"""cllinecache.py: Modify linecache so it works with translated CL scripts too

CL scripts have special filename "<CL script taskname>"

$Id$
"""

import linecache, string, os, sys
from stat import *
import iraf


def checkcache(orig_checkcache=linecache.checkcache):

	"""Discard cache entries that are out of date.
	(This is not checked upon each call!)"""

	# Rather than repeat linecache.checkcache code, we check & save the
	# CL script entries, call the original function, and then
	# restore the saved entries.  (Modelled after Idle/PyShell.py.)
	cache = linecache.cache
	save = {}
	for filename in cache.keys():
		if filename[:10] == "<CL script":
			entry = cache[filename]
			del cache[filename]
			# special CL script case - find original script file for time check
			if filename[10:13] == " CL":
				# temporary script created dynamically -- just save it
				save[filename] = entry
			else:
				size, mtime, lines, taskname = entry
				try:
					taskobj = iraf.getTask(taskname)
					fullname = taskobj.getFullpath()
					stat = os.stat(fullname)
					newsize = stat[ST_SIZE]
					newmtime = stat[ST_MTIME]
				except (os.error, iraf.IrafError):
					continue
				if size == newsize and mtime == newmtime:
					# save the ones that didn't change
					save[filename] = entry
	orig_checkcache()
	cache.update(save)


def updatecache(filename, orig_updatecache=linecache.updatecache):

	"""Update a cache entry and return its list of lines.  If something's
	wrong, discard the cache entry and return an empty list."""

	if filename[:10] == "<CL script":
		# special CL script case
		return updateCLscript(filename)
	else:
		# original version handles other cases
		return orig_updatecache(filename)


def updateCLscript(filename):
	cache = linecache.cache
	if cache.has_key(filename):
		del cache[filename]
	try:
		taskname = filename[11:-1]
		taskobj = iraf.getTask(taskname)
		fullname = taskobj.getFullpath()
		stat = os.stat(fullname)
		size = stat[ST_SIZE]
		mtime = stat[ST_MTIME]
		lines = string.split(taskobj.getCode(),'\n')
		cache[filename] = size, mtime, lines, taskname
		return lines
	except (iraf.IrafError, KeyError, AttributeError):
		return []


# insert these symbols into standard linecache module

_original_checkcache = linecache.checkcache
_original_updatecache = linecache.updatecache

def install():
	linecache.checkcache = checkcache
	linecache.updatecache = updatecache

def uninstall():
	linecache.checkcache = _original_checkcache
	linecache.updatecache = _original_updatecache

install()