- else:
- pos, node = p
+ if oid in self.oid2ofs:
self.hits += 1
self.total_hits += 1
- node.linkbefore(self.head)
- self.copy(oid, size, pos)
+ else:
+ self.add(oid, size)
- def check(self):
- d = dict(self.filemap)
- done = {}
- while d:
- pos, (size, oid) = d.popitem()
- next = pos + size
- if not (next in d or next in done or next == self.cachelimit):
- print "check", next, pos, size, repr(oid)
- self.dump()
- raise RuntimeError
- done[pos] = pos
-
- def dump(self):
- print len(self.filemap)
- L = list(self.filemap)
- L.sort()
- for k in L:
- v = self.filemap[k]
- print k, v[0], repr(v[1])
-
def add(self, oid, size):
avail = self.makeroom(size)
- assert oid not in self.cache
+ assert oid not in self.oid2ofs
self.filemap[self.offset] = size, oid
- node = Node(oid, size)
- node.linkbefore(self.head)
- self.cache[oid] = self.offset, node
+ self.oid2ofs[oid] = self.offset
self.offset += size
# All the space made available must be accounted for in filemap.
excess = avail - size
@@ -1061,102 +1007,48 @@
self.filemap[self.offset] = excess, None
def makeroom(self, need):
+ # Evict enough objects to make the necessary space available.
if self.offset + need > self.cachelimit:
self.offset = 0
pos = self.offset
- # Evict enough objects to make the necessary space available.
- self.compute_closeenough()
- evicted = False
while need > 0:
- if pos == self.cachelimit:
- print "wrap makeroom", need
- pos = 0
+ assert pos < self.cachelimit
try:
size, oid = self.filemap[pos]
- except:
+ except KeyError:
self.dump()
raise
-
- if not evicted and self.skip and oid and self.closeenough(oid):
- self.skips += 1
- self.total_skips += 1
- self.offset += size
- pos += size
- continue
-
- evicted = True
del self.filemap[pos]
-
- if oid is not None:
+ if oid:
self.evicts += 1
self.total_evicts += 1
- pos, node = self.cache.pop(oid)
- node.unlink()
+ _pos = self.oid2ofs.pop(oid)
+ assert pos == _pos
need -= size
pos += size
+ return pos - self.offset # total number of bytes freed
- return pos - self.offset
-
- def compute_closeenough(self):
- self.lru = {}
- n = int(len(self.cache) * self.skip)
- node = self.head.prev
- while n > 0:
- self.lru[node.oid] = True
- node = node.prev
- n -= 1
-
- def closeenough(self, oid):
- # If oid is in the top portion of the most recently used
- # elements, skip it.
- return oid in self.lru
-
- def copy(self, oid, size, pos):
- # Copy only if the distance is greater than omicron.
- dist = self.offset - pos
- if dist < 0:
- dist += self.cachelimit
- if dist < self.omicron * self.cachelimit:
- self.copies += 1
- self.total_copies += 1
- self.filemap[pos] = size, None
- pos, node = self.cache.pop(oid)
- node.unlink()
- self.add(oid, size)
-
def inval(self, oid):
- p = self.cache.get(oid)
- if p is None:
+ pos = self.oid2ofs.pop(oid, None)
+ if pos is None:
return
- pos, node = p
self.invals += 1
self.total_invals += 1
size, _oid = self.filemap[pos]
assert oid == _oid
self.filemap[pos] = size, None
- pos, node = self.cache.pop(oid)
- node.unlink()
def write(self, oid, size):
- p = self.cache.get(oid)
- if p is None:
- return
- pos, node = p
- oldsize, _oid = self.filemap[pos]
- assert oid == _oid
- if size == oldsize:
- return
- if size < oldsize:
- excess = oldsize - size
- self.filemap[pos] = size, oid
- self.filemap[pos + size] = excess, None
- else:
- self.filemap[pos] = oldsize, None
- pos, node = self.cache.pop(oid)
- node.unlink()
- self.add(oid, size)
+ if oid in self.oid2ofs:
+ # Delete the current record.
+ pos = self.oid2ofs.pop(oid)
+ size, _oid = self.filemap[pos]
+ assert oid == _oid
+ self.filemap[pos] = size, None
+ self.add(oid, size)
def report(self):
+ self.check()
free = used = total = 0
for size, oid in self.filemap.itervalues():
total += size
@@ -1169,6 +1061,25 @@
self.total_inuse = self.inuse
Simulation.report(self)
+ def check(self):
+ pos = oidcount = 0
+ while pos < self.cachelimit:
+ size, oid = self.filemap[pos]
+ if oid:
+ oidcount += 1
+ assert self.oid2ofs[oid] == pos
+ pos += size
+ assert oidcount == len(self.oid2ofs)
+ assert pos == self.cachelimit
+
+ def dump(self):
+ print len(self.filemap)
+ L = list(self.filemap)
+ L.sort()
+ for k in L:
+ v = self.filemap[k]
+ print k, v[0], repr(v[1])
+
class BuddyCacheSimulation(LRUCacheSimulation):
def __init__(self, cachelimit):
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