def __init__(self, logfileName, patternDef):
self.logfileName = logfileName
self.parseTree = ParseTree()
self.nodeMeta = {} # holds parseTree node metadata keyed by full node pathname
self.log = None
# each parser has it's own "compiled" pattern struct as it may contain logfile-specific
# {{var}} variable expansions
self.patternSpec = PatternSpec(self, patternDef)
class Parser(object):
"client log parser, instances maintain parsing state & parse tree for a given log file"
def __init__(self, logfileName, patternDef):
self.logfileName = logfileName
self.parseTree = ParseTree()
self.nodeMeta = {} # holds parseTree node metadata keyed by full node pathname
self.log = None
# each parser has it's own "compiled" pattern struct as it may contain logfile-specific
# {{var}} variable expansions
self.patternSpec = PatternSpec(self, patternDef)
def watchField(self, pattern, field):
"sets a watchpoint on the given parseTree field for the given pattern"
self.parseTree.watch(field, self._curryWatch(pattern))
def _curryWatch(self, pattern):
"generates a curried watchField callback function applied to the given pattern"
def fieldChanged(parseTree, key, val):
pattern.fieldChanged(parseTree, key, val)
return fieldChanged
def parse(self):
"perform a parse on my logfile"
# grab log copy
with open(self.logfileName) as logfile:
self.log = logfile.read()
# read logfile line-by-line, match against pattern-spec
with open(self.logfileName) as logfile:
lineNo = 0
line = logfile.readline()
while line:
line = line.strip()
self.patternSpec.match(line, lineNo)
line = logfile.readline()
lineNo += 1
# clean up
self.patternSpec.endParse(lineNo)
self.optimizeParseTree()
ordinalRE = re.compile(r'\d\d\d')
def optimizeParseTree(self):
"optimize parse-tree - remove unneeded ordinal levels, turn ordinal-indexes into lists"
def optimize(subtree):
keys = subtree.keys()
# look for keys that are 3-digit ordinals
if keys:
if all(self.ordinalRE.match(k) for k in keys):
if False and len(keys) == 1:
# single entry, elide level
return optimize(subtree[list(keys)[0]])
else:
# turn multi-entry into list
return [optimize(subtree[k]) for k in sorted(keys)]
else:
# non-ordinal index level, iterate keys & optimize subtrees
for k, v in subtree.items():
if isinstance(v, NameSpace):
subtree[k] = optimize(v)
return subtree
self.parseTree = optimize(self.parseTree)
